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Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2018	May 07, 2018
Document and Entity Information
Entity Registrant Name	Onconova Therapeutics, Inc.
Entity Central Index Key	0001130598
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		77,607,812
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 7,264	$ 4,024
Receivables	477	59
Prepaid expenses and other current assets	814	820
Total current assets	8,555	4,903
Property and equipment, net	48	64
Other non-current assets	12	12
Total assets	8,615	4,979
Current liabilities:
Accounts payable	7,034	6,186
Accrued expenses and other current liabilities	3,063	3,335
Deferred revenue	455	455
Total current liabilities	10,552	9,976
Warrant liability	961	1,773
Deferred revenue, non-current	3,977	4,091
Total liabilities	15,490	15,840
Commitments and contingencies
Stockholders' (deficit) equity:
Preferred stock, $0.01 par value, 5,000,000 authorized at March 31, 2018 and December 31, 2017, none issued and outstanding at March 31, 2018 and December 31, 2017
Common stock, $0.01 par value, 100,000,000 and 25,000,000 authorized at March 31, 2018 and December 31, 2017, 10,771,163 and 10,771,163 shares issued and outstanding at March 31, 2018 and December 31, 2017	194	108
Additional paid in capital	359,496	350,514
Accumulated other comprehensive income	11	3
Accumulated deficit	(367,406)	(362,316)
Total Onconova Therapeutics, Inc. stockholders' (deficit) equity	(7,705)	(11,691)
Non-controlling interest	830	830
Total stockholders' (deficit) equity	(6,875)	(10,861)
Total liabilities and stockholders' (deficit) equity	$ 8,615	$ 4,979

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	25,000,000
Common stock, shares issued	19,426,163	10,771,163
Common stock, shares outstanding	19,426,163	10,771,163

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Consolidated Statements of Operations
Revenue	$ 564	$ 210
Operating expenses:
General and administrative	1,889	2,116
Research and development	4,577	4,886
Total operating expenses	6,466	7,002
Loss from operations	(5,902)	(6,792)
Change in fair value of warrant liability	812	(1,549)
Net loss	(5,090)	(8,341)
Net loss attributable to Onconova Therapeutics, Inc.	$ (5,090)	$ (8,341)
Net loss per share of common stock, basic and diluted (in dollars per share)	$ (0.34)	$ (1.23)
Basic and diluted weighted average shares outstanding (in shares)	15,138,663	6,771,383

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (5,090)	$ (8,341)
Other comprehensive income (loss), before tax:
Foreign currency translation adjustments, net	8	5
Other comprehensive income (loss), net of tax	8	5
Comprehensive loss	(5,082)	(8,336)
Comprehensive loss attributable to Onconova Therapeutics, Inc	$ (5,082)	$ (8,336)

Condensed Consolidated Statements of Stockholders' Equity (Deficit) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Common Stock	Additional Paid in Capital	Accumulated deficit	Accumulated other comprehensive income (loss)	Non-controlling interest	Total
Balance at Dec. 31, 2017	$ 108	$ 350,514	$ (362,316)	$ 3	$ 830	$ (10,861)
Balance (in shares) at Dec. 31, 2017	10,771,163					10,771,163
Increase (Decrease) in Stockholders' Equity (Deficit)
Net loss			(5,090)			$ (5,090)
Other comprehensive loss				8		8
Stock-based compensation		327				327
Issuance of common stock and pre-funded warrants, net	$ 70	8,655				8,725
Issuance of common stock and pre-funded warrants, net (in shares)	7,005,000
Issuance of common stock upon exercise of warrants	$ 16					16
Issuance of common stock upon exercise of warrants (in shares)	1,650,000
Balance at Mar. 31, 2018	$ 194	$ 359,496	$ (367,406)	$ 11	$ 830	$ (6,875)
Balance (in shares) at Mar. 31, 2018	19,426,163					19,426,163

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (5,090)	$ (8,341)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	16	23
Change in fair value of warrant liabilities	(812)	1,549
Stock compensation expense	278	458
Changes in assets and liabilities:
Receivables	(418)	(95)
Prepaid expenses and other current assets	6	740
Accounts payable	848	84
Accrued expenses and other current liabilities	(223)	(361)
Deferred revenue	(114)	(113)
Net cash used in operating activities	(5,509)	(6,056)
Financing activities:
Proceeds from the sale of common stock and warrants, net of costs	8,725	40
Proceeds from the exercise of warrants	16
Net cash provided by financing activities	8,741	40
Effect of foreign currency translation on cash	8	5
Net increase (decrease) in cash and cash equivalents	3,240	(6,011)
Cash and cash equivalents at beginning of period	4,024	21,400
Cash and cash equivalents at end of period	$ 7,264	$ 15,389

Nature of Business	3 Months Ended
Nature of Business	Mar. 31, 2018
Nature of Business
Nature of Business	1. Nature of Business The Company Onconova Therapeutics, Inc. (the “Company”) was incorporated in the State of Delaware on December 22, 1998 and commenced operations on January 1, 1999. The Company’s headquarters are located in Newtown, Pennsylvania. The Company is a clinical-stage biopharmaceutical company focused on discovering and developing novel small molecule product candidates primarily to treat cancer. Using its proprietary chemistry platform, the Company has created an extensive library of targeted anti-cancer agents designed to work against specific cellular pathways that are important to cancer cells. The Company believes that the product candidates in its pipeline have the potential to be efficacious in a variety of cancers. The Company has three clinical-stage product candidates and several preclinical programs. In 2011, the Company entered into a license agreement, as subsequently amended, with SymBio Pharmaceuticals Limited (“SymBio”), which grants SymBio certain rights to commercialize rigosertib in Japan and Korea. On March 2, 2018, the Company entered into a License, Development and Commercialization Agreement with Pint International SA (which, together with its affiliate Pint Pharma GmbH, are collectively referred to as “Pint”). Under the terms of the agreement, the Company granted Pint an exclusive, royalty-bearing license, with the right to sublicense, under certain Company patent rights and know-how to develop and commercialize any pharmaceutical product containing rigosertib in all uses of rigosertib in certain Latin America countries. In 2012, the Company entered into a development and license agreement with Baxter Healthcare SA, the predecessor in interest to Baxalta GmbH (together with its affiliates, “Baxalta”), pursuant to which the Company granted an exclusive, royalty-bearing license for the research, development, commercialization and manufacture (in specified instances) of rigosertib in all therapeutic indications in Europe. The Baxalta agreement terminated effective August 30, 2016, at which time the rights the Company licensed to Baxalta reverted to the Company at no cost. The Company has retained development and commercialization rights to rigosertib in the rest of the world, including the United States. During 2012, Onconova Europe GmbH was established as a wholly owned subsidiary of the Company for the purpose of further developing business in Europe. In April 2013, GBO, LLC, a Delaware limited liability company, (“GBO”) was formed pursuant to an agreement with GVK Biosciences Private Limited, a private limited company located in India, (“GVK”) to collaborate and develop two programs using the Company’s technology platform. The two preclinical programs sublicensed to GBO have not been developed to clinical stage as initially hoped, and the Company is in discussions with GVK regarding the future of GBO. On March 21, 2018, the Company amended its certificate of incorporation to increase the number of authorized shares of common stock par value $0.01 per share from 25,000,000 to 100,000,000. Liquidity The Company has incurred recurring operating losses since inception. For the three months ended March 31, 2018, the Company incurred a net loss of $5,090,000 and as of March 31, 2018 the Company had generated an accumulated deficit of $367,406,000. The Company anticipates operating losses to continue for the foreseeable future due to, among other things, costs related to research, development of its product candidates and its preclinical programs, strategic alliances and its administrative organization. At March 31, 2018, the Company had cash and cash equivalents of $7,264,000. The Company will require substantial additional financing to fund its ongoing clinical trials and operations, and to continue to execute its strategy. From its inception through July 2013, the Company raised capital through the private issuance of preferred stock. On July 30, 2013, the Company completed its initial public offering (the “IPO”) of 594,167 shares of Common Stock, at a price of $150.00 per share. The Company received net proceeds of $79,811,000 from the sale, net of underwriting discounts and commissions and other estimated offering expenses. Immediately prior to the consummation of the IPO, all outstanding shares of preferred stock automatically converted into shares of Common Stock at the applicable conversion ratio then in effect. From the IPO through December 31, 2016, the Company closed on several offerings which included Common Stock and warrants. Total net proceeds from these offerings was approximately $24.9 million On April 26, 2017 the Company closed on an underwritten public offering of 2,476,190 shares of Common Stock. On May 17, 2017, the Company sold an additional 363,580 shares as a result of the underwriter’s exercise of its over-allotment option. Net proceeds from these transactions were approximately $5.3 million. (See Note 13) On November 14, 2017 the Company closed on a registered direct offering to select accredited investors of 920,000 shares of common stock. Net proceeds were approximately $1.1 million. (See Note 13) On February 12, 2018 the Company closed on an offering of units of common stock and warrants. The Company issued 7,005,000 shares of common stock, pre-funded warrants to purchase 2,942,500 share of common stock, and preferred stock warrants to purchase 1,044,487.5 shares of Series A convertible preferred stock. Each share of Series A convertible preferred stock is convertible into ten shares of common stock. Net proceeds were approximately $8.7 million. (See Note 13) On May 1, 2018 the Company closed on an offering of units of common stock and warrants. The Company issued 55,411,763 shares of common stock, pre-funded warrants to purchase 12,235,295 shares of common stock, and preferred stock warrants to purchase 1,691,176.450 shares of Series B convertible preferred stock. Each share of Series B convertible preferred stock is convertible into 40 shares of common stock. Net proceeds were approximately $25.6 million. (See Note 13) The Company has and may continue to delay, scale-back, or eliminate certain of its research and development activities and other aspects of its operations until such time as the Company is successful in securing additional funding. The Company continues to explore various dilutive and non-dilutive sources of funding, including equity financings, strategic alliances, business development and other sources. The future success of the Company is dependent upon its ability to obtain additional funding. There can be no assurance, however, that the Company will be successful in obtaining such funding in sufficient amounts, on terms acceptable to the Company, or at all. The Company currently anticipates that current cash and cash equivalents will be sufficient to meet its anticipated cash requirements into the fourth quarter of 2019.

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2018
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The condensed consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) for interim financial information. Certain information and footnotes normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The financial statements include the consolidated accounts of the Company, its wholly-owned subsidiary, Onconova Europe GmbH, and GBO. All significant intercompany transactions have been eliminated. Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2018, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2018 and 2017, the consolidated statement of stockholders’ (deficit) equity for the three months ended March 31, 2018 and the condensed consolidated statements of cash flows for the three months ended March 31, 2018 and 2017 are unaudited. The interim unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2018, the results of its operations for the three months ended March 31, 2018 and 2017, and its cash flows for the three months ended March 31, 2018 and 2017. The financial data and other information disclosed in these notes related to the three months ended March 31, 2018 and 2017 are unaudited. The results for the three months ended March 31, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 16, 2018. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment, which is the identification and development of oncology therapeutics. Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 16, 2018. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies. Fair Value Measurements The carrying amounts reported in the accompanying consolidated financial statements for cash and cash equivalents, accounts payable, and accrued liabilities approximate their respective fair values because of the short-term nature of these accounts. The fair value of the warrant liability is discussed in Note 7, “Fair Value Measurements.” Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (ASC 606), which the Company adopted effective January 1, 2018 using the modified retrospective method. There was no material impact to our financial position and results of operations as a result of the adoption. The Company applies ASC 606 to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. In accordance with ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration it is entitled to in exchange for the goods and services it transfers to the customer. At contract inception, the Company assesses the goods or services promised within each contract that falls under the scope of ASC 606, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. The Company derives revenue from collaboration and licensing agreements and the sale of products associated with material transfer, collaboration and supply agreements. License, Collaboration and Other Revenues The Company enters into licensing and collaboration agreements, under which it licenses certain of its product candidates’ rights to third parties. The Company recognizes revenue related to these agreements in accordance with ASC 606. The terms of these arrangements typically include payment of one or more of the following: non-refundable, up-front license fees; development, regulatory and commercial milestone payments; and royalties on net sales of the licensed product. In determining the appropriate amount of revenue to be recognized as it fulfills its obligation under each of its agreements, the Company performs the five steps described above. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price, which may include forecasted revenues, development timelines, reimbursement of personnel costs, discount rates and probabilities of technical and regulatory success. Licensing of Intellectual Property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front-fees. The Company evaluates the measure of progress each reporting period, and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal will not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensees, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in their period of adjustment. Manufacturing supply services. Arrangements that include a promise for future supply of drug substance or drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide material rights to the licensee and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded when the customer obtains control of the goods, which is upon shipment. Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some of all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue from its license agreements. Recent Accounting Pronouncements In February 2016, the FASB issued guidance which supersedes much of the current guidance for leases. The new standard requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all the leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. For leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients primarily focused on leases that commenced before the effective date of the new guidance, including continuing to account for leases that commence before the effective date in accordance with previous guidance, unless the lease is modified. The Company is evaluating the impact of the adoption of the standard on its consolidated financial statements. In March 2016, the FASB issued guidance that addresses the income tax effects of stock-based payments and eliminates the windfall pool concept, as all of the tax effects related to stock-based payments will now be recorded at settlement (or expiration) through the income statement. The new guidance also permits entities to make an accounting policy election for the impact of forfeitures on the recognition of expense for stock-based payment awards. Forfeitures can be estimated or recognized when they occur. The standard was effective for annual periods beginning after December 15, 2016 and interim periods within that reporting period. Early adoption was permitted in any interim or annual period, with any adjustment reflected as of the beginning of the fiscal year of adoption. The Company adopted the new guidance as of January 1, 2017. The adoption did not have a material impact on the Company’s consolidated financial statements and related disclosures. In November 2016, the FASB issued guidance requiring that amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The guidance is effective for interim and annual periods beginning in 2018 and should be applied using a retrospective transition method to each period presented. Early adoption is permitted. The Company adopted this guidance effective December 31, 2017. Restricted Cash was $50,000 at December 31 2017, 2016 and 2015. The adoption did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Revenue

3 Months Ended

Mar. 31, 2018

Revenue

Revenue

3. Revenue

The Company’s revenue during the three months ended March 31, 2018 and 2017 was from its license and collaboration agreements with SymBio and HanX (See Note 10).

Deferred revenue is as follows:

	Symbio
	Upfront Payment

Deferred balance at December 31, 2017	$	4,546,000
Recognition to revenue	114,000


Deferred balance at March 31, 2018	$	4,432,000

See Note 10, “License and Collaboration Agreements,” for a further discussion of the agreements with SymBio and HanX.

Net Loss Per Share of Common Stock

3 Months Ended

Mar. 31, 2018

Net Loss Per Share of Common Stock

Net Loss Per Share of Common Stock

4. Net Loss Per Share of Common Stock

The following potentially dilutive securities outstanding at March 31, 2018 and 2017 have been excluded from the computation of diluted weighted average shares outstanding, as they would be antidilutive (reflects the number of common shares as if the dilutive securities had been converted to common stock):

	March 31,
	2018	2017
Warrants	15,232,146	3,525,771
Stock options	1,118,849	891,518

	16,350,995	4,417,289

Warrants

3 Months Ended

Mar. 31, 2018

Warrants

Warrants

5. Warrants

Common Stock warrants are accounted for in accordance with applicable accounting guidance provided in ASC Topic 815, Derivatives and Hedging — Contracts in Entity’s Own Equity (ASC Topic 815), as either derivative liabilities or as equity instruments depending on the specific terms of the warrant agreement. Some of the Company’s warrants are classified as liabilities because in certain circumstances they could require cash settlement.

Warrants outstanding and warrant activity (reflects the number of common shares as if the warrants were converted to common stock) for the three months ended March 31, 2018 is as follows:

					Balance					Balance
		Exercise		Expiration	Decemeber 31,	Warrants	Warrants		Warrants	March 31,
Description	Classification	Price		Date	2017	Issued	Exercised		Expired	2018

Non-tradable warrants	Liability	$	11.50	July 2021	96,842	—	—		—	96,842
Tradable warrants	Liability	$	4.92	July 2021	3,192,022	—	—		—	3,192,022
Non-tradable pre-funded warrants	Equity	$	0.01	July 2023	5,907	—	—		—	5,907
Non-tradable warrants	Equity	$	0.45	*	—	9,947,500	—		—	9,947,500
Non-tradable warrants	Equity	$	1.2625	*	—	497,375	—		—	497,375
Non-tradable warrants	Equity	$	0.9400	March 2021	—	75,000	—		—	75,000
Non-tradable warrants	Equity	$	1.4100	March 2021	—	125,000	—		—	125,000
Non-tradable pre-funded warrants	Equity	$	0.01	none	—	2,942,500	(1,650,000	)	—	1,292,500

					3,294,771	13,587,375	(1,650,000	)	—	15,232,146

* These preferred stock warrants expire on the earlier of (A) the one-month anniversary of the date on which the Company publically releases topline results of the INSPIRE Pivotal phase 3 that compare the overall survival (OS) of patients in the rigosertib group vs the Physician’s Choice group, in all patients and in a subgroup of patients with IPSS-R very high risk and (B) December 31, 2019. These preferred stock warrants may be exercised on a cashless basis in certain circumstances specified therein.

Balance Sheet Detail

3 Months Ended

Mar. 31, 2018

Balance Sheet Detail

Balance Sheet Detail

6. Balance Sheet Detail

Prepaid expenses and other current assets:

	March 31,		December 31,
	2018		2017

Research and development	$	394,000	$	514,000
Manufacturing	33,000		48,000
Insurance	162,000		181,000
Other	225,000		77,000

	$	814,000	$	820,000

Property and equipment:

	March 31,			December 31,
	2018			2017

Property and equipment	$	2,228,000		$	2,228,000
Accumulated depreciation	(2,180,000		)	(2,164,000		)

	$	48,000		$	64,000

Accrued expenses and other current liabilities:

	March 31,		December 31,
	2018		2017

Research and development	$	1,884,000	$	1,912,000
Employee compensation	1,055,000		1,258,000
Professional fees	124,000		165,000

	$	3,063,000	$	3,335,000

Fair Value Measurements

3 Months Ended

Mar. 31, 2018

Fair Value Measurements

Fair Value Measurements

7. Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date.

The Company utilizes a valuation hierarchy for disclosure of the inputs to the valuations used to measure fair value. This hierarchy prioritizes the inputs into three broad levels as follows. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. Level 3 inputs are unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.

On January 5, 2016, the Company entered into a securities purchase agreement (the “Securities Purchase Agreement”) with an institutional investor providing for the issuance and sale by the Company of 193,684 shares of Common Stock, at a purchase price of $9.50 per share and warrants to purchase up to 96,842 shares of Common Stock (the “Warrants”) for aggregate gross proceeds of $1,840,000 (see Note 13). The Company has classified the warrants as a liability (see Note 5). The fair value was estimated using the Black-Scholes pricing model.

On July 29, 2016 the Company closed on a Rights Offering, issuing 3,599,786 shares of Common Stock, 3,192,022 Tradable Warrants and 656,400 Pre-Funded Warrants. The Tradable Warrants are exercisable for a period of five years for one share of Common Stock at an exercise price of $4.92 per share. After the one-year anniversary of issuance, the Company may redeem the Tradable Warrants for $0.001 per Tradable Warrant if the volume weighted average price of its Common Stock is above $12.30 for each of 10 consecutive trading days (see Note 13). The Company has classified the Tradable Warrants as a liability (see Note 5). The Tradable Warrants have been listed on the NASDAQ Capital Market since issuance and the Company regularly monitors the trading activity. During the period from issuance on July 29, 2016 through March 31, 2017 the Company determined that trading volume was insufficient to use the NASDAQ Capital Market value to determine the fair value of the warrant liability. The fair value was estimated using the Black-Scholes pricing model. During the quarter ended June 30, 2017, the Company determined that an active and orderly market for the Tradable Warrants had developed and that the NASDAQ Capital Market price was the best indicator of fair value of the warrant liability. Consequently, the Company changed its valuation technique from the Black-Scholes pricing model to the quoted market price, effective April 1, 2017. The change in valuation technique resulted in a reclassification of the liability within the valuation hierarchy form Level 3 to Level 1. The quoted market price was used to determine the fair value at December 31, 2017 and March 31, 2018.

The Company estimated the fair value of the non-tradable warrant liability at March 31, 2018, using the Black-Scholes option pricing model with the following weighted-average assumptions:

Risk-free interest rate	2.39	%
Expected volatility	74.07	%
Expected term	3.29 years
Expected dividend yield	0	%

Expected volatility is based on the historical volatility of the Company’s Common Stock since its IPO in July 2013.

The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017:

	Fair Value Measurement as of:
	March 31, 2018								December 31, 2017
	Level 1		Level 2		Level 3		Balance		Level 1		Level 2		Level 3		Balance

Tradable warrants liability	$	957,000	$	—	$	—	$	957,000	$	1,755,000	$	—	$	—	$	1,755,000
Non-tradable warrants liability	—		—		4,000		4,000		—		—		18,000		18,000

Total	$	957,000	$	—	$	4,000	$	961,000	$	1,755,000	$	—	$	18,000	$	1,773,000

The following table presents a reconciliation of the Company’s liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2018:

	Warrant Liability
Balance at December 31, 2017	$	18,000
Issuance of warrants	—

Change in fair value upon re-measurement	14,000

Balance at March 31, 2018	$	4,000

There were no transfers between Level 1 and Level 2 in any of the periods reported.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

Stock-Based Compensation

Stock-Based Compensation

8. Stock-Based Compensation

The 2007 Equity Compensation Plan as amended (the “2007 Plan”), amended, restated and renamed the Company’s 1999 Stock Based Compensation Plan (the “1999 Plan”), which provided for the granting of incentive and nonqualified stock options and restricted stock to its employees, directors and consultants at the discretion of the board of directors.

The 2013 Equity Compensation Plan (the “2013 Plan”), amended, restated and renamed the 2007 Plan. Under the 2013 Plan, the Company may grant incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, deferred share awards, performance awards and other equity-based awards to employees, directors and consultants. The Company initially reserved 610,783 shares of Common Stock for issuance, subject to adjustment as set forth in the 2013 Plan. The 2013 Plan includes an evergreen provision, pursuant to which the maximum aggregate number of shares that may be issued under the 2013 Plan is increased on the first day of each fiscal year by the lesser of (a) a number of shares equal to four percent (4%) of the issued and outstanding Common Stock of the Company, without duplication, (b) 200,000 shares and (c) such lesser number as determined by the Company’s board of directors, subject to specified limitations. At March 31, 2018, there were 33,779 shares available for future issuance.

Stock-based compensation expense includes stock options granted to employees and non-employees and has been reported in the Company’s statements of operations and comprehensive loss in either research and development expenses or general and administrative expenses depending on the function performed by the optionee. No net tax benefits related to the stock-based compensation costs have been recognized since the Company’s inception. The Company recognized stock-based compensation expense as follows for the three months ended March 31, 2018 and 2017:

	Three Months ended March 31,
	2018		2017
General and administrative	$	158,000	$	265,000
Research and development	120,000		193,000

	$	278,000	$	458,000

A summary of stock option activity for the three months ended March 31, 2018 is as follows:

			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted- Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance, December 31, 2017	57,632		894,996		$	57.02	6.72	$	0
Authorized	200,000		—
Granted	(330,849	)	330,849		$	1.41
Exercised	—		—		$	—
Forfeitures	106,996		(106,996	)	$	80.97

Balance, March 31, 2018	33,779		1,118,849		$	25.00	8.03	$	0

Vested or expected to vest, March 31, 2018			1,098,389		$	42.02	7.16	$	0

Exercisable at March 31, 2018			624,116		$	42.02	7.16	$	0

Information with respect to stock options outstanding and exercisable at March 31, 2018 is as follows:

Exercise Price	Shares	Exercisable
$1.09 - $6.50	802,214	336,045
$14.80 - $15.00	29,775	19,445
$23.20 - $39.80	75,369	59,635
$43.40 - $75.30	87,343	84,843
$132.80 - $151.20	118,798	118,798
$277.10 - $291.40	5,350	5,350

	1,118,849	624,116

Options granted after April 23, 2013

The Company accounts for all stock-based payments made after April 23, 2013 to employees and directors using an option pricing model for estimating fair value. Accordingly, stock-based compensation expense is measured based on the estimated fair value of the awards on the date of grant, net of forfeitures. Compensation expense is recognized for the portion that is ultimately expected to vest over the period during which the recipient renders the required services to the Company using the straight-line single option method. In accordance with authoritative guidance, the fair value of non-employee stock-based awards is re-measured as the awards vest, and the resulting increase in fair value, if any, is recognized as expense in the period the related services are rendered.

The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock options at the grant date. The Black-Scholes model requires the Company to make certain estimates and assumptions, including estimating the fair value of the Company’s Common Stock, assumptions related to the expected price volatility of the Common Stock, the period during which the options will be outstanding, the rate of return on risk-free investments and the expected dividend yield for the Company’s stock.

As of March 31, 2018, there was $1,074,000 of unrecognized compensation expense related to the unvested stock options issued from April 24, 2013 through March 31, 2018, which is expected to be recognized over a weighted-average period of approximately 1.95 years.

The weighted-average assumptions underlying the Black-Scholes calculation of grant date fair value include the following:

	Three Months ended March 31,
	2018			2017
Risk-free interest rate	2.60		%	2.07		%
Expected volatility	74.13		%	79.38		%
Expected term	5.78 years			6.00 years
Expected dividend yield	0		%	0		%
Weighted average grant date fair value	$	0.84		$	1.86

The weighted-average valuation assumptions were determined as follows:

Risk-free interest rate: The Company based the risk-free interest rate on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the assumed expected option term.

Expected term of options: Due to its lack of sufficient historical data, the Company estimates the expected life of its employee stock options using the “simplified” method, as prescribed in Staff Accounting Bulletin (SAB) No. 107, whereby the expected life equals the arithmetic average of the vesting term and the original contractual term of the option.

Expected stock price volatility: Expected volatility is based on the historical volatility of the Company’s Common Stock since its IPO in July 2013.

Expected annual dividend yield: The Company has never paid, and does not expect to pay, dividends in the foreseeable future. Accordingly, the Company assumed an expected dividend yield of 0.0%.

Estimated forfeiture rate: The Company’s estimated annual forfeiture rate on stock option grants was 4.14% in 2018 and 2017, based on the historical forfeiture experience.

Research Agreements	3 Months Ended
Research Agreements	Mar. 31, 2018
Research Agreements
Research Agreements	9. Research Agreements The Company has entered into various licensing and right-to-sublicense agreements with educational institutions for the exclusive use of patents and patent applications, as well as any patents that may develop from research being conducted by such educational institutions in the field of anticancer therapy, genes and proteins. Results from this research have been licensed to the Company pursuant to these agreements. Under one of these agreements with Temple University (“Temple”), the Company is required to make annual maintenance payments to Temple and royalty payments based upon a percentage of sales generated from any products covered by the licensed patents, with minimum specified royalty payments. As no sales had been generated through March 31, 2018 under the licensed patents, the Company has not incurred any royalty expenses related to this agreement. In addition, the Company is required to pay Temple a percentage of any sublicensing fees received by the Company.

License and Collaboration Agreements	3 Months Ended
License and Collaboration Agreements	Mar. 31, 2018
License and Collaboration Agreements
License and Collaboration Agreements	10. License and Collaboration Agreements SymBio Agreement In July 2011, the Company entered into a license agreement with SymBio, which has been subsequently amended, granting SymBio an exclusive, royalty-bearing license for the development and commercialization of rigosertib in Japan and Korea. Under the SymBio license agreement, SymBio is obligated to use commercially reasonable efforts to develop and obtain market approval for rigosertib inside the licensed territory and the Company has similar obligations outside of the licensed territory. The Company has also entered into an agreement with SymBio providing for it to supply SymBio with development-stage product. Under the SymBio license agreement, the Company also agreed to supply commercial product to SymBio under specified terms that will be included in a commercial supply agreement to be negotiated prior to the first commercial sale of rigosertib. The supply of development-stage product and the supply of commercial product will be at the Company’s cost plus a defined profit margin. Sales of development-stage product have been de minimis. The Company has additionally granted SymBio a right of first negotiation to license or obtain the rights to develop and commercialize compounds having a chemical structure similar to rigosertib in the licensed territory. Under the terms of the SymBio license agreement, the Company received an upfront payment of $7,500,000 in 2011. The Company is eligible to receive milestone payments of up to an aggregate of $22,000,000 from SymBio upon the achievement of specified development and regulatory milestones for specified indications. Of the regulatory milestones, $5,000,000 is due upon receipt of marketing approval in the United States for rigosertib IV in higher-risk MDS patients, $3,000,000 is due upon receipt of marketing approval in Japan for rigosertib IV in higher-risk MDS patients, $5,000,000 is due upon receipt of marketing approval in the United States for rigosertib oral in lower-risk MDS patients, and $5,000,000 is due upon receipt of marketing approval in Japan for rigosertib oral in lower-risk MDS patients. Furthermore, upon receipt of marketing approval in the United States and Japan for an additional specified indication of rigosertib, which the Company is currently not pursuing, an aggregate of $4,000,000 would be due. In addition to these pre-commercial milestones, the Company is eligible to receive tiered milestone payments based upon annual net sales of rigosertib by SymBio of up to an aggregate of $30,000,000. Further, under the terms of the SymBio license agreement, SymBio will make royalty payments to the Company at percentage rates ranging from the mid-teens to 20% based on net sales of rigosertib by SymBio. Royalties will be payable under the SymBio agreement on a country-by-country basis in the licensed territory, until the later of the expiration of marketing exclusivity in those countries, a specified period of time after first commercial sale of rigosertib in such country, or the expiration of all valid claims of the licensed patents covering rigosertib or the manufacture or use of rigosertib in such country. If no valid claim exists covering the composition of matter of rigosertib or the use of or treatment with rigosertib in a particular country before the expiration of the royalty term, and specified competing products achieve a specified market share percentage in such country, SymBio’s obligation to pay the Company royalties will continue at a reduced royalty rate until the end of the royalty term. In addition, the applicable royalties payable to the Company may be reduced if SymBio is required to pay royalties to third-parties for licenses to intellectual property rights necessary to develop, use, manufacture or commercialize rigosertib in the licensed territory. The license agreement with SymBio will remain in effect until the expiration of the royalty term. However, the SymBio license agreement may be terminated earlier due to the uncured material breach or bankruptcy of a party, or force majeure. If SymBio terminates the license agreement in these circumstances, its licenses to rigosertib will survive, subject to SymBio’s milestone and royalty obligations, which SymBio may elect to defer and offset against any damages that may be determined to be due from the Company. In addition, the Company may terminate the license agreement in the event that SymBio brings a challenge against it in relation to the licensed patents, and SymBio may terminate the license agreement without cause by providing the Company with written notice within a specified period of time in advance of termination. The Company assessed the SymBio arrangement in accordance with ASC 606 and determined that its performance obligations under the SymBio agreement include the exclusive, royalty-bearing, sublicensable license to rigosertib, the research and development services to be provided by the Company and its obligation to serve on a joint committee. The Company concluded that the license was not distinct since it was of no benefit to SymBio without the ongoing research and development services and that, as such, the license and the research and development services should be bundled as a single performance obligation. Since the provision of the license and research and development services, are considered a single performance obligation; the $7,500,000 upfront payment is being recognized as revenue ratably through December 2027, the expected period over which the Company expects the research and development services to be performed as the services are performed. SymBio’s purchases of rigosertib as development-stage product or for commercial requirements represent options under the agreement and revenues are therefore recognized when control of the product is transferred, which is typically when shipped. If SymBio orders the supplies from the Company, the Company expects the pricing for this supply to equal its third-party manufacturing cost plus a pre-negotiated percentage, which will not result in a significant incremental discount to market rates. HanX Agreement In December 2017, the Company entered into a license and collaboration agreement with HanX Biopharmaceuticals, Inc. (“HanX”), a company focused on development of novel oncology products, for the further development, registration and commercialization of ON 123300 in Greater China. ON 123300 is a preclinical compound which the Company believes has the potential to overcome the limitations of current generation CDK 4/6 inhibitors. The key feature of the collaboration is that HanX will provide all funding required for future Chinese IND enabling studies necessary for filing an IND with the Chinese Food and Drug Administration. The studies would be conducted to meet the Good Laboratory Practice (“GLP”) requirements of the FDA such that the Company could simultaneously file an IND with the US FDA. The Company and HanX will oversee the IND enabling studies. The Company will maintain global rights outside of China. Pursuant to the agreement, the Company received a $450,000 upfront payment on April 11, 2018. If the compound receives regulatory approval and is commercialized, the Company would receive regulatory and commercial milestone payments, as well as royalties on sales in the Greater China territory. The Company assessed the HanX arrangement for revenue recognition in accordance with ASC 606 and determined that the license was distinct and that control of the license had been transferred during the first quarter of 2018. As such, the Company recognized the $450,000 allocated to the license in the quarter ended March 31, 2018. Accordingly, the revenue is included in the consolidated statement of operations for the period ended March 31, 2018 and the amount receivable from HanX is included in receivables in the balance sheet at March 31, 2018. Pint Agreement On March 2, 2018, the Company entered into a License, Development and Commercialization Agreement (the “License Agreement”) and a Securities Purchase Agreement (the “Securities Purchase Agreement”) with Pint. Under the terms of the License Agreement, the Company granted Pint an exclusive, royalty-bearing license, with the right to sublicense, under certain Company patent rights and know-how to develop and commercialize any pharmaceutical product (the “Product”) containing rigosertib in all uses of rigosertib in humans in Latin American countries (the “Territory,” including Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, French Guiana, British Guiana, Suriname, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay and Venezuela). Pint agreed to make an upfront equity investment in the Company’s common stock. In addition, the Company could receive up to $41.5 million in additional regulatory, development and sales-based milestone payments, an additional equity investment, as well as tiered, double digit royalties based on net aggregate net sales in the Territory. Pint and the Company have also agreed to enter into a supply agreement providing for Pint purchasing rigosertib and the Product from the Company within 90 days of the FDA approval of an a New Drug Application (“NDA”) for the Product. Pint may terminate the License Agreement in whole (but not in part) at any time upon 45 days’ prior written notice. The License Agreement also contains certain provisions for termination by either party in the event of breach of the License Agreement by the other party, subject to a cure period, or bankruptcy of the other party. Under the terms of the Securities Purchase Agreement Pint agreed to make an upfront equity investment in the Company at a specified premium to the Company’s share price. Pursuant to the Securities Purchase Agreement, closing of the upfront equity investment occurred on April 4, 2018 and Pint purchased 816,945 shares of common stock for $1,250,000. In addition, under the Securities Purchase Agreement, if the FDA approves the NDA for the Product, Pint will reimburse the Company for certain research and development expenses. Half of the reimbursement amount will be paid in cash, the other half of the amount will be by an equity investment at a premium to the average of the volume weighted average price of common stock for the ten consecutive trading days ended on the day the FDA approves the NDA. Pursuant to the Securities Purchase Agreement, the common stock purchased by Pint is subject to certain lock-up restrictions and Pint is entitled to certain registration and participation rights. The Company assessed the Pint arrangement in accordance with ASC 606 and determined that the requirements to recognize revenue were not met as of March 31, 2018.

Preclinical Collaboration	3 Months Ended
Preclinical Collaboration	Mar. 31, 2018
Preclinical Collaboration
Preclinical Collaboration	11. Preclinical Collaboration In December 2012, the Company agreed to form GBO, an entity owned by the Company and GVK. The purpose of GBO is to collaborate on and develop two programs through filing of an investigational new drug application and/or conducting proof of concept studies using the Company’s technology platform. If a program failure occurs for one or both programs, the Company may contribute additional assets to GBO to establish a replacement program or programs. During 2013, GVK made an initial capital contribution of $500,000 in exchange for a 10% interest in GBO, and the Company made an initial capital contribution of a sublicense to all the intellectual property controlled by the Company related to the two specified programs in exchange for a 90% interest. Under the terms of the agreement, GVK may make additional capital contributions. The GVK percentage interest in GBO may change from the initial 10% to up to 50%, depending on the amount of its total capital contributions. During November 2014, GVK made an additional capital contribution of $500,000 which increased its interest in GBO to 17.5%. The Company evaluates its variable interests in GBO on a quarterly basis and has determined that it is the primary beneficiary. For thirty days following the 15-month anniversary of the commencement of either of the two programs, the Company will have an option to (i) cancel the license and (ii) purchase all rights in and to that program. There are three of these buy-back scenarios depending on the stage of development of the underlying assets. In addition, upon the occurrence of certain events, namely termination of the Company’s participation in the programs either with or without a change in control, GVK will be entitled to purchase or obtain the Company’s interest in GBO. GVK will have operational control of GBO and the Company will have strategic and scientific control. The two preclinical programs sublicensed to GBO have not been developed to clinical stage as initially hoped, and the Company is in discussions with GVK regarding the future of GBO. There was no activity in GBO during the three months ended March 31, 2018 and 2017.

Related-Party Transactions	3 Months Ended
Related-Party Transactions	Mar. 31, 2018
Related-Party Transactions
Related-Party Transactions	12. Related-Party Transactions The Company has entered into a research agreement, as subsequently amended, with the Mount Sinai School of Medicine (“Mount Sinai”), with which a member of its board of directors and a significant stockholder is affiliated. Mount Sinai is undertaking research on behalf of the Company on the terms set forth in the agreements. Mount Sinai, in connection with the Company, will prepare applications for patents generated from the research. Results from all projects will belong exclusively to Mount Sinai, but the Company will have an exclusive option to license any inventions. Payments to Mount Sinai under this research agreement for the three months ended March 31, 2018 and 2017 were $88,000 and $88,000, respectively. At March 31, 2018 and December 31, 2017, the Company had $614,000 and $526,000, respectively, payable to Mount Sinai under this agreement. The Company has entered into a consulting agreement with a member of its board of directors, who is also a significant stockholder of the Company. The board member provides consulting services to the Company on the terms set forth in the agreement. Payments to this board member for the three months ended March 31, 2018 and 2017 were $33,000 and $33,000, respectively. At March 31, 2018 and December 31, 2017, the Company had $33,000 and $33,000, respectively, payable under this agreement.

Securities Registrations and Sales Agreements	3 Months Ended
Securities Registrations and Sales Agreements	Mar. 31, 2018
Securities Registrations and Sales Agreements
Securities Registrations and Sales Agreements	13. Securities Registrations and Sales Agreements On October 8, 2015, the Company entered into a Purchase Agreement, and a registration rights agreement with Lincoln Park. A registration statement (Form S-1 No. 333-207533), relating to the shares, which was filed with the SEC became effective on November 3, 2015. Subject to the terms and conditions of the purchase agreement, including the effectiveness of a registration statement covering the resale of the shares, the Company may sell additional shares of its Common Stock, having an aggregate offering price of up to $15,000,000 to Lincoln Park from time to time until December 1, 2018. Upon execution of the Lincoln Park purchase agreement, Lincoln Park made an initial purchase of 84,676 shares of the Company’s Common Stock for $1,500,000. Subject to the terms and conditions of the purchase agreement, including the effectiveness of a registration statement covering the resale of the shares, the Company has the right to sell to and Lincoln Park is obligated to purchase up to an additional $15,000,000 of shares of Common Stock, subject to certain limitations, from time to time until December 1, 2018. The Company may direct Lincoln Park, at its sole discretion and subject to certain conditions, to purchase up to 10,000 shares of Common Stock on any business day, increasing to up to 25,000 shares depending upon the closing sale price of the Common Stock (such purchases, “Regular Purchases”). However, in no event shall a Regular Purchase be more than $1,000,000. The purchase price of shares of Common Stock related to the future funding will be based on the prevailing market prices of such shares at the time of sales. In addition, the Company may direct Lincoln Park to purchase additional amounts as accelerated purchases if on the date of a Regular Purchase the closing sale price of the Common Stock is not below the threshold price as set forth in the Purchase Agreement. The Company’s sales of shares of Common Stock to Lincoln Park under the Purchase Agreement were limited to no more than the number of shares that would result in the beneficial ownership by Lincoln Park and its affiliates, at any single point in time, of more than 4.99% of the then-outstanding shares of the Common Stock, which limit increased to 9.99% on May 1, 2016. Pursuant to the terms of the Lincoln Park purchase agreement and to comply with the listing rules of the NASDAQ Stock Market, the number of shares issued to Lincoln Park thereunder shall not exceed 19.99% of the Company’s shares outstanding on October 8, 2015 unless the approval of the Company’s stockholders is obtained. This limitation shall not apply if the average price paid for all shares issued and sold under the purchase agreement is equal to or greater than $15.56. The Company is not required or permitted to issue any shares of Common Stock under the Lincoln Park purchase agreement if such issuance would breach the Company’s obligations under the listing rules of the NASDAQ Stock Market. As consideration for entering into the purchase agreement, the Company issued to Lincoln Park 20,000 shares of Common Stock. Lincoln Park represented to the Company, among other things, that it was an “accredited investor” (as such term is defined in Rule 501(a) of Regulation D under the Securities Act of 1933, as amended (the “Securities Act”), and the Company sold the securities in reliance upon an exemption from registration contained in Section 4(2) under the Securities Act. The securities sold may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. The net proceeds to the Company under the Lincoln Park purchase agreement will depend on the frequency and prices at which the Company may sell shares of Common Stock to Lincoln Park. The Company expects that the proceeds received from the initial purchase and any additional proceeds from future sales to Lincoln Park will be used to fund the development of the Company’s clinical and preclinical programs, for other research and development activities and for general corporate purposes. In December 2016, the Company entered into a sales agreement (the “Sales Agreement”) with FBR Capital Markets & Co. (“FBR”) to create an at-the-market equity program (“ATM Program”) under which the Company from time to time may offer and sell shares of its common stock through FBR. The Shares to be sold under the Sales Agreement were issued and sold pursuant to the Company’s shelf registration statement on Form S-3 (File No 333-199219), previously filed with the SEC on October 8, 2014 and declared effective by the SEC on November 20, 2014. A prospectus supplement related to the Company’s ATM Program was filed with the SEC on December 5, 2016. Sales under the Sales Agreement were 12,764 shares for net proceeds of approximately $40,000. The Sales Agreement was terminated effective April 19, 2017. On April 20, 2017, the Company entered into an underwriting agreement with Laidlaw & Company (UK) Ltd. (“Laidlaw”), with respect to the issuance and sale in an underwritten public offering by the Company of 2,476,190 shares of Common Stock, at a price to the public of $2.10 per share. Pursuant to the underwriting agreement, the Company granted Laidlaw a 45-day option to purchase up to an additional 363,580 shares. The underwriting agreement contained customary representations, warranties and agreements by the Company, customary conditions to closing, indemnification obligations of the Company and Laidlaw, including for liabilities under the Securities Act of 1933, as amended (the “Securities Act”), other obligations of the parties and termination provisions. The offering closed on April 26, 2017 and the proceeds to the Company, net of expenses, were approximately $4.6 million. On May 12, 2017, Laidlaw exercised their option to purchase 363,580 additional shares. Closing on the additional shares was May 17, 2017 and the proceeds to the Company, net of expenses, were approximately $0.7 million. On November 9, 2017, the Company entered into a placement agency agreement with Laidlaw relating to the Company’s registered direct offering, issuance and sale to select accredited investors of 920,000 shares of the Company’s common stock at a price of $1.50 per share on a best efforts basis. These shares are registered under the Securities Act on the Company’s Registration Statement on Form S-3 (File No. 333-199219). The offering closed on November 14, 2017. The net proceeds to the Company from the offering, after deducting placement agent fees and other expenses, were approximately $1,082,000. The Company intends to use the net proceeds from this offering to fund the development of its clinical and preclinical programs, for other research and development activities and for general corporate purposes, which may include capital expenditures and funding its working capital needs. On February 8, 2018, the Company entered into an underwriting agreement (the “February 2018 Underwriting Agreement”) with H.C. Wainwright & Co., LLC (“HCW”), relating to the public offering (the “February 2018 Offering”) of 5,707,500 shares of the Company’s common stock, pre-funded warrants (the “February 2018 Pre-Funded Warrants”) to purchase an aggregate of 2,942,500 shares of common stock and preferred stock warrants (the “February 2018 Preferred Stock Warrants”) to purchase up to an aggregate of 865,000 shares of the Company’s Series A Convertible Preferred Stock, par value $0.01 per share (the “Series A Preferred Stock”). Each share of common stock or February 2018 Pre-Funded Warrant, as applicable, was sold together with a February 2018 Preferred Stock Warrant to purchase a 0.1 share of Series A Preferred Stock at a combined public offering price of $1.01 per share of common stock or $1.00 per February 2018 Pre-Funded Warrant, as applicable, and accompanying February 2018 Preferred Stock Warrant. The Company also granted HCW a 30-day option to purchase up to 1,297,500 additional shares of common stock at a purchase price of $1.00 per share and February 2018 Preferred Stock Warrants to purchase up to an aggregate of 129,750 shares of Series A Preferred Stock at a purchase price of $0.01 per February 2018 Preferred Stock Warrant, less the underwriting discounts and commissions. Prior to closing, HCW exercised this option in full to purchase 1,297,500 additional shares of common stock and February 2018 Preferred Stock Warrants to purchase 129,750 shares of Series A convertible preferred stock. The offering closed on February 12, 2018. Net proceeds from the offering were approximately $8.7 million after deducting underwriting discounts and commissions and other estimated offering expenses payable by the Company. The Company intends to use the net proceeds from the offering to fund the development of its clinical and preclinical programs, for other research and development activities and for general corporate purposes, which may include capital expenditures and funding its working capital needs. The February 2018 Pre-Funded Warrants are exercisable immediately at an exercise price of $0.01 per share, may be exercised until they are exercised in full, and may be exercised on a cashless basis in certain circumstances specified therein. The February 2018 Preferred Stock Warrants are exercisable immediately at an exercise price of $1.01 per 0.1 share of Series A Preferred Stock and will expire on the earlier of (A) the one-month anniversary of the date on which the Company publically releases topline results of the INSPIRE Pivotal phase 3 that compare the overall survival (OS) of patients in the rigosertib group vs the Physician’s Choice group, in all patients and in a subgroup of patients with IPSS-R very high risk and (B) December 31, 2019. The February 2018 Preferred Stock Warrants may be exercised on a cashless basis in certain circumstances specified therein. Each 0.1 share of Series A Preferred Stock will be convertible into one share of common stock. A holder of Series A Preferred Stock will be prohibited from converting Series A Preferred Stock into shares of common stock if, as a result of such conversion, the holder, together with its affiliates, would own more than 4.99% of the shares of the Company’s shares of common stock then issued and outstanding, which may be increased to 9.99% in certain circumstances. Shares of Series A Preferred Stock will generally have no voting rights, except as required by law and except that the consent of holders of a majority of the outstanding Series A Preferred Stock will be required to (i) alter or change adversely the powers, preferences or rights given to the Series A Preferred Stock or alter or amend the Certificate of Designation of the Series A Preferred Stock, (ii) amend any provision of the Company’s certificate of incorporation that would have a materially adverse effect on the rights of the holders of the Series A Preferred Stock, (iii) increase the number of authorized shares of Series A Preferred Stock, or (iv) enter into any agreement with respect to the foregoing. Shares of Series A Preferred Stock will not be entitled to receive any dividends, unless and until specifically declared by the Company’s board of directors, and will rank (i) on parity with the Company’s common stock on an as-converted basis, (ii) senior to any class or series of the Company’s capital stock created thereafter specifically ranking by its terms junior to the Series A Preferred Stock, (iii) on parity to any class or series of the Company’s capital stock created thereafter specifically, (iv) ranking by its terms on parity with the Series A Preferred Stock; and (v) junior to any class or series of the Company’s capital stock created thereafter specifically ranking by its terms senior to the Series A Preferred Stock. The exercise price and number of shares of common stock or Series A Preferred Stock issuable upon exercise of the Pre-Funded Warrants or Preferred Stock Warrants, as the case may be, and the conversion price and number of shares of common stock issuable upon the conversion of Series A Preferred Stock, is subject to adjustment in the event of any stock split, reverse stock split, stock dividend, recapitalization, reorganization or similar transaction, as described in the Pre-Funded Warrants, Preferred Stock Warrants and the Certificate of Designation of the Series A Preferred Stock, as applicable. The shares of common stock or Pre-Funded Warrants, as applicable, and the accompanying Preferred Stock Warrants could only be purchased together as a unit in the offering but were issued as separate securities. HCW acted as sole book-running manager for the offering, which was a firm commitment underwritten public offering pursuant to a registration statement on Form S-1 (Registration No. 333-222374) that was declared effective by the SEC on February 7, 2018. The offering was made only by means of a prospectus forming a part of the effective registration statement. The Company paid HCW a commission equal to 7.0% of the gross proceeds of the offering, a management fee equal to 1.0% of the gross proceeds of the offering and other expenses. As additional compensation, the Company issued warrants to HCW exercisable for 49,737.5 shares of Series A Preferred Stock, which are convertible into 497,375 shares of common stock subject to the terms of the Series A Preferred Stock. These warrants have substantially the same terms as the February 2018 Preferred Stock Warrants except that the exercise price per share is equal to $1.2625 per 0.1 share of Series A Preferred Stock.

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2018
Subsequent Events
Subsequent Events	14. Subsequent Events Securities Offering On April 27, 2018, the Company entered into an underwriting agreement with HCW relating to the public offering (the “April 2018 Offering”) of 46,588,234 shares of the Company’s common stock, pre-funded warrants (the “May 2018 Pre-Funded Warrants”) to purchase an aggregate of 12,235,295 shares of common stock and preferred stock warrants (the “May 2018 Preferred Stock Warrants”) to purchase up to an aggregate of 1,470,588.225 shares of the Company’s Series B Convertible Preferred Stock, par value $0.01 per share (the “Series B Preferred Stock”). Each share of common stock or April 2018 Pre-Funded Warrant, as applicable, was sold together with a May 2018 Preferred Stock Warrant to purchase a 0.025 share of Series B Preferred Stock at a combined public offering price of $0.425 per share of common stock or $0.415 per May 2018 Pre-Funded Warrant, as applicable, and accompanying May 2018 Preferred Stock Warrant. The Company also granted HCW a 30-day option to purchase up to 8,823,529 additional shares of common stock at a purchase price of $0.415 per share and May 2018 Preferred Stock Warrants to purchase up to an aggregate of 220,588.225 shares of Series B Preferred Stock at a purchase price of $0.01 per May 2018 Preferred Stock Warrant, less the underwriting discounts and commissions. Prior to closing, HCW exercised this option in full to purchase 8,823,529 additional shares of common stock and May 2018 Preferred Stock Warrants to purchase 220,588.225 shares of Series B convertible preferred stock. The offering closed on May 1, 2018. Net proceeds from the offering were approximately $25.6 million after deducting underwriting discounts and commissions and other estimated offering expenses payable by the Company. The Company intends to use the net proceeds from the offering to fund the development of its clinical and preclinical programs, for other research and development activities and for general corporate purposes, which may include capital expenditures and funding its working capital needs. The May 2018 Pre-Funded Warrants are exercisable immediately at an exercise price of $0.01 per share, may be exercised until they are exercised in full, and may be exercised on a cashless basis in certain circumstances specified therein. The May 2018 Preferred Stock Warrants are exercisable immediately at an exercise price of $0.425 per 0.025 share of Series B Preferred Stock (convertible into one share of Common Stock) and will expire on the 18-month anniversary of the date (the “New Charter Amendment Date”) on which the Company publicly announces through the filing of a Current Report on Form 8-K that the New Charter Amendment (defined below) has been filed with the Secretary of State of the State of Delaware. The May 2018 Preferred Stock Warrants may be exercised on a cashless basis in certain circumstances specified therein. Each 0.025 share of Series B Preferred Stock will be convertible into one share of common stock. The Company does not currently have a sufficient number of authorized shares of common stock to cover the shares issuable upon the conversion of Series B Preferred Stock. As a result, before any shares of Series B Preferred Stock can be converted, the Company needs to receive stockholder approval of an amendment (the “New Charter Amendment”) to its Tenth Amended and Restated Certificate of Incorporation, as amended, to sufficiently increase the authorized shares of common stock to cover the conversion of all outstanding shares of Series B Preferred Stock into common stock. The Company intends to seek such approval at a special meeting of stockholders on June 7, 2018. The Series B Preferred Stock is not convertible until the next business day after the Company files the New Charter Amendment with the Secretary of State of the State of Delaware. In addition, a holder of Series B Preferred Stock will be prohibited from converting Series B Preferred Stock into shares of common stock if, as a result of such conversion, the holder, together with its affiliates, would own more than 4.99% of the shares of the Company’s shares of common stock then issued and outstanding, which may be increased to 9.99% in certain circumstances. Shares of Series B Preferred Stock will generally have no voting rights, except as required by law and except that the consent of holders of a majority of the outstanding Series B Preferred Stock will be required to (i) alter or change adversely the powers, preferences or rights given to the Series B Preferred Stock or alter or amend the Certificate of Designation of the Series B Preferred Stock, (ii) amend any provision of the Company’s certificate of incorporation that would have a materially adverse effect on the rights of the holders of the Series B Preferred Stock, (iii) increase the number of authorized shares of Series B Preferred Stock, or (iv) enter into any agreement with respect to the foregoing. Shares of Series B Preferred Stock will not be entitled to receive any dividends, unless and until specifically declared by the Company’s board of directors, and will rank (i) on parity with the Company’s common stock on an as-converted basis, (ii) senior to any class or series of the Company’s capital stock created thereafter specifically ranking by its terms junior to the Series B Preferred Stock, (iii) on parity to any class or series of the Company’s capital stock created thereafter specifically, (iv) ranking by its terms on parity with the Series B Preferred Stock; and (v) junior to any class or series of the Company’s capital stock created thereafter specifically ranking by its terms senior to the Series B Preferred Stock. The exercise price and number of shares of common stock or Series B Preferred Stock issuable upon exercise of the Pre-Funded Warrants or Preferred Stock Warrants, as the case may be, and the conversion price and number of shares of common stock issuable upon the conversion of Series B Preferred Stock, is subject to adjustment in the event of any stock split, reverse stock split, stock dividend, recapitalization, reorganization or similar transaction, as described in the May 2018 Pre-Funded Warrants, May 2018 Preferred Stock Warrants and the Certificate of Designation of the Series B Preferred Stock, as applicable. The shares of common stock or May 2018 Pre-Funded Warrants, as applicable, and the accompanying May 2018 Preferred Stock Warrants could only be purchased together as a unit in the offering but were issued as separate securities. HCW acted as sole book-running manager for the offering, which was a firm commitment underwritten public offering pursuant to a registration statement on Form S-1 (Registration No. 333-224315) that was declared effective by the SEC on April 26, 2018. The offering was made only by means of a prospectus forming a part of the effective registration statement. The Company paid HCW a commission equal to 8.0% of the gross proceeds of the offering, a management fee equal to 1.0% of the gross proceeds of the offering and other expenses. In connection with the February 2018 Offering, the Company agreed to certain restrictions (the “Company Lock-Up”) set forth in Section 5(j) of the February 2018 Underwriting Agreement. The Company Lock-Up, among other items, prohibited the Company, during a period of one hundred and thirty-five (135) days from February 8, 2018, without the prior written consent of HCW, from offering or selling any Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock. In order to received HCW’s waiver of the Company Lock-Up, in connection with the April 2018 Offering, on April 16, 2018, the Company entered into a Lock-Up Waiver Agreement (the “Lock-Up Waiver Agreement”) with HCW and certain holders of the February 2018 Preferred Stock Warrants, pursuant to which (i) HCW waived the Company Lock-Up solely with respect to the April 2018 Offering, and (ii) the Company agreed to reduce the exercise price of the February 2018 Preferred Stock Warrants such that the exercise price of the February 2018 Preferred Stock Warrants shall be equal to 105% of the public offering price of common stock sold in the April 2018 Offering (but only to the extent that such public offering price is lower than the current exercise price of the February 2018 Preferred Stock Warrants) and that such repricing shall be effective concurrently with the closing of the April 2018 Offering. In accordance with the Lock-Up Waiver Agreements, the exercise price of the February 2018 Preferred Stock Warrants was repriced from $1.01 per 0.1 share of Series A Convertible Preferred Stock to $0.44625 per 0.1 share of Series A Convertible Preferred Stock when the April 2018 Offering closed on May 1, 2018. Special Meeting of Stockholders on June 7, 2018 On May 7, 2018, The Company filed with the SEC a preliminary proxy statement on Schedule 14A relating to the Special Meeting of Stockholders the Company intends to hold on June 7, 2018 to seek stockholders’ approval of an amendment to the Company’s Tenth Amended and Restated Certificate of Incorporation, as amended, to increase the number of authorized shares of capital stock from 105,000,000 shares to 255,000,000 shares in order to increase the number of authorized shares of common stock from 100,000,000 shares to 250,000,000 shares.

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2018
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) for interim financial information. Certain information and footnotes normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The financial statements include the consolidated accounts of the Company, its wholly-owned subsidiary, Onconova Europe GmbH, and GBO. All significant intercompany transactions have been eliminated.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2018, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2018 and 2017, the consolidated statement of stockholders’ (deficit) equity for the three months ended March 31, 2018 and the condensed consolidated statements of cash flows for the three months ended March 31, 2018 and 2017 are unaudited. The interim unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2018, the results of its operations for the three months ended March 31, 2018 and 2017, and its cash flows for the three months ended March 31, 2018 and 2017. The financial data and other information disclosed in these notes related to the three months ended March 31, 2018 and 2017 are unaudited. The results for the three months ended March 31, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 16, 2018.
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment, which is the identification and development of oncology therapeutics.
Significant Accounting Policies	Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 16, 2018. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies.
Fair Value Measurements	Fair Value Measurements The carrying amounts reported in the accompanying consolidated financial statements for cash and cash equivalents, accounts payable, and accrued liabilities approximate their respective fair values because of the short-term nature of these accounts. The fair value of the warrant liability is discussed in Note 7, “Fair Value Measurements.”
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (ASC 606), which the Company adopted effective January 1, 2018 using the modified retrospective method. There was no material impact to our financial position and results of operations as a result of the adoption. The Company applies ASC 606 to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. In accordance with ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration it is entitled to in exchange for the goods and services it transfers to the customer. At contract inception, the Company assesses the goods or services promised within each contract that falls under the scope of ASC 606, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. The Company derives revenue from collaboration and licensing agreements and the sale of products associated with material transfer, collaboration and supply agreements. License, Collaboration and Other Revenues The Company enters into licensing and collaboration agreements, under which it licenses certain of its product candidates’ rights to third parties. The Company recognizes revenue related to these agreements in accordance with ASC 606. The terms of these arrangements typically include payment of one or more of the following: non-refundable, up-front license fees; development, regulatory and commercial milestone payments; and royalties on net sales of the licensed product. In determining the appropriate amount of revenue to be recognized as it fulfills its obligation under each of its agreements, the Company performs the five steps described above. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price, which may include forecasted revenues, development timelines, reimbursement of personnel costs, discount rates and probabilities of technical and regulatory success. Licensing of Intellectual Property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front-fees. The Company evaluates the measure of progress each reporting period, and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal will not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensees, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in their period of adjustment. Manufacturing supply services. Arrangements that include a promise for future supply of drug substance or drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide material rights to the licensee and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded when the customer obtains control of the goods, which is upon shipment. Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some of all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue from its license agreements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued guidance which supersedes much of the current guidance for leases. The new standard requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all the leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. For leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients primarily focused on leases that commenced before the effective date of the new guidance, including continuing to account for leases that commence before the effective date in accordance with previous guidance, unless the lease is modified. The Company is evaluating the impact of the adoption of the standard on its consolidated financial statements. In March 2016, the FASB issued guidance that addresses the income tax effects of stock-based payments and eliminates the windfall pool concept, as all of the tax effects related to stock-based payments will now be recorded at settlement (or expiration) through the income statement. The new guidance also permits entities to make an accounting policy election for the impact of forfeitures on the recognition of expense for stock-based payment awards. Forfeitures can be estimated or recognized when they occur. The standard was effective for annual periods beginning after December 15, 2016 and interim periods within that reporting period. Early adoption was permitted in any interim or annual period, with any adjustment reflected as of the beginning of the fiscal year of adoption. The Company adopted the new guidance as of January 1, 2017. The adoption did not have a material impact on the Company’s consolidated financial statements and related disclosures. In November 2016, the FASB issued guidance requiring that amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The guidance is effective for interim and annual periods beginning in 2018 and should be applied using a retrospective transition method to each period presented. Early adoption is permitted. The Company adopted this guidance effective December 31, 2017. Restricted Cash was $50,000 at December 31 2017, 2016 and 2015. The adoption did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Revenue (Tables)

3 Months Ended

Mar. 31, 2018

Revenue

Schedule of deferred revenue

	Symbio
	Upfront Payment

Deferred balance at December 31, 2017	$	4,546,000
Recognition to revenue	114,000


Deferred balance at March 31, 2018	$	4,432,000

Net Loss Per Share of Common Stock (Tables)

3 Months Ended

Mar. 31, 2018

Net Loss Per Share of Common Stock

Schedule of antidilutive securities which have been excluded from the computation of diluted weighted average shares outstanding

	March 31,
	2018	2017
Warrants	15,232,146	3,525,771
Stock options	1,118,849	891,518

	16,350,995	4,417,289

Warrants (Tables)

3 Months Ended

Mar. 31, 2018

Warrants

Schedule of warrants outstanding and warrant activity

					Balance					Balance
		Exercise		Expiration	Decemeber 31,	Warrants	Warrants		Warrants	March 31,
Description	Classification	Price		Date	2017	Issued	Exercised		Expired	2018

Non-tradable warrants	Liability	$	11.50	July 2021	96,842	—	—		—	96,842
Tradable warrants	Liability	$	4.92	July 2021	3,192,022	—	—		—	3,192,022
Non-tradable pre-funded warrants	Equity	$	0.01	July 2023	5,907	—	—		—	5,907
Non-tradable warrants	Equity	$	0.45	*	—	9,947,500	—		—	9,947,500
Non-tradable warrants	Equity	$	1.2625	*	—	497,375	—		—	497,375
Non-tradable warrants	Equity	$	0.9400	March 2021	—	75,000	—		—	75,000
Non-tradable warrants	Equity	$	1.4100	March 2021	—	125,000	—		—	125,000
Non-tradable pre-funded warrants	Equity	$	0.01	none	—	2,942,500	(1,650,000	)	—	1,292,500

					3,294,771	13,587,375	(1,650,000	)	—	15,232,146

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

+ References + Details

Balance Sheet Detail (Tables)

3 Months Ended

Mar. 31, 2018

Balance Sheet Detail

Schedule of prepaid expenses and other current assets

	March 31,		December 31,
	2018		2017

Research and development	$	394,000	$	514,000
Manufacturing	33,000		48,000
Insurance	162,000		181,000
Other	225,000		77,000

	$	814,000	$	820,000

Schedule of property and equipment


	March 31,			December 31,
	2018			2017

Property and equipment	$	2,228,000		$	2,228,000
Accumulated depreciation	(2,180,000		)	(2,164,000		)

	$	48,000		$	64,000

Schedule of accrued expenses and other current liabilities

	March 31,		December 31,
	2018		2017

Research and development	$	1,884,000	$	1,912,000
Employee compensation	1,055,000		1,258,000
Professional fees	124,000		165,000

	$	3,063,000	$	3,335,000

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Measurements

Schedule of Black-Scholes option pricing model assumptions

The Company estimated the fair value of the non-tradable warrant liability at March 31, 2018, using the Black-Scholes option pricing model with the following weighted-average assumptions:

Risk-free interest rate	2.39	%
Expected volatility	74.07	%
Expected term	3.29 years
Expected dividend yield	0	%

Schedule of financial assets and liabilities measured at fair value on a recurring basis

	Fair Value Measurement as of:
	March 31, 2018								December 31, 2017
	Level 1		Level 2		Level 3		Balance		Level 1		Level 2		Level 3		Balance

Tradable warrants liability	$	957,000	$	—	$	—	$	957,000	$	1,755,000	$	—	$	—	$	1,755,000
Non-tradable warrants liability	—		—		4,000		4,000		—		—		18,000		18,000

Total	$	957,000	$	—	$	4,000	$	961,000	$	1,755,000	$	—	$	18,000	$	1,773,000

Schedule of reconciliation of liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)

	Warrant Liability
Balance at December 31, 2017	$	18,000
Issuance of warrants	—

Change in fair value upon re-measurement	14,000

Balance at March 31, 2018	$	4,000

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Stock-Based Compensation

Schedule of stock-based compensation expense

	Three Months ended March 31,
	2018		2017
General and administrative	$	158,000	$	265,000
Research and development	120,000		193,000

	$	278,000	$	458,000

Schedule of stock option activity

			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted- Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance, December 31, 2017	57,632		894,996		$	57.02	6.72	$	0
Authorized	200,000		—
Granted	(330,849	)	330,849		$	1.41
Exercised	—		—		$	—
Forfeitures	106,996		(106,996	)	$	80.97

Balance, March 31, 2018	33,779		1,118,849		$	25.00	8.03	$	0

Vested or expected to vest, March 31, 2018			1,098,389		$	42.02	7.16	$	0

Exercisable at March 31, 2018			624,116		$	42.02	7.16	$	0

Schedule of information with respect to stock options outstanding and exercisable

Information with respect to stock options outstanding and exercisable at March 31, 2018 is as follows:

Exercise Price	Shares	Exercisable
$1.09 - $6.50	802,214	336,045
$14.80 - $15.00	29,775	19,445
$23.20 - $39.80	75,369	59,635
$43.40 - $75.30	87,343	84,843
$132.80 - $151.20	118,798	118,798
$277.10 - $291.40	5,350	5,350

	1,118,849	624,116

Schedule of weighted-average assumptions used for estimating the fair value of the stock compensation granted

	Three Months ended March 31,
	2018			2017
Risk-free interest rate	2.60		%	2.07		%
Expected volatility	74.13		%	79.38		%
Expected term	5.78 years			6.00 years
Expected dividend yield	0		%	0		%
Weighted average grant date fair value	$	0.84		$	1.86

Nature of Business - The Company - Clinical-stage Product Candidates (Details)	Mar. 31, 2018 item
Nature of Business
Number of clinical-stage product candidates	3

Nature of Business - The Company - Preclinical Collaboration (Details) - Program	Mar. 31, 2018	Dec. 31, 2012
GBO
Preclinical Collaboration
Number of new programs to be collaborated and developed	2	2

Nature of Business - The Company (Details) - $ / shares	Mar. 31, 2018	Mar. 21, 2018	Mar. 20, 2018	Dec. 31, 2017
Nature of Business
Common Stock authorized (in shares)	100,000,000	100,000,000	25,000,000	25,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01		$ 0.01

Nature of Business - Liquidity - Financial Statement Items (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Nature of Business
Net loss	$ (5,090)	$ (8,341)
Accumulated deficit	367,406		$ 362,316
Cash and cash equivalents	$ 7,264	$ 15,389	$ 4,024	$ 21,400

Nature of Business - Liquidity - Sale of Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 30, 2013	Dec. 31, 2016
Sale of Securities
Aggregate offering price		$ 24,900
IPO
Sale of Securities
Issuance of stock (in shares)	594,167
Price per share (in dollars per share)	$ 150.00
Proceeds from initial public offering of common stock, net of issuance costs	$ 79,811

Nature of Business - Liquidity - Underwritten Public Offering (Details) - USD ($) $ in Millions	Nov. 14, 2017	Nov. 04, 2017	May 17, 2017	May 12, 2017	Apr. 26, 2017
The Offering
Sale of Securities
Issuance of stock (in shares)	920,000				2,476,190
Net proceeds from sales of common stock		$ 1.1	$ 5.3		$ 4.6
Underwriter's option \| Laidlaw
Sale of Securities
Issuance of stock (in shares)				363,580
Net proceeds from sales of common stock			$ 0.7
Underwriter's option \| Laidlaw \| Maximum
Sale of Securities
Issuance of stock (in shares)			363,580		363,580

Nature of Business - Liquidity - Rights Offering (Details) $ in Millions	May 01, 2018 USD ($) class shares	Feb. 12, 2018 USD ($) class shares	Jul. 29, 2016 shares
Series A Convertible Preferred Stock
Sale of Securities
Number of series denominated \| class		10
Series B Convertible Preferred Stock
Sale of Securities
Number of series denominated \| class	40
Dealer-Manager Agreement, rights offering
Sale of Securities
Issuance of stock (in shares)	55,411,763	7,005,000	3,599,786
Aggregate net proceeds \| $	$ 25.6	$ 8.7
Pre-funded warrants \| Series A Convertible Preferred Stock
Sale of Securities
Shares of common stock warrants will purchase (in shares)		1,044,487.5
Pre-funded warrants \| Series B Convertible Preferred Stock
Sale of Securities
Shares of common stock warrants will purchase (in shares)	1,691,176.450
Pre-funded warrants \| Securities Offering
Sale of Securities
Shares of common stock warrants will purchase (in shares)	12,235,295	2,942,500

Summary of Significant Accounting Policies - Segment Information (Details)	3 Months Ended
	Mar. 31, 2018 segment
Segment Information
Number of operating segments	1

Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ASU 2016-18
Recent Accounting Pronouncements
Restricted Cash	$ 50,000	$ 50,000	$ 50,000

Revenue (Details) $ in Thousands	3 Months Ended
Revenue (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Deferred revenue
Balance at the beginning of the period	$ 455
Balance at the end of the period	455
SymBio upfront payment
Deferred revenue
Balance at the beginning of the period	4,546
Recognition to revenue	114
Balance at the end of the period	$ 4,432

Net Loss Per Share of Common Stock (Details) - shares	3 Months Ended
Net Loss Per Share of Common Stock (Details) - shares	Mar. 31, 2018	Mar. 31, 2017
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares as they would be antidilutive
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares	16,350,995	4,417,289
Warrants
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares as they would be antidilutive
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares	15,232,146	3,525,771
Stock options
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares as they would be antidilutive
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares	1,118,849	891,518

Warrants (Details)	3 Months Ended
Warrants (Details)	Mar. 31, 2018 $ / shares shares
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	3,294,771
Warrants Issued (in shares)	13,587,375
Warrants Exercised (in shares)	(1,650,000)
Balance at end of the period (in shares)	15,232,146
Non-tradable warrants expiring July 2021, liability
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 11.50
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	96,842
Balance at end of the period (in shares)	96,842
Tradable warrants expiring July 2021, liability
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 4.92
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	3,192,022
Balance at end of the period (in shares)	3,192,022
Non-tradable pre-funded warrants expiring July 2023, equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 0.01
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	5,907
Balance at end of the period (in shares)	5,907
Non-tradable warrants with exercise price 0.45 equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 0.45
Warrants outstanding and warrant activity
Warrants Issued (in shares)	9,947,500
Balance at end of the period (in shares)	9,947,500
Non-tradable warrants with exercise price 1.2625 equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 1.2625
Warrants outstanding and warrant activity
Warrants Issued (in shares)	497,375
Balance at end of the period (in shares)	497,375
Non-tradable warrants with exercise price 0.9400 equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 0.9400
Warrants outstanding and warrant activity
Warrants Issued (in shares)	75,000
Balance at end of the period (in shares)	75,000
Non-tradable warrants with exercise price 1.4100 equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 1.4100
Warrants outstanding and warrant activity
Warrants Issued (in shares)	125,000
Balance at end of the period (in shares)	125,000
Non-tradable pre-funded warrants with exercise Price 0.01 equity
Warrants
Warrant exercise price (in dollars per share) \| $ / shares	$ 0.01
Warrants outstanding and warrant activity
Warrants Issued (in shares)	2,942,500
Warrants Exercised (in shares)	(1,650,000)
Balance at end of the period (in shares)	1,292,500

Balance Sheet Detail - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Prepaid expenses and other current assets:
Research and development	$ 394	$ 514
Manufacturing	33	48
Insurance	162	181
Other	225	77
Total	$ 814	$ 820

Balance Sheet Detail - Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property and equipment:
Property and equipment	$ 2,228	$ 2,228
Accumulated depreciation	(2,180)	(2,164)
Property and equipment, net	$ 48	$ 64

Balance Sheet Detail - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued expenses and other current liabilities:
Research and development	$ 1,884	$ 1,912
Employee compensation	1,055	1,258
Professional fees	124	165
Total	$ 3,063	$ 3,335

Fair Value Measurements - Securities Purchase Agreement (Details) - Securities Purchase Agreement $ / shares in Units, $ in Thousands	Jan. 05, 2016 USD ($) $ / shares shares
Sale of Securities
Issuance of stock (in shares)	193,684
Share price (in dollars per share) \| $ / shares	$ 9.50
Aggregate gross proceeds \| $	$ 1,840
Common Stock Warrants
Sale of Securities
Shares of common stock warrants will purchase (in shares)	96,842

Fair Value Measurements - Rights Offering (Details) - Dealer-Manager Agreement, rights offering - $ / shares	May 01, 2018	Feb. 12, 2018	Jul. 29, 2016
Sale of Securities
Issuance of stock (in shares)	55,411,763	7,005,000	3,599,786
Tradable warrants
Sale of Securities
Rights or warrants issued (in shares)			3,192,022
Exercisable, term (in years)			5 years
Shares into which each warrant can be converted (in shares)			1
Exercise price (in dollars per share)			$ 4.92
Redemption period (in years)			1 year
Redemption price (in dollars per share)			$ 0.001
Volume weighted average price per share of common stock (in dollars per share)			$ 12.30
Threshold consecutive trading days (in days)			10 days
Pre-funded warrants
Sale of Securities
Rights or warrants issued (in shares)			656,400

Fair Value Measurements - Fair Value Assumptions (Details) - Non-tradable Warrants	3 Months Ended
	Mar. 31, 2018
Assumption used to estimate the fair value of warrant liability by utilizing the Black-Scholes option pricing model
Risk-free interest rate (as a percent)	2.39%
Expected volatility (as a percent)	74.07%
Expected term	3 years 3 months 15 days
Expected dividend yield (as a percent)	0.00%

Fair Value Measurements - Fair Value Hierarchy Table (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Tradable warrants
Liabilities measured at fair value
Warrant liability	$ 957	$ 1,755
Level 1 \| Tradable warrants
Liabilities measured at fair value
Warrant liability	957	1,755
Recurring basis
Liabilities measured at fair value
Total	961	1,773
Recurring basis \| Non-tradable Warrants
Liabilities measured at fair value
Warrant liability	4	18
Recurring basis \| Level 1
Liabilities measured at fair value
Total	957	1,755
Recurring basis \| Level 3
Liabilities measured at fair value
Total	4	18
Recurring basis \| Level 3 \| Non-tradable Warrants
Liabilities measured at fair value
Warrant liability	$ 4	$ 18

Fair Value Measurements - Reconciliation of Level 3 Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Reconciliation of the warrant liability measured at fair value
Balance at the beginning of the period	$ 18
Change in fair value upon re-measurement	14
Balance at the end of the period	$ 4

Fair Value Measurements - Transfers (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Fair Value Measurements
Amount of transfers of assets out of Level 1 into Level 2	$ 0
Amount of transfers of assets out of Level 2 into Level 1	0
Amount of transfers of liabilities out of Level 1 into Level 2	0
Amount of transfers of liabilities out of Level 2 into Level 1	$ 0

Stock-Based Compensation - Common Stock Reserved for Issuance and Shares Available for Future Issuance (Details) - Stock options - shares	Mar. 31, 2018	Dec. 31, 2017	Jul. 31, 2013
Stock-Based Compensation
Common Stock reserved for issuance (in shares)			610,783
Evergreen provision, percentage of issued and outstanding common stock (as a percent)			4.00%
Evergreen provision, shares (in shares)			200,000
Common Stock available for future issuance (in shares)	33,779	57,632

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock-Based Compensation
Net tax benefits related to the stock-based compensation costs	$ 0
Total stock-based compensation	278	$ 458
General and administrative
Stock-Based Compensation
Total stock-based compensation	158	265
Research and development
Stock-Based Compensation
Total stock-based compensation	$ 120	$ 193

Stock-Based Compensation - Summary of Stock Option Activity (Details) - Stock options - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Shares Available for Grant
Balance at the beginning of the period (in shares)	57,632
Authorized (in shares)	200,000
Granted (in shares)	(330,849)
Forfeitures (in shares)	(106,996)
Balance at the end of the period (in shares)	33,779	57,632
Number of Shares
Balance at the beginning of the period (in shares)	894,996
Granted (in shares)	(330,849)
Forfeitures (in shares)	(106,996)
Balance at the end of the period (in shares)	1,118,849	894,996
Vested or expected to vest at the end of the period (in shares)	1,098,389
Exercisable at the end of the period (in shares)	624,116
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 57.02
Granted (in dollars per share)	1.41
Forfeitures (in dollars per share)	80.97
Balance at the end of the period (in dollars per share)	25.00	$ 57.02
Vested or expected to vest at the end of the period (in dollars per share)	42.02
Exercisable at the end of the period (in dollars per share)	$ 42.02
Additional Disclosures
Weighted average remaining contractual term	8 years 11 days	6 years 8 months 19 days
Weighted average remaining contractual term of options vested or expected to vest	7 years 1 month 28 days
Weighted average remaining contractual term of options exercisable	7 years 1 month 28 days
Aggregate intrinsic value of options outstanding	$ 0	$ 0
Aggregate intrinsic value of options vested or expected to vest	0
Aggregate intrinsic value of options exercisable	$ 0

Stock-Based Compensation - Stock Options Outstanding and Exercisable (Details) - Stock options	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Share-Based Compensation
Shares (in shares)	1,118,849
Exercisable (in shares)	624,116
Exercise Price Range $1.09 - $6.50
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 1.09
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 6.50
Shares (in shares)	802,214
Exercisable (in shares)	336,045
Exercise Price Range $14.80 - $15.00
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 14.80
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 15.00
Shares (in shares)	29,775
Exercisable (in shares)	19,445
Exercise Price Range $23.20 - $39.80
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 23.20
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 39.80
Shares (in shares)	75,369
Exercisable (in shares)	59,635
Exercise Price Range $43.40 - $75.30
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 43.40
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 75.30
Shares (in shares)	87,343
Exercisable (in shares)	84,843
Exercise Price Range $132.80 - $151.20
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 132.80
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 151.20
Shares (in shares)	118,798
Exercisable (in shares)	118,798
Exercise Price Range $277.10 - $291.40
Share-Based Compensation
Exercise price, lower range limit (in dollars per share) \| $ / shares	$ 277.10
Exercise price, upper range limit (in dollars per share) \| $ / shares	$ 291.40
Shares (in shares)	5,350
Exercisable (in shares)	5,350

Stock-Based Compensation - Options Granted after April 23, 2013 - Unrecognized Compensation Expense (Details) - Options granted after April 23, 2013 - Stock options $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Stock-Based Compensation
Unrecognized compensation expense related to unvested stock options	$ 1,074
Weighted-average period for recognizing unrecognized compensation expense related to unvested stock options (in years)	1 year 11 months 12 days

Stock-Based Compensation - Options Granted after April 23, 2013 - Fair Value Assumptions (Details) - Options granted after April 23, 2013 - Stock options - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Assumptions used
Risk-free interest rate (as a percent)	2.60%	2.07%
Expected volatility (as a percent)	74.13%	79.38%
Expected term (in years)	5 years 9 months 11 days	6 years
Expected dividend yield (as a percent)	0.00%	0.00%
Weighted average grant fair value (in dollars per share)	$ 0.84	$ 1.86
Annualized forfeiture rate (as a percent)	4.14%	4.14%

Research Agreements (Details) $ in Thousands	3 Months Ended
Research Agreements (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Temple
Research Agreements
Sales generated from products covered by the licensed patents	$ 0

License and Collaboration Agreements - SymBio Agreement (Details) - USD ($)			1 Months Ended	3 Months Ended
	Apr. 11, 2018	Mar. 02, 2018	Jul. 31, 2011	Mar. 31, 2018	Mar. 31, 2017
License and collaboration agreements
Revenue				$ 564,000	$ 210,000
License agreement \| HanX
License and collaboration agreements
Upfront payment received	$ 450,000
License agreement \| Rigosertib \| SymBio
License and collaboration agreements
Upfront payment received			$ 7,500,000
Aggregate milestone payments			22,000,000
Aggregate potential milestone payments based on annual net sales			$ 30,000,000
Percentage of royalty payments based on net sales of rigosertib (as a percent)			20.00%
License agreement \| Rigosertib \| Pint
License and collaboration agreements
Aggregate potential milestone payments based on annual net sales		$ 41,500,000
Prior written notice period for termination (in days)		45 days
License and collaboration \| HanX license payment \| HanX
License and collaboration agreements
Revenue				$ 450,000
Securities Purchase Agreement \| Common Stock \| Pint
License and collaboration agreements
Issuance of stock (in shares)		816,945
Value of stock issued		$ 1,250,000
United States and Japan \| License agreement \| Rigosertib \| SymBio
License and collaboration agreements
Aggregate milestone payments due upon receipt of marketing approval for an additional indication			$ 4,000,000
United States \| License agreement \| Rigosertib \| SymBio \| MDS IV indication
License and collaboration agreements
Regulatory milestones payments due upon receipt of marketing approval for indication			5,000,000
United States \| License agreement \| Rigosertib \| SymBio \| Rigosertib oral in lower risk MDS patients
License and collaboration agreements
Regulatory milestones payments due upon receipt of marketing approval for indication			5,000,000
Japan \| License agreement \| Rigosertib \| SymBio \| MDS IV indication
License and collaboration agreements
Regulatory milestones payments due upon receipt of marketing approval for indication			3,000,000
Japan \| License agreement \| Rigosertib \| SymBio \| Rigosertib oral in lower risk MDS patients
License and collaboration agreements
Regulatory milestones payments due upon receipt of marketing approval for indication			$ 5,000,000

Preclinical Collaboration (Details) - GBO $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
Preclinical Collaboration (Details) - GBO $ in Thousands	Nov. 30, 2014 USD ($)	Mar. 31, 2018 Program item	Dec. 31, 2013 USD ($)	Dec. 31, 2012 Program
Preclinical Collaboration
Number of new programs to be collaborated and developed \| Program		2		2
Ownership interest in the joint venture (as a percent)			90.00%
Period for which option available to cancel the license and purchase all rights following 15-month anniversary of commencement of program		30 days
Period of anniversary following which option available to cancel the license and purchase all rights for thirty days		15 months
Number of buy-back scenarios \| item		3
GVK BIO
Preclinical Collaboration
Initial capital contribution			$ 500
Ownership interest in the joint venture (as a percent)	17.50%		10.00%
Additional capital contributions	$ 500
GVK BIO \| Minimum
Preclinical Collaboration
Ownership interest in the joint venture (as a percent)			10.00%
GVK BIO \| Maximum
Preclinical Collaboration
Ownership interest in the joint venture (as a percent)			50.00%

Related-Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Mount Sinai
Related-Party Transactions
Payments to related party	$ 88	$ 88
Amounts due to related party	614		$ 526
Member of board of directors
Related-Party Transactions
Payments to related party	33	$ 33
Amounts due to related party	$ 33		$ 33

Securities Registrations and Sales Agreements - Sales and Purchase Agreements (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Oct. 08, 2015	Dec. 31, 2016
Securities Registrations and Sales Agreement
Aggregate offering price		$ 24,900
Lincoln Park \| Purchase agreement
Securities Registrations and Sales Agreement
Issuance of stock (in shares)	84,676
Aggregate offering price	$ 15,000
Net proceeds from sales of common stock	$ 1,500
Business day limit (in shares)	10,000
Business day limit contingent upon the closing price of the stock (in shares)	25,000
Regular purchase, one day limit	$ 1,000
Beneficial ownership percentage (as a percent)	4.99%
Beneficial ownership percentage after 180 days (as a percent)	9.99%
Maximum shares issued as a percentage of shares outstanding (as a percent)	19.99%
Minimum average price per share (in dollars per share)	$ 15.56
Stock issued as consideration (in shares)	20,000

Securities Registrations and Sales Agreements - FBR capital (Details) - ATM Program - FBR Capital Markets and Co. $ in Thousands	1 Months Ended
	Dec. 31, 2016 USD ($) shares
Sale of Securities
Issuance of stock (in shares) \| shares	12,764
Net proceeds from sales of common stock \| $	$ 40

Securities Registrations and Sales Agreements - Underwriting and Placement agency agreement (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 14, 2017	Nov. 09, 2017	Nov. 04, 2017	May 17, 2017	May 12, 2017	Apr. 26, 2017
The Offering
Issuance of stock (in shares)	920,000					2,476,190
Share price (in dollars per share)						$ 2.10
Net proceeds from sales of common stock			$ 1,100	$ 5,300		$ 4,600
Laidlaw \| Underwriter's option
Issuance of stock (in shares)					363,580
Period available to underwriters to purchase additional shares under the offering						45 days
Net proceeds from sales of common stock				$ 700
Laidlaw \| Placement Agency Agreement
Issuance of stock (in shares)		920,000
Share price (in dollars per share)		$ 1.50
Net proceeds from sales of common stock	$ 1,082
Maximum \| Laidlaw \| Underwriter's option
Issuance of stock (in shares)				363,580		363,580

Securities Registrations and Sales Agreements - underwriting agreement with HCW (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 12, 2018	Feb. 08, 2018	Nov. 14, 2017	Apr. 26, 2017	Mar. 31, 2018	Dec. 31, 2017
Subsidiary, Sale of Stock [Line Items]
Preferred stock, par value per share (in dollars per share)					$ 0.01	$ 0.01
Net proceeds from stock offering	$ 8.7
Minimum
Subsidiary, Sale of Stock [Line Items]
Maximum percentage of shareholding for conversion (in percentage)		4.99%
Maximum
Subsidiary, Sale of Stock [Line Items]
Maximum percentage of shareholding for conversion (in percentage)		9.99%
Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of common stock for each 0.1 share of preferred stock		1
Pre-funded warrants
Subsidiary, Sale of Stock [Line Items]
Warrant exercise price (in dollars per share)		$ 0.01
Preferred stock warrants \| Series A Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Warrant exercise price (in dollars per share)		$ 1.01
Number of securities converted from warrants as compensation		0.1
HCW
Subsidiary, Sale of Stock [Line Items]
Underwriters commission (in percentage)		7.00%
Management fee (in percentage)		1.00%
HCW \| Series A Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Number of securities converted from warrants as compensation		49,737.5
HCW \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of common stock shares for conversion preferred stock received as compensation		497,375
HCW \| Preferred stock warrants \| Series A Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Warrants exercise price received as compensation (in dollars per share)		$ 1.2625
Number of securities converted from each warrant as compensation		0.1
The Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of stock (in shares)			920,000	2,476,190
Share price (in dollars per share)				$ 2.10
The Offering \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Issuance of stock (in shares)		5,707,500
Share price (in dollars per share)		$ 1.01
The Offering \| Pre-funded warrants
Subsidiary, Sale of Stock [Line Items]
Warrant purchase price (in dollars per share)		$ 1.00
The Offering \| Pre-funded warrants \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of securities to each class of warrant (in shares)		2,942,500
The Offering \| Preferred stock warrants \| Series A Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Number of securities to each class of warrant (in shares)		865,000
Preferred stock, par value per share (in dollars per share)		$ 0.01
Portion of preferred stock for each warrant (in share)		0.1
Underwriter's option \| HCW
Subsidiary, Sale of Stock [Line Items]
Period available to underwriters to purchase additional shares under the offering		30 days
Underwriter's option \| HCW \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Issuance of stock (in shares)		1,297,500
Share price (in dollars per share)		$ 1.00
Lock-up period for purchased shares by counterparty (in days)		135 days
Underwriter's option \| HCW \| Preferred stock warrants \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of securities to each class of warrant (in shares)		129,750
Warrant purchase price (in dollars per share)		$ 0.01

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	May 01, 2018	Apr. 27, 2018	Apr. 16, 2018	Feb. 12, 2018	Feb. 08, 2018	Nov. 14, 2017	Apr. 26, 2017	May 07, 2018	May 06, 2018	Mar. 31, 2018	Mar. 21, 2018	Mar. 20, 2018	Dec. 31, 2017
Subsequent Events
Preferred stock, par value per share (in dollars per share)										$ 0.01			$ 0.01
Net proceeds from stock offering				$ 8.7
Common stock, shares authorized										100,000,000	100,000,000	25,000,000	25,000,000
Minimum
Subsequent Events
Maximum percentage of shareholding for conversion (in percentage)					4.99%
Maximum
Subsequent Events
Maximum percentage of shareholding for conversion (in percentage)					9.99%
Common Stock
Subsequent Events
Number of common stock for each 0.025 share of preferred stock					1
Pre-funded warrants
Subsequent Events
Warrant exercise price (in dollars per share)					$ 0.01
Preferred stock warrants \| Series A Convertible Preferred Stock
Subsequent Events
Warrant exercise price (in dollars per share)					$ 1.01
Number of securities converted from warrants as compensation					0.1
HCW
Subsequent Events
Underwriters commission (in percentage)					7.00%
Management fee (in percentage)					1.00%
HCW \| Series A Convertible Preferred Stock
Subsequent Events
Number of securities converted from warrants as compensation					49,737.5
The Offering
Subsequent Events
Issuance of stock (in shares)						920,000	2,476,190
Share price (in dollars per share)							$ 2.10
The Offering \| Common Stock
Subsequent Events
Issuance of stock (in shares)					5,707,500
Share price (in dollars per share)					$ 1.01
The Offering \| Pre-funded warrants
Subsequent Events
Warrant purchase price (in dollars per share)					$ 1.00
The Offering \| Pre-funded warrants \| Common Stock
Subsequent Events
Number of securities to each class of warrant (in shares)					2,942,500
The Offering \| Preferred stock warrants \| Series A Convertible Preferred Stock
Subsequent Events
Number of securities to each class of warrant (in shares)					865,000
Preferred stock, par value per share (in dollars per share)					$ 0.01
Portion of preferred stock for each warrant (in share)					0.1
Underwriter's option \| HCW
Subsequent Events
Period available to underwriters to purchase additional shares under the offering					30 days
Underwriter's option \| HCW \| Common Stock
Subsequent Events
Issuance of stock (in shares)					1,297,500
Share price (in dollars per share)					$ 1.00
Lock-up period for purchased shares by counterparty (in days)					135 days
Underwriter's option \| HCW \| Preferred stock warrants \| Common Stock
Subsequent Events
Number of securities to each class of warrant (in shares)					129,750
Warrant purchase price (in dollars per share)					$ 0.01
Subsequent Events
Subsequent Events
Net proceeds from stock offering	$ 25.6
Percentage of exercise price of warrants			105.00%
Capital stock, shares authorized								255,000,000	105,000,000
Common stock, shares authorized								250,000,000	100,000,000
Subsequent Events \| Minimum
Subsequent Events
Maximum percentage of shareholding for conversion (in percentage)		4.99%
Subsequent Events \| Maximum
Subsequent Events
Maximum percentage of shareholding for conversion (in percentage)		9.99%
Subsequent Events \| Common Stock
Subsequent Events
Number of common stock for each 0.025 share of preferred stock		1
Subsequent Events \| Pre-funded warrants
Subsequent Events
Warrant exercise price (in dollars per share)		$ 0.01
Subsequent Events \| Preferred stock warrants \| Series A Convertible Preferred Stock
Subsequent Events
Warrant exercise price (in dollars per share)	$ 0.44625
Number of securities converted from warrants as compensation	0.1
Subsequent Events \| Preferred stock warrants \| Series B Convertible Preferred Stock
Subsequent Events
Warrant exercise price (in dollars per share)		$ 0.425
Subsequent Events \| HCW
Subsequent Events
Underwriters commission (in percentage)		8.00%
Management fee (in percentage)		1.00%
Subsequent Events \| The Offering \| Common Stock
Subsequent Events
Issuance of stock (in shares)		46,588,234
Share price (in dollars per share)		$ 0.425
Subsequent Events \| The Offering \| Pre-funded warrants
Subsequent Events
Warrant purchase price (in dollars per share)		$ 0.415
Subsequent Events \| The Offering \| Pre-funded warrants \| Common Stock
Subsequent Events
Number of securities to each class of warrant (in shares)		12,235,295
Subsequent Events \| The Offering \| Preferred stock warrants \| Series B Convertible Preferred Stock
Subsequent Events
Number of securities to each class of warrant (in shares)		1,470,588.225
Preferred stock, par value per share (in dollars per share)		$ 0.01
Portion of preferred stock for each warrant (in share)		0.025
Subsequent Events \| Underwriter's option \| HCW
Subsequent Events
Period available to underwriters to purchase additional shares under the offering		30 days
Subsequent Events \| Underwriter's option \| HCW \| Common Stock
Subsequent Events
Issuance of stock (in shares)		8,823,529
Share price (in dollars per share)		$ 0.415
Subsequent Events \| Underwriter's option \| HCW \| Preferred stock warrants \| Common Stock
Subsequent Events
Number of securities to each class of warrant (in shares)		220,588.225
Warrant purchase price (in dollars per share)		$ 0.01