Arqule (ARQL) 10-K5 Mar 182017 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2017	Feb. 20, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ARQULE INC
Entity Central Index Key	1,019,695
Trading Symbol	arql
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-Known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		87,110,202
Entity Public Float			$ 88,251,483
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 20,229	$ 15,267
Marketable securities-short term	27,807	15,859
Prepaid expenses and other current assets	547	822
Total current assets	48,583	31,948
Property and equipment, net	115	180
Other assets	204	252
Total assets	48,902	32,380
Current liabilities:
Accounts payable and accrued expenses	8,259	8,700
Deferred revenue	1,500
Total current liabilities	9,759	8,700
Long-term liabilities:
Notes payable	14,607
Warrant liability	1,512
Total liabilities	25,878	8,700
Commitments and contingencies (Note 13)
Preferred stock, convertible, Series A $0.01 par value; 1,000,000, shares authorized; 8,370 and no shares issued and outstanding at December 31, 2017 and 2016, respectively, aggregate liquidation preference of $9,500	8,843
Stockholders' equity:
Common stock, $0.01 par value; 100,000,000 shares authorized; 87,110,202 and 71,146,209 shares issued and outstanding at December 31, 2017 and 2016, respectively	871	711
Additional paid-in capital	547,364	527,802
Accumulated other comprehensive income (loss)	(16)	2
Accumulated deficit	(534,038)	(504,835)
Total stockholders' equity	14,181	23,680
Total liabilities, preferred stock and stockholders' equity	$ 48,902	$ 32,380

BALANCE SHEETS (Parentheticals)

BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Series A Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A Preferred stock, shares authorized	1,000,000	1,000,000
Series A Preferred stock, shares issued	8,370	0
Series A Preferred stock, shares outstanding	8,370	0
Aggregate liquidation preference	$ 9,500	$ 9,500
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	87,110,202	71,146,209
Common stock, shares outstanding	87,110,202	71,146,209

STATEMENTS OF OPERATIONS AND CO

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Research and development revenue	$ 0	$ 4,709	$ 11,239
Costs and expenses:
Research and development	19,468	20,042	15,561
General and administrative	7,551	7,563	9,830
Total costs and expenses	27,019	27,605	25,391
Loss from operations	(27,019)	(22,896)	(14,152)
Interest income	238	178	101
Interest expense	(1,520)
Other income (expense)	(902)		277
Loss before income taxes	(29,203)	(22,718)	(13,774)
Provision for income taxes	0	0	0
Net loss	(29,203)	(22,718)	(13,774)
Unrealized gain (loss) on marketable securities	(18)	(1)	13
Comprehensive loss	$ (29,221)	$ (22,719)	$ (13,761)
Basic and diluted net loss per common share:
Net loss per common share (in dollars per share)	$ (0.39)	$ (0.33)	$ (0.22)
Weighted average basic and diluted common shares outstanding	74,813	69,714	62,808

STATEMENTS OF STOCKHOLDERS' EQU

STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	PREFERRED STOCK	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)	ACCUMULATED DEFICIT	Total
Balance at Dec. 31, 2014		$ 628	$ 508,270	$ (10)	$ (468,343)	$ 40,545
Balance (in shares) at Dec. 31, 2014		62,821,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted shares issued net of forfeitures and shares redeemed for taxes (in shares)		13,242
Employee stock purchase plan		$ 1	133			134
Employee stock purchase plan (in shares)		104,757
Stock based compensation expense			2,261			2,261
Change in unrealized gain (loss) on marketable securities				13		13
Net loss					(13,774)	(13,774)
Balance at Dec. 31, 2015		$ 629	510,664	3	(482,117)	29,179
Balance (in shares) at Dec. 31, 2015		62,939,780
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock and warrants from stock offerings, net		$ 80	15,094			15,174
Issuance of common stock and warrants from stock offerings, net (in shares)		8,027,900
Stock option exercises and issuance of common stock		$ 1	112			113
Stock option exercises and issuance of common stock (in shares)		97,498
Restricted shares issued net of forfeitures and shares redeemed for taxes (in shares)		29,828
Employee stock purchase plan		$ 1	67			68
Employee stock purchase plan (in shares)		51,203
Stock based compensation expense			1,865			1,865
Change in unrealized gain (loss) on marketable securities				(1)		(1)
Net loss					(22,718)	(22,718)
Balance at Dec. 31, 2016		$ 711	527,802	2	(504,835)	$ 23,680
Balance (in shares) at Dec. 31, 2016		71,146,209				71,146,209
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock and warrants from stock offering, net	$ 8,843
Issuance of preferred stock and warrants from stock offering, net (in shares)	8,370
Issuance of common stock and warrants from stock offerings, net		$ 160	17,764			$ 17,924
Issuance of common stock and warrants from stock offerings, net (in shares)		15,938,651
Restricted shares issued net of forfeitures and shares redeemed for taxes (in shares)		5,380
Employee stock purchase plan			17			17
Employee stock purchase plan (in shares)		19,962
Stock based compensation expense			1,434			1,434
Issuance of warrants from notes payable			347			347
Change in unrealized gain (loss) on marketable securities				(18)		(18)
Net loss					(29,203)	(29,203)
Balance at Dec. 31, 2017	$ 8,843	$ 871	$ 547,364	$ (16)	$ (534,038)	$ 14,181
Balance (in shares) at Dec. 31, 2017	8,370	87,110,202				87,110,202

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net loss	$ (29,203)	$ (22,718)	$ (13,774)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	65	101	161
Amortization of premium (discount) on marketable securities	(28)	48	464
Amortization of deferred gain on sale leaseback			(232)
Amortization of debt discount	330
Change in fair value of warrant liability	902
Non-cash stock compensation	1,434	1,865	2,261
Gain on sale of property and equipment			(277)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	322	(108)	1,029
Accounts payable and accrued expenses	(497)	2,466	(713)
Deferred revenue	1,500	(4,591)	(11,079)
Net cash used in operating activities	(25,175)	(22,937)	(22,160)
Cash flows from investing activities:
Purchases of marketable securities	(41,971)	(30,975)	(36,978)
Proceeds from sale or maturity of marketable securities	30,033	39,856	60,479
Proceeds from sale of property and equipment			298
Purchases of property and equipment		(15)	(315)
Net cash provided by (used in) investing activities	(11,938)	8,866	23,484
Cash flows from financing activities:
Proceeds from notes payable and warrants, net	14,624
Proceeds from common stock offerings and warrants, net	17,951	15,174
Proceeds from convertible preferred stock offering and warrants, net	9,483
Proceeds from stock option exercises and employee stock plan purchases	17	181	134
Net cash provided by financing activities	42,075	15,355	134
Net increase in cash and cash equivalents	4,962	1,284	1,458
Cash and cash equivalents, beginning of period	15,267	13,983	12,525
Cash and cash equivalents, end of period	20,229	15,267	13,983
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (IN THOUSANDS):
Interest paid on debt	1,190	0	0
Income taxes paid	$ 0	$ 0	$ 0

ORGANIZATION AND NATURE OF OPER

ORGANIZATION AND NATURE OF OPERATIONS	12 Months Ended
ORGANIZATION AND NATURE OF OPERATIONS	Dec. 31, 2017
Organization and Nature Of Operations [Abstract]
ORGANIZATION AND NATURE OF OPERATIONS	1. ORGANIZATION AND NATURE OF OPERATIONS We are a biopharmaceutical company engaged in the research and development of innovative therapeutics to treat cancers and rare diseases. Our mission is to discover, develop and commercialize novel small molecule drugs in areas of high unmet need that will dramatically extend and improve the lives of our patients. These product candidates target biological pathways implicated in a wide range of cancers and certain non-oncology indications. Our discovery and development efforts are guided, when possible, by an understanding of the role of biomarkers, which are indicators of a particular biological condition or process and may predict the clinical benefit of our compounds in defined patient populations. Our clinical-stage pipeline consists of five product candidates, all of which are in targeted patient populations, making ArQule a leader among companies our size in precision medicine. ArQule has a long history of kinase drug discovery and development, having discovered and introduced ten kinase inhibitors into clinical trials. Our drug discovery efforts have been informed by our historical expertise in chemistry, our work in rational drug design and by our insight into kinase binding and regulation. We have applied this knowledge to produce significant chemical matter for a number of kinase targets and to build an extensive library of proprietary compounds with the potential to target multiple kinases in oncology and other therapeutic areas, such as rare diseases. We may bring further preclinical programs forward and interrogate our library against new targets beyond kinases either directly or with collaborators. Our proprietary pipeline of product candidates is directed toward molecular targets and biological processes with demonstrated roles in the development of both human cancers and rare, non-oncology diseases. All of these programs are being developed in targeted, biomarker-defined patient populations. By seeking out subgroups of patients that are most likely to respond to our drugs, we intend to identify small, often orphan, indications that allow for focused and efficient development. At the same time, in addition to pursuing these potentially fast-to-market strategies, we also pursue development in other indications that could allow us to expand the utility of the drugs if approved. The pipeline includes the following wholly-owned compounds: • ARQ 531, an orally bioavailable, potent and reversible inhibitor of both wild type and C481S-mutant BTK, in Phase 1 for B-cell malignancies refractory to other therapeutic options; • Miransertib (ARQ 092), a selective inhibitor of AKT, a serine/threonine kinase, in Phase 1/2 in rare Overgrowth Diseases and in Phase 1 for multiple oncology indications and in the rare disease, Proteus syndrome, in partnership with the National Institutes of Health (NIH); • Derazantinib (ARQ 087), a multi-kinase inhibitor designed to preferentially inhibit the FGFR family of kinases, in a registrational trial in intrahepatic cholangiocarcinoma (iCCA) in patients with FGFR2 fusions; • ARQ 751, a next-generation inhibitor of AKT, in Phase 1 for solid tumors harboring the AKT1 or PI3K mutation; and • ARQ 761, a ß-lapachone analog being evaluated as a promoter of NQO1-mediated programmed cancer cell death, in Phase 1/2 in multiple oncology indications in partnership with The University of Texas Southwest Medical Center. Tivantinib (ARQ 197), an orally administered, small molecule inhibitor of the c-Met receptor tyrosine kinase and its biological pathway is no longer being developed. We licensed commercial rights to tivantinib for human cancer indications to Daiichi Sankyo Co., Ltd. (“Daiichi Sankyo”) in the U.S., Europe, South America and the rest of the world, excluding Japan and certain other Asian countries, where we had licensed commercial rights to Kyowa Hakko Kirin Co., Ltd. (“Kyowa Hakko Kirin”). Our uses of cash for operating activities have primarily consisted of salaries and wages for our employees, facility and facility-related costs for our offices and laboratories, fees paid in connection with preclinical and clinical studies, laboratory supplies and materials, and professional fees. The sources of our cash flow from operating activities have historically consisted primarily of payments received from our collaborators for services performed or upfront payments for future services. In the year ended December 31, 2017 and 2016, our net use of cash was primarily driven by payments for operating expenses which resulted in net cash outflows of $25.2 million and $22.9 million, respectively. Our cash requirements may vary materially from those now planned depending upon the results of our drug discovery and development strategies, our ability to enter into additional corporate collaborations and the terms of such collaborations, results of research and development, unanticipated required capital expenditures, competitive and technological advances, acquisitions and other factors. We cannot guarantee that we will be able to develop any of our drug candidates into a commercial product. In January 2017, we entered into a loan and security agreement (the “Loan Agreement”) with a principal balance of $15 million (see Note 8). The terms of the Loan Agreement require payments of interest on a monthly basis through September 2018 and payments of interest and principal from October 2018 to August 2021. The original maturity date of the loan was August 1, 2021 and in a February 2018 amendment was extended by one year to August 1, 2022 with principal payments commencing on September 1, 2019. In September 2017, we sold 2.0 million shares of common stock through an at-the-market (ATM) offering and raised net proceeds of $2.3 million. In October 2017, we entered into definitive stock purchase agreements with certain institutional investors. In conjunction with this stock offering we issued 13,938,651 shares of our common stock and warrants for 3,123,674 shares of our common stock for aggregate net proceeds of $15.6 million. Each warrant is exercisable for $1.75 per share and expires in four years from the date of issuance. In November 2017, we entered into definitive securities purchase agreements with certain institutional investors. In conjunction with this stock offering the Company raised net proceeds of $9.5 million through the sale of 8,370 shares of series A convertible preferred stock (Series A Preferred) and warrants covering 2,260 shares of Series A Preferred (Warrants). Each share of Series A Preferred together with the associated Warrant is priced at $1,135 and will automatically convert into 1,000 shares of common stock upon the adoption of an amendment to the Company’s restated certificate of incorporation to increase the number of authorized shares of common stock thereunder. The Warrants have a pre-conversion exercise price of $1,750 per share of Series A Preferred (post-conversion price of $1.75 per share of common stock), are exercisable immediately and expire approximately four years from the date of the adoption of the amendment to the Company’s restated certificate of incorporation. In February 2018 Roivant Sciences and ArQule, Inc. announced the initiation of a collaboration to pursue the development of derazantinib, a pan-FGFR (fibroblast growth factor receptor) inhibitor, in Greater China. As part of the collaboration, ArQule has granted a Roivant subsidiary (Sinovant) an exclusive license to develop and commercialize derazantinib in the People’s Republic of China, Hong Kong, Macau, and Taiwan. Deal terms include an upfront payment to ArQule of $3 million and an additional $2.5 million development milestone within the first year. ArQule is also eligible for an additional $82 million in regulatory and sales milestones. Upon commercialization, ArQule will receive double digit royalties in the low teens from Sinovant on net sales of derazantinib in the Greater China territory. We anticipate that our cash, cash equivalents and marketable securities on hand at December 31, 2017, financial support from our licensing agreements, and the one year extension of our loan agreement mentioned above will be sufficient to finance our operations for at least 12 months from the issuance date of these financial statements. We expect that we will need to raise additional capital or incur indebtedness to continue to fund our operations in the future. Our ability to raise additional funds will depend on financial, economic and market conditions, and due to global capital and credit market conditions or for other reasons, we may be unable to raise capital when needed, or on terms favorable to us. If necessary funds are not available, we may have to delay, reduce the scope of, or eliminate some of our development programs, potentially delaying the time to market for any of our product candidates.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Dec. 31, 2017
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant accounting policies followed in the preparation of these financial statements are as follows: Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Cash Equivalents and Marketable Securities We consider all highly liquid investments purchased within three months of original maturity date to be cash equivalents. We invest our available cash primarily in commercial paper, money market funds and U.S. Treasury bill funds. We generally classify our marketable securities as available-for-sale at the time of purchase and re-evaluate such designation as of each balance sheet date. The Company classifies its investments as either current or long-term based upon the investments’ contractual maturities and the Company’s ability and intent to convert such instruments to cash within one year. We report available-for-sale investments at fair value as of each balance sheet date and include any unrealized gains and, to the extent deemed temporary, unrealized losses in stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense) in the statement of operations and comprehensive loss. For any of our marketable securities classified as trading securities, changes in the fair value of those securities are recorded as other income (expense) in the statement of operations and comprehensive loss. At December 31, 2017 we had no trading securities. We conduct quarterly reviews to determine the fair value of our investment portfolio and to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. In the event that the cost basis of a security exceeds its fair value, we evaluate, among other factors, the duration of the period that, and extent to which, the fair value is less than cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, and operational and financing cash flow factors, overall market conditions and trends, our intent to sell the investment and if it is more likely than not that we would be required to sell the investment before its anticipated recovery. Unrealized losses on available-for- sale securities that are determined to be temporary, and not related to credit loss, are recorded in accumulated other comprehensive income (loss). For available-for-sale debt securities with unrealized losses, we perform an analysis to assess whether we intend to sell or whether we would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. Where we intend to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is reflected in the statement of operations and comprehensive loss as an impairment loss. Regardless of our intent to sell a security, we perform additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. We did not recognize any other-than-temporary impairments during the years ended December 31, 2017, 2016 or 2015. Credit losses are identified where we do not expect to receive cash flows sufficient to recover the amortized cost basis of a security. Fair Value Measurements Certain assets of the Company are carried at fair value under GAAP. 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. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. At December 31, 2017 and 2016 our financial instruments consist of cash, cash equivalents, investments in corporate debt securities, accounts payable, notes payable and accrued expenses. At December 31, 2017 and 2016 our financial instruments also included marketable securities and warrant liabilities which are reported at fair value. The warrant liability is carried at fair value and determined to be a Level 3 liability in the fair value hierarchy described above. The carrying values of cash, cash equivalents, investments in corporate debt securities, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. The carrying value of the Company’s notes payable approximates its fair value. Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives. Assets under capital leases and leasehold improvements are amortized over the shorter of their estimated useful lives or the term of the respective leases by use of the straight-line method. Maintenance and repair costs are expensed as incurred. Depreciation and amortization expense for the years ended December 31, 2017, 2016 and 2015 was $65, $101 and $161, respectively. Revenue Recognition—Research and Development Revenue Research and development revenue is generated primarily through collaborative research and development agreements and license agreements. The terms of the agreements may include nonrefundable upfront payments, funding for research and development, milestone payments and royalties on any product sales derived from collaborations. We recognize revenues when all of the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; our price to the customer is fixed or determinable; and collectability is reasonably assured. We elected the milestone method of revenue recognition, which may impact any new collaboration agreements or material modifications to existing agreements, in the event we elect the policy of utilizing the milestone method to recognize future substantive milestones. Research and development payments associated with the collaboration agreements in effect prior to January 1, 2011 were recognized as research and development revenue using the contingency adjusted performance model. Under this model, when payments are earned, revenue is immediately recognized on a pro-rata basis in the period we achieve the milestone based on the time elapsed from inception of the agreement to the time the milestone is earned over the estimated duration of the development period under the agreement. Thereafter, the remaining portion of the milestone payment is recognized on a straight-line basis over the remaining estimated development period under the agreement. This estimated development period may ultimately be shorter or longer depending upon the outcome of the development work, resulting in accelerated or deferred recognition of the development revenue. Royalty payments will be recognized as revenue when earned. The costs associated with satisfying research and development contracts are included in research and development expense as incurred. Research and Development Costs Costs of research and development, which are expensed as incurred, are comprised of the following types of costs incurred in performing research and development activities and those incurred in connection with research and development revenue: salaries and benefits, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs. Impairment or Disposal of Long-Lived Assets We assess our long-lived assets for impairment whenever events or changes in circumstances (a “triggering event”) indicate that the carrying value of a group of long-lived assets may not be recoverable. If such circumstances are determined to exist, an estimate of undiscounted future cash flows produced by the long-lived asset, including its eventual residual value, is compared to the carrying value to determine whether impairment exists. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values. Segment Data The chief operating decision maker uses aggregated-financial information in determining how to allocate resources and assess performance. For this reason, we have determined that we are principally engaged in one operating segment. See Note 14 with respect to significant customers. Substantially all of our revenue since inception has been generated in the U.S. and all of our long-lived assets are located in the U.S. Other Income (Expense) Other income (expense) in 2017 includes a non-cash expense of $902 from an increase in fair value of our preferred stock warrant liability. Other income (expense) was $0 in 2016 and in 2015 includes a gain of $277 from the sale of property and equipment. Income Taxes Income taxes have been accounted for using the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if, based upon the weight of all available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. For uncertain tax positions that meet “a more likely than not” threshold, the Company recognizes the benefit of uncertain tax positions in the financial statements. Earnings (Loss) Per Share Net loss per share is computed using the weighted average number of common shares outstanding. Basic and diluted net loss per share amounts are equivalent for the periods presented as the inclusion of potential common shares in the number of shares used for the diluted computation would be anti-dilutive to loss per share. Potential common shares, for the year ended December 31, 2017, include 10,622,455 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options, 354,330 shares that would be issued upon the exercise of the warrants from our January 2017 loan agreement, 3,123,674 shares that would be issued upon the exercise of the warrants from our October 2017 common stock offering, 8,370,000 common shares that would be issued upon the conversion of the shares from our November 2017 preferred stock offering and 2,259,000 common shares that would be issued upon the exercise of the warrants from our November 2017 preferred stock offering. Potential common shares for the year ended December 31, 2016, include 8,715,048 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options and options to purchase 3,567,956 shares that would have been issued upon the exercise of the options from our February 2016 common stock offering. The options issued in conjunction with the February 2016 common stock offering expired in 2017. Potential common shares, for the year ended December 31, 2015, include 8,305,950 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options. Stock-Based Compensation Our stock-based compensation cost is measured at the grant date, based on the calculated fair value of the award, and is recognized as an expense over the employees’ requisite service period (generally the vesting period of the equity grant). We estimate the fair value of stock options using the Black-Scholes valuation model. Key input assumptions used to estimate the fair value of stock options include the exercise price of the award, expected option term, expected volatility of our stock over the option’s expected term, risk-free interest rate over the option’s expected term, and the expected annual dividend yield. We believe that the valuation technique and approach utilized to develop the underlying assumptions are appropriate in calculating the fair values of our stock options granted. The following table presents stock-based compensation expense for the years ended December 31, 2017, 2016 and 2015 included in our Statements of Operations and Comprehensive Loss: 2017 2016 2015 Research and development $ 359 $ 514 $ 682 General and administrative 1,075 1,351 1,579 Total stock-based compensation expense $ 1,434 $ 1,865 $ 2,261 In the years ended December 31, 2017, 2016 and 2015, no stock-based compensation expense was capitalized and there were no recognized tax benefits associated with the stock-based compensation charges. The fair value of stock options and employee stock purchase plan shares granted in the years ended December 31, 2017, 2016 and 2015 respectively were estimated on the grant date using the Black-Scholes option-pricing model with the following assumptions: 2017 2016 2015 Dividend yield(1) 0.0% 0.0% 0.0% Weighted average expected volatility factor(2) 62% 63% 66% Risk free interest(3) 1.9–2.1% 1.2–1.8% 1.3–1.7% Expected term, excluding options issued pursuant to the Employee Stock Purchase Plan(4) 6.1–7.1 years 5.8–7.2 years 5.6–6.8 years Expected term—Employee Stock Purchase Plan(5) 6 months 6 months 6 months (1) We have historically not paid dividends on our common stock and we do not anticipate paying any dividends in the foreseeable future. (2) Measured using an average of historical daily price changes of our stock over a period equal to our expected term. (3) The risk-free interest rate for periods equal to the expected term of share option based on the U.S. Treasury yield in effect at the time of grant. (4) The expected term is the number of years that we estimate, based on historical experience, that options will be outstanding before exercise or cancellation. The range in expected term is the result of certain groups of employees exhibiting different exercising behavior. (5) The expected term of options issued in connection with our Employee Stock Purchase Plan is 6 months based on the terms of the plan. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption. In May 2017 the FASB issued Accounting Standard Update (“ASU”) No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting. This new standard provides clarity and reduces both (1) diversity in practice and (2) cost and complexity when applying the guidance in Topic 718, Compensation-Stock Compensation, to a change to the terms or conditions of a share-based payment award. This new standard will be effective for us on January 1, 2018. The adoption of this standard is not expected to have a material impact on our financial position or results of operations. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This new standard clarifies certain aspects of the statement of cash flows, including the classification of debt prepayment or debt extinguishment costs or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, distributions received from equity method investees and beneficial interests in securitization transactions. This new standard also clarifies that an entity should determine each separately identifiable source of use within the cash receipts and payments on the basis of the nature of the underlying cash flows. In situations in which cash receipts and payments have aspects of more than one class of cash flows and cannot be separated by source or use, the appropriate classification should depend on the activity that is likely to be the predominant source or use of cash flows for the item. This new standard will be effective for us on January 1, 2018. The adoption of this standard is not expected to have a material impact on our statements of cash flows upon adoption. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The new standard involves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. We adopted this ASU in 2017 and it did not have a material impact on our financial position, results of operations or statement of cash flows. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The new standard requires that all lessees recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The new standard will be effective for us on January 1, 2019. We are currently evaluating the potential impact that this standard may have on our financial position and results of operations. In November 2015, the FASB issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes (Topic 740), which requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position to simplify the presentation of deferred income taxes. The standard is effective prospectively for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016, with early adoption permitted. This new standard became effective for us on January 1, 2017. We adopted this standard in 2017 and determined that this ASU did not have a material impact on our disclosures. In May 2014 the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes all existing revenue recognition requirements, including most industry specific guidance. This new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. The FASB subsequently issued amendments to ASU No. 2014-09 that have the same effective date and transition date. These new standards became effective for us on January 1, 2018, and will be adopted using the modified retrospective method through a cumulative-effect adjustment directly to retained earnings as of that date. We have performed a review of these new standards as compared to our current accounting policies for customer contracts and collaborative relationships. During the fourth quarter of 2017 we finalized our assessments over the impact that these new standards will have on our consolidated results of operations, financial position and disclosures. As of December 31, 2017, we have not identified any accounting changes that would materially impact the amount of reported revenues with respect to our revenues from collaboration agreements; however, the adoption of these new standards may result in a change in the timing of revenue recognition related to certain of our licensing activities. As of December 31, 2017, we expect to recognize an adjustment of $1.5 million to retained earnings reflecting the cumulative impact for the accounting changes related to certain license arrangements made upon adoption of these new standards.

COLLABORATIONS AND ALLIANCES

COLLABORATIONS AND ALLIANCES	12 Months Ended
COLLABORATIONS AND ALLIANCES	Dec. 31, 2017
Organization, Consolidation and Presentation Of Financial Statements [Abstract]
COLLABORATIONS AND ALLIANCES	3. COLLABORATIONS AND ALLIANCES Daiichi Sankyo Tivantinib Agreement As previously reported, on December 18, 2008, we entered into a license, co-development and co-commercialization agreement with Daiichi Sankyo to conduct research, clinical trials and the commercialization of tivantinib in human cancer indications in the U.S., Europe, South America and the rest of the world, excluding Japan, China (including Hong Kong), South Korea and Taiwan, where Kyowa Hakko Kirin has exclusive rights for development and commercialization. Under the terms of our tivantinib collaboration agreement with Daiichi Sankyo we shared development costs equally with our share of Phase 3 costs funded solely from milestones and royalties. In each quarter the tivantinib collaboration costs we incurred were compared with those of Daiichi Sankyo. If our costs for the quarter exceeded Daiichi Sankyo’s, we recognized revenue on the amounts due to us under the contingency adjusted performance model. Revenue was calculated on a pro-rata basis using the time elapsed from inception of the agreement over the estimated duration of the development period under the agreement. If our costs for the quarter were less than those of Daiichi Sankyo, we reported the amount due to Daiichi Sankyo as contra-revenue in that quarter. To the extent that our share of Phase 3 collaboration costs exceeded the amount of milestones and royalties received, that excess was netted against milestones and royalties earned and was not reported as contra-revenue. Our cumulative share of the Daiichi Sankyo Phase 3 costs through December 31, 2017 totaled $110.7 million. Our cumulative share of Phase 3 collaboration costs has exceeded the amount of milestones received through December 31, 2017 by $70.7 million which are not required to be repaid upon expiration of the agreement. On March 22, 2016, we and Daiichi Sankyo announced that the DMC of the METIV-HCC study conducted the planned interim assessment, and it was determined the trial would continue to its final analysis. Accordingly, we reviewed the estimated development period and extended it to December 2016. On February 17, 2017, we and Daiichi Sankyo announced that the METIV-HCC trial did not meet its primary endpoint of improving OS. On February 17, 2017, we and Daiichi Sankyo announced that the METIV-HCC trial did not meet its primary end point of improving OS. As a result, Daiichi Sankyo and we have discontinued development of tivantinib. No revenue was recognized in 2017. For the years ended December 31, 2016 and 2015, $2.8 million, net of $0.1 million of contra-revenue and $5.5 million, net of $0.1 million of contra-revenue, respectively, was recognized as revenue. At December 31, 2017 and 2016, there was no deferred revenue related to this agreement. Kyowa Hakko Kirin Licensing Agreement As previously reported, on April 27, 2007, we entered into an exclusive license agreement with Kyowa Hakko Kirin to develop and commercialize tivantinib in Japan and parts of Asia. Revenue for this agreement was recognized using the contingency-adjusted performance model with an estimated development period through December 31, 2016. On March 27, 2017, we reported that Kyowa Hakko Kirin announced top-line results of the JET-HCC Phase 3 trial of tivantinib in Japan, and that the trial did not meet its primary endpoint of improving PFS. Our joint development of tivantinib has subsequently been discontinued. As a result, Kyowa Hakko Kirin has discontinued development of tivantinib in the Asian territory. Revenue for this agreement was recognized using the contingency-adjusted performance model with an estimated development period that ended on December 31, 2016. For the years ended December 31, 2016 and 2015, $1.9 million and $5.7 million, respectively, was recognized as revenue. At December 31, 2017 and 2016 there was no deferred revenue related to this agreement. Other Licensing Agreements In October 2017 we entered into a non-exclusive license agreement for certain library compounds. The licensed compounds were delivered and are subject to quality and acceptance testing. We have recorded deferred revenue of $1.5 million related to this licensing agreement. Roivant Sciences Licensing Agreement In February 2018 Roivant Sciences and ArQule, Inc. announced the initiation of a collaboration to pursue the development of derazantinib, a pan-FGFR inhibitor, in Greater China. As part of the collaboration, ArQule has granted a Roivant subsidiary (Sinovant) an exclusive license to develop and commercialize derazantinib in the People’s Republic of China, Hong Kong, Macau, and Taiwan. Deal terms include an upfront payment to ArQule of $3 million and an additional $2.5 million development milestone to be paid within the first year. ArQule is also eligible for an additional $82 million in regulatory and sales milestones. Upon commercialization, ArQule will receive double digit royalties in the low teens from Sinovant on net sales of derazantinib in the Greater China territory.

MARKETABLE SECURITIES AND FAIR

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS	12 Months Ended
MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS	Dec. 31, 2017
Marketable Securities and Fair Value Measurements [Abstract]
MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS	4. MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS We generally classify our marketable securities as available-for-sale at the time of purchase and re-evaluate such designation as of each balance sheet date. Since we generally intend to convert them into cash as necessary to meet our liquidity requirements our marketable securities are classified as cash equivalents if the original maturity, from the date of purchase, is ninety days or less and as short-term investments if the original maturity, from the date of purchase, is in excess of ninety days but less than one year. Our marketable securities are classified as long-term investments if the maturity date is in excess of one year of the balance sheet date. We report available-for-sale investments at fair value as of each balance sheet date and include any unrealized gains and, to the extent deemed temporary, unrealized losses in stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense) in the statement of operations and comprehensive loss. We conduct quarterly reviews to determine the fair value of our investment portfolio and to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. In the event that the cost basis of a security exceeds its fair value, we evaluate, among other factors, the duration of the period that, and extent to which, the fair value is less than cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, and operational and financing cash flow factors, overall market conditions and trends, our intent to sell the investment and if it is more likely than not that we would be required to sell the investment before its anticipated recovery. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded in accumulated other comprehensive income (loss). For available-for-sale debt securities with unrealized losses, we perform an analysis to assess whether we intend to sell or whether we would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. Where we intend to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is reflected in the statement of operations and comprehensive loss as an impairment loss. Regardless of our intent to sell a security, we perform additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where we do not expect to receive cash flows sufficient to recover the amortized cost basis of a security. We invest our available cash primarily in commercial paper, money market funds, and U.S. Treasury bill funds that have investment grade ratings. The following is a summary of the fair value of available-for-sale marketable securities we held at December 31, 2017 and December 31, 2016: December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Security type Corporate debt securities-short term $ 27,823 $ 1 $ (17 ) $ 27,807 Total available-for-sale marketable securities $ 27,823 $ 1 $ (17 ) $ 27,807 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Security type Corporate debt securities-short term $ 15,857 $ 7 $ (5 ) $ 15,859 Total available-for-sale marketable securities $ 15,857 $ 7 $ (5 ) $ 15,859 None of our available-for-sale marketable securities were in a continuous unrealized loss position for more than 12 months at December 31, 2017 or 2016. The following tables present information about our assets and liabilities that are measured at fair value on a recurring basis for the year ended December 31, 2017 and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value. There were no transfers in or out of Level 1 or Level 2 measurements for the year ended December 31, 2017: December 31, 2017 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents $ 19,889 $ 19,889 $ — $ — Corporate debt securities-short term 27,807 — 27,807 — Total $ 47,696 $ 19,889 $ 27,807 $ — December 31, 2017 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Warrant liability $ 1,512 $ — $ — $ 1,512 Due to the lack of market quotes relating to our preferred stock warrants, the fair value of the preferred stock warrants was determined at December 31, 2017 using the Black-Scholes model, which is based on Level 3 inputs. As of December 31, 2017, inputs used in the Black-Scholes model are presented below. The assumptions used may change as the underlying sources of these assumptions and market conditions change. Based on the Black-Scholes model, the Company recorded a preferred stock warrants liability of $1,512 at December 31, 2017. The following are the Black-Scholes inputs to the warrant liability valuation at December 31, 2017: 2017 Warrant stock price $1.75 Exercise price 1.65 Expected volatility 53.3% Risk-free interest 2.07% Expected term 3.85 years Dividends none The following table presents information about our assets and liabilities that are measured at fair value on a recurring basis for the year ended December 31, 2016 and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value. There were no transfers in or out of Level 1 or Level 2 measurements for the year ended December 31, 2016: December 31, 2016 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents $ 12,923 $ 12,923 $ — $ — Corporate debt securities-short term 15,859 — 15,859 — Total $ 28,782 $ 12,923 $ 15,859 $ —

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
PROPERTY AND EQUIPMENT	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	5. PROPERTY AND EQUIPMENT Property and equipment consist of the following at December 31, 2017 and 2016: USEFUL 2017 2016 Machinery and equipment 5 $ 1,939 $ 1,939 Leasehold improvements 3–5 232 232 Furniture and fixtures 7 40 40 Computer equipment 3 2,497 2,497 4,708 4,708 Less: Accumulated depreciation and amortization 4,593 4,528 Net property and equipment $ 115 $ 180 In January 2015, we entered into a lease agreement for our headquarters facility in Burlington, MA of approximately 15,000 square feet. The lease commenced on May 1, 2015 for a term of five years and three months with an average annual rental rate of $455.

OTHER ASSETS

OTHER ASSETS	12 Months Ended
OTHER ASSETS	Dec. 31, 2017
Other Assets [Abstract]
OTHER ASSETS	6. OTHER ASSETS Other assets include the following at December 31, 2017 and 2016: 2017 2016 Security deposits $ 204 $ 252 Total other assets $ 204 $ 252

ACCOUNTS PAYABLE AND ACCRUED EX

ACCOUNTS PAYABLE AND ACCRUED EXPENSES	12 Months Ended
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	Dec. 31, 2017
Payables and Accruals [Abstract]
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	7. ACCOUNTS PAYABLE AND ACCRUED EXPENSES Accounts payable and accrued expenses include the following at December 31, 2017 and 2016: 2017 2016 Accounts payable $ 537 $ 710 Accrued payroll 1,448 1,856 Accrued outsourced preclinical and clinical fees 5,409 5,461 Accrued professional fees 492 363 Other accrued expenses 373 310 $ 8,259 $ 8,700

LOAN AGREEMENT

LOAN AGREEMENT	12 Months Ended
LOAN AGREEMENT	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
LOAN AGREEMENT	8. LOAN AGREEMENT In January 2017, Oxford Finance LLC, as collateral agent and a lender (the “Lender”), and any additional lenders that may become parties thereto, entered into a loan and security agreement with us (the “Loan Agreement”). Pursuant to the terms of the Loan Agreement, the Lender issued us a loan in the principal amount of $15.0 million. The loan will bear interest at the rate equal to (a) the greater of (i) the 30 day U.S. LIBOR rate reported in the Wall Street Journal on the date occurring on the last business day of the month that immediately precedes the month in which the interest will accrue or (ii) 0.65% (b) plus 6.85%. The applicable interest rate on the loan at December 31, 2017 was 8.22%. The Loan Agreement required interest-only payments for 18 months, followed by an amortization period of 36 months. The original maturity date of the loan was August 1, 2021 and in February 2018 we signed an amendment with the lender which extended the maturity date by one year to August 1, 2022 with principal payments commencing on September 1, 2019. We have considered the amended maturity as of December 31, 2017. The expected remaining repayment of the $15 million loan principal at December 31, 2017 is as follows: 2019 $ 1,667 2020 5,000 2021 5,000 2022 3,333 $ 15,000 Upon the earlier of prepayment or the maturity date, we will pay to the Lender a final payment of 6% of the full principal amount of the loan. We may elect to prepay all amounts owed prior to the maturity date, provided that a prepayment fee also is paid equal to (i) 3% of the outstanding principal balance if prepayment occurs in months 1-12 following the closing, (ii) 2.0% of the outstanding principal balance in months 13-24 following the closing, and (iii) 1% thereafter. Pursuant to the terms of the Loan Agreement, we are bound by certain affirmative covenants setting forth actions that are required during the term of the Loan Agreement, including, without limitation, certain information delivery requirements, obligations to maintain certain insurance, and certain notice requirements. Additionally, we are bound by certain negative covenants setting forth actions that are not permitted to be taken during the term of the Loan Agreement without consent, including, without limitation, incurring certain additional indebtedness, entering into certain mergers, acquisitions or other business combination transactions, or incurring any non-permitted lien or other encumbrance on our assets. We are in compliance with the loan covenants at December 31, 2017. Upon the occurrence of an event of default under the Loan Agreement (subject to cure periods for certain events of default), all amounts owed by us thereunder will begin to bear interest at a rate that is 5% higher than the rate that is otherwise applicable and may be declared immediately due and payable by the Lender. Events of default under the Loan Agreement include, among other things, the following: the occurrence of certain bankruptcy events; the failure to make payments under the Loan Agreement when due; the occurrence of a material adverse change in our business, operations or financial condition; the rendering of certain types of fines or judgments against us; any breach by us of any covenant (subject to cure for certain covenants only) made in the Loan Agreement; and the failure of any representation or warranty made by us in connection with the Loan Agreement to be correct in all material respects when made. We have granted Lender, a security interest in substantially all of our personal property, rights and assets, other than intellectual property, to secure the payment of all amounts owed to the Lender under the Loan Agreement. We have also agreed not to encumber any of our intellectual property without required lenders’ prior written consent. In connection with entering into the Loan Agreement, we issued to the Lender warrants to purchase an aggregate of 354,330 shares of our common stock (the “Lender Warrants”). The warrants are exercisable immediately, have a per-share exercise price of $1.27 and have a term of ten years. We have recorded the relative fair value of the warrants as a discount to the carrying value of the notes payable with a corresponding increase to additional paid in capital. In February 2018, the Loan Agreement was amended requiring payments of interest on a monthly basis through August 2019 and payments of interest and principal from September 2019 to August 2022. In connection with entering into the amendment we issued to the Lender warrants to purchase an aggregate of 93,168 shares of our common stock. The warrants are exercisable immediately, have a per-share exercise price of $1.61 and have a term of ten years. The amendment was determined a modification of debt according to ASC 470 Debt.

PREFERRED STOCK AND WARRANT LIA

PREFERRED STOCK AND WARRANT LIABILITY	12 Months Ended
PREFERRED STOCK AND WARRANT LIABILITY	Dec. 31, 2017
Preferred Stock And Warrant Liability [Abstract]
PREFERRED STOCK AND WARRANT LIABILITY	9. PREFERRED STOCK AND WARRANT LIABILITY Our amended Certificate of Incorporation authorizes the issuance of up to 1 million shares of $0.01 par value preferred stock. In November 2017, we entered into definitive securities purchase agreements with certain institutional investors. In conjunction with this stock offering the Company raised net proceeds of $9.5 million through the sale of 8,370 shares of series A convertible preferred stock (Series A Preferred) and warrants covering 2,260 shares of Series A Preferred (Warrants). Each share of Series A Preferred together with the associated Warrant is priced at $1,135 and will automatically convert into 1,000 shares of common stock upon the adoption of an amendment to the Company’s restated certificate of incorporation to increase the number of authorized shares of common stock thereunder. The amount reported as preferred stock at December 31, 2017 is $8.9 million which is net of the $0.6 million warrant liability established on the date of issuance in November 2017. The Warrants have a pre-conversion exercise price of $1,750 per share of Series A Preferred (post-conversion price of $1.75 per share of common stock), are exercisable immediately and expire approximately four years from the date of the adoption of the amendment to the Company’s restated certificate of incorporation. The fair value of the warrants on the date they were issued was $0.6 million which was recorded as a warrant liability. At December 31, 2017 the fair value of the warrant liability increased to $1.5 million and consequently a $0.9 million non-cash expense was recorded. Upon conversion of the preferred stock to common stock the warrant liability will be extinguished with an offsetting amount included as additional paid-in capital in stockholders’ equity. In November 2017, the Company issued Series A preferred stock and warrants to purchase shares of Series A preferred stock for aggregate net proceeds of $9.5 million. The terms of the Series A preferred, specifically the terms of the liquidation preference, require the classification of the preferred stock as temporary equity, which is reflected in our balance sheet as of December 31, 2017. In addition, the terms of the preferred stock for which the warrants are exercisable require that the fair value allocated to the warrants at the date of issuance be recorded as a liability. The warrant liability is marked to market value through the income statement as a non-cash gain or loss at each reporting period. The Series A Preferred Stockholders vote on an as converted basis together as one class with the holders of common stock. If declared by the board, the Series A Preferred are eligible for a dividend on an as-converted basis. The Series A Preferred automatically converts into common stock upon the adoption of an amendment to the Company’s restated certificate of incorporation to increase the number of authorized shares of common stock. If the Company’s restated certificate of incorporation has not been adopted by July 1, 2018, the Series A Preferred will obtain a dividend in kind until such time as the restated certificate of incorporation is adopted. In the case of a liquidation event or deemed liquidation event defined by the definitive securities purchase agreements the holders of Series A Preferred Stock have a liquidation preference on the greater of the Series A Preferred Stock stated value or the consideration that would have been paid on such Series A Preferred Stock in the applicable liquidation event.

COMMON STOCK

COMMON STOCK	12 Months Ended
COMMON STOCK	Dec. 31, 2017
Common Stock [Abstract]
COMMON STOCK	10. COMMON STOCK Our amended Certificate of Incorporation authorizes the issuance of up to 100 million shares of $0.01 par value common stock. At December 31, 2017, we have 450,494 shares reserved for future issuance of common stock options pursuant to the 2014 Equity Incentives Plan (“Equity Incentives Plan”). In October 2017, we entered into definitive securities purchase agreements with certain institutional investors. In conjunction with this stock offering, we issued 13,938,651 shares of our common stock and warrants for 3,123,674 shares of our common stock for aggregate net proceeds of $15.6 million. Each warrant is exercisable for $1.75 per share and expires in four years from the date of issuance. In September 2017, we sold 2.0 million shares of common stock through an at-the-market (“ATM”) offering and raised net proceeds of approximately $2.3 million. In February 2016, we entered into definitive stock purchase agreements with certain institutional and accredited investors. In conjunction with this stock offering we issued 8,027,900 shares of our common stock and non-transferable options for 3,567,956 shares of our common stock for aggregate net proceeds of $15.2 million. Each option was exercisable for $2.50 per share and they all expired in March 2017.

EQUITY INCENTIVE PLANS

EQUITY INCENTIVE PLANS	12 Months Ended
EQUITY INCENTIVE PLANS	Dec. 31, 2017
Disclosure Of Compensation Related Costs, Share-Based Payments [Abstract]
EQUITY INCENTIVE PLANS	11. EQUITY INCENTIVE PLANS In 2014, our stockholders approved our 2014 Equity Incentives Plan and authorized 3,750,000 shares of common stock for issuance pursuant to future awards under that plan. In addition, any shares from our Amended and Restated 1994 Equity Incentive Plan that expire, are cancelled or forfeited after the effective date of the 2014 Equity Incentives Plan may also be issued for future awards under the 2014 Equity Incentives Plan. All shares are awarded at the discretion of our Board of Directors in a variety of stock based forms including stock options, restricted stock and performance based stock units, and stock appreciation rights. Pursuant to the 2014 Equity Incentives Plan, incentive stock options may not be granted at less than the fair market value of our common stock at the date of the grant, and the option term may not exceed ten years. Stock options issued pursuant to the 2014 Equity Incentives Plan generally vest over four years. For holders of 10% or more of our voting stock, options may not be granted at less than 110% of the fair market value of the common stock at the date of the grant, and the option term may not exceed five years. Stock appreciation rights granted in tandem with an option shall have an exercise price not less than the exercise price of the related option. As of December 31, 2017, no stock appreciation rights have been issued. At December 31, 2017, there were 450,494 shares available for future grants under the 2014 Equity Incentives Plan. During 2014, our stockholders approved an amendment to the 1996 Director Stock Option Plan to increase the number of shares available to 1,200,000. Under the terms of the 1996 Director Stock Option Plan, options to purchase shares of common stock are automatically granted (A) to the Chairman of the Board of Directors (1) upon his or her initial election or appointment in the amount of 25,000 and vesting over three years and (2) upon his or her re-election or continuation on our board immediately after each annual meeting of stockholders in the amount of 25,000 and vesting one year from the date of grant, and (B) to each other Director (1) upon his or her initial election to our board in the amount of 30,000 and vesting over three years and (2) upon his or her re-election or continuation on our board in the amount of 20,000 and vesting one year from the date of grant. All options granted pursuant to the 1996 Director Plan have a term of ten years with exercise prices equal to fair market value on the date of grant. At December 31, 2017, options to purchase 760,000 shares of common stock are outstanding and exercisable under the 1996 Director Plan which terminated in 2017. Additionally, under the 2014 Equity Incentives Plan options issued to Directors to purchase 280,000 shares of common stock are outstanding at December 31, 2017 of which 125,000 are exercisable. Option activity under the Plans for the year ended December 31, 2017 was as follows: Stock Options Number of Shares Weighted Average Exercise Price Outstanding as of December 31, 2016 8,715,048 $ 3.71 Granted 2,572,500 1.19 Exercised — — Cancelled (665,093 ) 5.16 Outstanding as of December 31, 2017 10,622,455 $ 3.01 Exercisable as of December 31, 2017 6,342,885 $ 4.10 The following table summarizes information about options outstanding at December 31, 2017: Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding at December 31, 2017 Weighted Average Remaining Contractual Life Weighted Average Exercise Price Exercisable as of December 31, 2017 Weighted Average Exercise Price $1.16–1.41 2,572,702 8.36 $ 1.05 458,102 $ 1.16 1.42–2.35 2,756,150 8.21 1.69 776,600 1.73 2.36–3.80 2,407,565 4.05 2.88 2,222,145 2.90 3.81–5.60 982,650 0.64 4.18 982,650 4.18 5.61–8.40 1,903,388 3.41 7.13 1,903,388 7.13 10,622,455 5.74 $ 3.01 6,342,885 $ 4.10 The aggregate intrinsic value of options outstanding at December 31, 2017 was $1,687. The weighted average grant date fair value of options granted in year ended December 31, 2017, 2016 and 2015 was $0.72, $1.10, and $0.77, per share, respectively. In the year ended December 31, 2017 no options were exercised. In the year ended December 31, 2016 97,498 options were exercised. Options vested, expected to vest and exercisable at December 31, 2017 are as follows: Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Vested and unvested expected to vest at December 31, 2017 10,415,678 $ 3.01 5.74 $ 1,629 Exercisable at December 31, 2017 6,342,885 $ 4.10 3.88 $ 247 The total compensation cost not yet recognized as of December 31, 2017 related to non-vested option awards was $2,287 which will be recognized over a weighted-average period of 2.5 years. During the year ended December 31, 2017, 198,513 shares were forfeited with a weighted average grant date fair value of $0.97 per share and a weighted average exercise price of $1.63 per share. During the year ended December 31, 2017, 466,580 shares expired with a weighted average grant date fair value of $3.62 per share and a weighted average exercise price of $6.66 per share. The weighted average remaining contractual life for options exercisable at December 31, 2017 was 3.9 years. In 2013, we granted 242,697 shares of restricted stock to employees, vesting annually over a four-year period. No restricted stock was granted in 2017, 2016, 2015 or 2014. The weighted average fair value of the restricted stock at the time of grant in 2013 was $2.51 per share, and is being expensed ratably over the vesting period. We recognized share-based compensation expense related to restricted stock of $8, $73 and $76 for the year ended December 31, 2017, 2016 and 2015, respectively. Restricted stock activity under the equity incentives plan for the year ended December 31, 2017 was as follows: Restricted Stock Number of Shares Weighted Average Grant Date Fair Value Unvested as of December 31, 2016 29,276 $ 2.51 Granted — — Vested (29,276 ) 2.51 Cancelled — 2.51 Unvested as of December 31, 2017 — $ 2.51 The fair value of restricted stock vested in 2017, 2016 and 2015 was $48, $55 and $78, respectively. In April 2017, the Company amended its chief executive officer’s (the “CEO’s”) and chief operating officer’s (the “COO’s”) employment agreements to grant them a maximum of 600,000 and 300,000 performance-based stock options, respectively, that vest upon the achievement of certain performance and market based targets. In April 2017, the Company amended its chief medical officer’s (the “CMO’s”) employment agreement to grant him 260,000 performance-based stock options that vest upon the achievement of certain performance based targets. In April 2017, certain other employees were granted a total of 270,000 performance-based stock options that vest upon the achievement of certain performance based targets. Through December 31, 2017 no expense has been recorded for any performance-based stock options granted to the CEO, COO, CMO, or to any other employees. In 1996, the stockholders adopted the 1996 Employee Stock Purchase Plan. This plan enables eligible employees to exercise rights to purchase our common stock at 85% of the fair market value of the stock on the date the right was granted or the date the right is exercised, whichever is lower. Rights to purchase shares under the 1996 Employee Stock Purchase Plan are granted by the Board of Directors. The rights are exercisable during a period determined by the Board of Directors; however, in no event will the period be longer than twenty-seven months. The 1996 Employee Stock Purchase Plan is available to substantially all employees, subject to certain limitations. In 2011, our stockholders approved an amendment to the Purchase Plan to increase the aggregate number of shares of the Company’s common stock that may be issued to 2,400,000. As of December 31, 2017, 2,217,705 shares have been purchased and no shares are available under this plan which was terminated in 2017. We recognized share-based compensation expense related to the 1996 Employee Stock Purchase Plan of $17, $60 and $60 for the year ended December 31, 2017, 2016 and 2015, respectively.

INCOME TAXES

INCOME TAXES	12 Months Ended
INCOME TAXES	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	12. INCOME TAXES There was no current or deferred tax expense for the years ended December 31, 2017, 2016 or 2015 due to our loss before income taxes and our valuation allowance. We have recorded a full valuation allowance against our deferred tax assets based upon the weight of available evidence, as it is more likely than not that the deferred tax assets will not be realized. The following is a reconciliation between the U.S. federal statutory rate and the effective tax rate for the years ended December 31, 2017, 2016 and 2015: 2017 2016 2015 Income tax (benefit) expense at statutory rate $ (9,929 ) $ (7,724 ) $ (4,683 ) State tax (benefit) expense, net of Federal tax (benefit) expense (1,452 ) (1,146 ) (677 ) Permanent items 508 263 239 Effect of change in valuation allowance and State NOL expiration (39,972 ) 8,837 4,945 Tax credits (544 ) (228 ) (74 ) Change in tax rate on beginning assets 51,445 — — Other (56 ) (2 ) 250 Tax expense (benefit) $ — $ — $ — The income tax effect of temporary differences comprising the deferred tax assets and deferred tax liabilities on the accompanying balance sheets is a result of the following at December 31, 2017 and 2016: 2017 2016 Deferred tax assets: Net operating loss carryforwards $ 100,421 $ 135,642 Tax credit carryforwards 26,771 25,264 Equity based compensation 3,381 9,610 Book depreciation in excess of tax 49 56 Reserves and accruals 171 181 Other 16 28 130,809 170,781 Valuation allowance (130,809 ) (170,781 ) Deferred tax liabilities — — Net deferred tax assets $ — $ — Total valuation allowance decreased by $39,972 for the year ended December 31, 2017, and increased by $8,837 and $4,945 for the years ended December 31, 2016 and 2015, respectively. We have evaluated positive and negative evidence bearing upon the realizability of our deferred tax assets, which are comprised principally of federal and state net operating loss (“NOL”), net capital loss, and research and development credit carryforwards. We have determined that it is more likely than not that we will not recognize the benefits of our federal and state deferred tax assets and, as a result, we have established a full valuation allowance against our net deferred tax assets as of December 31, 2017. The Tax Cuts and Jobs Act was enacted on December 22, 2017. The Act reduces the US federal corporate tax rate from 35% to 21%, requires companies to re-measure the deferred tax assets and deferred tax liabilities as of the date of enactment. We re-measured deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21%. The amount recorded related to the re-measurement of our deferred tax balance before Valuation Allowance was $51,445 which is offset by the full valuation allowance. As of December 31, 2017, we had federal NOL, state NOL, and research and development credit carryforwards of approximately $409,409, $228,565 and $28,253 respectively, which expire at various dates through 2037. Approximately $15,080 of our federal NOL and $929 of our state NOL are attributable to stock-based compensation windfall deductions as of 12/31/2016. We recorded a deferred tax asset for previously unrecognized excess tax benefit, offset by valuation allowance upon the adoption in 2017 of ASU 2016-09, “Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” As of December 31, 2017, and 2016 we had no unrecognized tax benefits. We do not expect that the total amount of unrecognized tax benefits will significantly increase in the next twelve months. Our policy is to recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2017 and 2016, we had no accrued interest or penalties related to uncertain tax positions. Our U.S. federal tax returns for the tax years 2013 through 2017 and our state tax returns for the tax years 2013 through 2017 remain open to examination. Prior tax years remain open to the extent of net operating loss and tax credit carryforwards. Utilization of NOL and research and development credit carryforwards may be subject to a substantial annual limitation in the event of an ownership change that has occurred previously or could occur in the future pursuant to Section 382 and 383 of the Internal Revenue Code of 1986, as amended, as well as similar state provisions. An ownership change may limit the amount of NOL and research and development credit carryforwards that can be utilized annually to offset future taxable income, and may, in turn, result in the expiration of a portion of those carryforwards before utilization. In general, an ownership change, as defined by Section 382, results from transactions that increase the ownership of certain stockholders or public groups in the stock of a corporation by more than 50 percentage points over a three-year period. We undertook a detailed study of our NOL and research and development credit carryforwards through January 31, 2018, to determine whether such amounts are likely to be limited by Sections 382 or 383. As a result of this analysis, we currently do not believe any Sections 382 or 383 limitations will significantly impact our ability to offset income with available NOL and research and development credit carryforwards. However, future ownership changes under Section 382 may limit our ability to fully utilize these tax benefits.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	13. COMMITMENTS AND CONTINGENCIES Leases We lease a facility under a non-cancelable operating lease that terminates on July 31, 2020 and the minimum lease commitment for our leased facility is as follows: YEAR ENDING DECEMBER 31, OPERATING LEASES 2018 $ 560 2019 519 2020 254 Thereafter — Total minimum lease payments $ 1,333 Rent expense under our non-cancelable operating lease was approximately $546, $540, and $1,569 for the years ended December 31, 2017, 2016 and 2015, respectively. In January 2015, we entered into a lease agreement for our headquarters facility. The lease commenced on May 1, 2015 for a term of five years and three months with an average annual rental rate of $455. The lease obligation for the new facility is included in the table above.

CONCENTRATION OF CREDIT RISK

CONCENTRATION OF CREDIT RISK	12 Months Ended
CONCENTRATION OF CREDIT RISK	Dec. 31, 2017
Risks and Uncertainties [Abstract]
CONCENTRATION OF CREDIT RISK	14. CONCENTRATION OF CREDIT RISK Revenue from one customer represented approximately 40% of total revenue during 2016 and 49% in 2015. Revenue from another customer represented approximately 60% of total revenue during 2016 and 51% in 2015. There were no revenues recognized in 2017.

SELECTED QUARTERLY FINANCIAL DA

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	15. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) FIRST SECOND THIRD FOURTH 2017 Net revenues $ — $ — $ — $ — Net loss (7,576 ) (7,201 ) (6,666 ) (7,760 ) Basic and diluted net loss per share: Net loss per share $ (0.11 ) $ (0.10 ) $ (0.09 ) $ (0.09 ) FIRST SECOND THIRD FOURTH 2016 Net revenues $ 1,227 $ 1,072 $ 1,223 $ 1,187 Net loss (4,981 ) (5,100 ) (5,817 ) (6,820 ) Basic and diluted earnings (loss) per share: Net loss per share $ (0.08 ) $ (0.07 ) $ (0.08 ) $ (0.10 )

SUMMARY OF SIGNIFICANT ACCOUN22

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities We consider all highly liquid investments purchased within three months of original maturity date to be cash equivalents. We invest our available cash primarily in commercial paper, money market funds and U.S. Treasury bill funds. We generally classify our marketable securities as available-for-sale at the time of purchase and re-evaluate such designation as of each balance sheet date. The Company classifies its investments as either current or long-term based upon the investments’ contractual maturities and the Company’s ability and intent to convert such instruments to cash within one year. We report available-for-sale investments at fair value as of each balance sheet date and include any unrealized gains and, to the extent deemed temporary, unrealized losses in stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense) in the statement of operations and comprehensive loss. For any of our marketable securities classified as trading securities, changes in the fair value of those securities are recorded as other income (expense) in the statement of operations and comprehensive loss. At December 31, 2017 we had no trading securities. We conduct quarterly reviews to determine the fair value of our investment portfolio and to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. In the event that the cost basis of a security exceeds its fair value, we evaluate, among other factors, the duration of the period that, and extent to which, the fair value is less than cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, and operational and financing cash flow factors, overall market conditions and trends, our intent to sell the investment and if it is more likely than not that we would be required to sell the investment before its anticipated recovery. Unrealized losses on available-for- sale securities that are determined to be temporary, and not related to credit loss, are recorded in accumulated other comprehensive income (loss). For available-for-sale debt securities with unrealized losses, we perform an analysis to assess whether we intend to sell or whether we would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. Where we intend to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is reflected in the statement of operations and comprehensive loss as an impairment loss. Regardless of our intent to sell a security, we perform additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. We did not recognize any other-than-temporary impairments during the years ended December 31, 2017, 2016 or 2015. Credit losses are identified where we do not expect to receive cash flows sufficient to recover the amortized cost basis of a security.
Fair Value Measurements	Fair Value Measurements Certain assets of the Company are carried at fair value under GAAP. 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. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. At December 31, 2017 and 2016 our financial instruments consist of cash, cash equivalents, investments in corporate debt securities, accounts payable, notes payable and accrued expenses. At December 31, 2017 and 2016 our financial instruments also included marketable securities and warrant liabilities which are reported at fair value. The warrant liability is carried at fair value and determined to be a Level 3 liability in the fair value hierarchy described above. The carrying values of cash, cash equivalents, investments in corporate debt securities, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. The carrying value of the Company’s notes payable approximates its fair value.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives. Assets under capital leases and leasehold improvements are amortized over the shorter of their estimated useful lives or the term of the respective leases by use of the straight-line method. Maintenance and repair costs are expensed as incurred. Depreciation and amortization expense for the years ended December 31, 2017, 2016 and 2015 was $65, $101 and $161, respectively.
Revenue Recognition-Research and Development Revenue	Revenue Recognition—Research and Development Revenue Research and development revenue is generated primarily through collaborative research and development agreements and license agreements. The terms of the agreements may include nonrefundable upfront payments, funding for research and development, milestone payments and royalties on any product sales derived from collaborations. We recognize revenues when all of the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; our price to the customer is fixed or determinable; and collectability is reasonably assured. We elected the milestone method of revenue recognition, which may impact any new collaboration agreements or material modifications to existing agreements, in the event we elect the policy of utilizing the milestone method to recognize future substantive milestones. Research and development payments associated with the collaboration agreements in effect prior to January 1, 2011 were recognized as research and development revenue using the contingency adjusted performance model. Under this model, when payments are earned, revenue is immediately recognized on a pro-rata basis in the period we achieve the milestone based on the time elapsed from inception of the agreement to the time the milestone is earned over the estimated duration of the development period under the agreement. Thereafter, the remaining portion of the milestone payment is recognized on a straight-line basis over the remaining estimated development period under the agreement. This estimated development period may ultimately be shorter or longer depending upon the outcome of the development work, resulting in accelerated or deferred recognition of the development revenue. Royalty payments will be recognized as revenue when earned. The costs associated with satisfying research and development contracts are included in research and development expense as incurred.
Research and Development Costs	Research and Development Costs Costs of research and development, which are expensed as incurred, are comprised of the following types of costs incurred in performing research and development activities and those incurred in connection with research and development revenue: salaries and benefits, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs.
Impairment or Disposal of Long-Lived Assets	Impairment or Disposal of Long-Lived Assets We assess our long-lived assets for impairment whenever events or changes in circumstances (a “triggering event”) indicate that the carrying value of a group of long-lived assets may not be recoverable. If such circumstances are determined to exist, an estimate of undiscounted future cash flows produced by the long-lived asset, including its eventual residual value, is compared to the carrying value to determine whether impairment exists. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values.
Segment Data	Segment Data The chief operating decision maker uses aggregated-financial information in determining how to allocate resources and assess performance. For this reason, we have determined that we are principally engaged in one operating segment. See Note 14 with respect to significant customers. Substantially all of our revenue since inception has been generated in the U.S. and all of our long-lived assets are located in the U.S.
Other Income (Expense)	Other Income (Expense) Other income (expense) in 2017 includes a non-cash expense of $902 from an increase in fair value of our preferred stock warrant liability. Other income (expense) was $0 in 2016 and in 2015 includes a gain of $277 from the sale of property and equipment.
Income Taxes	Income Taxes Income taxes have been accounted for using the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if, based upon the weight of all available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. For uncertain tax positions that meet “a more likely than not” threshold, the Company recognizes the benefit of uncertain tax positions in the financial statements.
Earnings (Loss) Per Share	Earnings (Loss) Per Share Net loss per share is computed using the weighted average number of common shares outstanding. Basic and diluted net loss per share amounts are equivalent for the periods presented as the inclusion of potential common shares in the number of shares used for the diluted computation would be anti-dilutive to loss per share. Potential common shares, for the year ended December 31, 2017, include 10,622,455 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options, 354,330 shares that would be issued upon the exercise of the warrants from our January 2017 loan agreement, 3,123,674 shares that would be issued upon the exercise of the warrants from our October 2017 common stock offering, 8,370,000 common shares that would be issued upon the conversion of the shares from our November 2017 preferred stock offering and 2,259,000 common shares that would be issued upon the exercise of the warrants from our November 2017 preferred stock offering. Potential common shares for the year ended December 31, 2016, include 8,715,048 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options and options to purchase 3,567,956 shares that would have been issued upon the exercise of the options from our February 2016 common stock offering. The options issued in conjunction with the February 2016 common stock offering expired in 2017. Potential common shares, for the year ended December 31, 2015, include 8,305,950 shares that would be issued upon the exercise of outstanding employee and Board of Director stock options.
Stock-Based Compensation	Stock-Based Compensation Our stock-based compensation cost is measured at the grant date, based on the calculated fair value of the award, and is recognized as an expense over the employees’ requisite service period (generally the vesting period of the equity grant). We estimate the fair value of stock options using the Black-Scholes valuation model. Key input assumptions used to estimate the fair value of stock options include the exercise price of the award, expected option term, expected volatility of our stock over the option’s expected term, risk-free interest rate over the option’s expected term, and the expected annual dividend yield. We believe that the valuation technique and approach utilized to develop the underlying assumptions are appropriate in calculating the fair values of our stock options granted. The following table presents stock-based compensation expense for the years ended December 31, 2017, 2016 and 2015 included in our Statements of Operations and Comprehensive Loss: 2017 2016 2015 Research and development $ 359 $ 514 $ 682 General and administrative 1,075 1,351 1,579 Total stock-based compensation expense $ 1,434 $ 1,865 $ 2,261 In the years ended December 31, 2017, 2016 and 2015, no stock-based compensation expense was capitalized and there were no recognized tax benefits associated with the stock-based compensation charges. The fair value of stock options and employee stock purchase plan shares granted in the years ended December 31, 2017, 2016 and 2015 respectively were estimated on the grant date using the Black-Scholes option-pricing model with the following assumptions: 2017 2016 2015 Dividend yield(1) 0.0% 0.0% 0.0% Weighted average expected volatility factor(2) 62% 63% 66% Risk free interest(3) 1.9–2.1% 1.2–1.8% 1.3–1.7% Expected term, excluding options issued pursuant to the Employee Stock Purchase Plan(4) 6.1–7.1 years 5.8–7.2 years 5.6–6.8 years Expected term—Employee Stock Purchase Plan(5) 6 months 6 months 6 months (1) We have historically not paid dividends on our common stock and we do not anticipate paying any dividends in the foreseeable future. (2) Measured using an average of historical daily price changes of our stock over a period equal to our expected term. (3) The risk-free interest rate for periods equal to the expected term of share option based on the U.S. Treasury yield in effect at the time of grant. (4) The expected term is the number of years that we estimate, based on historical experience, that options will be outstanding before exercise or cancellation. The range in expected term is the result of certain groups of employees exhibiting different exercising behavior. (5) The expected term of options issued in connection with our Employee Stock Purchase Plan is 6 months based on the terms of the plan.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption. In May 2017 the FASB issued Accounting Standard Update (“ASU”) No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting. This new standard provides clarity and reduces both (1) diversity in practice and (2) cost and complexity when applying the guidance in Topic 718, Compensation-Stock Compensation, to a change to the terms or conditions of a share-based payment award. This new standard will be effective for us on January 1, 2018. The adoption of this standard is not expected to have a material impact on our financial position or results of operations. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This new standard clarifies certain aspects of the statement of cash flows, including the classification of debt prepayment or debt extinguishment costs or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, distributions received from equity method investees and beneficial interests in securitization transactions. This new standard also clarifies that an entity should determine each separately identifiable source of use within the cash receipts and payments on the basis of the nature of the underlying cash flows. In situations in which cash receipts and payments have aspects of more than one class of cash flows and cannot be separated by source or use, the appropriate classification should depend on the activity that is likely to be the predominant source or use of cash flows for the item. This new standard will be effective for us on January 1, 2018. The adoption of this standard is not expected to have a material impact on our statements of cash flows upon adoption. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The new standard involves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. We adopted this ASU in 2017 and it did not have a material impact on our financial position, results of operations or statement of cash flows. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The new standard requires that all lessees recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The new standard will be effective for us on January 1, 2019. We are currently evaluating the potential impact that this standard may have on our financial position and results of operations. In November 2015, the FASB issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes (Topic 740), which requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position to simplify the presentation of deferred income taxes. The standard is effective prospectively for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016, with early adoption permitted. This new standard became effective for us on January 1, 2017. We adopted this standard in 2017 and determined that this ASU did not have a material impact on our disclosures. In May 2014 the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes all existing revenue recognition requirements, including most industry specific guidance. This new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. The FASB subsequently issued amendments to ASU No. 2014-09 that have the same effective date and transition date. These new standards became effective for us on January 1, 2018, and will be adopted using the modified retrospective method through a cumulative-effect adjustment directly to retained earnings as of that date. We have performed a review of these new standards as compared to our current accounting policies for customer contracts and collaborative relationships. During the fourth quarter of 2017 we finalized our assessments over the impact that these new standards will have on our consolidated results of operations, financial position and disclosures. As of December 31, 2017, we have not identified any accounting changes that would materially impact the amount of reported revenues with respect to our revenues from collaboration agreements; however, the adoption of these new standards may result in a change in the timing of revenue recognition related to certain of our licensing activities. As of December 31, 2017, we expect to recognize an adjustment of $1.5 million to retained earnings reflecting the cumulative impact for the accounting changes related to certain license arrangements made upon adoption of these new standards.

SUMMARY OF SIGNIFICANT ACCOUN23

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of stock-based compensation expense	2017 2016 2015 Research and development $ 359 $ 514 $ 682 General and administrative 1,075 1,351 1,579 Total stock-based compensation expense $ 1,434 $ 1,865 $ 2,261
Schedule of fair value of stock options and employee stock purchase plan under the Black-Scholes option-pricing model	2017 2016 2015 Dividend yield(1) 0.0% 0.0% 0.0% Weighted average expected volatility factor(2) 62% 63% 66% Risk free interest(3) 1.9–2.1% 1.2–1.8% 1.3–1.7% Expected term, excluding options issued pursuant to the Employee Stock Purchase Plan(4) 6.1–7.1 years 5.8–7.2 years 5.6–6.8 years Expected term—Employee Stock Purchase Plan(5) 6 months 6 months 6 months (1) We have historically not paid dividends on our common stock and we do not anticipate paying any dividends in the foreseeable future. (2) Measured using an average of historical daily price changes of our stock over a period equal to our expected term. (3) The risk-free interest rate for periods equal to the expected term of share option based on the U.S. Treasury yield in effect at the time of grant. (4) The expected term is the number of years that we estimate, based on historical experience, that options will be outstanding before exercise or cancellation. The range in expected term is the result of certain groups of employees exhibiting different exercising behavior. (5) The expected term of options issued in connection with our Employee Stock Purchase Plan is 6 months based on the terms of the plan.

MARKETABLE SECURITIES AND FAI24

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS (Tables)	Dec. 31, 2017
Marketable Securities and Fair Value Measurements [Abstract]
Schedule of fair value of available-for-sale marketable securities	December 31, 2017 Amortized Cost Gross Gains Gross Losses Fair Value Security type Corporate debt securities-short term $ 27,823 $ 1 $ (17 ) $ 27,807 Total available-for-sale marketable securities $ 27,823 $ 1 $ (17 ) $ 27,807 December 31, 2016 Amortized Cost Gross Gains Gross Losses Fair Value Security type Corporate debt securities-short term $ 15,857 $ 7 $ (5 ) $ 15,859 Total available-for-sale marketable securities $ 15,857 $ 7 $ (5 ) $ 15,859
Schedule of assets and liabilities that are measured at fair value on recurring basis	December 31, Quoted Prices in Significant Significant Cash equivalents $ 19,889 $ 19,889 $ — $ — Corporate debt securities-short term 27,807 — 27,807 — Total $ 47,696 $ 19,889 $ 27,807 $ — December 31, Quoted Prices in Significant Inputs Significant Warrant liability $ 1,512 $ — $ — $ 1,512 December 31, Quoted Prices in Significant Significant Cash equivalents $ 12,923 $ 12,923 $ — $ — Corporate debt securities-short term 15,859 — 15,859 — Total $ 28,782 $ 12,923 $ 15,859 $ —
Schedule of warrant liability	2017 Warrant stock price $1.75 Exercise price 1.65 Expected volatility 53.3% Risk-free interest 2.07% Expected term 3.85 years Dividends none

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
PROPERTY AND EQUIPMENT (Tables)	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	USEFUL 2017 2016 Machinery and equipment 5 $ 1,939 $ 1,939 Leasehold improvements 3–5 232 232 Furniture and fixtures 7 40 40 Computer equipment 3 2,497 2,497 4,708 4,708 Less: Accumulated depreciation and amortization 4,593 4,528 Net property and equipment $ 115 $ 180

OTHER ASSETS (Tables)

OTHER ASSETS (Tables)	12 Months Ended
OTHER ASSETS (Tables)	Dec. 31, 2017
Other Assets [Abstract]
Schedule of other assets	2017 2016 Security deposits $ 204 $ 252 Total other assets $ 204 $ 252

ACCOUNTS PAYABLE AND ACCRUED 27

ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Tables)	12 Months Ended
ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Tables)	Dec. 31, 2017
Payables and Accruals [Abstract]
Schedule of accounts payable and accrued expenses	2017 2016 Accounts payable $ 537 $ 710 Accrued payroll 1,448 1,856 Accrued outsourced preclinical and clinical fees 5,409 5,461 Accrued professional fees 492 363 Other accrued expenses 373 310 $ 8,259 $ 8,700

LOAN AGREEMENT (Tables)

LOAN AGREEMENT (Tables)	12 Months Ended
LOAN AGREEMENT (Tables)	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
Schedule of expected remaining repayment	2019 $ 1,667 2020 5,000 2021 5,000 2022 3,333 $ 15,000

EQUITY INCENTIVE PLANS (Tables)

EQUITY INCENTIVE PLANS (Tables)	12 Months Ended
EQUITY INCENTIVE PLANS (Tables)	Dec. 31, 2017
Disclosure Of Compensation Related Costs, Share-Based Payments [Abstract]
Schedule of activity of options under stock plans	Stock Options Number of Shares Weighted Average Exercise Price Outstanding as of December 31, 2016 8,715,048 $ 3.71 Granted 2,572,500 1.19 Exercised — — Cancelled (665,093 ) 5.16 Outstanding as of December 31, 2017 10,622,455 $ 3.01 Exercisable as of December 31, 2017 6,342,885 $ 4.10
Schedule of options outstanding	Options Outstanding Options Exercisable Range of Exercise Prices Number December 31, 2017 Weighted Average Contractual Life Weighted Average Exercise Price Exercisable as of December 31, 2017 Weighted Average Exercise Price $1.16–1.41 2,572,702 8.36 $ 1.05 458,102 $ 1.16 1.42–2.35 2,756,150 8.21 1.69 776,600 1.73 2.36–3.80 2,407,565 4.05 2.88 2,222,145 2.90 3.81–5.60 982,650 0.64 4.18 982,650 4.18 5.61–8.40 1,903,388 3.41 7.13 1,903,388 7.13 10,622,455 5.74 $ 3.01 6,342,885 $ 4.10
Schedule of options vested, expected to vest and exercisable	Options Weighted-Average Weighted-Average Aggregate Vested and unvested expected to vest at December 31, 2017 10,415,678 $ 3.01 5.74 $ 1,629 Exercisable at December 31, 2017 6,342,885 $ 4.10 3.88 $ 247
Schedule of restricted stock activity under the equity incentives plan	Restricted Stock Number of Shares Weighted Average Fair Value Unvested as of December 31, 2016 29,276 $ 2.51 Granted — — Vested (29,276 ) 2.51 Cancelled — 2.51 Unvested as of December 31, 2017 — $ 2.51

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
INCOME TAXES (Tables)	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of company's effective income tax rate	2017 2016 2015 Income tax (benefit) expense at statutory rate $ (9,929 ) $ (7,724 ) $ (4,683 ) State tax (benefit) expense, net of Federal tax (benefit) expense (1,452 ) (1,146 ) (677 ) Permanent items 508 263 239 Effect of change in valuation allowance and State NOL expiration (39,972 ) 8,837 4,945 Tax credits (544 ) (228 ) (74 ) Change in tax rate on beginning assets 51,445 — — Other (56 ) (2 ) 250 Tax expense (benefit) $ — $ — $ —
Schedule of company's deferred tax assets and deferred tax liabilities	2017 2016 Deferred tax assets: Net operating loss carryforwards $ 100,421 $ 135,642 Tax credit carryforwards 26,771 25,264 Equity based compensation 3,381 9,610 Book depreciation in excess of tax 49 56 Reserves and accruals 171 181 Other 16 28 130,809 170,781 Valuation allowance (130,809 ) (170,781 ) Deferred tax liabilities — — Net deferred tax assets $ — $ —

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Tables)	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of minimum lease commitment for our leased facility	YEAR ENDING DECEMBER 31, OPERATING LEASES 2018 $ 560 2019 519 2020 254 Thereafter — Total minimum lease payments $ 1,333

SELECTED QUARTERLY FINANCIAL 32

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of unaudited quarterly financial data	FIRST SECOND THIRD FOURTH 2017 Net revenues $ — $ — $ — $ — Net loss (7,576 ) (7,201 ) (6,666 ) (7,760 ) Basic and diluted net loss per share: Net loss per share $ (0.11 ) $ (0.10 ) $ (0.09 ) $ (0.09 ) FIRST SECOND THIRD FOURTH 2016 Net revenues $ 1,227 $ 1,072 $ 1,223 $ 1,187 Net loss (4,981 ) (5,100 ) (5,817 ) (6,820 ) Basic and diluted earnings (loss) per share: Net loss per share $ (0.08 ) $ (0.07 ) $ (0.08 ) $ (0.10 )

ORGANIZATION AND NATURE OF OP33

ORGANIZATION AND NATURE OF OPERATIONS (Detail Textuals) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Feb. 28, 2018	Nov. 30, 2017	Oct. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2017
Organization and nature of operations
Net use of cash					$ (25,175)	$ (22,937)	$ (22,160)
Proceeds from stock offering				$ 2,300	$ 17,951	$ 15,174
Number of stock issued under agreement				2,000,000
Definitive stock purchase agreements
Organization and nature of operations
Number of stock issued under agreement			13,938,651
Proceeds from sale of common stock			$ 15,600
Number of warrants issued to purchase common stock			3,123,674
Exercise price of warrants or rights			$ 1.75
Term of warrant			4 years
Definitive stock purchase agreements \| Series A convertible preferred stock and warrants
Organization and nature of operations
Proceeds from stock offering		$ 9,500
Value of each share of Series A Preferred and Warrant		$ 1,135
Number of common stock issued upon conversion		1,000
Definitive stock purchase agreements \| Series A convertible preferred stock
Organization and nature of operations
Number of stock issued under agreement		8,370
Definitive stock purchase agreements \| Series A Preferred Warrants
Organization and nature of operations
Number of stock issued under agreement		2,260
Warrants, pre-conversion exercise price		$ 1,750
Post-conversion price of common stock		$ 1.75
Term of warrant		4 years
Oxford Finance Llc \| Loan Agreement
Organization and nature of operations
Loan principal amount								$ 15,000
Roivant Sciences \| Subsequent event \| Roivant Sciences Licensing Agreement
Organization and nature of operations
Upfront payment	$ 3,000
Additional development milestone	2,500
Regulatory and sales milestones	$ 82,000

SUMMARY OF SIGNIFICANT ACCOUN34

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,434	$ 1,865	$ 2,261
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	359	514	682
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,075	$ 1,351	$ 1,579

SUMMARY OF SIGNIFICANT ACCOUN35

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - The fair value of stock options and employee stock purchase plan shares Valuaton assumptions (Details 1) - Stock Options		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	[1]	6 years 1 month 6 days	5 years 9 months 18 days	5 years 7 months 6 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	[1]	7 years 1 month 6 days	7 years 2 months 12 days	6 years 9 months 18 days
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	[2]	0.00%	0.00%	0.00%
Weighted average expected volatility factor	[3]	62.00%	63.00%	66.00%
Expected term	[4]	6 months	6 months	6 months
Employee stock purchase plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest	[5]	1.90%	1.20%	1.30%
Employee stock purchase plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest	[5]	2.10%	1.80%	1.70%

[1]	The expected term is the number of years that we estimate, based on historical experience, that options will be outstanding before exercise or cancellation. The range in expected term is the result of certain groups of employees exhibiting different exercising behavior.
[2]	We have historically not paid dividends on our common stock and we do not anticipate paying any dividends in the foreseeable future.
[3]	Measured using an average of historical daily price changes of our stock over a period equal to our expected term.
[4]	The expected term of options issued in connection with our Employee Stock Purchase Plan is 6 months based on the terms of the plan.
[5]	The risk-free interest rate for periods equal to the expected term of share option based on the U.S. Treasury yield in effect at the time of grant.

SUMMARY OF SIGNIFICANT ACCOUN36

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Detail Textuals) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Retained Earnings Adjustments [Line Items]
Depreciation method	straight-line method
Depreciation and amortization expense	$ 65	$ 101	$ 161
Number of operating segments \| Segment	1
Other income (expense)	$ 902	0	0
Gain on sale of property plant and equipment		$ 277	$ 277
Other Licensing Agreements \| Accounting Standards Update 2014-09
Retained Earnings Adjustments [Line Items]
Cumulative impact for accounting changes	$ 1,500

SUMMARY OF SIGNIFICANT ACCOUN37

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Detail Textuals 1) - Stock Options - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Exercise of outstanding employee and Board of Director stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share	10,622,455	8,715,048	8,305,950
Exercise of warrants from January 2017 loan agreement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share	354,330
Exercise of warrants from October 2017 common stock offering
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share	3,123,674
Conversion of shares from November 2017 preferred stock offering
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share	8,370,000
Exercise of warrants from November 2017 preferred stock offering
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share	2,259,000
Exercise of options from February 2016 common stock offering
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of common stock not included in computations of diluted net loss per share		3,567,956

COLLABORATIONS AND ALLIANCES (D

COLLABORATIONS AND ALLIANCES (Detail Textuals) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2017
Daiichi Sankyo Tivantinib Agreement \| Phase 3 collaboration costs
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cumulative share of phase 3 collaboration costs		$ 110,700
Cumulative share of phase 3 collaboration costs in excess of milestones amounts received		70,700
Net revenue			$ 2,800	$ 5,500
Contra revenue recognized			100	100
Deferred revenue		0	0
Kyowa Hakko Kirin Licensing Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Net revenue			1,900	$ 5,700
Deferred revenue		$ 0	$ 0
Other Licensing Agreements
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue					$ 1,500
Roivant Sciences Licensing Agreement \| Roivant Sciences \| Subsequent event
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront payment	$ 3,000
Additional development milestone	2,500
Regulatory and sales milestones	$ 82,000

MARKETABLE SECURITIES AND FAI39

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS - Summary of fair value of available-for-sale securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 27,823	$ 15,857
Gross Unrealized Gains	1	7
Gross Unrealized Losses	(17)	(5)
Fair Value	27,807	15,859
Corporate debt securities \| Short term
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,823	15,857
Gross Unrealized Gains	1	7
Gross Unrealized Losses	(17)	(5)
Fair Value	$ 27,807	$ 15,859

MARKETABLE SECURITIES AND FAI40

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS - Assets measured at fair value on a recurring basis (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 19,889	$ 12,923
Corporate debt securities-short term	27,807	15,859
Total	47,696	28,782
Warrant liability	1,512
Fair Value, Measurements, Recurring \| Corporate debt securities \| Quoted Prices in Active Markets (Level 1) \| Short term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	19,889	12,923
Corporate debt securities-short term	0	0
Total	19,889	12,923
Warrant liability	0
Fair Value, Measurements, Recurring \| Corporate debt securities \| Significant Other Observable Inputs (Level 2) \| Short term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Corporate debt securities-short term	27,807	15,859
Total	27,807	15,859
Warrant liability	0
Fair Value, Measurements, Recurring \| Corporate debt securities \| Significant Unobservable Inputs (Level 3) \| Short term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Corporate debt securities-short term	0	0
Total	0	$ 0
Warrant liability	$ 1,512

MARKETABLE SECURITIES AND FAI41

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS - Warrant liability valuation (Details 2) - Warrant liability	12 Months Ended
	Dec. 31, 2017$ / shares
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrant stock price	$ 1.75
Exercise price	$ 1.65
Expected volatility	53.30%
Risk-free interest	2.07%
Expected term	3 years 10 months 6 days
Dividends	0.00%

MARKETABLE SECURITIES AND FAI42

MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS (Detail Textuals) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Marketable Securities and Fair Value Measurements [Abstract]
Valuation method	Black-Scholes model
Warrant liability	$ 1,512

PROPERTY AND EQUIPMENT - Proper

PROPERTY AND EQUIPMENT - Property and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,708	$ 4,708
Less: Accumulated depreciation and amortization	4,593	4,528
Net property and equipment	$ 115	180
Machinery and equipment
Property, Plant and Equipment [Line Items]
USEFUL LIFE ESTIMATED (YEARS)	5 years
Property and equipment, gross	$ 1,939	1,939
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 232	232
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
USEFUL LIFE ESTIMATED (YEARS)	3 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
USEFUL LIFE ESTIMATED (YEARS)	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
USEFUL LIFE ESTIMATED (YEARS)	7 years
Property and equipment, gross	$ 40	40
Computer equipment
Property, Plant and Equipment [Line Items]
USEFUL LIFE ESTIMATED (YEARS)	3 years
Property and equipment, gross	$ 2,497	$ 2,497

PROPERTY AND EQUIPMENT (Detail

PROPERTY AND EQUIPMENT (Detail Textuals) - Lease Agreement $ in Thousands	1 Months Ended
	Jan. 31, 2015USD ($)ft²
Property, Plant and Equipment [Line Items]
Area of land \| ft²	15,000
Lease term	5 years 3 months
Lease average annual rental rate amount \| $	$ 455

OTHER ASSETS - Components of Ot

OTHER ASSETS - Components of Other assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Assets, Noncurrent [Abstract]
Security deposits	$ 204	$ 252
Total other assets	$ 204	$ 252

ACCOUNTS PAYABLE AND ACCRUED 46

ACCOUNTS PAYABLE AND ACCRUED EXPENSES - Summary of accounts payable and accrued expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable	$ 537	$ 710
Accrued payroll	1,448	1,856
Accrued outsourced preclinical and clinical fees	5,409	5,461
Accrued professional fees	492	363
Other accrued expenses	373	310
Accounts payable and accrued expenses, Total	$ 8,259	$ 8,700

LOAN AGREEMENT (Details)

LOAN AGREEMENT (Details) $ in Thousands	Dec. 31, 2017USD ($)
Long-term Debt, Unclassified [Abstract]
2,019	$ 1,667
2,020	5,000
2,021	5,000
2,022	3,333
Loan principal amount	$ 15,000

LOAN AGREEMENT (Detail Textuals

LOAN AGREEMENT (Detail Textuals) - Oxford Finance Llc - Loan Agreement - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		12 Months Ended
	Feb. 28, 2018	Jan. 31, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Loan principal amount		$ 15
Interest rate description		(a) the greater of (i) the 30 day U.S. LIBOR rate reported in the Wall Street Journal on the date occurring on the last business day of the month that immediately precedes the month in which the interest will accrue or (ii) 0.65% (b) plus 6.85%
Interest rate		0.65%
Basis spread interest rate		6.85%
Applicable interest rate			8.22%
Period of interest rate payments		18 months
Amortization period		36 months
Maturity date		Aug. 1, 2021
Percentage of final principal payment		6.00%
Percentage of prepayment fee if payment made in 1 to 12 months		3.00%
Percentage of prepayment fee if payment made in 13 to 24 months		2.00%
Percentage of prepayment fee if payment made thereafter 24 months		1.00%
Additional interest rate after default		5.00%
Subsequent event
Debt Instrument [Line Items]
Maturity date	Aug. 1, 2022
Term of payment of interest after amendment	Monthly basis through August 2019
Term of payment of interest and principal after amendment	From September 2019 to August 2022
Lender Warrants
Debt Instrument [Line Items]
Number of warrants issued to purchase common stock		354,330
Pre-share exercise price of warrants or rights		$ 1.27
Exercise term of warrants or rights		10 years
Lender Warrants \| Subsequent event
Debt Instrument [Line Items]
Number of warrants issued to purchase common stock	93,168
Pre-share exercise price of warrants or rights	$ 1.61
Exercise term of warrants or rights	10 years

PREFERRED STOCK AND WARRANT L49

PREFERRED STOCK AND WARRANT LIABILITY (Detail Textuals) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Nov. 30, 2017	Oct. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Preferred Stock And Warrant Liability [Line Items]
Series A Preferred stock, shares authorized				1,000,000	1,000,000
Series A Preferred stock, par value (in dollars per share)				$ 0.01	$ 0.01
Proceeds from stock offering			$ 2,300	$ 17,951	$ 15,174
Number of stock issued under agreement			2,000,000
Change in fair value of warrant liability				902
Definitive stock purchase agreements
Preferred Stock And Warrant Liability [Line Items]
Number of stock issued under agreement		13,938,651
Exercise price of warrants or rights		$ 1.75
Term of warrant		4 years
Definitive stock purchase agreements \| Series A convertible preferred stock and warrants
Preferred Stock And Warrant Liability [Line Items]
Proceeds from stock offering	$ 9,500
Value of each share of Series A Preferred and Warrant	$ 1,135
Number of common stock issued upon conversion	1,000
Amount reported as preferred stock				8,900
Warrant liability	$ 600
Definitive stock purchase agreements \| Series A convertible preferred stock
Preferred Stock And Warrant Liability [Line Items]
Number of stock issued under agreement	8,370
Definitive stock purchase agreements \| Series A Preferred Warrants
Preferred Stock And Warrant Liability [Line Items]
Number of stock issued under agreement	2,260
Warrants, pre-conversion exercise price	$ 1,750
Post-conversion price of common stock	$ 1.75
Term of warrant	4 years
Change in fair value of warrant liability	$ 600
Fair value of warrants liability increased				1,500
Non-cash expense				$ 900

COMMON STOCK (Detail Textuals)

COMMON STOCK (Detail Textuals) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Oct. 31, 2017	Sep. 30, 2017	Feb. 29, 2016	Dec. 31, 2017	Dec. 31, 2016
Common Stock [Line Items]
Common stock, shares authorized				100,000,000	100,000,000
Common stock, par value (in dollars per share)				$ 0.01	$ 0.01
Number of common stock issued under agreement		2,000,000
Proceeds from stock offering		$ 2,300		$ 17,951	$ 15,174
2014 Equity Incentives Plan \| Stock Options
Common Stock [Line Items]
Number of shares available for grant				450,494
Definitive stock purchase agreements
Common Stock [Line Items]
Number of shares available for grant			8,027,900
Number of common stock issued under agreement	13,938,651
Number of warrants issued to purchase common stock	3,123,674
Proceeds from Issuance of Common Stock	$ 15,600
Exercise price	$ 1.75
Term of warrant	4 years
Number of non transferable options issued			3,567,956
Aggregate net proceeds			$ 15,200
Stock option exercise price			$ 2.50

EQUITY INCENTIVE PLANS - Option

EQUITY INCENTIVE PLANS - Option activity (Details) - Equity Incentive Plan - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Number of Shares
Outstanding as of December 31, 2016	8,715,048
Granted	2,572,500		1,150,119
Exercised	0	(97,498)
Cancelled	(665,093)
Outstanding as of December 31, 2017	10,622,455	8,715,048
Exercisable as of December 31, 2017	6,342,885
Weighted Average Exercise Price
Outstanding as of December 31, 2016	$ 3.71
Granted	1.19
Exercised	0
Cancelled	5.16
Outstanding as of December 31, 2017	3.01	$ 3.71
Exercisable as of December 31, 2017	$ 4.10

EQUITY INCENTIVE PLANS - Summar

EQUITY INCENTIVE PLANS - Summary of options outstanding (Details 1) - Equity Incentive Plan - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options Outstanding at December 31, 2017	10,622,455	8,715,048
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 8 months 27 days
Options Outstanding, Weighted Average Exercise Price	$ 3.01	$ 3.71
Options Exercisable as of December 31, 2017	6,342,885
Options Exercisable, Weighted Average Exercise Price	$ 4.10
Range of Exercise Prices : $ 1.16 - 1.41
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Lower Limit	1.16
Range of Exercise Prices, Upper Limit	$ 1.41
Number of Options Outstanding at December 31, 2017	2,572,702
Options Outstanding, Weighted Average Remaining Contractual Life	8 years 4 months 10 days
Options Outstanding, Weighted Average Exercise Price	$ 1.05
Options Exercisable as of December 31, 2017	458,102
Options Exercisable, Weighted Average Exercise Price	$ 1.16
Range of Exercise Prices : $ 1.42 - 2.35
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Lower Limit	1.42
Range of Exercise Prices, Upper Limit	$ 2.35
Number of Options Outstanding at December 31, 2017	2,756,150
Options Outstanding, Weighted Average Remaining Contractual Life	8 years 2 months 16 days
Options Outstanding, Weighted Average Exercise Price	$ 1.69
Options Exercisable as of December 31, 2017	776,600
Options Exercisable, Weighted Average Exercise Price	$ 1.73
Range of Exercise Prices : $ 2.36 - 3.80
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Lower Limit	2.36
Range of Exercise Prices, Upper Limit	$ 3.80
Number of Options Outstanding at December 31, 2017	2,407,565
Options Outstanding, Weighted Average Remaining Contractual Life	4 years 18 days
Options Outstanding, Weighted Average Exercise Price	$ 2.88
Options Exercisable as of December 31, 2017	2,222,145
Options Exercisable, Weighted Average Exercise Price	$ 2.90
Range of Exercise Prices : $ 3.81 - 5.60
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Lower Limit	3.81
Range of Exercise Prices, Upper Limit	$ 5.60
Number of Options Outstanding at December 31, 2017	982,650
Options Outstanding, Weighted Average Remaining Contractual Life	7 months 21 days
Options Outstanding, Weighted Average Exercise Price	$ 4.18
Options Exercisable as of December 31, 2017	982,650
Options Exercisable, Weighted Average Exercise Price	$ 4.18
Range of Exercise Prices : $ 5.61 - 8.40
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Lower Limit	5.61
Range of Exercise Prices, Upper Limit	$ 8.40
Number of Options Outstanding at December 31, 2017	1,903,388
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 4 months 28 days
Options Outstanding, Weighted Average Exercise Price	$ 7.13
Options Exercisable as of December 31, 2017	1,903,388
Options Exercisable, Weighted Average Exercise Price	$ 7.13

EQUITY INCENTIVE PLANS - Shares

EQUITY INCENTIVE PLANS - Shares vested, expected to vest and exercisable (Details 2) - Stock Options $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested and unvested expected to vest, Options \| shares	10,415,678
Vested and unvested expected to vest, weighted-average exercise price \| $ / shares	$ 3.01
Vested and unvested expected to vest, weighted-average remaining contractual term (in years)	5 years 8 months 27 days
Vested and unvested expected to vest, aggregate intrinsic value \| $	$ 1,629
Exercisable, Options \| shares	6,342,885
Exercisable, weighted-average exercise price \| $ / shares	$ 4.10
Exercisable, weighted-average remaining contractual term (in years)	3 years 10 months 17 days
Exercisable, aggregate intrinsic value \| $	$ 247

EQUITY INCENTIVE PLANS - Restri

EQUITY INCENTIVE PLANS - Restricted stock activity (Details 3) - Restricted Stock - Equity Incentive Plan - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2013
Number of Shares
Unvested as of December 31, 2016	29,276
Granted	0
Vested	(29,276)
Cancelled	0
Unvested as of December 31, 2017	0
Weighted Average Grant Date Fair Value
Unvested as of December 31, 2016	$ 2.51
Granted	0
Vested	2.51	$ 2.51
Cancelled	2.51
Unvested as of December 31, 2017	$ 2.51

EQUITY INCENTIVE PLANS (Detail

EQUITY INCENTIVE PLANS (Detail Textuals) - 2014 Equity Incentives Plan - Stock Options - shares	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	3,750,000
Options granted term	10 years
Award vesting period	4 years
Percentage of ownership	10.00%
Percentage of market fair value of the common stock	110.00%
Options weighted average remaining contractual term for major investors	5 years
Number of shares available for grant		450,494

EQUITY INCENTIVE PLANS (Detai56

EQUITY INCENTIVE PLANS (Detail Textuals 1) - 1996 Director Stock Option Plan - Stock Options - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized		1,200,000
Options granted term		10 years
Options to purchase shares of common stock	760,000
Number of options outstanding	280,000
Number of shares exercisable	125,000
Board of Directors Chairman
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for initial election		25,000
Award vesting period for initial election		3 years
Number of shares authorized for re-election		25,000
Award vesting period for re - election		1 year
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for initial election		30,000
Award vesting period for initial election		3 years
Number of shares authorized for re-election		20,000
Award vesting period for re - election		1 year

EQUITY INCENTIVE PLANS (Detai57

EQUITY INCENTIVE PLANS (Detail Textuals 2) - Equity Incentive Plan - Stock Options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options outstanding	$ 1,687
Weighted average grant date fair value of options granted	$ 0.72	$ 1.10	$ 0.77
Exercised	0	97,498
Compensation cost not yet recognized	$ 2,287
Compensation cost related to non-vested option awards recognition period	2 years 6 months
Number of the non-vested options forfeited during the period	198,513
Weighted average grant date fair value of the options non vested which are forfeited during the period	$ 0.97
Weighted average exercise price of the options non vested which are forfeited during the period	$ 1.63
Number of the non-vested options shares expired during the period	466,580
Weighted average grant date fair value of the options non vested which are expired during the period	$ 3.62
Weighted average exercise price of the options non vested which are expired during the period	$ 6.66
Weighted average remaining contractual life for options exercisable	3 years 10 months 24 days

EQUITY INCENTIVE PLANS (Detai58

EQUITY INCENTIVE PLANS (Detail Textuals 3) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1,434	$ 1,865	$ 2,261
Equity Incentive Plan \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted	0
Award vesting period				4 years
Weighted average fair value of the restricted stock vested	$ 2.51			$ 2.51
Share-based compensation expense	$ 8	73	76
Fair value of the stock vested during the period	$ 48	$ 55	$ 78
Equity Incentive Plan \| Restricted Stock \| Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted				242,697

EQUITY INCENTIVE PLANS (Detai59

EQUITY INCENTIVE PLANS (Detail Textuals 4) - Employment agreement - Performance-based stock units	1 Months Ended
	Apr. 30, 2017shares
Chief executive officer (CEO)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	600,000
Chief operating officer (COO)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	300,000
Chief medical officer (CMO)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	260,000
Other employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	270,000

EQUITY INCENTIVE PLANS (Detai60

EQUITY INCENTIVE PLANS (Detail Textuals 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1,434	$ 1,865	$ 2,261
Stock Options \| 1996 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of market fair value of the common stock	85.00%
Options exercises period	27 months
Number of shares authorized				2,400,000
Number of shares purchased	2,217,705
Share-based compensation expense	$ 17	$ 60	$ 60

INCOME TAXES - Reconciliation b

INCOME TAXES - Reconciliation between the U.S. federal statutory rate and the effective tax rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax (benefit) expense at statutory rate	$ (9,929)	$ (7,724)	$ (4,683)
State tax (benefit) expense, net of Federal tax (benefit) expense	(1,452)	(1,146)	(677)
Permanent items	508	263	239
Effect of change in valuation allowance and State NOL expiration	(39,972)	8,837	4,945
Tax credits	(544)	(228)	(74)
Change in tax rate on beginning assets	51,445	0	0
Other	(56)	(2)	250
Tax expense (benefit)	$ 0	$ 0	$ 0

INCOME TAXES - Income tax effec

INCOME TAXES - Income tax effect of temporary differences comprising the deferred tax assets and deferred tax liabilities (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 100,421	$ 135,642
Tax credit carryforwards	26,771	25,264
Equity based compensation	3,381	9,610
Book depreciation in excess of tax	49	56
Reserves and accruals	171	181
Other	16	28
Deferred tax assets, gross	130,809	170,781
Valuation allowance	(130,809)	(170,781)
Deferred tax liabilities	0	0
Net deferred tax assets	$ 0	$ 0

INCOME TAXES (Detail Textuals)

INCOME TAXES (Detail Textuals) - USD ($) $ in Thousands	12 Months Ended
INCOME TAXES (Detail Textuals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Amount of valuation allowance increase (decrease)	$ (39,972)	$ 8,837	$ 4,945
US federal corporate tax rate	35.00%
Future federal statutory income tax rate	21.00%
Deferred tax balance before valuation allowance	$ 51,445	0	$ 0
Increase in ownership percentage of certain stockholders or public groups	more than 50 percentage points
Ownership change, increase in ownership percentage, term	3 years
Federal income tax
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 409,409
Net operating loss generated from excess tax deduction from share based awards		15,080
State income tax
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	228,565
Net operating loss generated from excess tax deduction from share based awards		$ 929
Research and development credit carryforwards
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 28,253

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Minimum lease commitments for all leased facilities, net of sublease income (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 560
2,019	519
2,020	254
Thereafter	0
Total minimum lease payments	$ 1,333

COMMITMENTS AND CONTINGENCIES65

COMMITMENTS AND CONTINGENCIES (Detail Textuals) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies Disclosure [Line Items]
Rent expense under non-cancelable operating leases		$ 546	$ 540	$ 1,569
Lease Agreement
Commitments And Contingencies Disclosure [Line Items]
Lease term	5 years 3 months
Lease average annual rental rate amount	$ 455

CONCENTRATION OF CREDIT RISK (D

CONCENTRATION OF CREDIT RISK (Detail Textuals) - Customer Concentration Risk - Revenue	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Customer One
Concentration Risk [Line Items]
Percentage of total sales accounted	40.00%	49.00%
Customer Two
Concentration Risk [Line Items]
Percentage of total sales accounted	60.00%	51.00%

SELECTED QUARTERLY FINANCIAL 67

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) - Quarterly financial data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 0	$ 0	$ 0	$ 0	$ 1,187	$ 1,223	$ 1,072	$ 1,227	$ 0	$ 4,709	$ 11,239
Net loss	$ (7,760)	$ (6,666)	$ (7,201)	$ (7,576)	$ (6,820)	$ (5,817)	$ (5,100)	$ (4,981)	$ (29,203)	$ (22,718)	$ (13,774)
Basic and diluted net loss per common share:
Net loss per share (in dollars per share)	$ (0.09)	$ (0.09)	$ (0.10)	$ (0.11)	$ (0.10)	$ (0.08)	$ (0.07)	$ (0.08)	$ (0.39)	$ (0.33)	$ (0.22)