Mirati Therapeutics (MRTX) 10-K 11 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Mar. 09, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	MIRATI THERAPEUTICS, INC.
Entity Central Index Key	1576263
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Entity Filer Category	Accelerated Filer
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		16,164,311
Entity Public Float			$174.90

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$6,593,000	$14,235,000
Short-term investments	22,710,000	47,835,000
Other current assets	3,354,000	2,145,000
Total current assets	32,657,000	64,215,000
Property and equipment, net	496,000	322,000
Other assets	326,000	0
Total assets	33,479,000	64,537,000
Current liabilities
Accounts payable and accrued liabilities	5,396,000	5,245,000
Warrant liability	0	33,407,000
Total current liabilities	5,396,000	38,652,000
Other liability	21,000	0
Total current liabilities	5,417,000	38,652,000
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value, 10,000,000 shares authorized; none issued and outstanding at both December 31, 2014 and December 31, 2013	0	0
Common stock, $0.001 par value; 100,000,000 authorized; 13,566,726 and 13,446,976 issued and outstanding at December 31, 2014 and December 31, 2013, respectively	14,000	13,000
Additional paid-in capital	260,616,000	214,756,000
Accumulated other comprehensive income	9,521,000	9,507,000
Accumulated deficit	-242,089,000	-198,391,000
Total stockholders' equity	28,062,000	25,885,000
Total liabilities and stockholders' equity	$33,479,000	$64,537,000

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	13,566,726	13,446,976
Common stock, shares outstanding	13,566,726	13,446,976

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Expenses
Research and development	$26,071	$19,797	$15,081
General and administrative	12,699	11,177	5,417
Restructuring costs	334	1,025	0
Total operating expenses	39,104	31,999	20,498
Loss from operations	-39,104	-31,999	-20,498
Other income (expense), net	-77	-1,084	251
Change in fair value of warrant liability	-4,517	-19,799	0
Loss before income taxes	-43,698	-52,882	-20,247
Income tax benefit (expense)	0	23	-39
Net loss	-43,698	-52,859	-20,286
Unrealized gain (loss) on available-for-sale investments	-14	13	0
Comprehensive loss	($43,684)	($52,872)	($20,286)
Basic and diluted net loss per share (in dollars per share)	($3.24)	($4.78)	($3)
Weighted average number of shares used in computing net loss per share, basic and diluted (in shares)	13,483,467	11,057,040	6,762,985

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Common stock warrants	Additional paid-in capital	Accumulated other comprehensive income	Accumulated deficit
In Thousands, except Share data, unless otherwise specified
Beginning balance at Dec. 31, 2011	$27,305	$6	$6,247	$132,312	$8,945	($120,205)
Beginning balance (in shares) at Dec. 31, 2011		6,358,253
Increase (Decrease) in Stockholders' Equity
Net loss	-20,286					-20,286
Stock-based compensation expense	2,009			2,009
Costs of reorganization	-15			-15
Issuance of common stock, net of costs	19,886	4		19,882
Issuance of common stock, net of costs (in shares)		3,593,819
Issuance of warrants, net of costs	4,942		4,942
Net exercise of warrants	0		-36	36
Net exercise of warrants (in shares)		5,653
Foreign currency translation	575				575
Unrealized loss on investments	0
Ending balance at Dec. 31, 2012	34,416	10	11,153	154,224	9,520	-140,491
Ending balance (in shares) at Dec. 31, 2012		9,957,725
Increase (Decrease) in Stockholders' Equity
Net loss	-52,859					-52,859
Reclassification of warrants	-16,194		-11,153			-5,041
Reclassification of stock option liability	1,369			1,369
Stock-based compensation expense	1,823			1,823
Issuance of common stock, net of costs	54,196	3		54,193
Issuance of common stock, net of costs (in shares)		3,337,500
Exercise of options for cash	540			540
Exercise of options for cash (in shares)		40,534
Exercise of warrants for cash	21			21
Exercise of warrants for cash (in shares)		2,896
Net exercise of warrants	2,586			2,586
Net exercise of warrants (in shares)		108,321
Unrealized loss on investments	-13				-13
Ending balance at Dec. 31, 2013	25,885	13	0	214,756	9,507	-198,391
Ending balance (in shares) at Dec. 31, 2013	13,446,976	13,446,976
Increase (Decrease) in Stockholders' Equity
Net loss	-43,698					-43,698
Reclassification of warrants	36,931			36,931
Stock-based compensation expense	7,050			7,050
Exercise of options for cash	887	1		886
Exercise of options for cash (in shares)	76,224	76,224
Net exercise of warrants	993			993
Net exercise of warrants (in shares)	43,526	43,526
Unrealized loss on investments	14				14
Ending balance at Dec. 31, 2014	$28,062	$14	$0	$260,616	$9,521	($242,089)
Ending balance (in shares) at Dec. 31, 2014	13,566,726	13,566,726

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net loss	($43,698)	($52,859)	($20,286)
Non-cash adjustments reconciling net loss to operating cash flows
Depreciation of property and equipment	199	171	123
Amortization of premium on investments	534	0	0
Share-based compensation expense	7,050	1,823	2,009
Loss on disposal of property and equipment	0	40	0
Change in lease incentive liability	0	-70	85
Change in fair value of warrant liability	4,517	19,799	0
Change in fair value adjustment of share-based compensation liability	0	1,369	0
Change in restructuring costs	13	0	0
Changes in operating assets and liabilities
Other current assets	-1,209	340	-15
Other assets	-326	0	0
Accounts payable and accrued liabilities	151	-68	1,434
Other liabilities	21	0	0
Cash flows used for operating activities	-32,748	-29,455	-16,650
Investing activities:
Purchases of short-term investments	-10,468	-68,408	-29,431
Disposal and maturities of short-term investments	35,073	39,138	29,716
Purchases of property and equipment	-386	-204	-230
Proceeds from disposal of property and equipment	0	4	0
Cash flows provided by / (used for) investing activities	24,219	-29,470	55
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	0	54,196	19,886
Proceeds from issuance of warrants, net of issuance costs	0	0	4,927
Proceeds from exercise of common stock options and warrants	887	561	0
Cash flows provided by financing activities	887	54,757	24,813
Increase / (decrease) in cash and cash equivalents	-7,642	-4,168	8,218
Effect of exchange rate changes on cash and cash equivalents	0	0	303
Cash and cash equivalents, beginning of year	14,235	18,403	9,882
Cash and cash equivalents, end of year	6,593	14,235	18,403
Income taxes paid	0	35	34
Net exercise of warrants	$993	$2,586	$0

DESCRIPTION_OF_BUSINESS

DESCRIPTION OF BUSINESS	12 Months Ended
	Dec. 31, 2014
DESCRIPTION OF BUSINESS
DESCRIPTION OF BUSINESS	Description of Business
	Mirati Therapeutics, Inc. (“Mirati” or the “Company”) is a clinical-stage biopharmaceutical company focused on developing a pipeline of targeted oncology products. The Company focuses its development programs on drugs intended to treat specific genetically defined and selected subsets of cancer patients with unmet needs.
	The Company's common stock has been listed on the NASDAQ Capital Market since July 15, 2013 under the ticker symbol "MRTX." The Company has a wholly owned subsidiary in Canada, MethylGene, Inc. (“MethylGene”). MethylGene’s common stock was listed on the Toronto Stock Exchange from June 29, 2004 until July 26, 2013 under the ticker symbol “MYG”. The Company also has an indirect, wholly-owned subsidiary, MethylGene US Inc., which was incorporated in Princeton, New Jersey on December 20, 2011 and started business activity in 2012. MethylGene US Inc. ceased operations effective January 1, 2014. During the first half of 2013, the Company conducted the majority of its operations through MethylGene and MethylGene US Inc. As a result of the arrangement agreement discussed in Note 2 under the heading "Basis of Presentation," Mirati became the parent company in June 2013 and primary operating company during the last half of 2013. Refer to Note 2 for further discussion of the Company’s corporate structure.

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Summary of Significant Accounting Policies
	Basis of Presentation
	These consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States ("GAAP"). These consolidated financial statements include the accounts of the Company, MethylGene and MethylGene US Inc. All significant inter-company transactions, balances and expenses have been eliminated upon consolidation.
	Mirati was incorporated under the laws of the State of Delaware on April 29, 2013. The Company was created to enter into an arrangement agreement described below.
	On May 8, 2013, the Company's Board of Directors approved and the Company entered into an arrangement agreement with MethylGene. Subject to the terms and conditions of the arrangement agreement, which was consummated on June 28, 2013, the shareholders of MethylGene received one share of the Company's common stock in exchange for every 50 common shares of MethylGene, which had the effect of a 50 for 1 reverse split of the common shares pursuant to a court-approved plan of arrangement under Section 192 of the Canada Business Corporations Act. Such transaction is referred to herein as the Arrangement. In addition, all outstanding options and warrants to purchase common shares of MethylGene became exercisable on a 50-for-1 basis for shares of our common stock, and a proportionate adjustment was made to the exercise price or conversion price, as applicable. The accompanying financial statements and notes to the financial statements give retroactive effect to the reverse split of our common stock for all periods presented. Upon completion of the Arrangement, MethylGene became the Company's wholly-owned subsidiary. The shares of the Company's common stock issued at the closing of the Arrangement were issued in reliance upon the exemption from registration under Section 3(A)(10) of the Securities Act of 1933, as amended.
	These consolidated financial statements are presented in U.S. dollars, which effective January 1, 2013, is also the functional currency of the Company.
	Use of Estimates
	The preparation of the Company's audited consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period.
	Reported amounts and note disclosures reflect the overall economic conditions that are most likely to occur and anticipated measures management intends to take. Actual results could differ materially from those estimates. Estimates and assumptions are reviewed quarterly. Any revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.
	Cash, Cash Equivalents and Short-term Investments
	Cash and cash equivalents consist of cash and highly liquid securities with original maturities of ninety days or less. Investments with an original maturity of more than ninety days are considered short-term investments and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income, if any, are determined on a specific identification basis.
	Concentration of Credit Risk
	The Company invests its excess cash in accordance with its investment policy. The Company's investments are comprised primarily of commercial paper and debt instruments of financial institutions, corporations, U.S. government-sponsored agencies and the U.S. Treasury. The Company mitigates credit risk by maintaining a diversified portfolio and limiting the amount of investment exposure as to institution, maturity and investment type. Financial instruments that potentially subject the Company to significant credit risk consist principally of cash equivalents and short-term investments.
	Foreign Currency Transactions
	Foreign currency transactions are initially recorded by the Company using the exchange rates prevailing at the date of the transaction. At the balance sheet date, monetary assets and liabilities denominated in foreign currencies are translated at the period-end rates of exchange. Non-monetary assets and liabilities are translated at the historical exchange rates. Exchange gains and losses arising from the translation of foreign currency items are included in other income (expense) in the consolidated statements of operations and comprehensive loss. The Company recognized net foreign exchange losses of $0.2 million, $1.3 million and an immaterial amount in other income (expense) in the consolidated statement of operations and comprehensive loss for the years ended December 31, 2014, 2013 and 2012, respectively.
	Property and Equipment
	Property and equipment is stated at historical cost less accumulated depreciation. Historical cost includes expenditures that are directly attributable to the acquisition of the items. All repairs and maintenance are charged to net loss during the financial period in which they are incurred.
	Depreciation of property and equipment is calculated using the straight-line method over the estimated useful lives of the assets, as follows:
	Computer equipment		3 years
	Office and other equipment		6 years
	Laboratory equipment		6 years
	Leasehold improvements		The lesser of the lease term or the life of the asset
	On disposal or impairment of property and equipment, the cost and related accumulated depreciation is removed from the consolidated financial statements and the net amount, less any proceeds, is included in net loss.
	Impairment of Long-Lived Assets
	The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset 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. Fair value is estimated through discounted cash flow models to project cash flows from the asset. The Company recognized immaterial impairment charges related to property and equipment for the years ended December 31, 2014 and 2013, and no impairment charges in 2012.
	Reclassification of Warrants
	In 2011 and 2012, MethylGene issued common stock warrants in connection with the issuance of common stock through private placements (referred to as the 2011 Warrants and the 2012 Warrants). The exercise prices of the 2011 and 2012 Warrants were denominated in Canadian dollars. Upon the issuance of the 2011 and 2012 Warrants, the net proceeds were allocated to common stock and warrants based on their relative fair values, and the fair value of the issued common stock warrants was calculated utilizing the Black-Scholes option-pricing model. The allocated fair value was then recorded as warrants within stockholders’ equity on the consolidated balance sheet.
	Effective January 1, 2013, the Company changed its functional currency which changed how the 2011 and 2012 warrants are accounted for as they continued to have exercise prices denominated in Canadian dollars. Upon the change in functional currency, the warrants were classified as a current liability and a warrant liability of $16.2 million which represented the fair market value of the warrants at that date in accordance with accounting standards. The initial fair value recorded as warrants within stockholders’ equity of $11.2 million was reversed. The change in fair value related to periods prior to January 1, 2013 of $5.0 million was recorded as an adjustment to accumulated deficit. At each reporting period subsequent to January 1, 2013, the fair value of the warrant liability was recalculated and any corresponding increase or decrease to the warrant liability was recorded as change in fair value of warrant liability on the consolidated statement of operations and comprehensive loss. The estimated fair value was determined using the Black-Scholes option-pricing model based on the estimated value of the underlying common stock at the valuation measurement date, the remaining contractual term of the warrants, risk-free interest rates, expected dividends and expected volatility of the price of the underlying common stock.
	During the second half of 2014, the Company amended all of its outstanding warrant agreements to allow for the warrants to be denominated in U.S. Dollars. As a result of this amendment, the amended warrants qualified for equity classification and were reclassified into stockholders’ equity at their fair value as of the amendment date and revaluations of fair value are no longer required.
	Prior to the amendments, for all of the warrants classified as liabilities during the relevant periods, the Company recorded warrant valuation expense of $4.5 million and $19.8 million for the years ended December 31, 2014 and 2013, respectively. No such expense was recorded for the year ended December 31, 2012 as the functional currency was the Canadian dollar.
	Reclassification of Share-Based Compensation Liability
	The Company granted stock options denominated in Canadian dollars under its 1997 Equity Plan to Canadian and United States, or US, based employees and directors until July 26, 2013. Following the delisting of the Company’s shares from the Toronto Stock Exchange, the options denominated in Canadian dollars that were granted to US-based employees and US-based directors were subject to liability accounting ("liability options") with fair value calculated using the Black-Scholes option-pricing model. The Company revalued the liability options as of July 26, 2013 and recorded a share-based compensation liability of $1.1 million with a corresponding reduction of additional paid-in capital.
	At each reporting period subsequent to July 26, 2013, the Company adjusted the fair value of the liability options and any corresponding increase or decrease to the liability was recorded as either a reduction of additional paid in capital or as stock compensation expense on the consolidated statement of operations and comprehensive loss, as appropriate. During the year ended December 31, 2013 these fair value adjustments resulted in an increase to additional paid in capital of $0.3 million and total stock compensation expense of $1.4 million. Effective November 30, 2013 the Company amended the agreements underlying the liability options such that the exercise price was converted from Canadian dollars to the equivalent US dollar exercise price by applying the exchange rate for the conversion of Canadian dollars into U.S. dollars based on the Bank of Canada’s noon buying rate for one U.S. dollar on the date the option was granted. The fair value of the liability options as of November 30, 2013 was $2.2 million and was reclassified from share-based compensation liability to additional paid-in capital.
	Share-Based Compensation
	The Company has a stock option compensation plan in which the fair value of stock options granted is determined at the date of the grant using the Black-Scholes option-pricing model and is expensed over the vesting period of the options. Share-based compensation is recognized using the graded accelerated vesting method. In determining the expense, the Company deducts the number of options that are expected to be forfeited at the time of a grant and revises this estimate, if necessary, in subsequent years if actual forfeitures differ from those estimated. The stock-based compensation expense attributable to awards under the Company's 2013 Employee Stock Purchase Plan ("ESPP") was also determined using the Black-Scholes option pricing model.
	The determination of the fair value of share-based compensation awards utilizing the Black-Scholes model is affected by the Company's stock price and a number of assumptions, including but not limited to expected stock price volatility over the term of the awards and the expected term of stock options. Changes in the assumptions can materially affect the fair value estimates.
	Investment Tax Credits
	The Company's accounts include claims for investment tax credits ("ITCs") relating to scientific research and experimental development activities of the Company. The qualification and recording of these activities for investment tax credit purposes are established by the Canadian federal and Provincial Tax Acts and are subject to audit by the taxation authorities. Refundable ITCs are reflected as reductions of expenses or reductions of the cost of the assets to which they relate when there is reasonable assurance that the assistance will be received and all conditions have been complied with. The non-refundable ITCs are carried forward for a time and will be recognized when it is more likely than not that the Company will become subject to Canadian federal taxes, at which time, said ITCs are applied as a reduction of tax expense. As operations in Canada ceased in early 2014, there were no new investment tax credits earned for the year ended December 31, 2014.
	Research and Development Expenses
	Research and development expenditures are charged to net loss in the period in which they are incurred and are comprised of the following types of costs incurred in performing research and development activities: salaries and benefits, share-based compensation expense, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs.
	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 applicable 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 consolidated financial statements.
	Segment Reporting
	Operating segments are components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker for purposes of making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating primarily in the United States.
	Fair Value Measurements
	The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.
	The authoritative guidance for fair value measurements defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or the most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact, and (iv) willing to transact. The guidance prioritizes the inputs used in measuring fair value into the following hierarchy:
	•	Level 1- Quoted prices (unadjusted) in active markets for identical assets or liabilities;
	•	Level 2- Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and
	•	Level 3- Unobservable inputs in which little or no market activity exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing.
	The following table summarizes the assets and liabilities measured at fair value on a recurring basis (in thousands):
		December 31,				Level 1			Level 2		Level 3
		2014
	Assets
	Cash and cash equivalents	$	6,593			$	4,590		$	2,003	$	—
	Short-term investments	22,710				—			22,710		—
		$	29,303			$	4,590		$	24,713	$	—
		December 31,				Level 1			Level 2		Level 3
		2013
	Assets
	Cash and cash equivalents	$	14,235			$	12,431		$	1,804	$	—
	Short-term investments	47,835				—			47,835		—
		$	62,070			$	12,431		$	49,639	$	—
	Liabilities
Warrant liability	$	33,407			$	—		$	—	$	33,407
	$	33,407			$	—		$	—	$	33,407
The Company’s investments in Level 1 assets are valued based on publicly available quoted market prices for identical securities as of December 31, 2014 and December 31, 2013. The Company determines the fair value of Level 2 related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. There were no transfers between fair value measurement levels for the years ended December 31, 2014 and 2013.
The following table presents a rollforward of the fair value of the warrant liability, which included Level 3 measurements (in thousands):
		Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3)
Warrant liability:
Balance at January 1, 2013		$	—
Fair value upon reclassification of balance as of January 1, 2013		16,194
Change in fair value of warrant liability		19,799
included in net loss
Fair value of warrants exercised		(2,586		)
Balance at December 31, 2013		33,407
Change in fair value of warrant liability included in net loss		4,517
Fair value of warrants exercised		(993		)
Reclassification of warrants to stockholders' equity		(36,931		)
Balance at December 31, 2014		$	—
The Company estimated the fair value of warrants at the time of issuance and subsequent remeasurement through the date of reclassification into equity using the Black-Scholes option-pricing model at each reporting date, using the following inputs: the risk-free interest rates; the expected dividend rates; the remaining expected life of the warrants; and the expected volatility of the price of the underlying common stock. The estimates are based, in part, on subjective assumptions and changes to these assumptions could have a significant impact on the fair value of the warrants.
The following assumptions were used in the Black-Scholes option-pricing model as of the warrant amendments dates to determine the fair value of the warrants to reclassify into equity:
		Sep-14					Dec-14
		2011 Warrants			2012 Warrants		2011 Warrants
Risk-free interest rate		1.2	%		1.2	%	1	%
Volatility		108.6	%		100.8	%	62.8% - 63.9%
Dividend yield		—			—		—
Expected life in years		1.6			3.2		1.3
The following assumptions were used in the Black-Scholes option-pricing model to determine the fair value of the warrant liability as of December 31, 2013. All 2011 and 2012 warrants were amended and did not require a valuation as of December 31, 2014.
		31-Dec-13
		2011 Warrants			2012 Warrants
Risk-free interest rate		1.2	%		1.6	%
Volatility		112	%		115.9	%
Dividend yield		—			—
Expected life in years		2.3			3.9
Net Loss Per Share
Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. Common share equivalents outstanding, determined using the treasury stock method, are comprised of shares that may be issued under the Company’s stock option and warrant agreements.
The following table presents the weighted average number of potentially dilutive securities not included in the calculation of diluted net loss per share due to the anti-dilutive effect of the securities:
		Year ended
		December 31,
		2014			2013		2012
Common stock options		253,595			495		15,663
Common stock warrants		1,515,445			644,426		690,046
Total		1,769,040			644,921		705,709

RECENT_ACCOUNTING_PRONOUNCEMEN

RECENT ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Dec. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
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 the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on our consolidated financial position or results of operations upon adoption.
	In May 2014, the FASB issued Accounting Standard Update ("ASU") 2014-09, Revenue from Contracts with Customers (Topic 606), which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the impact that this standard will have on its consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. Under the new guidance, management will be required to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures in certain circumstances. The provisions of this ASU are effective for annual periods beginning after December 15, 2016, and for annual and interim periods thereafter, early adoption is permitted. The Company has not elected to early adopt and is currently evaluating the potential changes from this ASU to its future financial reporting and disclosures.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	Investments
	The following tables summarize our short-term investments (in thousands):
			As of December 31, 2014
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Corporate debt securities (1)	1 year or less	21,208	3	(1	)	21,210
	Commercial paper (1)	1 year or less	1,500	—	—		1,500
			22,708	3	(1	)	22,710
			As of December 31, 2013
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Government sponsored enterprise (1)	2 years or less	3,001	—	(3	)	2,998
	Corporate debt securities (1)	2 years or less	31,319	—	(22	)	31,297
	Commercial paper (1)	1 year or less	8,485	12	—		8,497
	Guaranteed investment certificates (2)	1 year or less	5,046	—	(3	)	5,043
			47,851	12	(28	)	47,835
	(1) Investments are designated as available-for-sale investments.
	(2) Investments are designated as trading investments.
	Unrealized gains and losses on available-for-sale securities are included as a component of comprehensive loss. At December 31, 2014, the Company did not have any securities in material unrealized loss positions. The Company reviews its investments to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. The Company does not intend to sell any investments prior to recovery of their amortized cost basis for any investments in an unrealized loss position.

OTHER_CURRENT_ASSETS

OTHER CURRENT ASSETS	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
OTHER CURRENT ASSETS	Other Current Assets
	Other current assets consisted of the following (in thousands):
		December 31,
		2014		2013
		(in thousands)
	Prepaid expenses	1,827		667
	Refundable research and development tax credits	809		809
	Security deposits and other receivables	622		506
	Interest receivables	96		163
		$	3,354	$	2,145

PROPERTY_AND_EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	Property and Equipment, Net
	Property and equipment consisted of the following (in thousands):
		December 31,
		2014			2013
		(in thousands)
	Computer equipment	$	329		$	1,534
	Office and other equipment	56			122
	Laboratory equipment	346			1,794
	Leasehold improvements	—			53
		$	731		$	3,503
	Less: Accumulated depreciation	(235		)	(3,181		)
		$	496		$	322
	The Company incurred depreciation expense of $0.2 million, $0.2 million and $0.1 million for the years ended December 31, 2014, 2013 and 2012, respectively. During the year ended December 31, 2014, in connection with the Company's closure of its Canadian office as described further in Note 8, the Company disposed of several fully depreciated assets with a gross book value of $3.2 million that were no longer in use.

ACCOUNTS_PAYABLE_AND_ACCRUED_L

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES	Accounts Payable and Accrued Liabilities
	Accounts payable and accrued liabilities consisted of the following (in thousands):
		December 31,
		2014		2013
		(in thousands)
	Accounts payable	$	1,655	$	1,302
	Accrued expenses	2,327		2,335
	Accrued compensation and benefits	1,414		1,608
		$	5,396	$	5,245

RESTRUCTURING

RESTRUCTURING	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
RESTRUCTURING	Restructuring
	On October 1, 2013, the Company announced a plan to terminate approximately 75% of its total workforce in connection with the closing of its Montreal, Quebec and Princeton, New Jersey offices (the "Restructuring") due to the consolidation of Company operations to the San Diego facility. Restructuring costs were comprised of employee separation and facilities closure related costs and were reported as a separate line item in the accompanying consolidated statement of operations and comprehensive loss. A rollforward of the accrued restructuring liability is presented below (in thousands):
	Balance as of October 1, 2013	$	—
	Accrued restructuring charges	1,025
	Payments	(729		)
	Balance as of December 31, 2013	296
	Accrued restructuring charges	334
	Payments	(630		)
	Balance as of December 31, 2014	$	—
	The restructuring activities associated with the office closures were substantially complete as of March 31, 2014, and all restructuring costs incurred have been paid to date.

STOCKHOLDERS_EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	Stockholders' Equity
	Common Stock
	As of December 31, 2014, the following shares were reserved for future issuance:
		December 31,
		2014
	Common stock options outstanding and available for future grant	1,891,107
	Warrants to purchase common stock	2,465,713
	Employee Stock Purchase Plan	300,000
		4,656,820
	Warrants
	As of December 31, 2014 the following warrants for common stock were issued and outstanding:
	Issue date		Expiration date	Exercise price (Denominated in US Dollars)		Number of warrants outstanding
	April 4, 2011		April 4, 2016	$	6.74	1,397,921
	November 21, 2012		November 21, 2017	$	7.86	1,067,792
						2,465,713
	On April 4, 2011 and November 21, 2012 the Company's wholly owned subsidiary, MethylGene, completed private placement financing transactions which resulted in the issuance of common stock warrants. The April 4, 2011 common stock warrants were issued with an exercise price of CND$7.46 and the November 21, 2012 common stock warrants were issued with an exercise price of CND$8.70. During the last half of 2014, the Company amended all of these outstanding warrant agreements to allow for the warrants to be denominated in U.S. Dollars.
	During the year ended December 31, 2014, warrants for 73,964 shares of the Company's common stock were exercised via cashless exercises and the Company issued a total of 43,526 shares of common stock.

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	Share-Based Compensation
	Equity Incentive Plan
	The Company has in place a stock option plan (the "Stock Option Plan") for the benefit of employees, directors, officers and consultants of the Company. In May 2013 our Board of Directors adopted the 2013 Equity Incentive Plan (the "2013 Plan"). The 2013 Plan was approved by our stockholders in connection with the Arrangement. The 2013 Plan is a continuation of and successor to the Stock Option Plan and no further grants will be made under the Stock Option Plan. As of December 31, 2014, there were 0.4 million stock options available to be issued.
	To date, share-based compensation awards under either the Stock Option Plan or the 2013 Plan consist of incentive and non-qualified stock options. Stock options granted under each of the plans must have an exercise price equal to at least 100% of the fair market value of our common stock on the date of grant and generally vest over four years. The Stock Option Plan has contractual terms ranging from five to seven years and the 2013 Plan has contractual terms ranging from seven to ten years.
	The following table summarizes our stock option activity and related information for the year ended December 31, 2014:
		Number of		Weighted			Weighted-Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (millions)
		options		average
				exercise
				price
	Balance, December 31, 2013	968,923		$	11.13
	Granted	599,410		$	18.64
	Exercised	(76,224	)	$	11.2
	Canceled/forfeited	(34,640	)	$	15.44
	Expired	(2,609	)	$	55.8
	Balance, December 31, 2014	1,454,860		$	14
	Options exercisable at December 31, 2014	431,088		$	12.25		7		$	3.21
	Options vested and expected to vest at December 31, 2014	1,383,082		$	14.89		8.1		$	6.83
	The total intrinsic value of stock options exercised was $0.6 million and $0.2 million for the years ended December 31, 2014 and 2013, respectively. The Company received total cash of $0.9 million and $0.5 million for the exercise of options for the years ended December 31, 2014 and 2013. There were no options exercised during the year ended December 31, 2012. The total fair value of options vested during the years ended December 31, 2014, 2013, and 2012 was $3.0 million, $2.0 million, and $2.4 million respectively. Upon option exercise, the Company issues new shares of our common stock.
	Total share-based compensation expense by operating statement classification is presented below (in thousands):
		Year ended December 31,
		2014			2013			2012
	Research and development expense	$	2,565		$	245		$	817
	General and administrative expense	4,485			2,947			1,192
		$	7,050		$	3,192		$	2,009
	In the years ended December 31, 2014, 2013 and 2012, no share-based compensation expense was capitalized and there were no recognized tax benefits associated with the share-based compensation charge.
	The fair value of options granted is estimated at the date of grant using the Black-Scholes option pricing model. The assumptions used for the specified reporting periods and the resulting estimates of weighted-average estimated fair value per share of options granted during those periods are as follows:
			Year Ended
			December 31,
			2014	2013		2012
	Risk-free interest rate		2.10%	2.00%		1.20%
	Dividend yield		—%	—%		—%
	Volatility factor		113.00%	112.90%		116.40%
	Expected term (in years)		6.7	7		4.4
	Weighted average estimated fair value per share		$16.09	$9.75		$9.00
	Risk-Free Interest Rate - The risk-free interest rate is the rate for periods equal to the expected term of the stock option based on either the Canadian Treasury yield (for grants prior to July 16, 2013), or U.S. Treasury zero-coupon bonds (for grants after July 16, 2013).
	Dividend Yield - The dividend yield is based on the Company’s history and expectation of dividend payouts. The Company has not paid, and does not intend to pay, dividends.
	Volatility Factor - The expected volatility assumption was determined by examining the historical volatility of the Company's stock.
	Expected Term - The expected term represents the weighted average period the stock options are expected to be outstanding. Prior to the fourth quarter of 2013, the Company estimated the life of the options using historical data as well as various assumptions regarding the Company's expected progress on its development programs. As a result of the Arrangement, beginning in the fourth quarter of 2013, the Company began to use the simplified method for estimating the expected term as provided by the Securities and Exchange Commission. The simplified method calculates the expected term as the average time-to-vesting and the contractual life of the options. The Company believes this methodology is more appropriate as the Company's historical stock option activity is no longer predictive of future activity due to the Arrangement, the Company's listing on NASDAQ and subsequent delisting from the TSX and the organizational changes announced on October 1, 2013.
	The total compensation cost not yet recognized as of December 31, 2014 related to non-vested option awards was $7.1 million which will be recognized over a weighted-average period of 1.5 years.
	2013 Employee Stock Purchase Plan
	In May 2013, the Company's Board of Directors adopted the ESPP. The ESPP was approved by the Company's stockholders in connection with the Arrangement. In December 2014, the ESPP became effective and the first purchase period began. The ESPP permits eligible employees to make payroll deductions to purchase up to $25,000 of the Company’s common stock on regularly scheduled purchase dates at a discount. Offering periods under the ESPP are not more than six months in duration and shares are purchased at 85% of the lower of the closing price for the Company’s common stock on the first day of the offering period or the date of purchase. The ESPP initially authorized the issuance of 300,000 shares of the Company’s common stock pursuant to rights granted to employees for their payroll deductions. As of December 31, 2014, no shares have yet been issued out of the plan.

EMPLOYEE_BENEFIT_PLAN

EMPLOYEE BENEFIT PLAN	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
EMPLOYEE BENEFIT PLAN	Employee Benefit Plan
	The Company has a defined contribution 401(k) plan (the Plan) for all employees. Employees are eligible to participate in the Plan if they are at least 21 years of age or older. Under the terms of the Plan, employees may make voluntary contributions as a percentage of compensation. The Company matches up to 4% of an employee's contributions, subject to a limit of $2,500 per year. During the years ended December 31, 2014, expense associated with the Company's matching contribution totaled $0.1 million and an immaterial amount for the years ended December 31, 2013 and 2012, respectively.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	Income Taxes
	The Company's provisions for income tax benefit (expense) are as follows (in thousands):
		Year ended December 31,
	Current:	2014			2013			2012
	Federal	$	—		$	23		$	(30	)
	State	—			—			(9		)
	Canada	—			—			—
	Total current tax expense (benefit)	$	—		$	23		$	(39	)
	Tax Expense or Benefit
	The differences between the effective income tax rate and the statutory tax rates during the years ended 2014, 2013 and 2012 are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Net loss before tax	$	(43,698	)	$	(52,882	)	$	(20,247	)
	Statutory combined US federal and state tax rate (2012 - statutory combined Canadian federal and provincial tax rate)	39.83		%	39.83		%	26.9		%
	Statutory federal and provincial taxes	$	(17,405	)	$	(21,063	)	$	(5,446	)
	Increase (decrease) in taxes recoverable resulting from:
	Effect of change in valuation allowance	12,273			8,537			5,145
	Non-deductible share-based compensation	930			1,085			539
	Non-deductible warrant expenses for tax purposes	1,799			8,403			—
	Tax credits	(180		)	(96		)	(70		)
	Share issue costs - temporary difference	(184		)	(184		)	(183		)
	Share issue costs - permanent difference	—			206			—
	Effect of foreign jurisdiction tax expense	—			—			39
	Differential in income tax rates of foreign subsidiary	3,047			3,059			—
	Other differences	(280		)	30			15
	Income tax expense (benefit)	$	—		$	(23	)	$	39
	The combined statutory tax rate used for fiscal 2014 and 2013 differs from the previous year due to the change in home jurisdiction under the consolidation process pursuant to the plan of arrangement agreement, which was consummated on June 28, 2013.
	Deferred Tax
	The following table summarizes the significant components of our deferred tax assets (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Tangible and intangible depreciable assets	$	185		$	874
	Stock compensation	2,360			—
	Manufactured drug product inventory to be used in research	1,425			1,459
	Provisions	554			93
	Financing fees	261			445
	Net operating loss carry forwards	23,243			13,099
	Scientific research and experimental development expenditures	5,715			5,766
	Research and development tax credits	266			—
	Total gross deferred tax assets	34,009			21,736
	Less valuation allowance	(34,009		)	(21,736		)
	Net deferred tax assets	$	—		$	—
	Total valuation allowance increased by $12.3 million for the year ended December 31, 2014. The Company has determined that it is more likely than not that it will not recognize the benefits of its US federal and state deferred tax assets and its Canadian federal and provincial deferred tax assets and, as a result, has established a full valuation allowance against its deferred tax assets as of December 31, 2014.
	For Canadian federal income tax purposes, the Company's Canadian federal scientific research and experimental development expenditures amounted to $20.1 million, $20.7 million and $15.2 million for the years ended December 31, 2014, 2013 and 2012, respectively and for provincial income tax purposes amounted to $22.7 million, $22.4 million and $16.8 million for the years ended December 31, 2014, 2013 and 2012, respectively. As operations in Canada ceased in during 2014, the expenditures incurred for the year ended December 31, 2014 were much lower than previous years. These expenditures are available to reduce future taxable income and have an unlimited carry forward period. Scientific research and development expenditures are subject to verification by the taxation authorities, and accordingly, these amounts may vary by a material amount.
	The Company also has accumulated share issue expenses that have not been deducted for income tax purposes amounting to approximately $1.0 million, $1.7 million and $2.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. The benefits of these expenses have not been recognized in the financial statements.
	The Company's net operating loss carry forwards, or NOLs, for US federal and state income taxes were $10.3 million and $9.5 million, respectively, for the year ended December 31, 2014. In addition, the Company has research and development tax credit carryforwards for federal and state income tax purposes as of December 31, 2014 of $0.2 million and $0.1 million, respectively. The Company's NOLs for Canadian federal and provincial income tax purposes, were $71.6 million and $71.0 million, respectively, for the year ended December 31, 2014.
	The NOLs are available to offset future taxable income from US federal and state tax sources and Canadian federal and provincial tax sources and the tax benefits of which have not been recognized in the consolidated financial statements. The NOLs expire as follows (in thousands):
		US						Canada
		Federal			State			Federal			Provincial
	Expires in:
	2030	$	—		$	—		$	5,907		$	5,985
	2031	—			—			7,059			7,066
	2032	—			—			13,312			12,433
	2033	3,261			2,286			18,623			19,385
	2034	7,012			7,185			26,741			26,149
		$	10,273		$	9,471		$	71,642		$	71,018
	The future utilization of the US federal and state NOLs carryforwards to offset future taxable income may be subject to an annual limitation as a result of ownership changes that may have occurred previously or may occur in the future. The Tax Reform Act of 1986, or the Act, limits a company's ability to utilize certain tax credit carryforwards and net operating loss carryforwards in the event of a cumulative change in ownerships in excess of 50% as defined in the Act. The Canadian Federal and Provincial Tax Acts maintain similar rules in the case of acquisition of control.
	The Company files income tax returns in the US (federal and state) and Canada (federal and provincial). The Company’s U.S. operations have not been audited for any open taxation years. The Company has experienced losses for U.S. tax purposes and therefore, the taxation authorities may review any loss year, if and when the losses are utilized.
	The Company's Canadian operations have been audited for provincial tax purposes up to and including December 31, 2009. For Canadian federal tax purposes, the Company remains subject to audit for the December 31, 2010 and subsequent taxation years. Where taxation years remain open, the Company considers it reasonably possible that issues may be raised or tax positions agreed to with the taxation authorities, which may result in increases or decreases of the balance of non-refundable ITCs and NOLs. However, an estimate of such increases and decreases cannot be currently made.
	A reconciliation of the beginning and ending amounts of unrecognized tax positions are as follows (in thousands):
		Federal									Provincial/State
		December 31,									December 31,
		2014			2013			2012			2014		2013		2012
Unrecognized tax positions, beginning of year	$	35		$	43		$	42		$	6	$	2	$	1
Gross decrease — current period tax positions	—			—			—			—		—		—
Gross increase — current period tax positions	35			—			1			12		—		1
Gross decrease — prior period tax positions	(28		)	(13		)	—			—		—		—
Gross increase — prior period tax positions	—			5			—			—		4		—
Unrecognized tax positions, end of year	$	42		$	35		$	43		$	18	$	6	$	2
Included in the balance of unrecognized tax positions at December 31, 2014 is $0.1 million and an immaterial amount for 2013 and 2012, that if recognized, would not impact the Company's income tax benefit or effective tax rate as long as the Company's deferred tax assets remain subject to a full valuation allowance. The Company does not expect any significant increases or decreases to the Company's unrecognized tax positions within the next 12 months.
The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense. The Company had no accrual for interest or penalties on tax matters as at December 31, 2014 and 2013 and the Company had no ongoing tax audits as of December 31, 2014.

INVESTMENT_TAX_CREDITS

INVESTMENT TAX CREDITS	12 Months Ended
	Dec. 31, 2014
INVESTMENT TAX CREDITS
INVESTMENT TAX CREDITS	Investment Tax Credits
	The Company is eligible to claim Canadian federal and provincial ITCs for eligible scientific research and development expenditures. The Company records ITCs based on management's best estimates of the amount to be recovered and ITCs claimed are subject to audit by the taxation authorities and accordingly, may vary by a material amount.
	The Company recorded provincial refundable ITCs as a reduction of research and development expenditures of $0.9 million and $1.7 million (including a $1.1 million favorable adjustment resulting from a statutory audit), for the years ended December 31, 2013 and 2012, respectively. The Company has an ongoing audit related to the provincial refundable ITCs for the year ended December 31, 2013. The Company did not record provincial refundable ITCs as a reduction of research and development expenditures for the year ended December 31, 2014 because the primary operations of the Company were moved from Canada to San Diego, California in early 2014.
	The Company's non-refundable Canadian federal ITCs as of December 31, 2014 are $3.9 million, and relate to scientific research and development expenditures, which may be utilized to reduce Canadian federal income taxes payable in future years. The benefits of the non-refundable Canadian federal ITCs have not been recognized in the financial statements and will be recorded as reduction of tax expense when realized.
	The non-refundable investment tax credits expire as follows (in thousands):
		FEDERAL ITC
	Expires in:
	2030	$	764
	2031	1,000
	2032	1,125
	2033	$	1,018
		$	3,907

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	Commitments and Contingencies
	On June 24, 2014, the Company entered into a lease agreement for approximately 18,000 square feet of completed office and laboratory space located in San Diego, California. The office space under the lease will serve as the Company's new corporate headquarters, replacing the current facilities. The lease will commence in three phases, with 2,300 square feet of space which commenced on July 1, 2014 at an initial monthly rent of approximately $5,900 per month, 14,000 square feet of space becoming available in the first quarter of 2015 at an initial monthly rent of $14,000 per month, and the final 1,600 square feet of space becoming available in the first quarter of 2016 at an initial monthly rent of approximately $4,200 per month.  Each portion of the leased property will be subject to a 3% annual rent increase following availability.  In addition to such base monthly rent, the Company will be obligated to pay triple net lease charges for operating expenses, taxes, insurance and utilities applicable to the leased property.  The lease will expire on January 31, 2018 with respect to the entire premises. Future minimum payments required under the lease are summarized as follows (in thousands):
	Year Ending December 31:
	2015	$	223
	2016	290
	2017	303
	2018	25
	Total minimum lease payments	$	841
	Total lease expense for the years ended December 31, 2014, 2013 and 2012 was $0.4 million, $0.4 million, and $0.3 million, respectively.

QUARTERLY_FINANCIAL_DATA_Notes

QUARTERLY FINANCIAL DATA (Notes)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	Selected Quarterly Financial Data (Unaudited)
	The following is a summary of the quarterly results of the Company for the years ended December 31, 2014 and 2013 (unaudited, in thousands, except for per share data):
		Quarted Ended												Year Ended
	2014:00:00	First			Second			Third			Fourth			December 31,
	Operating Loss	$	(7,979	)	$	(10,134	)	$	(10,548	)	$	(10,443	)	$	(39,104	)
	Net loss	$	(13,656	)	$	(11,038	)	$	(8,617	)	$	(10,387	)	$	(43,698	)
	Per common share:
	Loss per share, basic	$	(1.01	)	$	(0.82	)	$	(0.64	)	$	(0.77	)	$	(3.24	)
	Loss per share, diluted	$	(1.01	)	$	(0.82	)	$	(0.72	)	$	(0.77	)	$	(3.24	)
		Three Months Ended												Year Ended
	2013:00:00	First			Second			Third			Fourth			December 31,
	Operating Loss	$	(8,006	)	$	(6,898	)	$	(9,209	)	$	(7,886	)	$	(31,999	)
	Net loss	$	(4,217	)	$	(8,012	)	$	(29,398	)	$	(11,232	)	$	(52,859	)
	Per common share:
	Loss per share, basic	$	(0.42	)	$	(0.80	)	$	(2.95	)	$	(0.96	)	$	(4.78	)
	Loss per share, diluted	$	(0.68	)	$	(0.80	)	$	(2.95	)	$	(0.96	)	$	(4.78	)

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	Subsequent Events
	Sale of Common Stock
	In February 2015, the Company completed a follow-on offering whereby it issued an aggregate 2,587,500 shares of common stock at $20.00 per share. Proceeds from the follow-on offering, net of underwriting discounts, commissions and offering expenses, were approximately $48.2 million.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation
	These consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States ("GAAP"). These consolidated financial statements include the accounts of the Company, MethylGene and MethylGene US Inc. All significant inter-company transactions, balances and expenses have been eliminated upon consolidation.
	Mirati was incorporated under the laws of the State of Delaware on April 29, 2013. The Company was created to enter into an arrangement agreement described below.
	On May 8, 2013, the Company's Board of Directors approved and the Company entered into an arrangement agreement with MethylGene. Subject to the terms and conditions of the arrangement agreement, which was consummated on June 28, 2013, the shareholders of MethylGene received one share of the Company's common stock in exchange for every 50 common shares of MethylGene, which had the effect of a 50 for 1 reverse split of the common shares pursuant to a court-approved plan of arrangement under Section 192 of the Canada Business Corporations Act. Such transaction is referred to herein as the Arrangement. In addition, all outstanding options and warrants to purchase common shares of MethylGene became exercisable on a 50-for-1 basis for shares of our common stock, and a proportionate adjustment was made to the exercise price or conversion price, as applicable. The accompanying financial statements and notes to the financial statements give retroactive effect to the reverse split of our common stock for all periods presented. Upon completion of the Arrangement, MethylGene became the Company's wholly-owned subsidiary. The shares of the Company's common stock issued at the closing of the Arrangement were issued in reliance upon the exemption from registration under Section 3(A)(10) of the Securities Act of 1933, as amended.
	These consolidated financial statements are presented in U.S. dollars, which effective January 1, 2013, is also the functional currency of the Company.
Use of Estimates	Use of Estimates
	The preparation of the Company's audited consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period.
	Reported amounts and note disclosures reflect the overall economic conditions that are most likely to occur and anticipated measures management intends to take. Actual results could differ materially from those estimates. Estimates and assumptions are reviewed quarterly. Any revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.
Cash and cash equivalents	Cash, Cash Equivalents and Short-term Investments
	Cash and cash equivalents consist of cash and highly liquid securities with original maturities of ninety days or less. Investments with an original maturity of more than ninety days are considered short-term investments and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income, if any, are determined on a specific identification basis.
Concentration of Credit Risk	Concentration of Credit Risk
	The Company invests its excess cash in accordance with its investment policy. The Company's investments are comprised primarily of commercial paper and debt instruments of financial institutions, corporations, U.S. government-sponsored agencies and the U.S. Treasury. The Company mitigates credit risk by maintaining a diversified portfolio and limiting the amount of investment exposure as to institution, maturity and investment type. Financial instruments that potentially subject the Company to significant credit risk consist principally of cash equivalents and short-term investments.
Foreign currency translation	Foreign Currency Transactions
	Foreign currency transactions are initially recorded by the Company using the exchange rates prevailing at the date of the transaction. At the balance sheet date, monetary assets and liabilities denominated in foreign currencies are translated at the period-end rates of exchange. Non-monetary assets and liabilities are translated at the historical exchange rates. Exchange gains and losses arising from the translation of foreign currency items are included in other income (expense) in the consolidated statements of operations and comprehensive loss.
Property and equipment	Property and Equipment
	Property and equipment is stated at historical cost less accumulated depreciation. Historical cost includes expenditures that are directly attributable to the acquisition of the items. All repairs and maintenance are charged to net loss during the financial period in which they are incurred.
	Depreciation of property and equipment is calculated using the straight-line method over the estimated useful lives of the assets, as follows:
	Computer equipment		3 years
	Office and other equipment		6 years
	Laboratory equipment		6 years
	Leasehold improvements		The lesser of the lease term or the life of the asset
	On disposal or impairment of property and equipment, the cost and related accumulated depreciation is removed from the consolidated financial statements and the net amount, less any proceeds, is included in net loss.
Impairment of long-lived assets	Impairment of Long-Lived Assets
	The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset 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. Fair value is estimated through discounted cash flow models to project cash flows from the asset.
Reclassification of warrants	Reclassification of Warrants
	In 2011 and 2012, MethylGene issued common stock warrants in connection with the issuance of common stock through private placements (referred to as the 2011 Warrants and the 2012 Warrants). The exercise prices of the 2011 and 2012 Warrants were denominated in Canadian dollars. Upon the issuance of the 2011 and 2012 Warrants, the net proceeds were allocated to common stock and warrants based on their relative fair values, and the fair value of the issued common stock warrants was calculated utilizing the Black-Scholes option-pricing model. The allocated fair value was then recorded as warrants within stockholders’ equity on the consolidated balance sheet.
	Effective January 1, 2013, the Company changed its functional currency which changed how the 2011 and 2012 warrants are accounted for as they continued to have exercise prices denominated in Canadian dollars. Upon the change in functional currency, the warrants were classified as a current liability and a warrant liability of $16.2 million which represented the fair market value of the warrants at that date in accordance with accounting standards. The initial fair value recorded as warrants within stockholders’ equity of $11.2 million was reversed. The change in fair value related to periods prior to January 1, 2013 of $5.0 million was recorded as an adjustment to accumulated deficit. At each reporting period subsequent to January 1, 2013, the fair value of the warrant liability was recalculated and any corresponding increase or decrease to the warrant liability was recorded as change in fair value of warrant liability on the consolidated statement of operations and comprehensive loss. The estimated fair value was determined using the Black-Scholes option-pricing model based on the estimated value of the underlying common stock at the valuation measurement date, the remaining contractual term of the warrants, risk-free interest rates, expected dividends and expected volatility of the price of the underlying common stock.
	During the second half of 2014, the Company amended all of its outstanding warrant agreements to allow for the warrants to be denominated in U.S. Dollars. As a result of this amendment, the amended warrants qualified for equity classification and were reclassified into stockholders’ equity at their fair value as of the amendment date and revaluations of fair value are no longer required.
Reclassification of share-based compensation liability	Reclassification of Share-Based Compensation Liability
	The Company granted stock options denominated in Canadian dollars under its 1997 Equity Plan to Canadian and United States, or US, based employees and directors until July 26, 2013. Following the delisting of the Company’s shares from the Toronto Stock Exchange, the options denominated in Canadian dollars that were granted to US-based employees and US-based directors were subject to liability accounting ("liability options") with fair value calculated using the Black-Scholes option-pricing model. The Company revalued the liability options as of July 26, 2013 and recorded a share-based compensation liability of $1.1 million with a corresponding reduction of additional paid-in capital.
	At each reporting period subsequent to July 26, 2013, the Company adjusted the fair value of the liability options and any corresponding increase or decrease to the liability was recorded as either a reduction of additional paid in capital or as stock compensation expense on the consolidated statement of operations and comprehensive loss, as appropriate.
Share-based compensation	Share-Based Compensation
	The Company has a stock option compensation plan in which the fair value of stock options granted is determined at the date of the grant using the Black-Scholes option-pricing model and is expensed over the vesting period of the options. Share-based compensation is recognized using the graded accelerated vesting method. In determining the expense, the Company deducts the number of options that are expected to be forfeited at the time of a grant and revises this estimate, if necessary, in subsequent years if actual forfeitures differ from those estimated.
Investment tax credits	Investment Tax Credits
	The Company's accounts include claims for investment tax credits ("ITCs") relating to scientific research and experimental development activities of the Company. The qualification and recording of these activities for investment tax credit purposes are established by the Canadian federal and Provincial Tax Acts and are subject to audit by the taxation authorities. Refundable ITCs are reflected as reductions of expenses or reductions of the cost of the assets to which they relate when there is reasonable assurance that the assistance will be received and all conditions have been complied with. The non-refundable ITCs are carried forward for a time and will be recognized when it is more likely than not that the Company will become subject to Canadian federal taxes, at which time, said ITCs are applied as a reduction of tax expense.
Research and development expenses	Research and Development Expenses
	Research and development expenditures are charged to net loss in the period in which they are incurred and are comprised of the following types of costs incurred in performing research and development activities: salaries and benefits, share-based compensation expense, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs.
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 applicable 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 consolidated financial statements.
Segment Reporting	Segment Reporting
	Operating segments are components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker for purposes of making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating primarily in the United States.
Fair value measurements	Fair Value Measurements
	The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.
	The authoritative guidance for fair value measurements defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or the most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact, and (iv) willing to transact. The guidance prioritizes the inputs used in measuring fair value into the following hierarchy:
	•	Level 1- Quoted prices (unadjusted) in active markets for identical assets or liabilities;
	•	Level 2- Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable; and
	•	Level 3- Unobservable inputs in which little or no market activity exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing.
	The following table summarizes the assets and liabilities measured at fair value on a recurring basis (in thousands):
		December 31,				Level 1			Level 2		Level 3
		2014
	Assets
	Cash and cash equivalents	$	6,593			$	4,590		$	2,003	$	—
	Short-term investments	22,710				—			22,710		—
		$	29,303			$	4,590		$	24,713	$	—
		December 31,				Level 1			Level 2		Level 3
		2013
	Assets
	Cash and cash equivalents	$	14,235			$	12,431		$	1,804	$	—
	Short-term investments	47,835				—			47,835		—
		$	62,070			$	12,431		$	49,639	$	—
	Liabilities
	Warrant liability	$	33,407			$	—		$	—	$	33,407
		$	33,407			$	—		$	—	$	33,407
	The Company’s investments in Level 1 assets are valued based on publicly available quoted market prices for identical securities as of December 31, 2014 and December 31, 2013. The Company determines the fair value of Level 2 related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. There were no transfers between fair value measurement levels for the years ended December 31, 2014 and 2013.
	The following table presents a rollforward of the fair value of the warrant liability, which included Level 3 measurements (in thousands):
			Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3)
	Warrant liability:
	Balance at January 1, 2013		$	—
	Fair value upon reclassification of balance as of January 1, 2013		16,194
	Change in fair value of warrant liability		19,799
	included in net loss
	Fair value of warrants exercised		(2,586		)
	Balance at December 31, 2013		33,407
	Change in fair value of warrant liability included in net loss		4,517
	Fair value of warrants exercised		(993		)
	Reclassification of warrants to stockholders' equity		(36,931		)
	Balance at December 31, 2014		$	—
	The Company estimated the fair value of warrants at the time of issuance and subsequent remeasurement through the date of reclassification into equity using the Black-Scholes option-pricing model at each reporting date, using the following inputs: the risk-free interest rates; the expected dividend rates; the remaining expected life of the warrants; and the expected volatility of the price of the underlying common stock. The estimates are based, in part, on subjective assumptions and changes to these assumptions could have a significant impact on the fair value of the warrants.
	The following assumptions were used in the Black-Scholes option-pricing model as of the warrant amendments dates to determine the fair value of the warrants to reclassify into equity:
			Sep-14					Dec-14
			2011 Warrants			2012 Warrants		2011 Warrants
	Risk-free interest rate		1.2	%		1.2	%	1	%
	Volatility		108.6	%		100.8	%	62.8% - 63.9%
	Dividend yield		—			—		—
	Expected life in years		1.6			3.2		1.3
	The following assumptions were used in the Black-Scholes option-pricing model to determine the fair value of the warrant liability as of December 31, 2013. All 2011 and 2012 warrants were amended and did not require a valuation as of December 31, 2014.
			31-Dec-13
			2011 Warrants			2012 Warrants
	Risk-free interest rate		1.2	%		1.6	%
	Volatility		112	%		115.9	%
	Dividend yield		—			—
	Expected life in years		2.3			3.9
Net loss per share	Net Loss Per Share
	Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. Common share equivalents outstanding, determined using the treasury stock method, are comprised of shares that may be issued under the Company’s stock option and warrant agreements.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of estimated useful lives of assets	Depreciation of property and equipment is calculated using the straight-line method over the estimated useful lives of the assets, as follows:
	Computer equipment		3 years
	Office and other equipment		6 years
	Laboratory equipment		6 years
	Leasehold improvements		The lesser of the lease term or the life of the asset
Schedule of assets and liabilities that are measured at fair value on a recurring basis
		December 31,				Level 1			Level 2		Level 3
		2014
	Assets
	Cash and cash equivalents	$	6,593			$	4,590		$	2,003	$	—
	Short-term investments	22,710				—			22,710		—
		$	29,303			$	4,590		$	24,713	$	—
		December 31,				Level 1			Level 2		Level 3
		2013
	Assets
	Cash and cash equivalents	$	14,235			$	12,431		$	1,804	$	—
	Short-term investments	47,835				—			47,835		—
		$	62,070			$	12,431		$	49,639	$	—
	Liabilities
	Warrant liability	$	33,407			$	—		$	—	$	33,407
		$	33,407			$	—		$	—	$	33,407
Schedule of rollforward of the fair value of the liability which includes Level 3 measurements	The following table presents a rollforward of the fair value of the warrant liability, which included Level 3 measurements (in thousands):
			Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3)
	Warrant liability:
	Balance at January 1, 2013		$	—
	Fair value upon reclassification of balance as of January 1, 2013		16,194
	Change in fair value of warrant liability		19,799
	included in net loss
	Fair value of warrants exercised		(2,586		)
	Balance at December 31, 2013		33,407
	Change in fair value of warrant liability included in net loss		4,517
	Fair value of warrants exercised		(993		)
	Reclassification of warrants to stockholders' equity		(36,931		)
	Balance at December 31, 2014		$	—
Schedule of assumptions used to calculate fair value of the liability	The following assumptions were used in the Black-Scholes option-pricing model as of the warrant amendments dates to determine the fair value of the warrants to reclassify into equity:
			Sep-14					Dec-14
			2011 Warrants			2012 Warrants		2011 Warrants
	Risk-free interest rate		1.2	%		1.2	%	1	%
	Volatility		108.6	%		100.8	%	62.8% - 63.9%
	Dividend yield		—			—		—
	Expected life in years		1.6			3.2		1.3
	The following assumptions were used in the Black-Scholes option-pricing model to determine the fair value of the warrant liability as of December 31, 2013. All 2011 and 2012 warrants were amended and did not require a valuation as of December 31, 2014.
			31-Dec-13
			2011 Warrants			2012 Warrants
	Risk-free interest rate		1.2	%		1.6	%
	Volatility		112	%		115.9	%
	Dividend yield		—			—
	Expected life in years		2.3			3.9
Schedule of potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive	The following table presents the weighted average number of potentially dilutive securities not included in the calculation of diluted net loss per share due to the anti-dilutive effect of the securities:
			Year ended
			December 31,
			2014			2013		2012
	Common stock options		253,595			495		15,663
	Common stock warrants		1,515,445			644,426		690,046
	Total		1,769,040			644,921		705,709

INVESTMENTS_Tables

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale and Trading Securities Reconciliation	The following tables summarize our short-term investments (in thousands):
			As of December 31, 2014
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Corporate debt securities (1)	1 year or less	21,208	3	(1	)	21,210
	Commercial paper (1)	1 year or less	1,500	—	—		1,500
			22,708	3	(1	)	22,710
			As of December 31, 2013
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Government sponsored enterprise (1)	2 years or less	3,001	—	(3	)	2,998
	Corporate debt securities (1)	2 years or less	31,319	—	(22	)	31,297
	Commercial paper (1)	1 year or less	8,485	12	—		8,497
	Guaranteed investment certificates (2)	1 year or less	5,046	—	(3	)	5,043
			47,851	12	(28	)	47,835
	(1) Investments are designated as available-for-sale investments.
	(2) Investments are designated as trading investments.

OTHER_CURRENT_ASSETS_Tables

OTHER CURRENT ASSETS (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of other current assets	Other current assets consisted of the following (in thousands):
		December 31,
		2014		2013
		(in thousands)
	Prepaid expenses	1,827		667
	Refundable research and development tax credits	809		809
	Security deposits and other receivables	622		506
	Interest receivables	96		163
		$	3,354	$	2,145

PROPERTY_AND_EQUIPMENT_Tables

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Property and equipment consisted of the following (in thousands):
		December 31,
		2014			2013
		(in thousands)
	Computer equipment	$	329		$	1,534
	Office and other equipment	56			122
	Laboratory equipment	346			1,794
	Leasehold improvements	—			53
		$	731		$	3,503
	Less: Accumulated depreciation	(235		)	(3,181		)
		$	496		$	322

ACCOUNTS_PAYABLE_AND_ACCRUED_L1

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Schedule of accounts payable and accrued liabilities	Accounts payable and accrued liabilities consisted of the following (in thousands):
		December 31,
		2014		2013
		(in thousands)
	Accounts payable	$	1,655	$	1,302
	Accrued expenses	2,327		2,335
	Accrued compensation and benefits	1,414		1,608
		$	5,396	$	5,245

RESTRUCTURING_Tables

RESTRUCTURING (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Restructuring and related costs	Restructuring costs were comprised of employee separation and facilities closure related costs and were reported as a separate line item in the accompanying consolidated statement of operations and comprehensive loss. A rollforward of the accrued restructuring liability is presented below (in thousands):
	Balance as of October 1, 2013	$	—
	Accrued restructuring charges	1,025
	Payments	(729		)
	Balance as of December 31, 2013	296
	Accrued restructuring charges	334
	Payments	(630		)
	Balance as of December 31, 2014	$	—

STOCKHOLDERS_EQUITY_Tables

STOCKHOLDERS' EQUITY (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Schedule of Shares Reserved for Future Issuance	As of December 31, 2014, the following shares were reserved for future issuance:
		December 31,
		2014
	Common stock options outstanding and available for future grant	1,891,107
	Warrants to purchase common stock	2,465,713
	Employee Stock Purchase Plan	300,000
		4,656,820
Schedule of warrants issued and outstanding	As of December 31, 2014 the following warrants for common stock were issued and outstanding:
	Issue date		Expiration date	Exercise price (Denominated in US Dollars)		Number of warrants outstanding
	April 4, 2011		April 4, 2016	$	6.74	1,397,921
	November 21, 2012		November 21, 2017	$	7.86	1,067,792
						2,465,713

STOCKBASED_COMPENSATION_STOCKB

STOCK-BASED COMPENSATION STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of changes to the number of stock options granted by the Company and their weighted average exercise price	The following table summarizes our stock option activity and related information for the year ended December 31, 2014:
		Number of		Weighted			Weighted-Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (millions)
		options		average
				exercise
				price
	Balance, December 31, 2013	968,923		$	11.13
	Granted	599,410		$	18.64
	Exercised	(76,224	)	$	11.2
	Canceled/forfeited	(34,640	)	$	15.44
	Expired	(2,609	)	$	55.8
	Balance, December 31, 2014	1,454,860		$	14
	Options exercisable at December 31, 2014	431,088		$	12.25		7		$	3.21
	Options vested and expected to vest at December 31, 2014	1,383,082		$	14.89		8.1		$	6.83
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	Total share-based compensation expense by operating statement classification is presented below (in thousands):
		Year ended December 31,
		2014			2013			2012
	Research and development expense	$	2,565		$	245		$	817
	General and administrative expense	4,485			2,947			1,192
		$	7,050		$	3,192		$	2,009
Schedule of assumptions used to estimate the fair value of options granted at the date of grant using the Black-Scholes option pricing model	The assumptions used for the specified reporting periods and the resulting estimates of weighted-average estimated fair value per share of options granted during those periods are as follows:
			Year Ended
			December 31,
			2014	2013		2012
	Risk-free interest rate		2.10%	2.00%		1.20%
	Dividend yield		—%	—%		—%
	Volatility factor		113.00%	112.90%		116.40%
	Expected term (in years)		6.7	7		4.4
	Weighted average estimated fair value per share		$16.09	$9.75		$9.00

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense	The Company's provisions for income tax benefit (expense) are as follows (in thousands):
		Year ended December 31,
	Current:	2014			2013			2012
	Federal	$	—		$	23		$	(30	)
	State	—			—			(9		)
	Canada	—			—			—
	Total current tax expense (benefit)	$	—		$	23		$	(39	)
Schedule of Effective Income Tax Reconciliation	The differences between the effective income tax rate and the statutory tax rates during the years ended 2014, 2013 and 2012 are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Net loss before tax	$	(43,698	)	$	(52,882	)	$	(20,247	)
	Statutory combined US federal and state tax rate (2012 - statutory combined Canadian federal and provincial tax rate)	39.83		%	39.83		%	26.9		%
	Statutory federal and provincial taxes	$	(17,405	)	$	(21,063	)	$	(5,446	)
	Increase (decrease) in taxes recoverable resulting from:
	Effect of change in valuation allowance	12,273			8,537			5,145
	Non-deductible share-based compensation	930			1,085			539
	Non-deductible warrant expenses for tax purposes	1,799			8,403			—
	Tax credits	(180		)	(96		)	(70		)
	Share issue costs - temporary difference	(184		)	(184		)	(183		)
	Share issue costs - permanent difference	—			206			—
	Effect of foreign jurisdiction tax expense	—			—			39
	Differential in income tax rates of foreign subsidiary	3,047			3,059			—
	Other differences	(280		)	30			15
	Income tax expense (benefit)	$	—		$	(23	)	$	39
Schedule of deferred tax	The following table summarizes the significant components of our deferred tax assets (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Tangible and intangible depreciable assets	$	185		$	874
	Stock compensation	2,360			—
	Manufactured drug product inventory to be used in research	1,425			1,459
	Provisions	554			93
	Financing fees	261			445
	Net operating loss carry forwards	23,243			13,099
	Scientific research and experimental development expenditures	5,715			5,766
	Research and development tax credits	266			—
	Total gross deferred tax assets	34,009			21,736
	Less valuation allowance	(34,009		)	(21,736		)
	Net deferred tax assets	$	—		$	—
Schedule of expiration of NOLs	The NOLs expire as follows (in thousands):
		US						Canada
		Federal			State			Federal			Provincial
	Expires in:
	2030	$	—		$	—		$	5,907		$	5,985
	2031	—			—			7,059			7,066
	2032	—			—			13,312			12,433
	2033	3,261			2,286			18,623			19,385
	2034	7,012			7,185			26,741			26,149
		$	10,273		$	9,471		$	71,642		$	71,018
Schedule of reconciliation of the beginning and ending gross amounts of unrecognized tax positions	A reconciliation of the beginning and ending amounts of unrecognized tax positions are as follows (in thousands):
		Federal									Provincial/State
		December 31,									December 31,
		2014			2013			2012			2014		2013		2012
	Unrecognized tax positions, beginning of year	$	35		$	43		$	42		$	6	$	2	$	1
	Gross decrease — current period tax positions	—			—			—			—		—		—
	Gross increase — current period tax positions	35			—			1			12		—		1
	Gross decrease — prior period tax positions	(28		)	(13		)	—			—		—		—
	Gross increase — prior period tax positions	—			5			—			—		4		—
	Unrecognized tax positions, end of year	$	42		$	35		$	43		$	18	$	6	$	2

INVESTMENT_TAX_CREDITS_Tables

INVESTMENT TAX CREDITS (Tables)	12 Months Ended
	Dec. 31, 2014
INVESTMENT TAX CREDITS
Schedule of non-refundable investment tax credits expiration	The non-refundable investment tax credits expire as follows (in thousands):
		FEDERAL ITC
	Expires in:
	2030	$	764
	2031	1,000
	2032	1,125
	2033	$	1,018
		$	3,907

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum annual payment required in the next year	Future minimum payments required under the lease are summarized as follows (in thousands):
	Year Ending December 31:
	2015	$	223
	2016	290
	2017	303
	2018	25
	Total minimum lease payments	$	841

QUARTERLY_FINANCIAL_DATA_Table

QUARTERLY FINANCIAL DATA (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Data	The following is a summary of the quarterly results of the Company for the years ended December 31, 2014 and 2013 (unaudited, in thousands, except for per share data):
		Quarted Ended												Year Ended
	2014:00:00	First			Second			Third			Fourth			December 31,
	Operating Loss	$	(7,979	)	$	(10,134	)	$	(10,548	)	$	(10,443	)	$	(39,104	)
	Net loss	$	(13,656	)	$	(11,038	)	$	(8,617	)	$	(10,387	)	$	(43,698	)
	Per common share:
	Loss per share, basic	$	(1.01	)	$	(0.82	)	$	(0.64	)	$	(0.77	)	$	(3.24	)
	Loss per share, diluted	$	(1.01	)	$	(0.82	)	$	(0.72	)	$	(0.77	)	$	(3.24	)
		Three Months Ended												Year Ended
	2013:00:00	First			Second			Third			Fourth			December 31,
	Operating Loss	$	(8,006	)	$	(6,898	)	$	(9,209	)	$	(7,886	)	$	(31,999	)
	Net loss	$	(4,217	)	$	(8,012	)	$	(29,398	)	$	(11,232	)	$	(52,859	)
	Per common share:
	Loss per share, basic	$	(0.42	)	$	(0.80	)	$	(2.95	)	$	(0.96	)	$	(4.78	)
	Loss per share, diluted	$	(0.68	)	$	(0.80	)	$	(2.95	)	$	(0.96	)	$	(4.78	)

SUMMARY_OF_SIGNIFICANT_ACCOUNT3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 28, 2013	Nov. 30, 2013	Jul. 26, 2013	Jan. 02, 2013
Foreign currency translation
Net foreign exchange losses recognized in other income	($200,000)	$1,300,000
Reclassification of Warrants
Warrant liability	0	33,407,000					16,200,000
Initial fair value of warrants recorded within stockholders equity that was reversed							11,200,000
Change in fair value related to periods prior to January 1, 2013 recorded as an increase to accumulated deficit							5,000,000
Change in fair value of warrant liability included in net loss	4,517,000	19,799,000	0
Reclassification of Share-based compensation liability
Share-based compensation liability						1,100,000
Increase in additional paid-in capital due to reclassification of share-based compensation liability		300,000
Increase in stock compensation expense		1,400,000
Fair value of liability options					$2,200,000
MethylGene
Basis of presentation
Ratio of reverse split of the common shares				50
Exercisable ratio of outstanding options and warrants				50

SUMMARY_OF_SIGNIFICANT_ACCOUNT4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2)	12 Months Ended
	Dec. 31, 2014
Computer equipment
Property and equipment
Estimated useful lives	3 years
Office and other equipment
Property and equipment
Estimated useful lives	6 years
Laboratory equipment
Property and equipment
Estimated useful lives	6 years

SUMMARY_OF_SIGNIFICANT_ACCOUNT5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share (in shares)	1,769,040	644,921	705,709
Common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share (in shares)	253,595	495	15,663
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share (in shares)	1,515,445	644,426	690,046

SUMMARY_OF_SIGNIFICANT_ACCOUNT6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jan. 02, 2013
In Thousands, unless otherwise specified
Liabilities
Warrant liability	$0	$33,407	$16,200
Recurring basis | Total
Assets
Cash and cash equivalents	6,593	14,235
Short-term investments	22,710	47,835
Assets	29,303	62,070
Liabilities
Warrant liability		33,407
Liabilities		33,407
Recurring basis | Level 1
Assets
Cash and cash equivalents	4,590	12,431
Short-term investments	0	0
Assets	4,590	12,431
Liabilities
Warrant liability		0
Liabilities		0
Recurring basis | Level 2
Assets
Cash and cash equivalents	2,003	1,804
Short-term investments	22,710	47,835
Assets	24,713	49,639
Liabilities
Warrant liability		0
Liabilities		0
Recurring basis | Level 3
Assets
Cash and cash equivalents	0	0
Short-term investments	0	0
Assets	0	0
Liabilities
Warrant liability		33,407
Liabilities		$33,407

SUMMARY_OF_SIGNIFICANT_ACCOUNT7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of year:	$33,407	$0
Fair value upon reclassification of balance as of January 1, 2013		16,194
Change in fair value of warrant liability included in net loss	4,517	19,799	0
Fair value of warrants exercised	-993	-2,586
Balance at end of year:	0	33,407	0
Common stock warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability, Reclassification to Equity	($36,931)

SUMMARY_OF_SIGNIFICANT_ACCOUNT8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 6)	0 Months Ended	1 Months Ended	12 Months Ended
	Sep. 12, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate (as a percent)	1.20%
Volatility (as a percent)	100.80%
Dividend yield (as a percent)	0.00%
Expected life	3 years 2 months 12 days
2011 Warrants
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate (as a percent)	1.20%	1.00%	1.20%
Volatility (as a percent)	108.60%		112.00%
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Expected life	1 year 7 months 6 days	1 year 3 months 18 days	2 years 3 months 18 days
2012 Warrants
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate (as a percent)			1.60%
Volatility (as a percent)			115.90%
Dividend yield (as a percent)			0.00%
Expected life			3 years 10 months 24 days
Minimum | 2011 Warrants
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Volatility (as a percent)		62.80%
Maximum | 2011 Warrants
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Volatility (as a percent)		63.90%

INVESTMENTS_Details

INVESTMENTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$22,708		$47,851
Gross unrealized gains	3		12
Gross unrealized losses	-1		-28
Estimated fair value	22,710		47,835
U.S. Treasury securities and debt securities of U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period			2 years	[1]
Available-for-Sale, Amortized cost			3,001	[1]
Available-for-Sale, Gross unrealized gains			0	[1]
Available-for-Sale, Gross unrealized losses			-3	[1]
Available-for-Sale, Estimated fair value			2,998	[1]
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period	1 year	[1]	2 years	[1]
Available-for-Sale, Amortized cost	21,208	[1]	31,319	[1]
Available-for-Sale, Gross unrealized gains	3	[1]	0	[1]
Available-for-Sale, Gross unrealized losses	-1	[1]	-22	[1]
Available-for-Sale, Estimated fair value	21,210	[1]	31,297	[1]
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period	1 year	[1]	1 year	[1]
Available-for-Sale, Amortized cost	1,500	[1]	8,485	[1]
Available-for-Sale, Gross unrealized gains	0	[1]	12	[1]
Available-for-Sale, Gross unrealized losses	0	[1]	0	[1]
Available-for-Sale, Estimated fair value	1,500	[1]	8,497	[1]
Guaranteed investment certificates
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading, maximum maturity period			1 year	[2]
Trading, Amortized cost			5,046	[2]
Trading, Gross unrealized gains			0	[2]
Trading, Gross unrealized losses			-3	[2]
Trading, Estimated fair value			$5,043	[2]
[1]	Investments are designated as available-for-sale investments.
[2]	Investments are designated as trading investments.

OTHER_CURRENT_ASSETS_Details

OTHER CURRENT ASSETS (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$1,827	$667
Refundable research and development tax credits	809	809
Security deposits and other receivables	622	506
Interest receivables	96	163
Other current assets	$3,354	$2,145

PROPERTY_AND_EQUIPMENT_Details

PROPERTY AND EQUIPMENT (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and equipment
Property and equipment, gross	$731	$3,503
Less: Accumulated depreciation	-235	-3,181
Property and equipment, net	496	322
Depreciation expenses	199	171	123
Computer equipment
Property and equipment
Property and equipment, gross	329	1,534
Office and other equipment
Property and equipment
Property and equipment, gross	56	122
Laboratory equipment
Property and equipment
Property and equipment, gross	346	1,794
Leasehold improvements
Property and equipment
Property and equipment, gross	$0	$53

ACCOUNTS_PAYABLE_AND_ACCRUED_L2

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accounts payable	$1,655	$1,302
Accrued expenses	2,327	2,335
Accrued compensation and benefits	1,414	1,608
Total accounts payable and accrued liabilities	$5,396	$5,245

RESTRUCTURING_Details

RESTRUCTURING (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring and Related Activities [Abstract]
Percentage of workforce positions eliminated		75.00%
Restructuring Reserve [Rollforward]
Restructuring reserve at beginning of period	$0	$296
Accrued restructuring charges	1,025	334	1,025	0
Payments	-729	-630
Restructuring reserve at end of period	$296	$0	$296

STOCKHOLDERS_EQUITY_Details

STOCKHOLDERS' EQUITY (Details)	Dec. 31, 2014
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	4,656,820
Warrants to purchase common stock
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	2,465,713
Stock Option Plan
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	1,891,107
Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	300,000

STOCKHOLDERS_EQUITY_Details_2

STOCKHOLDERS' EQUITY (Details 2)	0 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 12, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Apr. 04, 2011	Dec. 31, 2014	Nov. 21, 2012
			USD ($)	USD ($)	Common Stock	Common Stock	Common Stock	Private Placement April 2011	Private Placement April 2011	Private Placement November 2012	Private Placement November 2012
						USD ($)	USD ($)	April 4, 2011 Warrants	April 4, 2011 Warrants	November 21, 2012 Warrants	November 21, 2012 Warrants
Warrants - issued and outstanding
Exercise price (in dollars per share)								6.74	7.46	7.86	8.7
Number of warrants (in shares)		2,465,713						1,397,921		1,067,792
Number of warrants exercised (in shares)		73,964
Net exercise of warrants (in shares)		43,526			43,526	108,321	5,653
Assumptions used for calculation of fair value of warrants issued
Weighted average risk-free interest rate (as a percent)	1.20%
Volatility factor (as a percent)	100.80%
Expected life	3 years 2 months 12 days
Fair value of warrants				$4,942
Amount recorded as increase in common stock			$54,196	$19,886		$3	$4

STOCKBASED_COMPENSATION_Detail

STOCK-BASED COMPENSATION (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	31-May-13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options available for issue	400,000
Intrinsic value of options exercised	$600,000	$200,000	$0
Cash received from exercise of stock options	900,000	500,000
Exercise of options (in shares)	76,224
Fair value of options vested	3,000,000	2,000,000	2,400,000
Capitalized costs	0	0	0
Tax benefit from compensation expense	0		0
Compensation cost not yet recognized	7,100,000
Compensation cost not yet recognized, period for recognition	1 year 5 months 24 days
Exercise price required percentage of fair market value	100.00%
Award vesting period	4 years
Stock Option Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual terms	5 years
Stock Option Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual terms	7 years
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, Shares Authorized for Purchase	$25,000
Employee Stock Purchase Plan, Purchase Discount, Percent	85.00%
Employee Stock Purchase Plan, Shares Reserved for Future Issuance				300,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	0
2013 Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual terms	7 years
2013 Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual terms	10 years

STOCKBASED_COMPENSATION_Detail1

STOCK-BASED COMPENSATION (Details 2) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, beginning of year (in shares)	968,923
Granted (in shares)	599,410
Exercise of options (in shares)	-76,224
Canceled (in shares)	-34,640
Expired (in shares)	-2,609
Balance, end of year (in shares)	1,454,860
Options exercisable, end of year (in shares)	431,088
Vested and unvested expected to vest options outstanding (in shares)	1,383,082
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance, beginning of year (in dollars per share)	$11.13
Granted (in dollars per share)	$18.64
Exercised (in dollars per share)	$11.20
Canceled (in dollars per share)	$15.44
Expired (in dollars per share)	$55.80
Balance, end of year (in dollars per share)	$14
Options exercisable, end of year (in dollars per share)	$12.25
Vested and unvested expected to vest options outstanding, Weighted-Average Exercise Price (in dollars per share)	$14.89
Options exercisable, Weighted-Average Remaining Contractual Term (years)	7 years
Options vested and expected to vest, Weighted-Average Remaining Contractual Term (years)	8 years 1 month
Options exercisable, Aggregate Intrinsic Value	$3.21
Options vested and expected to vest, Aggregate Intrinsic Value	$6.83

STOCKBASED_COMPENSATION_Detail2

STOCK-BASED COMPENSATION (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$7,050	$3,192	$2,009
Research and development expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,565	245	817
General and administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$4,485	$2,947	$1,192

STOCKBASED_COMPENSATION_Detail3

STOCK-BASED COMPENSATION (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.10%	2.00%	1.20%
Dividend yield	0.00%	0.00%	0.00%
Volatility factor	113.00%	112.90%	116.40%
Expected term (in years)	6 years 8 months	7 years	4 years 4 months 24 days
Weighted average estimated fair value per share	$16.09	$9.75	$9

EMPLOYEE_BENEFIT_PLAN_Details

EMPLOYEE BENEFIT PLAN (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Percentage of employee contributions matched	4.00%
Maximum employer contribution per employee	$2,500
Matching contribution amount	$100,000

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	ongoing_tax_audit
Current income tax expense
Federal	$0	$23,000	($30,000)
State	0	0	-9,000
Canada	0	0	0
Total current tax expense (benefit)	0	23,000	-39,000
Deferred tax asset
Tangible and intangible depreciable assets	185,000	874,000
Stock compensation	2,360,000	0
Manufactured drug product inventory to be used in research	1,425,000	1,459,000
Provisions	554,000	93,000
Financing fees	261,000	445,000
Net operating loss carry forwards	23,243,000	13,099,000
Scientific research and experimental development expenditures	5,715,000	5,766,000
Research and development tax credits	266,000	0
Total gross deferred tax assets	34,009,000	21,736,000
Less valuation allowance	-34,009,000	-21,736,000
Net deferred tax assets and liabilities	0	0
Additional disclosures
Amount of increase in valuation allowance	-12,300,000
Share issue expenses not deducted	1,000,000	1,700,000	2,400,000
Reconciliation of the beginning and ending gross amounts of unrecognized tax positions
Unrecognized tax benefits that would not impact effective tax rate	100,000
Accrual for interest or penalties on tax matters	0	0
Number of ongoing tax audits	0
Canadian Federal
Additional disclosures
Scientific research and experimental development expenses deductible for income tax purposes	20,100,000	20,700,000	15,200,000
Net operating loss carry forwards (NOLs)	71,642,000
Reconciliation of the beginning and ending gross amounts of unrecognized tax positions
Unrecognized tax positions, beginning of year	35,000	43,000	42,000
Gross decrease b current period tax positions	0	0	0
Gross increase b current period tax positions	35,000	0	1,000
Gross decrease b prior period tax positions	-28,000	-13,000	0
Gross increase b prior period tax positions	0	5,000	0
Unrecognized tax positions, end of year	42,000	35,000	43,000
Canadian Federal | 2030
Additional disclosures
Net operating loss carry forwards (NOLs)	5,907,000
Canadian Federal | 2031
Additional disclosures
Net operating loss carry forwards (NOLs)	7,059,000
Canadian Federal | 2032
Additional disclosures
Net operating loss carry forwards (NOLs)	13,312,000
Canadian Federal | 2033
Additional disclosures
Net operating loss carry forwards (NOLs)	18,623,000
Canadian Federal | 2034
Additional disclosures
Net operating loss carry forwards (NOLs)	26,741,000
Canadian Provincial
Additional disclosures
Scientific research and experimental development expenses deductible for income tax purposes	22,700,000	22,400,000	16,800,000
Net operating loss carry forwards (NOLs)	71,018,000
Reconciliation of the beginning and ending gross amounts of unrecognized tax positions
Unrecognized tax positions, beginning of year	6,000	2,000	1,000
Gross decrease b current period tax positions	0	0	0
Gross increase b current period tax positions	12,000	0	1,000
Gross decrease b prior period tax positions	0	0	0
Gross increase b prior period tax positions	0	4,000	0
Unrecognized tax positions, end of year	18,000	6,000	2,000
Canadian Provincial | 2030
Additional disclosures
Net operating loss carry forwards (NOLs)	5,985,000
Canadian Provincial | 2031
Additional disclosures
Net operating loss carry forwards (NOLs)	7,066,000
Canadian Provincial | 2032
Additional disclosures
Net operating loss carry forwards (NOLs)	12,433,000
Canadian Provincial | 2033
Additional disclosures
Net operating loss carry forwards (NOLs)	19,385,000
Canadian Provincial | 2034
Additional disclosures
Net operating loss carry forwards (NOLs)	26,149,000
US Federal
Additional disclosures
Net operating loss carry forwards (NOLs)	10,273,000
US Federal | 2030
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US Federal | 2031
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US Federal | 2032
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US Federal | 2033
Additional disclosures
Net operating loss carry forwards (NOLs)	3,261,000
US Federal | 2034
Additional disclosures
Net operating loss carry forwards (NOLs)	7,012,000
US State
Additional disclosures
Net operating loss carry forwards (NOLs)	9,471,000
US State | 2030
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US State | 2031
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US State | 2032
Additional disclosures
Net operating loss carry forwards (NOLs)	0
US State | 2033
Additional disclosures
Net operating loss carry forwards (NOLs)	2,286,000
US State | 2034
Additional disclosures
Net operating loss carry forwards (NOLs)	7,185,000
Research Tax Credit Carryforward [Member] | US Federal
Additional disclosures
Tax Credit Carryforward, Amount		200,000
Research Tax Credit Carryforward [Member] | US State
Additional disclosures
Tax Credit Carryforward, Amount		$100,000

INCOME_TAXES_Details_2

INCOME TAXES (Details 2) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax [Line Items]
Net Income (Loss) Attributable to Parent									($43,698)	($52,859)	($20,286)
Net loss before tax	-10,387	-8,617	-11,038	-13,656	-11,232	-29,398	-8,012	-4,217	-43,698	-52,882	-20,247
Statutory combined US federal and state tax rate (2012 - statutory combined Canadian federal and provincial tax rate)									39.83%	39.83%	26.90%
Income tax expense (benefit)									0	-23	39
United States Federal and State [Member]
Income Tax [Line Items]
Statutory federal and provincial taxes									-17,405
Effect of change in valuation allowance									12,273
Non-deductible share-based compensation									930
Non-deductible warrant expenses for tax purposes									1,799
Tax credits									-180
Share issue costs - temporary difference									-184
Share issue costs - permanent difference									0
Effect of foreign jurisdiction tax expense									0
Differential in income tax rates of foreign subsidiary									3,047
Other differences									-280
Income tax expense (benefit)									0
Canadian Federal and Provincial [Member]
Income Tax [Line Items]
Statutory federal and provincial taxes										-21,063	-5,446
Effect of change in valuation allowance										8,537	5,145
Non-deductible share-based compensation										1,085	539
Non-deductible warrant expenses for tax purposes										8,403	0
Tax credits										-96	-70
Share issue costs - temporary difference										-184	-183
Share issue costs - permanent difference										206	0
Effect of foreign jurisdiction tax expense										0	39
Differential in income tax rates of foreign subsidiary										3,059	0
Other differences										30	15
Income tax expense (benefit)										($23)	$39

INVESTMENT_TAX_CREDITS_Details

INVESTMENT TAX CREDITS (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Canadian Provincial
INVESTMENT TAX CREDITS
Refundable ITCs recorded as a reduction of research and development expenditures	$900,000	$1,700,000
Favorable adjustment included in refundable ITCs resulting from a statutory audit	1,100,000	1,100,000
Canadian Federal
INVESTMENT TAX CREDITS
Non-refundable ITCs related to scientific research and development expenditures	3,907,000	4,000,000	3,100,000
Canadian Federal | 2030
INVESTMENT TAX CREDITS
Non-refundable ITCs related to scientific research and development expenditures	764,000
Canadian Federal | 2031
INVESTMENT TAX CREDITS
Non-refundable ITCs related to scientific research and development expenditures	1,000,000
Canadian Federal | 2032
INVESTMENT TAX CREDITS
Non-refundable ITCs related to scientific research and development expenditures	1,125,000
Canadian Federal | 2033
INVESTMENT TAX CREDITS
Non-refundable ITCs related to scientific research and development expenditures	$1,018,000

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 24, 2014
Future minimum annual payments
2014	$223,000
2016	290,000
2017	303,000
2018	25,000
Total minimum lease payments	841,000
Operating Leases, Rent Expense, Net [Abstract]
Lease expense	400,000	400,000	300,000
Building
Operating Leased Assets [Line Items]
Area of space leased				18,000
Annual rent increase (percent)				3.00%
Building | Lease Agreement Phase One
Operating Leased Assets [Line Items]
Area of space leased				2,000
Monthly lease rent				5,900
Building | Lease Agreement Phase Two
Operating Leased Assets [Line Items]
Area of space leased				14,000
Monthly lease rent				14,000
Building | Lease Agreement Phase Three
Operating Leased Assets [Line Items]
Area of space leased				2,000
Monthly lease rent				$4,200

QUARTERLY_FINANCIAL_DATA_Detai

QUARTERLY FINANCIAL DATA (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Operating Loss	($10,443)	($10,548)	($10,134)	($7,979)	($7,886)	($9,209)	($6,898)	($8,006)	($39,104)	($31,999)	($20,498)
Net loss	($10,387)	($8,617)	($11,038)	($13,656)	($11,232)	($29,398)	($8,012)	($4,217)	($43,698)	($52,882)	($20,247)
Loss per share, basic (in US$ per share)		$0	$0	$0	$0	$0	$0	$0	($3,240)
Loss per share, diluted (in US$ per share)	$0	$0	$0	$0	($960)	($2,950)	($800)	($680)	($3,240)	$0

SUBSEQUENT_EVENTS_SUBSEQUENT_E

SUBSEQUENT EVENTS SUBSEQUENT EVENTS (Details) (USD $)	12 Months Ended			1 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2015
Subsequent Event [Line Items]
Proceeds from issuance of common stock, net of issuance costs	$0	$54,196	$19,886
Subsequent Event [Member]
Subsequent Event [Line Items]
Issuance of common stock, net of costs (in shares)				2,588,000
Share price of stock issued (in US$ per share)				$20
Proceeds from issuance of common stock, net of issuance costs				$48,200