Mirati Therapeutics (MRTX) 10-Q 10 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Nov. 03, 2014
Document and Entity Information	'	'
Entity Registrant Name	'Mirati Therapeutics, Inc.	'
Entity Central Index Key	'0001576263	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Smaller Reporting Company	'
Entity Common Stock, Shares Outstanding	'	13,536,929
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$4,915	$14,235
Short-term investments	32,792	47,835
Other current assets	2,638	2,145
Total current assets	40,345	64,215
Property and equipment, net	524	322
Other long-term assets	440	0
Total assets	41,309	64,537
Current liabilities	'	'
Accounts payable and accrued liabilities	5,404	5,245
Warrant liability	167	33,407
Total liabilities	5,571	38,652
Stockholders’ equity	'	'
Preferred stock, $0.001 par value, 10,000,000 shares authorized; none issued and outstanding at both June 30, 2014 and December 31, 2013	0	0
Common stock, $0.001 par value; 100,000,000 authorized; 13,522,805 and 13,446,976 issued and outstanding at both June 30, 2014 and December 31, 2013	14	13
Additional paid-in capital	257,898	214,756
Accumulated other comprehensive income	9,528	9,507
Accumulated deficit	-231,702	-198,391
Total stockholders’ equity	35,738	25,885
Total liabilities and stockholders’ equity	$41,309	$64,537

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 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 (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	13,522,805	13,446,976
Common stock, shares outstanding (in shares)	13,522,805	13,446,976

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Expenses	'	'	'	'
Research and development	$7,029	$5,492	$19,472	$15,477
General and administrative	3,519	3,717	8,855	8,636
Restructuring costs	0	0	334	0
Total operating expenses	10,548	9,209	28,661	24,113
Loss from operations	-10,548	-9,209	-28,661	-24,113
Other income (expense), net	24	462	-106	-789
Change in fair value of warrant liability	1,907	-20,596	-4,544	-16,609
Loss before income taxes	-8,617	-29,343	-33,311	-41,511
Income tax expense	0	55	0	115
Net loss	-8,617	-29,398	-33,311	-41,626
Unrealized gain on available-for-sale investments	-12	0	22	0
Comprehensive loss	($8,629)	($29,398)	($33,289)	($41,626)
Basic net loss per share (in dollars per share)	($0.64)	($2.95)	($2.47)	($4.18)
Diluted net loss per share (in dollars per share)	($0.72)	($2.95)	($2.47)	($4.18)
Weighted average number of shares used in computing net loss per share, basic (shares)	13,527,113	9,957,896	13,478,735	9,957,792
Weighted average number of shares used in computing net loss per share, diluted (shares)	14,717,253	9,957,896	13,478,735	9,957,792

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities:	'	'
Net loss	($33,311)	($41,626)
Non-cash adjustments reconciling net loss to operating cash flows:	'	'
Depreciation of property and equipment	154	105
Amortization of premium on investments	439	0
Share-based compensation expense	4,822	1,097
Change in fair value of warrant liability	4,544	16,609
Change in fair value of share-based compensation liability	0	899
Restructuring costs	13	0
Lease incentive liability	0	-53
Changes in operating assets and liabilities:	'	'
Other current assets	-493	-57
Other long-term assets	-440	0
Accounts payable and accrued liabilities	111	1,283
Cash flows used for operating activities	-24,161	-21,743
Investing activities:	'	'
Purchases of property and equipment	-320	-196
Purchases of short-term investments	-8,968	-25,725
Security deposit, restricted cash equivalents and marketable securities	0	-32
Disposal and maturities of short-term investments	23,593	36,887
Cash flows provided by (used in) investing activities	14,305	10,934
Financing activities:	'	'
Proceeds from exercise of common stock options	536	22
Cash flows provided by financing activities	536	22
Decrease in cash and cash equivalents	-9,320	-10,787
Cash and cash equivalents, beginning of period	14,235	18,403
Cash and cash equivalents, end of period	$4,915	$7,616

Description_of_Business

Description of Business	9 Months Ended
	Sep. 30, 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 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. has no 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	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Basis of Presentation
	The unaudited consolidated financial statements contained in this Quarterly Report on Form 10-Q have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC") and, therefore, certain information and disclosures normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") have been omitted.
	In the opinion of management, the information reflects all adjustments necessary to make the results of operations for the interim periods a fair statement of such operations. All such adjustments are of a normal recurring nature. Interim results are not necessarily indicative of results for the full year. The consolidated balance sheet at December 31, 2013 has been derived from the audited consolidated financial statements at that date, but does not include all information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. These unaudited consolidated financial statements should be read in conjunction with the audited financial statements included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2013 filed with the SEC on March 17, 2014.
	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 MethylGene’s 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 the Company’s common stock, and a proportionate adjustment was made to the exercise 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 condensed interim 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 unaudited 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. All 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 at the date of acquisition 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.
	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), net in the consolidated statements of operations and comprehensive loss.  The Company recognized net foreign exchange losses of $0.2 million for the nine months ended September 30, 2014 which includes an immaterial amount for the three months ended September 30, 2014, and a gain of $0.4 million and a loss of $1.0 million for the three and nine months ended September 30, 2013 in other income (expense), net in the consolidated statement of operations and comprehensive loss.
	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 was recorded 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 is recalculated and any corresponding increase or decrease to the warrant liability is recorded as change in fair value of warrant liability on the consolidated statement of operations and comprehensive loss. The estimated fair value is 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 third quarter 2014, the Company amended the majority 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, or $36.8 million. Consequently due to the equity classification, revaluations of the fair value of the amended warrants are no longer required. The warrants that did not participate in the amendment will continue to be classified as a current liability with quarterly revaluations.
	The fair value of the warrant liability associated with the warrants that did not participate in the amendment was $0.2 million at September 30, 2014. For all of the warrants classified as liabilities during the relevant periods, the Company recorded a gain of $1.9 million and a loss of $4.5 million for the three and nine months ended September 30, 2014, respectively, and a loss of $20.6 million and a loss of $16.6 million for the three and nine months ended September 30, 2013, respectively, which are recorded as change in fair value of warrant liability in the consolidated statement of operations and comprehensive loss.
	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):
		September 30,				Level 1			Level 2			Level 3
		2014
	Assets
	Cash and cash equivalents	$	4,915			$	2,362		$	2,553		$	—
	Short-term investments	32,792				—			32,792			—
		$	37,707			$	2,362		$	35,345		$	—
	Liabilities
	Warrant liability	$	167			$	—		$	—		$	167
		$	167			$	—		$	—		$	167
		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 September 30, 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 during the three and nine months ended September 30, 2014.
	The following table presents a rollforward of the fair value of the warrant liability which includes 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		4,544
	Fair value of warrants exercised		(993		)
	Reclassification of warrants to stockholders' equity		(36,791		)
	Balance at September 30, 2014		167
	The Company estimates the fair value of warrants at the time of issuance and subsequent remeasurement 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 could differ materially in the future. Changes to these assumptions can 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 date to determine the fair value of the warrants to reclassify into equity:
			September 12, 2014
		2011 Warrants			2012 Warrants
Risk-free interest rate		1.2	%		1.2	%
Volatility		108.6	%		100.8	%
Dividend yield		—			—
Expected life in years		1.6			3.2
The following assumptions were used in the Black-Scholes option-pricing model to determine the fair value of the warrant liability for all remaining 2011 warrants. All 2012 warrants were amended and did not require a valuation as of September 30, 2014.
		September 30, 2014			31-Dec-13
		2011 Warrants			2011 Warrants		2012 Warrants
Risk-free interest rate		1.1	%		1.2	%	1.6	%
Volatility		108	%		112	%	115.9	%
Dividend yield		—			—		—
Expected life in years		1.5			2.3		3.9
Net loss per share
Net loss per share is calculated by dividing the net loss of the Company by the weighted average number of shares of common stock outstanding during the period.  The calculation of diluted loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the warrants and the presumed exercise of such securities are dilutive to loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of the warrants from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any, under the treasury stock method. The gain on fair value of warrant liability for the three months ended September 30, 2014 resulted in a dilutive impact as detailed further below:
	Three Months Ended
	September 30, 2014
Numerator:
Net loss	$	(8,617	)
Minus: Gain on fair value of warrant liabilities	1,907
Adjusted net loss	$	(10,524	)
Denominator:
Weighted average number of shares used in computing net loss per share, basic	13,527,113
Plus: Effect of dilutive potential common shares from warrants	1,190,140
Weighted average number of shares used in computing net loss per share, diluted	14,717,253
Diluted net loss per share	$	(0.72	)
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:
		Three Months Ended					Nine Months Ended
		30-Sep-14					30-Sep-14
		2014			2013		2014			2013
Common stock options		252,678			51,393		264,723			1,436
Common stock warrants		280,720			481,765		1,552,441			92,192
Total		533,398			533,158		1,817,164			93,628

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board ("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. This ASU is not expected to have an impact on the Company's financial statements or disclosures.
	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. The Company is currently evaluating the potential changes from this ASU to its future financial reporting and disclosures.

Investments

Investments	9 Months Ended
	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	The following tables summarize our short-term investments (dollars in thousands):
			As of September 30, 2014
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Corporate debt securities(1)	2 years or less	32,784	11	(3	)	32,792
			32,784	11	(3	)	32,792
			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 September 30, 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	9 Months Ended
	Sep. 30, 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):
		September 30		December 31
		2014		2013
	Refundable research and development tax credits	$	809	$	809
	Interest receivables	224		306
	Prepaid expenses	859		667
	Commodity taxes and other	290		227
	Other	456		136
		$	2,638	$	2,145

Property_and_Equipment_net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Property and Equipment, net	'
	Property and equipment, net
	Property and equipment consisted of the following (in thousands):
		September 30			December 31
		2014			2013
	Computer equipment	$	325		$	1,534
	Office and other equipment	56			122
	Laboratory equipment	283			1,794
	Leasehold improvements	51			53
		$	715		$	3,503
	Less: Accumulated depreciation	(191		)	(3,181		)
		$	524		$	322
	The Company incurred depreciation expense of $39,000 and $41,000 for the three months ended September 30, 2014 and 2013, and $0.2 million and $0.1 million for the nine months ended September 30, 2014 and 2013. During the nine months ended September 30, 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	9 Months Ended
	Sep. 30, 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):
		September 30		31-Dec
		2014		2013
	Accounts payable	$	1,934	$	1,302
	Accrued expenses	2,239		2,335
	Accrued compensation and benefits	1,215		1,608
	Deferred rent	16		—
		$	5,404	$	5,245

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 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 activities were reported as a separate line item in the accompanying consolidated statement of operations and comprehensive loss and were comprised of the following components (in thousands):
	Balance as of October 1, 2013	$	—
	Charges against the accrual	1,025
	Payments	(729		)
	Balance as of December 31, 2013	296
	Charges against the accrual	334
	Payments	(630		)
	Balance as of September 30, 2014	—
	The restructuring activities associated with the office closures were complete as of September 30, 2014, and all restructuring costs incurred have been paid to date.

Warrants

Warrants	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Warrants	'
	Warrants
	As of September 30, 2014 the following warrants for common stock were issued and outstanding:
	Issue date	Expiration date	Exercise price			Number of warrants outstanding
	April 4, 2011	April 4, 2016	$	6.66	-1	13,274
	April 4, 2011	April 4, 2016	$	6.74	-2	1,384,647
	November 21, 2012	November 21, 2017	$	7.86	-2	1,067,792
						2,465,713
	(1) - Denominated in Canadian Dollars. Exercise price stated in US Dollars as of September 30, 2014.
	(2) - Denominated in US Dollars.
	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 third quarter 2014, the Company amended the majority of these outstanding warrant agreements to allow for the warrants to be denominated in U.S. Dollars.
	During the three and nine months ended September 30, 2014, warrants for 3,620 and 73,964 shares of the Company's common stock were exercised via cashless exercises and the Company issued a net of 2,346 and 43,526 shares.

Stockbased_compensation

Stock-based compensation	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-based compensation	'
	Stock-based compensation
	Total stock-based compensation expense by operating statement classification is presented below (in thousands):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
	Research and development expense	$	859	$	(106	)	$	1,929	$	(39	)
	General and administrative expense	1,732		1,857			2,893		2,035
		$	2,591	$	1,751		$	4,822	$	1,996
	In connection with management changes during the first half of 2013, certain unvested stock options were canceled, resulting in a one-time favorable adjustment to stock-based compensation expense. During the three and nine months ended September 30, 2014, 11,778 and 46,427 shares were issued pursuant to stock option exercises amounting to net proceeds of $0.1 million and $0.5 million, respectively.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	On June 24, 2014, the Company entered into a lease agreement (the “lease”) with ARE-SD Region No. 20, LLC for approximately 18,000 square feet of completed office and laboratory space located in San Diego, California (the “property”). 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 on or after February 1, 2015 at an initial monthly rent of $14,000 per month, and the final 1,600 square feet of space becoming available on February 1, 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:
	2014 (Three months remaining)	$	12
	2015	224
	2016	291
	2017	304
	2018	25
	Total minimum lease payments	$	856

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The unaudited consolidated financial statements contained in this Quarterly Report on Form 10-Q have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC") and, therefore, certain information and disclosures normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") have been omitted.
	In the opinion of management, the information reflects all adjustments necessary to make the results of operations for the interim periods a fair statement of such operations. All such adjustments are of a normal recurring nature. Interim results are not necessarily indicative of results for the full year. The consolidated balance sheet at December 31, 2013 has been derived from the audited consolidated financial statements at that date, but does not include all information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. These unaudited consolidated financial statements should be read in conjunction with the audited financial statements included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2013 filed with the SEC on March 17, 2014.
	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 MethylGene’s 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 the Company’s common stock, and a proportionate adjustment was made to the exercise 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 condensed interim 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 unaudited 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. All 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 at the date of acquisition of ninety days or less.
Short-term Investments	'
	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.
Foreign Currency Transactions	'
	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), net in the consolidated statements of operations and comprehensive loss.
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 was recorded 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 is recalculated and any corresponding increase or decrease to the warrant liability is recorded as change in fair value of warrant liability on the consolidated statement of operations and comprehensive loss. The estimated fair value is 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.
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.
Fair Value of Financial Instruments	'
	The Company estimates the fair value of warrants at the time of issuance and subsequent remeasurement 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 could differ materially in the future. Changes to these assumptions can have a significant impact on the fair value of the warrants.
	The Company’s investments in Level 1 assets are valued based on publicly available quoted market prices for identical securities as of September 30, 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 during the three and nine months ended September 30, 2014.
Net loss per share	'
	Net loss per share
	Net loss per share is calculated by dividing the net loss of the Company by the weighted average number of shares of common stock outstanding during the period.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block]	'
	The gain on fair value of warrant liability for the three months ended September 30, 2014 resulted in a dilutive impact as detailed further below:
		Three Months Ended
		September 30, 2014
	Numerator:
	Net loss	$	(8,617	)
	Minus: Gain on fair value of warrant liabilities	1,907
	Adjusted net loss	$	(10,524	)
	Denominator:
	Weighted average number of shares used in computing net loss per share, basic	13,527,113
	Plus: Effect of dilutive potential common shares from warrants	1,190,140
	Weighted average number of shares used in computing net loss per share, diluted	14,717,253
	Diluted net loss per share	$	(0.72	)
Schedule of assets and liabilities that are measured at fair value on a recurring basis	'
	The following table summarizes the assets and liabilities measured at fair value on a recurring basis (in thousands):
		September 30,				Level 1			Level 2			Level 3
		2014
	Assets
	Cash and cash equivalents	$	4,915			$	2,362		$	2,553		$	—
	Short-term investments	32,792				—			32,792			—
		$	37,707			$	2,362		$	35,345		$	—
	Liabilities
	Warrant liability	$	167			$	—		$	—		$	167
		$	167			$	—		$	—		$	167
		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 includes 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		4,544
	Fair value of warrants exercised		(993		)
	Reclassification of warrants to stockholders' equity		(36,791		)
	Balance at September 30, 2014		167
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 date to determine the fair value of the warrants to reclassify into equity:
			September 12, 2014
			2011 Warrants			2012 Warrants
	Risk-free interest rate		1.2	%		1.2	%
	Volatility		108.6	%		100.8	%
	Dividend yield		—			—
	Expected life in years		1.6			3.2
	The following assumptions were used in the Black-Scholes option-pricing model to determine the fair value of the warrant liability for all remaining 2011 warrants. All 2012 warrants were amended and did not require a valuation as of September 30, 2014.
			September 30, 2014			31-Dec-13
			2011 Warrants			2011 Warrants		2012 Warrants
	Risk-free interest rate		1.1	%		1.2	%	1.6	%
	Volatility		108	%		112	%	115.9	%
	Dividend yield		—			—		—
	Expected life in years		1.5			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:
			Three Months Ended					Nine Months Ended
			30-Sep-14					30-Sep-14
			2014			2013		2014			2013
	Common stock options		252,678			51,393		264,723			1,436
	Common stock warrants		280,720			481,765		1,552,441			92,192
	Total		533,398			533,158		1,817,164			93,628

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Available-for-sale and Trading Securities Reconciliation	'
	The following tables summarize our short-term investments (dollars in thousands):
			As of September 30, 2014
		Maturity (in years)	Amortized cost	Gross unrealized gains	Gross unrealized losses		Estimated fair value
	Corporate debt securities(1)	2 years or less	32,784	11	(3	)	32,792
			32,784	11	(3	)	32,792
			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)	9 Months Ended
	Sep. 30, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Schedule of other current assets	'
	Other current assets consisted of the following (in thousands):
		September 30		December 31
		2014		2013
	Refundable research and development tax credits	$	809	$	809
	Interest receivables	224		306
	Prepaid expenses	859		667
	Commodity taxes and other	290		227
	Other	456		136
		$	2,638	$	2,145

Property_and_Equipment_net_Tab

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Schedule of Property and Equipment	'
	Property and equipment consisted of the following (in thousands):
		September 30			December 31
		2014			2013
	Computer equipment	$	325		$	1,534
	Office and other equipment	56			122
	Laboratory equipment	283			1,794
	Leasehold improvements	51			53
		$	715		$	3,503
	Less: Accumulated depreciation	(191		)	(3,181		)
		$	524		$	322

Accounts_payable_and_accrued_l1

Accounts payable and accrued liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Payables and Accruals [Abstract]	'
Schedule of accounts payable and accrued liabilities	'
	Accounts payable and accrued liabilities consisted of the following (in thousands):
		September 30		31-Dec
		2014		2013
	Accounts payable	$	1,934	$	1,302
	Accrued expenses	2,239		2,335
	Accrued compensation and benefits	1,215		1,608
	Deferred rent	16		—
		$	5,404	$	5,245

Restructuring_Tables

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2014
Restructuring and Related Activities [Abstract]	'
Schedule of Restructuring and Related Costs	'
	Restructuring activities were reported as a separate line item in the accompanying consolidated statement of operations and comprehensive loss and were comprised of the following components (in thousands):
	Balance as of October 1, 2013	$	—
	Charges against the accrual	1,025
	Payments	(729		)
	Balance as of December 31, 2013	296
	Charges against the accrual	334
	Payments	(630		)
	Balance as of September 30, 2014	—

Warrants_Tables

Warrants (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Schedule of Warrants Issued and Outstanding	'
	As of September 30, 2014 the following warrants for common stock were issued and outstanding:
	Issue date	Expiration date	Exercise price			Number of warrants outstanding
	April 4, 2011	April 4, 2016	$	6.66	-1	13,274
	April 4, 2011	April 4, 2016	$	6.74	-2	1,384,647
	November 21, 2012	November 21, 2017	$	7.86	-2	1,067,792
						2,465,713

Stockbased_compensation_Tables

Stock-based compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Employee Service Share-based Compensation Allocation	'
	Total stock-based compensation expense by operating statement classification is presented below (in thousands):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
	Research and development expense	$	859	$	(106	)	$	1,929	$	(39	)
	General and administrative expense	1,732		1,857			2,893		2,035
		$	2,591	$	1,751		$	4,822	$	1,996

Commitments_and_Contingencies_1

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Schedule of Future Minimum Rental Payments for Operating Leases	'
	Future minimum payments required under the lease are summarized as follows (in thousands):
	Year Ending December 31:
	2014 (Three months remaining)	$	12
	2015	224
	2016	291
	2017	304
	2018	25
	Total minimum lease payments	$	856

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended				0 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jan. 02, 2013	Jun. 28, 2013	Sep. 30, 2014	Dec. 31, 2013
							MethylGene	Common stock warrants	Common stock warrants
Basis of Presentation [Line Items]	'	'	'	'	'	'	'	'	'
Ratio of reverse split of the common shares	'	'	'	'	'	'	50	'	'
Exercisable ratio of outstanding options and warrants	'	'	'	'	'	'	50	'	'
Marketable Securities	'	'	'	'	'	'	'	'	'
Minimum original maturity period of marketable securities	'	'	'90 days	'	'	'	'	'	'
Foreign Currency Transactions	'	'	'	'	'	'	'	'	'
Net foreign exchange (losses) gains recognized in other income (expense)	'	$400,000	$200,000	$1,000,000	'	'	'	'	'
Reclassification of Warrants	'	'	'	'	'	'	'	'	'
Warrant liability	167,000	'	167,000	'	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	'	'	'
Reclassification of warrants to stockholders' equity	'	'	'	'	'	'	'	36,791,000	'
Loss (gain) from change in fair value of warrant liability included in net loss	($1,907,000)	$20,596,000	$4,544,000	$16,609,000	'	'	'	$4,544,000	$19,799,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Fair Value Measurements (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Jan. 02, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Warrant liability	$167	$33,407	$16,200
Recurring basis | Total	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Cash and cash equivalents	4,915	14,235	'
Short-term investments	32,792	47,835	'
Assets	37,707	62,070	'
Warrant liability	167	33,407	'
Liabilities	167	33,407	'
Recurring basis | Level 1	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Cash and cash equivalents	2,362	12,431	'
Short-term investments	0	0	'
Assets	2,362	12,431	'
Warrant liability	0	0	'
Liabilities	0	0	'
Recurring basis | Level 2	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Cash and cash equivalents	2,553	1,804	'
Short-term investments	32,792	47,835	'
Assets	35,345	49,639	'
Warrant liability	0	0	'
Liabilities	0	0	'
Recurring basis | Level 3	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Cash and cash equivalents	0	0	'
Short-term investments	0	0	'
Assets	0	0	'
Warrant liability	167	33,407	'
Liabilities	$167	$33,407	'

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Change in Warrant Liability (Details) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Dec. 31, 2013
					Common stock warrants	Common stock warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'	'
Balance at beginning of period	'	'	'	'	$33,407	$0
Fair value upon reclassification of balance as of January 1, 2013	'	'	'	'	'	16,194
Change in fair value of warrant liability	-1,907	20,596	4,544	16,609	4,544	19,799
Fair value of warrants exercised	'	'	'	'	-993	-2,586
Reclassification of warrants to stockholders' equity	'	'	'	'	-36,791	'
Balance at end of period	'	'	'	'	$167	$33,407

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Fair Value Assumptions (Details)	0 Months Ended	9 Months Ended	12 Months Ended
	Sep. 12, 2014	Sep. 30, 2014	Dec. 31, 2013
2011 Warrants	'	'	'
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]	'	'	'
Risk-free interest rate (as a percent)	1.20%	1.10%	1.20%
Volatility (as a percent)	108.60%	108.00%	112.00%
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Expected life in years	'1 year 7 months 6 days	'1 year 6 months	'2 years 3 months 18 days
2012 Warrants	'	'	'
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]	'	'	'
Risk-free interest rate (as a percent)	1.20%	'	1.60%
Volatility (as a percent)	100.80%	'	115.90%
Dividend yield (as a percent)	0.00%	'	0.00%
Expected life in years	'3 years 2 months 12 days	'	'3 years 10 months 24 days

Summary_of_Significant_Account7

Summary of Significant Accounting Policies - Net Loss per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Net loss	($8,617)	($29,398)	($33,311)	($41,626)
Minus: Gain on fair value of warrant liabilities	1,907	-20,596	-4,544	-16,609
Adjusted net loss	($10,524)	'	'	'
Weighted average number of shares used in computing net loss per share, basic (shares)	13,527,113	9,957,896	13,478,735	9,957,792
Plus: Effect of dilutive potential common shares from warrants	1,190,140	'	'	'
Weighted average number of shares used in computing net loss per share, diluted (shares)	14,717,253	9,957,896	13,478,735	9,957,792
Diluted net loss per share (in dollars per share)	($0.72)	($2.95)	($2.47)	($4.18)
Antidilutive securities	533,398	533,158	1,817,164	93,628
Common stock options	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities	252,678	51,393	264,723	1,436
Common stock warrants	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities	280,720	481,765	1,552,441	92,192

Investments_Details

Investments (Details) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'		'
Available-for-sale, Amortized cost	$32,784		'
Available-for-sale, Gross unrealized gain	11		'
Available-for-sale, Gross unrealized losses	-3		'
Available-for-sale, Estimated fair value	32,792		'
Amortized cost	'		47,851
Gross unrealized gains	'		12
Gross unrealized losses	'		-28
Estimated fair value	'		47,835
Government sponsored enterprise	'		'
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 gain	'		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	'2 years	[1]	'2 years	[1]
Available-for-sale, Amortized cost	32,784	[1]	31,319	[1]
Available-for-sale, Gross unrealized gain	11	[1]	0	[1]
Available-for-sale, Gross unrealized losses	-3	[1]	-22	[1]
Available-for-sale, Estimated fair value	32,792	[1]	31,297	[1]
Commercial paper	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Available-for-sale, Maximum maturity period	'		'1 year	[1]
Available-for-sale, Amortized cost	'		8,485	[1]
Available-for-sale, Gross unrealized gain	'		12	[1]
Available-for-sale, Gross unrealized losses	'		0	[1]
Available-for-sale, Estimated fair value	'		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 $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'	'
Refundable research and development tax credits	$809	$809
Interest and other receivables	224	306
Prepaid expenses	859	667
Commodity taxes and other	290	227
Other	456	136
Other current assets	$2,638	$2,145

Property_and_Equipment_net_Det

Property and Equipment, net (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, Gross	$715,000	'	$715,000	'	$3,503,000
Less: Accumulated depreciation	-191,000	'	-191,000	'	-3,181,000
Property and equipment, Net	524,000	'	524,000	'	322,000
Depreciation of property and equipment	39,000	41,000	154,000	105,000	'
Property plant and equipment disposed of	'	'	3,200,000	'	'
Computer equipment	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, Gross	325,000	'	325,000	'	1,534,000
Office and other equipment	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, Gross	56,000	'	56,000	'	122,000
Laboratory equipment	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, Gross	283,000	'	283,000	'	1,794,000
Leasehold improvements	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, Gross	$51,000	'	$51,000	'	$53,000

Accounts_payable_and_accrued_l2

Accounts payable and accrued liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]	'	'
Accounts payable	$1,934	$1,302
Accrued expenses	2,239	2,335
Accrued compensation and benefits	1,215	1,608
Deferred rent	16	0
Total accounts payable and accrued liabilities	$5,404	$5,245

Restructuring_Details

Restructuring (Details) (USD $)	0 Months Ended	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Oct. 02, 2013	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Restructuring and Related Activities [Abstract]	'	'	'	'	'	'
Percent of positions eliminated	75.00%	'	'	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'	'	'	'
Beginning balance	'	'	$0	'	$296	'
Charges against the accrual	'	0	1,025	0	334	0
Payments	'	'	-729	'	-630	'
Ending balance	'	$0	$296	$0	$0	$0

Warrants_Details

Warrants (Details)	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Apr. 04, 2011	Sep. 30, 2014	Sep. 30, 2014	Nov. 21, 2012	Sep. 30, 2014
		November 21, 2012 Warrants	November 21, 2012 Warrants	Private Placement April 2011	Private Placement April 2011	Private Placement April 2011	Private Placement November 2012	Private Placement November 2012
				April 4, 2011 Warrants	April 4, 2011 Warrants	April 4, 2011 Warrants	November 21, 2012 Warrants	November 21, 2012 Warrants
					CAD	USD		USD
Class of Warrant or Right [Line Items]	'	'	'	'	'	'	'	'
Exercise price of warrants (in dollars per share)	'	'	'	7.46	6.66	6.74	8.7	7.86
Number of warrants outstanding	2,465,713	'	'	'	13,274	1,384,647	'	1,067,792
Warrants exercised	'	3,620	73,964	'	'	'	'	'
Shares of common stock issued	'	2,346	43,526	'	'	'	'	'

Stockbased_compensation_Detail

Stock-based compensation (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Allocated share-based compensation expense	$2,591,000	$1,751,000	$4,822,000	$1,996,000
Shares issued	11,778	'	46,427	'
Cash received from exercise of options	100,000	'	500,000	'
Research and development expense	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Allocated share-based compensation expense	859,000	-106,000	1,929,000	-39,000
General and administrative expense	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Allocated share-based compensation expense	$1,732,000	$1,857,000	$2,893,000	$2,035,000

Commitments_and_Contingencies_2

Commitments and Contingencies Narrative (Details) (Building, USD $)	9 Months Ended
	Sep. 30, 2014
	sqft
Operating Leased Assets [Line Items]	'
Annual rent increase (Percentage)	3.00%
Lease Agreement Phase One	'
Operating Leased Assets [Line Items]	'
Square feet of space	2,300
Minimum monthly rental expense	$5,900
Lease Agreement Phase Two	'
Operating Leased Assets [Line Items]	'
Square feet of space	14,000
Minimum monthly rental expense	14,000
Lease Agreement Phase Three	'
Operating Leased Assets [Line Items]	'
Square feet of space	1,600
Minimum monthly rental expense	$4,200

Commitments_and_Contingencies_3

Commitments and Contingencies Future Minimum Payments (Details) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'
2014 (Six months remaining)	$12
2015	224
2016	291
2017	304
2018	25
Total minimum lease payments	$856