Diadexus (VXGN) 10-K 12 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. 06, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	DDXS
Entity Registrant Name	diaDexus, Inc.
Entity Central Index Key	1036968
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	No
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		56,902,666
Entity Public Float			$35.30

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$14,946	$16,847
Accounts receivable, net of reserve of $6 and $5 at December 31, 2014 and 2013, respectively	4,101	3,027
Inventories	578	460
Prepaid expenses and other current assets	500	845
Total current assets	20,125	21,179
Restricted cash	1,400	1,400
Property and equipment, net	637	968
Other long-term assets	131	100
Total assets	22,293	23,647
Current liabilities:
Accounts payable	1,023	611
Notes payable, current portion	957	2,763
Deferred revenues, current portion	120	228
Deferred rent, current portion	128	51
Unfavorable lease obligations	820	697
Accrued and other current liabilities	3,074	2,203
Total current liabilities	6,122	6,553
Non-current portion of notes payable	13,791	7,047
Non-current portion of deferred rent	208	336
Non-current portion of unfavorable lease obligation	957	1,777
Other long term liabilities	369	414
Total liabilities	21,447	16,127
Commitments and contingencies (Note 14)
Stockholders’ equity:
Preferred Stock, $0.01 par value, 19,979,500 shares authorized; none issued or outstanding
Common stock, $0.01 par value; 100,000,000 shares authorized; 56,749,678 and 54,751,685 shares issued and outstanding at December 31, 2014 and December 31, 2013, respectively	567	548
Additional paid-in capital	208,642	206,868
Accumulated deficit	-208,363	-199,896
Total stockholders’ equity	846	7,520
Total liabilities and stockholders’ equity	$22,293	$23,647

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]
Accounts receivable, reserve	$6	$5
Preferred Stock, par value	$0.01	$0.01
Preferred Stock, shares authorized	19,979,500	19,979,500
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	56,749,678	54,751,685
Common stock, shares outstanding	56,749,678	54,751,685

Statements_of_Comprehensive_Lo

Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Product sales	$21,204	$24,548
Service revenue	4,994	13
Royalty revenue		18
License revenue	225	305
Total revenues	26,423	24,884
Operating costs and expenses:
Product costs of revenue	6,764	7,222
Service costs of revenue	598
Sales and marketing	10,083	7,482
Research and development	6,347	4,709
General and administrative	9,613	7,486
Total operating costs and expenses	33,405	26,899
Loss from operations	-6,982	-2,015
Interest income, interest expense and other income (expense), net:
Interest income	3	4
Interest expense	-1,560	-488
Other income (expense), net	87	340
Loss before income tax	-8,452	-2,159
Income tax provision	15	5
Net loss	-8,467	-2,164
Net Loss and Comprehensive loss	($8,467)	($2,164)
Basic and diluted net loss per share:	($0.15)	($0.04)
Weighted average shares used in computing basic and diluted net loss per share	55,198,104	54,329,424

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net loss	($8,467,000)	($2,164,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on disposal of assets	-5,000	-340,000
Depreciation and amortization	509,000	531,000
Stock-based compensation	838,000	632,000
Provision for doubtful accounts and rebate reserve (reversal)	1,000	5,000
Non-cash interest expense	35,000	31,000
Inventory obsolescence reserve	93,000
Non-cash interest associated with notes payable	471,000	140,000
Unfavorable lease	-697,000	-589,000
Changes in operating assets and liabilities:
Accounts receivable	-1,075,000	-243,000
Inventory	-211,000	-326,000
Prepaid expenses, other current assets and other long-term assets	395,000	3,000
Accounts payable	431,000	174,000
Accrued liabilities and other long-term liabilities	885,000	342,000
Deferred rent	-51,000	24,000
Deferred revenue	-107,000	-314,000
Net cash used in operating activities	-6,955,000	-2,094,000
Investing activities:
Purchases of property and equipment	-211,000	-302,000
Maturities of available-for-sale investments		747,000
Proceeds from sale of assets, net	4,000	634,000
Net cash provided (used) by investing activities	-207,000	1,079,000
Financing activities:
Proceeds from notes payable	15,000,000	5,000,000
Principal repayment of loan	-10,000,000
Debt issuance costs	-224,000	-50,000
Proceeds from stock option exercises	485,000	61,000
Net cash provided by financing activities	5,261,000	5,011,000
Net increase (decrease) in cash and cash equivalents	-1,901,000	3,996,000
Cash and cash equivalents, beginning of year	16,847,000	12,851,000
Cash and cash equivalents, end of year	14,946,000	16,847,000
Supplemental disclosure:
Cash paid for interest	921,000	315,000
Non-cash investing and financing transactions
Issuance of warrants for common stock in connection with debt	470,000	136,000
Net change in accounts payable from acquisition of property and equipment	-19,000	-32,000
Net change in accrued liabilities from acquisition of property and equipment	($10,000)	($16,000)

Statements_of_Stockholders_Equ

Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Deficit [Member]
In Thousands, except Share data
Beginning Balance at Dec. 31, 2012	$8,855	$539	$206,048	($197,732)
Beginning Balance, Shares at Dec. 31, 2012		53,890,314
Stock-based compensation— under ASC 718	632		632
Issuance and sale of common stock under stock-based compensation plans	61	5	56
Issuance and sale of common stock under stock-based compensation plans, Shares		474,587
Issuance of warrants	136		136
Issuance and sale of common stock under warrants		4	-4
Issuance and sale of common stock under warrants, Shares		386,784
Net loss	-2,164			-2,164
Ending Balance at Dec. 31, 2013	7,520	548	206,868	-199,896
Ending Balance, Shares at Dec. 31, 2013		54,751,685
Stock-based compensation— under ASC 718	839		839
Issuance and sale of common stock under stock-based compensation plans	484	19	465
Issuance and sale of common stock under stock-based compensation plans, Shares		1,956,285
Issuance of warrants	470		470
Net loss	-8,467			-8,467
Ending Balance at Dec. 31, 2014	$846	$567	$208,642	($208,363)
Ending Balance, Shares at Dec. 31, 2014		56,749,678

Business_Overview

Business Overview	12 Months Ended
	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Overview	1. Business Overview
	Formation of the Company
	diaDexus is a diagnostics company developing and commercializing products that deliver healthcare providers with relevant information to assist in the management of their patients throughout the course of cardiac disease.  Our capabilities include proprietary manufacturing, assay development, FDA regulatory clearances, and marketing and selling products.  These capabilities have enabled our evolution from a single-product business into a multi-product company with growth potential to develop additional products from our portfolio of advanced cardiac biomarkers. Since our inception, we have incurred losses, and we have relied primarily on private placements of preferred stock and debt financing, as well as on revenue generated from the sale of products, to fund our operations. As of December 31, 2014, we had an accumulated deficit of $208.4 million, working capital of $14.0 million and stockholders’ equity of $0.8 million.
	We may require additional funds to uplist our Common Stock from the OTC Bulletin Board to NASDAQ and to broadly commercialize our products and develop new products. Our ability to fund our operations and to conduct the required development activities related to any new product candidates will be significantly limited if we are unable to obtain the necessary capital. We expect to seek to raise funds through equity or debt offerings, bank facilities, or other sources of capital. Additional funding may not be available when needed or on terms acceptable to us and we may need to implement additional cost cutting actions. The consent of Oxford Finance LLC will likely be required for additional debt financings. Any additional equity financing may be dilutive to stockholders, and debt financing, if available, may involve restrictive covenants. We cannot assure you that we will be able to raise any such additional funding.
	In August 2014, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Oxford Finance LLC (“Oxford”) to borrow up to $15 million, the entire amount of which was borrowed at a fixed interest rate of 6.95% per annum. The Loan Agreement contains a number of customary representations and warranties and customary covenants, including covenants regarding delivery of financial statements, maintenance of inventory, payment of taxes, maintenance of insurance, dispositions of property, business combinations or acquisitions, incurrence of additional indebtedness and transactions with affiliates. If the Company breaches any of these covenants or it is unable to make a required payment of principal or interest, or it experiences a material adverse change to its business, it could result in a default under the Loan and Security Agreement and the amount of the loan balance, plus accrued and unpaid interest, and final payment, and the prepayment fee, and other obligations due the lender would be come immediately payable.
	Our commercially-available products consist of the only two FDA-cleared tests to measure Lp-PLA2: The PLAC® Test ELISA Kit (the “PLAC ELISA Test”) first cleared by the FDA in 2003 and The PLAC® Test for Lp-PLA2 Activity (the “PLAC Activity Test) cleared in December 2014.  We pioneered the testing of Lp-PLA2 (lipoprotein-associated phospholipase A2), a cardiovascular risk marker that provides new information, over and above traditional risk factors measured in a lipid panel, and has over a decade of peer-reviewed literature evidencing this biomarker’s utility.  There is substantial clinical evidence validating this novel biomarker’s utility from over a decade of peer-reviewed literature, including The New England Journal of Medicine from March 30, 2014.  We sell our diagnostic products to laboratories and promote these products to the laboratories’ sales representatives as well as directly to healthcare providers to support our laboratory partners’ efforts. Physicians order testing for their patients from these laboratories and use the results to aid in assessing patient risk for coronary heart disease.
	Our company was initially incorporated in November 1995. In July 2010, we completed a reverse merger with former diaDexus, Inc., which was the successor to a company initially formed as a joint venture between SmithKlineBeecham Corporation (now GlaxoSmithKline LLC (“GSK”)) and Incyte Pharmaceuticals, Inc. Upon formation in September 1997, SmithKlineBeecham Corporation granted former diaDexus, Inc. an exclusive license to certain diagnostic intellectual property, including exclusive rights to develop diagnostic assays for Lp-PLA2. In November 2010, in connection with the reverse merger, we changed our name to diaDexus, Inc. Beginning in 2014, we assembled a new team of leaders, each with extensive experience in their respective functions.  This leadership team is responsible for the execution of strategies to evolve from a one-product business built around the first PLAC ELISA Test into a multi-product company with a portfolio of diagnostic products for growth.
	The following table summarizes the indications and regulatory status of our major products:
	Products		Indications	Regulatory Status
	PLAC® Test ELISA Kit		An aid in predicting risk for coronary heart disease (CHD) and ischemic stroke associated with atherosclerosis	Clearance from FDA first obtained for marketing in the U.S. in July 2003 for CHD and in June 2005 for ischemic stroke. CE mark in Europe. Commercialized in the U.S.
	PLAC® Test for Lp-PLA2 Activity		Used in conjunction with clinical evaluation and patient risk assessment as an aid in predicting risk of CHD in patients with no prior history of cardiovascular events,	Clearance from FDA obtained for marketing in the U.S. in December 2014. CE mark in Europe. Commercialized in Europe since March 2012. Launched in the U.S. January 2015.
	proADM		Aid in predication of heart failure, specific indication to be determined	In development on the ELISA platform for research use only (RUO) for pharmaceutical companies and for 510(k) submission to the FDA.  Evaluating development on other commercial platforms.
	proET-1		Aid in predication of heart failure, specific indication to be determined	n/a
	proANP		Aid in predication of heart failure, specific indication to be determined	n/a
	The PLAC ELISA test is available nationally through leading clinical reference labs and advanced cardiovascular specialty laboratories.  The launch of the new PLAC Activity Test is focused on a broad base of independent labs, hospital labs, and physician office labs.  Each test is covered under the established reimbursement code for Lp-PLA2 tests.
	Validation and Clinical Utility
	Our PLAC Tests are blood tests that measure Lp-PLA2 mass or activity levels, respectively, delivering valuable information to healthcare providers for the prediction of cardiac disease risk.  We pioneered the testing of Lp-PLA2 (lipoprotein-associated phospholipase A2), a marker of vascular-specific inflammation that provides new information, over and above traditional risk factors. In the REGARDS study, the validation study for FDA clearance of PLAC Activity Test, high PLAC Activity versus low PLAC Activity showed a greater hazard ratio for predicting subsequent coronary heart disease events than nearly all other established cardiovascular risk factors, including LDL and HDL.
	LDL alone has proven not to be a reliable predictor of CHD, with 50% of cardiovascular events occurring in patients with normal lipid levels. The PLAC Tests are designed to uncover this hidden risk and is recommended as an addition to a lipid panel for individuals with two or more risk factors for coronary heart disease.  In a consensus recommendation from the June 2008 supplement of the American Journal of Cardiology, leading cardiologists and neurologists proposed the PLAC ELISA Test should be used as an adjunct to traditional risk factor assessment to identify moderate and high-risk individuals who may actually be at an increased risk for heart attack or stroke. If a PLAC Test is elevated, healthcare providers can advise:
	·	Lifestyle changes, including smoking cessation programs, diabetes and hypertension management
	·	Lowering the LDL threshold for considering therapeutic intervention (i.e. individuals with high PLAC would have LDL threshold lowered from 130 to 100 in considering therapeutic intervention)
	·	Intensification of lipid-monitoring treatment
	·	Annual testing of Lp-PLA2
	All references in these notes to financial statements to the “Company,” “we,” “us” and “our” refer to diaDexus, Inc. (f/k/a VaxGen, Inc.), a Delaware corporation, unless the context requires otherwise.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying financial statements have been prepared in accordance with US generally accepted accounting principles (“GAAP”). Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, stockholders’ equity or cash flow.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets, including assets held for sale, and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results may differ significantly from those estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with original maturities of 90 days or less to be cash equivalents. Cash equivalents consist primarily of money market accounts.
	Restricted Cash
	Restricted cash represents term deposits, which expire in December 2016, held at one financial institution as collateral for the lease of the Company’s facilities in South San Francisco.
	Allowance for Doubtful Accounts
	The Allowance for Doubtful Accounts reflects our best estimate of probable losses inherent in the accounts receivable balance. We determine the allowance based on known troubled accounts, historical experience, and other currently available evidence. Activity in the allowance for doubtful accounts was as follows:
		2014		2013
	Balance, beginning of the period	$                             5		$                            -
	Charges to costs	1		5
	Write offs	—		—
	Balance, end of the period	$                             6		$                             5
	Inventory
	Inventories are stated as the lower of cost or market. Cost is determined using the first in, first out method. Market value is determined as the lower of replacement cost or net realizable value.
	Property and Equipment
	Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Laboratory equipment, computers, software, and office furniture are depreciated over three years. Leasehold improvements are recorded at cost and amortized over the term of the lease or their useful life, whichever is shorter. Maintenance and repairs are expensed as incurred.
	Segments
	The Company has one reportable segment and uses one measurement of profitability to manage its business. All long-lived assets are maintained in the United States of America.
	Revenues by geography are based on the billing address of the customer. The following table sets forth revenues by geographic area (in thousands):
		Years Ended December 31,
		2014			2013
	United States	$	26,043		$	24,316
	Europe		302			330
	Rest of the world		78			238
		$	26,423		$	24,884
	Revenue Recognition
	Revenues are generated from product sales, royalties earned, license fees and contract service arrangements, and recorded net of customer and distributor discounts. Revenue is recognized when the four basic criteria of revenue recognition are met: (i) a contractual agreement exists; (ii) delivery of product has occurred and risk of loss and title has transferred, transfer of technology (intellectual property) has been completed or services have been rendered; (iii) the fee is fixed or determinable; and (iv) collectability is reasonably assured. Service revenue is recognized as the contractually obligated services are performed, provided that the fee is fixed and determinable and collectability is reasonably assured.
	License fee revenue including nonrefundable upfront fees, is deferred and recognized over the term of the underlying agreements. Royalty revenue is recognized when reportable product sales are confirmed. Revenue from technology licenses or other payments under collaborative agreements where the Company has a continuing obligation to perform is recognized as revenue over the expected period of the continuing performance obligation. The term of these underlying agreements ranges from two to ten years.
	Starting in January 2013, the Company includes excise tax collected from customer product sales. The Company recognized $311,000 and $354,000 in charged excise tax within product revenue and product costs, respectively, for the year ended December 31, 2014. For the year ended December 31, 2013, there was $402,000 and $455,000 excise tax recognized within product revenue and product costs.
	Accruals
	In connection with the process of preparing financial statements, the Company estimates accrued expenses. This process involves communicating with our applicable personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of our service providers invoice us monthly in arrears for services performed. The Company makes estimates of accrued expenses as of each balance sheet date in the financial statements based on known facts and circumstances. The Company periodically confirms the accuracy of estimates with selected service providers and makes adjustments, if necessary.
	Research and Development
	Research and development expenses include internal and external costs. Internal costs include product development, regulatory support for technology, laboratory materials and supply costs and other technical support costs, including salaries and consultant fees. External expenses consist of sponsored research studies and investigator sponsored trials. Research and development costs are expensed as incurred.
	Impairment of Long-Lived Assets
	In accordance with Accounting Standards Codification (“ASC”) Subtopic ASC 360-10, impairment of long-lived assets is measured or assessed when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. 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. Long-lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
	Stock-Based Compensation
	The Company recognizes stock-based compensation expense for all stock-based payment awards in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all stock-based payments made to employees and directors including employee stock option awards, based on estimated fair value. Stock-based compensation expense for expected-to-vest stock-based awards is valued under the single-option approach and amortized on a straight-line basis, net of estimated forfeitures. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s statements of operations for all periods presented.
	The assumptions used in computing the fair value of stock-based awards reflect the Company’s best estimates, but involve uncertainties relating to market and other conditions, many of which are outside of the Company’s control. In addition, the Company’s estimate of future stock-based compensation expense will be affected by a number of items including the Company’s stock price, the number of stock options the Company’s board of directors may grant in future periods, as well as a number of complex and subjective valuation adjustments and the related tax effect.
	The fair value of nonvested restricted stock units (“RSUs”) is based on the Company’s closing stock price on the date of grant.
	The net loss for the years ended December 31, 2014 and 2013 include employee stock-based compensation expense of $839,000 and $632,000, respectively. As of December 31, 2014, the total unrecorded stock-based compensation expense for unvested stock options, net of expected forfeitures, was $2.0 million, which is expected to be amortized over a weighted-average period of 2.85 years.
	Fair Value Measurements
	In accordance with ASC Subtopic 820-10 the carrying amounts of certain financial instruments of the Company, including cash equivalents, marketable securities and liabilities, continue to be valued at fair value. ASC Subtopic 820-10 defines fair value and provides guidance for using fair value to measure assets and liabilities and is applicable whenever assets or liabilities are required or permitted to be measured at fair value.
	The fair value estimates presented reflect the information available to the Company as of December 31, 2014. See Note 4, “Fair Value Measurements.”
	Deferred Rent
	Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the buildings the Company leases. The leases provide for fixed increases in minimum annual rental payments and the total amount of rental payments due over the lease terms are being charged to rent expense ratably over the life of the leases.
	Comprehensive Income (Loss)
	Comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from investments or contributions by stockholders. The Company’s unrealized gains on available-for-sale securities represent the component of comprehensive income (loss) excluded from the Company’s net loss.
	Income Taxes
	The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	On January 1, 2009, the Company adopted ASC 740-10-25. For the years ended December 31, 2014 and 2013, the Company did not have any additional unrecognized tax benefits and there was no effect on its financial condition or results of operations as a result of adopting ASC 740-10-25. The Company’s practice is to recognize interest and/or penalties related to income tax matters in interest expense as incurred.
	. ,
	Recent Accounting Pronouncements
	In July 2013, Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-11, “Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carry forward, a Similar Tax Loss, or a Tax Credit Carry forward Exists (a consensus of the FASB Emerging Issues Task Force).” The amendments in this ASU provide guidance on the financial statements presentation of an unrecognized tax benefit when a net operating loss carry forward, a similar tax loss, or a tax credit carry forward exists. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carry forward, a similar tax loss, or a tax credit carry forward with certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU do not require new recurring disclosures and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The company does not believe that this requirement will have any substantial impact on the presentation of its reporting of our  financial operating results.
	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” The amendment in this ASU provides guidance on the revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The core principle of this update provides guidance to identify the performance obligations under the contract(s) with a customer and how to allocate the transactions proceeds to the performance obligations in the contract. It further provides guidance to recognize revenue when (or as) the entity satisfies a performance obligation. The company is currently assessing the future impact of this ASU on its financial statements.
	In August 2014 the FASB issued Accounting Standards Update No 2014-15: Presentation of Financial Statement Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). The update sets forth a requirement for management to evaluate whether there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U,S, auditing standards. Specifically, the amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation every reporting period, including interim periods, (3) provide principles for considering the mitigating effect of management’s plans.,(4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans. (5) require an express statement of other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date the financial statements are issued (or available to be issued). ASU will be effective for the Company in fiscal year 2016. The Company is currently assessing the future impact of this ASU date on its financial statements.

Cash_and_Cash_Equivalents

Cash and Cash Equivalents	12 Months Ended
	Dec. 31, 2014
Cash And Cash Equivalents [Abstract]
Cash and Cash Equivalents	3. Cash and Cash Equivalents
	The Company maintains its cash in bank accounts, which at times may exceed federally insured limits. The Company has not experienced any losses on such accounts. The Company considers all highly liquid investments purchased with an original maturity of 90 days or less at the time of purchase to be cash equivalents.
	The following is a summary of cash, and cash equivalents, as of December 31, 2014 and 2013 (in thousands):
		31-Dec-14
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	10,894	$	—	$	—	$	10,894
	Money market funds		4,052		—		—		4,052
	Total cash and cash equivalents	$	14,946	$	—	$	—	$	14,946
		31-Dec-13
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	12,800	$	—	$	—	$	12,800
	Money market funds		4,047		—		—		4,047
	Total cash and cash equivalents	$	16,847	$	—	$	—	$	16,847

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements
	In accordance with ASC 820, the Company discloses and recognizes the fair value of its assets and liabilities using a hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The guidance establishes three levels of the fair value hierarchy as follows:
	Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities;
	Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities;
	Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of December 31, 2014 and 2013 (in thousands):
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2014		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level 1		Level 2
	Assets:
	Cash	$	10,894	$	10,894	$	—	$	—
	Money market funds		4,052		4,052		—		—
	Restricted cash		1,400		—		1,400		—
		$	16,346	$	14,946	$	1,400	$	—
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2013		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level 1		Level 2
	Assets:
	Cash	$	12,800	$	12,800	$	—	$	—
	Money market funds		4,047		4,047		—		—
	Restricted cash		1,400		—		1,400		—
		$	18,247	$	16,847	$	1,400	$	—
	The fair value of the notes payable is based on Level 2 inputs and approximates its book value. The fair value of the notes payable is based on the present value of expected future cash flow and assumptions about current interest rates and the credit worthiness of the Company. As of December 31, 2014, the notes payable is carried at face value of $15.0 million less any unamortized debt discount. (See Note 10 Notes Payable).
	The carrying value of other financial instruments, including cash, accounts receivable, accounts payable and other payables, approximates fair value due to their short maturities.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventory	5. Inventory
	Inventory consists of the following (in thousands):
		December 31,		December 31,
		2014		2013
	Finished goods	$	234	$	361
	Work in process		271		-
	Raw materials		73		99
		$	578	$	460

Assets_Held_for_Sale

Assets Held for Sale

12 Months Ended

Dec. 31, 2014

Property Plant And Equipment Assets Held For Sale Disclosure [Abstract]

Assets Held for Sale

6. Assets Held for Sale

Prior to the period reflected in this report, the Company had committed to a plan to sell the equipment related to its manufacturing facility and had determined that these assets met the criteria for, and had been classified as, “held for sale” in accordance with ASC Topic 360. The market approach was use in determining the fair market value of these assets.

Total assets held for sale are as follows (in thousands):

Fair Value Measurements Using

Description

December 31,

Quoted

Significant

Significant

Year Ended

2014

Prices in

Other

Unobservable

December 31,

Active

Observable

Inputs

2014

Markets for

Inputs

(Level 3)

Total

Identical

(Level 2)

Gains (Losses)

Assets

(Level 1)

Assets held for sale

—

—

—

—

$

5

Fair Value Measurements Using

Description

December 31,

Quoted

Significant

Significant

Year Ended

2013

Prices in

Other

Unobservable

December 31,

Active

Observable

Inputs

2013

Markets for

Inputs

(Level 3)

Total

Identical

(Level 2)

Gains (Losses)

Assets

(Level 1)

Assets held for sale

$

—

$

—

$

—

$

—

$

340

The measurement of the assets held for sale at fair value incorporated significant unobservable inputs as a result of a lack of any available observable market information to determine the fair value. The calculation of the fair value of assets held for sale used a market valuation technique that relied on Level 3 inputs, including quoted prices for similar assets. The 2012, the Company signed an agreement to sell the assets for $695,000, net of disposal cost. All assets were transferred and sold to the purchaser as of December 31, 2013 and the Company recognized net gain of $340,000, which are included as other income (expenses), net in the statement of comprehensive loss for year ended December 31, 2013.      .

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	7. Property, Plant and Equipment
	Property and equipment are recorded at cost. Expenditures for major additions and improvements are capitalized, and maintenance and repairs are charged to expense as incurred. When property and equipment are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations for the respective period. Depreciation is provided over the estimated useful lives of the related assets using the straight-line method. The estimated useful lives for significant property and equipment categories are as follows:
	Office and laboratory equipment	3 years
	Computer equipment and software	3 years
	Leasehold improvements	Term of lease agreement
	The following is a summary of property and equipment at cost less accumulated depreciation as of December 31, 2014 and 2013 (in thousands):
		December 31,			December 31,
		2014			2013
	Laboratory equipment	$	2,402		$	2,299
	Leasehold improvements		616			616
	Computer and software		336			299
	Furniture and fixtures		101			81
	Construction in progress		49			149
			3,504			3,444
	Less: Accumulated depreciation and amortization		(2,867	)		(2,476	)
		$	637		$	968
	Depreciation and amortization expense for the years ended December 31, 2014 and 2013 was $0.5 million for each year.

Total_Accrued_and_Other_Curren

Total Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2014
Payables And Accruals [Abstract]
Total Accrued and Other Current Liabilities	8. Total Accrued and Other Current Liabilities
	Other current liabilities include the following as of December 31, 2014 and 2013 (in thousands):
		December 31,		December 31,
		2014		2013
	Accrued payroll and related expenses	$	1,084	$	1,481
	Accrued collaborative research obligations		612		46
	Accrued restructuring charges		736		—
	Accrued Board of Director fees		248		115
	Accrued property and equipment		—		11
	Other current liabilities		394		550
	Total accrued and other current liabilities	$	3,074	$	2,203
	During 2014, the Company entered into several transition agreements with key employees including its Chief Executive Officer, Chief Business Officer, and Chief Financial Officer. As of December 31, 2014, the Company has incurred $1.3 million in restructuring charges under these agreements. These costs are recorded in operating expenses in the Statements of Comprehensive Loss and the associated liabilities are recorded in accrued Other Current Liabilities in the Balance Sheet. As of December 31, 2014, the Company has made $0.6 million in payments under these agreements.  As of December 31, 2014, the accrued balance due under these agreements was $736,000. This accrued balance will be paid out during 2015. See Note. 15“Restructuring and Other Charges” for a further discussion of costs, payments and the ending accrual balance related to these restructuring charges.
	Accrued collaborative research obligations represent $0.6 million in payments payable to B.R.A.H.M.s GmbH, for the license of three heart failure markers. This balance will be settled in March 2015.

Concentration_of_Credit_Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2014
Risks And Uncertainties [Abstract]
Concentration of Credit Risk	9. Concentration of Credit Risk
	Revenues from the following distributor and large laboratory customers represented a significant portion of total revenue for the years ended December 31, 2014 and 2013 and accounts receivable as of December 31, 2014 and 2013. Below are the top five customers that constitute the noted percentages of our revenues and accounts receivable for 2013 and 2014.
		Revenue						Accounts Receivable
		December 31,			December 31,			December 31,			December 31,
		2014			2013			2014			2013
	Customer A		29	%		44	%		7	%		36	%
	Customer B		19	%		4	%		61	%		2	%
	Customer C		15	%		14	%		4	%		10	%
	Customer D		11	%		10	%		3	%		15	%
	Customer E		3	%		6	%		1	%		11	%
	Total		77	%		78	%		76	%		74	%

Notes_Payable

Notes Payable	12 Months Ended
	Dec. 31, 2014
Notes Payable [Abstract]
Notes Payable	10. Notes Payable
	In August 2014, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Oxford Finance LLC (“Oxford”) to borrow up to $15 million, the entire amount of which was borrowed at a fixed interest rate of 6.95% per annum. The obligations under the Loan Agreement are payable in 48 monthly installments which began in October 2014, with interest only payments to be made from October 2014 to September 2015, followed by 36 months of equal principal and interest payments. If the Company’s trailing six month revenues equal or exceed $15 million at the end of the fiscal month ending July 31, 2015, the Company may continue to make interest only payments through September 2016 followed by 24 months of equal principal and interest payments.
	The Company paid an initial fee of $150,000 for access to this loan and will be required to pay an additional $1.5 million following the earlier of loan maturity or termination. The Company may prepay all, but not less than all, of the loan amount with 10 days advance notice to Oxford and payment of a prepayment premium. In connection with the Loan Agreement, the Company issued a warrant to Oxford to purchase 909,090 shares of the Company’s common stock (see Note 13 of these Notes to Financial Statements).
	The Company granted Oxford a security interest in substantially all of the Company’s personal property to secure the Company’s payment and other obligations under the Loan Agreement. The security interest does not extend to patents, trademarks and other intellectual property rights (except for the rights to payment related to the sale, licensing or disposition of such intellectual property rights) or certain other specified property.
	The Loan Agreement contains a number of customary representations and warranties and customary covenants, including covenants regarding delivery of financial statements, maintenance of inventory, payment of taxes, maintenance of insurance, dispositions of property, business combinations or acquisitions, incurrence of additional indebtedness and transactions with affiliates. The Company is also restricted from paying dividends or making other distributions or payments of its capital stock except for repurchases of stock pursuant to employee stock purchase plans, employee restricted stock agreements, stockholder rights plans, director or consultant stock option plans, or similar plans, provided such repurchases do not exceed $250,000 in the aggregate per fiscal year. If the Company breaches any of these covenants or it is unable to make a required payment of principal or interest, or it experiences a material adverse change to its business, it could result in a default under the Loan and Security Agreement and the amount of the loan balance, plus accrued and unpaid interest, and final payment, and the prepayment fee, and other obligations due the lender would be come immediately payable. As of December 31, 2014, the Company was in compliance with all the covenants.
	The Company recorded debt discount of $470,000 associated with the Loan Agreement and the amount will be amortized as interest expense over the term of the Loan Agreement using the effective interest method. Concurrent with the execution of the Loan Agreement, in August 2014, the Company used $8.4 million of the proceeds received from the loan to repay its existing loan with Comerica Bank. All Loan and Security Agreements previously entered with Comerica Bank were terminated upon receipt of this repayment. The Company was in compliance with all the covenants with Comerica Bank prior to the repayment.
	The Company accounted for the repayment to Comerica Bank as a debt extinguishment since the issuance of the new loan is with another unrelated creditor. Accordingly, the Company accelerated and expensed the unamortized debt discount of $132,000, debt issuance costs of $82,000 and balloon payment of $117,000 to interest expense in August 2014.
	The Company recorded $81,000 of loss from the debt extinguishment as interest expense in August 2014. This amount represents a pre-payment premium pursuant to the Amended Loan and Security Agreement entered into with Comerica Bank.
	Future minimum payments for the notes payable are as follows (in thousands):
	2015	$	2,170
	2016		5,554
	2017		5,554
	2018		5,665
	Total minimum payments		18,943
	Less: Amount representing interest		(3,943	)
	Present value of minimum payments		15,000
	Less: Unamortized debt discount		(252	)
	Notes payable, net		14,748
	Less: Notes payable, current portion		(957	)
	Non-current portion of notes payable	$	13,791

Basic_and_Diluted_Net_Loss_per

Basic and Diluted Net Loss per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Basic and Diluted Net Loss per Share	11. Basic and Diluted Loss per Share
	Basic net loss per common share is based on the weighted average number of common shares outstanding during the period. Diluted net loss per common share is based on the weighted average number of common shares and other dilutive securities outstanding during the period, provided that including these dilutive securities do not increase the net loss per share.
	The effect of the options and warrants was anti-dilutive for the years ended December 31, 2014 and 2013. The following table shows the total outstanding securities considered anti-dilutive and therefore, excluded from the computation of diluted net loss per share (in thousands):
		As of December 31,
		2014		2013
	Options to purchase common stock		10,797		9,705
	Warrants to purchase common stock		1,175		266
	Restricted stock units		—		42
	Total		11,972		10,013

Stock_Based_Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	12. Stock Based Compensation
	Stock Option Plans
	2012 Equity Incentive Award Plan
	The Company’s stockholders approved the 2012 Equity Incentive Award Plan (the “2012 Plan”) at the 2012 Annual Meeting of Stockholders on May 17, 2012 and approved 3,000,000 shares of common stock authorized for issuance. Upon approval of the 2012 Plan, all shares of common stock that remained available for issuance under the 1996 Stock Option Plan (the “1996 Plan”) and the 1998 Director Stock Option Plan (the “Director Plan”) were added to the shares reserved under the 2012 Plan. In addition, pursuant to the 2012 Plan, any shares of common stock subject to awards previously granted under the 1996 Plan, the Director Plan and certain non-plan option agreements entered into with certain individuals as of March 31, 2012 that terminate, expire or lapse will become available for issuance under the 2012 Plan. The 2012 Plan provides for the granting of options, restricted stock awards, restricted stock unit award, performance awards, dividend equivalents awards, deferred stock awards, deferred stock unit awards, stock payment awards and stock appreciation rights to employees, non-employee directors and consultants. Options granted under the 2012 Plan may be designated as qualified or nonqualified at the discretion of the Compensation Committee of the Board of Directors. Generally, shares issuable upon exercise of options vest ratably over four years, beginning one year from the date of grant; however, options can vest upon grant. Option terms expire no later than 10 years from the date of grant, or 5 years from the date the option is granted to a greater than 10% stockholder. The stock options are exercisable at not less than the fair market value of the stock at the date of grant, or not less than 110% of the fair market value of the stock at the date of grant if granted to a greater than 10% stockholder. The Company has also granted restricted stock unit (“RSU”) awards under the 2012 Plan. RSU awards entitle the recipient to receive one share of the Company’s common stock for every RSU upon vesting. RSUs generally vest annually. As of December 31, 2014, options to purchase 7,410,373 shares of common stock were outstanding. There were no shares of common stock that were issuable upon the settlement of outstanding RSUs and 2,821,781 shares were available for issuance under the 2012 Plan.
	1996 Stock Option Plan
	The 1996 Plan initially had 4,750,000 shares of common stock authorized for issuance and a provision that automatically increased this number by 3.5% of the issued and outstanding common stock on the last trading day of the December immediately preceding each fiscal year through January 2007. Options granted under the 1996 Plan were designated as qualified or nonqualified at the discretion of the Compensation Committee of the Board of Directors. Generally, shares issuable upon exercise of options vest ratably over four years, beginning one year from the date of grant; however, options could vest upon grant. All options expire no later than 10 years from the date of grant. Qualified stock options are exercisable at not less than the fair market value of the stock at the date of grant, and nonqualified stock options are exercisable at prices determined at the discretion of the Board of Directors, but not less than 85% of the fair market value of the stock at the date of grant. On May 17, 2012, the 1996 Plan was terminated in connection with the effectiveness of the 2012 Plan. All 1,555,492 shares that were available for issuance under the 1996 Plan were transferred to the 2012 Plan, and the 6,398,904 shares that were subject to awards outstanding under the 1996 Plan remained outstanding pursuant to the terms of the 1996 Plan. As of December 31, 2014, options to purchase 2,104,225 shares of common stock were outstanding pursuant to the terms of the 1996 Plan.
	1998 Director Stock Option Plan
	The Director Plan for non-employee directors had 300,000 shares of common stock authorized for issuance. On May 17, 2012, the Director Plan was terminated in connection with the effectiveness of the 2012 Plan. All 130,000 shares that were available for issuance under the Director Plan were transferred to the 2012 Plan, and the 170,000 shares that were subject to awards outstanding under the Director Plan remained outstanding pursuant to the terms of the Director Plan. As of December 31, 2014, there were no options to purchase shares of common stock that were outstanding pursuant to the terms of the Director Plan.
	Non-Plan Grants
	In October 2004, the Company granted non-qualified stock options to purchase 30,000 shares of common stock outside of the Company’s stock option plans to its former director with an exercise price of $12.27 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2014, none of these options remain outstanding.
	In September 2011, the Company granted non-qualified stock options to purchase 1,530,000 shares of common stock outside of the Company’s stock option plans to its former Chief Executive Officer with an exercise price of $0.25 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2014, 1,282,083 options remained outstanding.
	In October 2011, the Company granted non-qualified stock options to purchase 1,130,000 shares of common stock outside of the Company’s stock option plans to its former Chief Business Officer with an exercise price of $0.26 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2014, none of these options remained outstanding.
	On February 1, 2012, the Company granted non-qualified stock options to purchase 1,060,000 shares of common stock outside of the Company’s stock option plans to its former Chief Financial Officer with an exercise price of $0.28 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2014, none of these options remained outstanding.
	Restricted Stock Units
	On August 6, 2013, the Company awarded an aggregate of 41,708 RSUs to its directors with a grant-date fair value equal to approximately $55,000 in the aggregate. Each RSU entitles the recipient to receive one share of the Company’s common stock upon vesting. RSUs awarded to directors generally vest annually. The fair value of nonvested RSUs is based on the Company’s closing stock price on the date of grant. As of December 31, 2014, all of these RSU’s were vested, and none remain outstanding.
	A summary for the year ended December 31, 2014 is as follows:
		Shares of			Average Grant			Weighted		Aggregate
		Underlying			Date Fair Value			Remaining Vesting		Intrinsic
		RSUs			Price per Share			Period		Value
								(In years)
	Nonvested as of December 31, 2012		-			-
	Granted		41,708		$	1.33			0.5	$	37,537
	Vested and released		-			-					-
	Nonvested as of December 31, 2013		41,708		$	1.33			0.5	$	37,537
	Granted		-			-					-
	Vested and released		(41,708	)	$	1.33			0.5	$	(37,537	)
	Nonvested as of December 31, 2014		—			—			—		—
	Stock Based Compensation Expense
	The following table summarizes stock compensation expense related to employee stock options and employee stock-based compensation expense for the years ended December 31, 2014 and 2013 which were incurred as follows (in thousands):
		Years Ended December 31,
		2014			2013
	Stock-based compensation expense:
	General and administrative	$	623		$	361
	Research and development		61			135
	Sales and marketing		125			113
	Product costs		29			23
	Total stock-based compensation expense	$	838		$	632
	Valuation Assumptions
	The compensation expense related to stock options recognized was determined using the Black-Scholes option valuation model. Option valuation models require the input of subjective assumptions and these assumptions can vary over time. The weighted average assumptions used were as follows:
		Years ended December 31,
		2014			2013
	Dividend yield		0	%		0	%
	Risk-free interest rate		1.5	%		0.9	%
	Expected volatility		98.4	%		84.7	%
	Forfeiture rate		15	%		13.9	%
	Expected term (years)		4.15			4.06
	Fair value per share at grant date	$	0.37		$	0.61
	The expected stock price volatility assumption was determined by examining the historical volatilities for industry peers, and the trading history for the Company’s common stock. For the year ended December 31, 2014, volatility assumption was determined by examining historical volatilities of the trading history for the Company’s common stock for that period. The Company will continue to analyze its own historical stock price volatility as more historical data for the Company’s common stock becomes available. The risk-free interest rate assumption is based on the US Treasury instruments whose term was consistent with the expected term of the Company’s stock options. The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. Different estimates of volatility and expected term could materially change the value of an option and the resulting expense. The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. The Company considers option vesting terms, contractual terms and historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior.
	Employee Stock-Based Compensation
	The table below presents information related to stock option activity, net of options previously exercised:
		Number of			Weighted-			Weighted-		Aggregate
		Options			Average			Average		Intrinsic
		Outstanding			Exercise			Remaining		Value
					Price			Contractual
								Term
								(In years)
	Outstanding as of December 31, 2012		8,963,226		$	0.47
	Options granted		1,563,910			1
	Options exercised		(664,568	)		0.26
	Options cancelled/forfeited/expired		(157,484	)		4.53
	Outstanding as of December 31, 2013		9,705,084			0.5			7.92		5,112,805
	Options granted		5,789,500			0.51
	Options exercised		(2,432,239	)		0.28
	Options cancelled/forfeited/expired		(2,265,664	)		0.89
Outstanding as of December 31, 2014		10,796,681		$	0.45			6.35	$	1,264,881
Exercisable as of December 31, 2014		5,167,878		$	0.42			4.57	$	869,314
Vested and expected to vest as of December 31, 2014		9,411,926		$	0.45			6.13	$	1,166,624
The following table summarizes information relating to stock options outstanding as of December 31, 2014:
	Options Outstanding								Options Exercisable
Range of Exercise Price	Number			Weighted			Weighted		Number			Weighted
	Outstanding			Average			Average		Exercisable			Average
				Remaining			Exercise					Exercise
				Contractual			Price					Price
				Life (In Years)
0.14		51,000			6.95		$	0.14		40,250		$	0.14
0.25		1,288,083			0.23		$	0.25		1,287,333		$	0.25
0.26-- 0.29		1,597,225			3.99		$	0.27		1,568,317		$	0.27
0.33--0.36		1,587,018			7.88		$	0.35		917,021		$	0.35
0.39		330,000			6.05		$	0.39		323,125		$	0.39
0.41		3,078,000			9.96		$	0.41		1,666		$	0.41
0.44--0.68		1,257,312			1.92		$	0.63		60,437		$	0.44
0.72--0.75		1,082,918			9.05		$	0.73		500,022		$	0.74
0.77--1.19		195,125			6.88		$	0.92		139,707		$	0.96
1.32		330,000			8.6		$	1.32		330,000		$	1.32
$0.14 – $1.32		10,796,681			6.35		$	0.45		5,167,878		$	0.42
The estimated fair value of grants of stock options to non-employees of the Company is charged to expense in the financial statements. These options vest in the same manner as the employee options granted under the option plan as described above.
The intrinsic value of options exercised during the year ended December 31, 2014 was $446,000.
Stock based compensation expense recognized during the years ended December 31, 2014 and 2013 includes compensation expense for stock based awards granted to employees based on the grant date fair value estimated in accordance with the provisions of ASC 718. As of December 31, 2014, the total remaining unrecognized cost of approximately $2.0 million is expected to be recognized over approximately three years.
Shares Reserved for Future Issuance
The Company had reserved shares of common stock for future issuance as of December 31, 2014 and 2013 as follows:
	As of December 31,
	2014			2013
Options to purchase common stock		10,796,681			9,705,084
Warrants to purchase common stock		1,174,694			265,604
Restricted stock units		—			41,708
Shares available for option grants		2,821,781			2,345,617
Total		14,793,156			12,358,013

Stock_Warrants

Stock Warrants	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stock Warrants	13. Stock Warrants
	The Company issues warrants to investors as part of its overall financing strategy and to vendors in order to reduce costs. In connection with the loan and security agreement the Company entered into with Comerica bank (Note 9) in September 2011, the Company issued a warrant to purchase 480,769 shares of the Company’s common stock, at an exercise price of $0.26 per share. The warrant expires in September 2018. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 88.03%, risk-free interest rate of 1.36%, exercise price of $0.26 and an expected life of 7 years. The fair value of the warrant was determined to be $94,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. Through August 2012, the discount was amortized to interest expense using the effective interest rate method over the 48-month term of the original loan. Comerica exercised this warrant in August 2013. In August 2014, this Loan Agreement was terminated and the outstanding balance was paid to Comerica. All unamortized balances related to this loan were charged to interest expense in August 2014.
	In connection with the First Amended Loan and Security Agreement, the Company issued a warrant to purchase 168,919 shares of the Company’s common stock, at an exercise price of $0.37 per share. This warrant expires in September 2019. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 89.87%, risk-free interest rate of 1.03%, exercise price of $0.37 and an expected life of 7 years. The fair value of the warrant was determined to be $48,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. In August 2014 this Loan Agreement was terminated and the outstanding balance was paid to Comerica. All unamortized balances related to this loan were charged to interest expense in August 2014.
	In connection with the Second Amended Loan and Security Agreement the Company issued a warrant to purchase 96,685 shares of the Company’s common stock, at an exercise price of $1.81 per share. This warrant expires in October 2020. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 89.01%, risk-free interest rate of 2.05%, exercise price of $1.81 and an expected life of 7 years. The fair value of the warrant was determined to be $136,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. In August 2014 this Loan Agreement was terminated and the outstanding balance was paid to Comerica. All unamortized balances related to this loan were charged to interest expense in August 2014.
	In August 2013, the Company issued 386,784 shares of common stock pursuant to a cashless exercise of Comerica’s warrant to purchase 480,769 shares at an exercise price of $0.26 per share. As of December 31, 2014, there were warrants outstanding to purchase 1,174,694 shares of the Company’s common stock, with a weighted-average exercise price of $0.71 per share and an aggregate exercise price of $0.8 million.
	In August 2014, in connection with the Loan and Security Agreement, the Company entered into with Oxford, (see Note 10 to these Notes to Financial Statements). The Company issued Oxford a warrant to purchase 909,090 shares of the Company’s common stock, at an exercise price of $0.66 per share and with an expiration date of August 2021.
	The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 90.29%, risk-free interest rate of 2.06%, exercise price of $0.66 and expected life of 7 years. The fair value of the warrant was determined to be $470,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. The discount is being amortized to interest expense using the effective interest rate method over the remaining term of the loan which matures in September 2018.
	The following table summarizes information about all warrants outstanding as of December 31, 2014:
		Warrants Outstanding and Exercisable
	Exercise Price	Number		Weighted		Weighted
		Outstanding		Average		Average
				Remaining		Exercise
				Contractual		Price
				Life (In Years)
	0.37		168,919		4.7	$	0.37
	0.66		909,090		6.62	$	0.66
	1.81		96,685		5.8	$	1.81
			1,174,694		6.25	$	0.71

Leases_Commitments_and_Conting

Leases, Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Leases, Commitments and Contingencies	14. Leases, Commitments and Contingencies
	The Company leases an office and laboratory facility (the “349 Facility”) under a long-term, non-cancelable operating lease agreement, which expires in December 2016.
	In connection with its leased facilities, the Company recognized a liability for asset retirement obligations representing the present value of estimated remediation costs to be incurred at the expiration of the 349 Facility lease. The following table describes changes to the Company’s asset retirement obligation liability for the years ended December 31, 2014 and 2013 (in thousands):
		Years Ended December 31,
		2014		2013
	Asset retirement obligation, beginning of year	$	334	$	302
	Accretion expense		35		32
	Asset retirement obligation, end of year	$	369	$	334
	In 2010, the Company recorded a lease obligation associated with the 349 Facility, which contained a lease payment that exceeded current market rates. Accordingly, the Company recognized a $4.1 million unfavorable lease obligation in 2010. The Company amortizes the unfavorable lease obligation using the effective interest rate method. The carrying amount, net of accumulated amortization, of the unfavorable lease liability, was $1.8 million as of December 31, 2014.
	Rent expense for the Company’s facilities was $1.8 million and $1.9 million for the years ended December 31, 2014 and 2013, respectively. The terms of the lease for the 349 Facility provides for rental payments on a graduated scale. The Company recognizes rent expense on a straight-line basis over the lease period. Deferred rent of $336,000 and $387,000 as of December 31, 2014 and 2013, respectively, is included in the accompanying balance sheet.
	At December 31, 2014, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating
		Leases
	2015		2,658
	2016		2,738
	Total minimum lease payments	$	5,396
	In March 2014, the Company entered into a License and Supply Agreement (“the Agreement”) with B.R.A.H.M.S GmbH. Under terms of the agreement, the Company paid 750,000 Euros in April 2014 and it is obligated to pay another 500,000 Euros in March 2015. The Company may pay up to 500,000 Euros in development and regulatory milestones and post-launch commercialized milestones up to a total of 1,000,000 Euros and royalties on future sales.
	Legal Proceedings
	The Company is from time to time subject to various claims and legal actions during the ordinary course of business. The Company believes that there are currently no claims or legal actions that would reasonably be expected to have a material adverse effect on its results of operations, future cash flows or financial condition

Restructuring_and_Other_Charge

Restructuring and Other Charges	12 Months Ended
	Dec. 31, 2014
Restructuring And Other Charges [Abstract]
Restructuring and Other Charges	15. Restructuring and Other Charges
	During the 12 months ended December 31, 2014, the Company incurred $1,238,000 in employee severance costs and $60,000 in other costs. These costs are recorded in operating expenses in the Statements of Comprehensive Loss and the associated liabilitiesare recorded in the Balance Sheets. The Company paid $550,000 in employee severance costs and $12,000 in other costs during the year ended December 31, 2014. As of December 31, 2014, the entire balance of $736,000 in restructuring accrual was classified as short-term and recorded within accrued and other current liabilities in the Balance Sheet. The Company does not expect to incur any additional restructuring expenses in 2015 that relates to the restructuring activities undertaken in 2014. The following table summarizes changes in the restructuring accrual for the twelve months ended December 31, 2014.
		For 12 months Ended December 31, 2014
		Employee	Other	Total
		Severance Costs	Costs
	Beginning balance	$                          —	$                          —	$                          —
	Charges	1,238	60	1,298
	Payments	-550	-12	-562
	Ending  Balance	$                         688	$                           48	$                         736

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes
	Provision for Income Tax
	The Company files US Federal and California state tax returns and the tax provision is composed as follows (in thousands):
		December 31,
		2014			2013
	Current Tax Expense:
	Federal	$	0		$	—
	State		15			5
	Total current tax expense		15			5
	Deferred Tax Expense:
	Federal		—			—
	State		—			—
	Total deferred tax expense		—			—
	Net tax provision (benefit)	$	15		$	5
	The differences between the US statutory tax rate and the Company’s effective tax rate are as follows:
		December 31,
		2014			2013
	Statutory rate		34	%		34	%
	State taxes, net of Federal benefit		4.6			11.5
	Change in state rate		(3.4	)		(22.9	)
	R&D credit		(1.4	)		(7.3	)
	Permanent differences		(0.7	)		(3.6	)
	State minimum taxes		(0.1	)		(0.3	)
	Change in valuation allowance		(32.7	)		(13.5	)
	Other		(0.5	)		1.9
	Effective tax rate		(0.2	)%		(0.2	)%
	As of December 31, 2014, the Company had approximately $244 million of federal, $162 million of California, and $27 million of other state net operating loss carryforwards available to offset future taxable income. These loss carry forwards begin to expire in 2019 for federal purposes, in 2016 for California purposes and in 2015 for other state purposes.
	As of December 31, 2014, the Company had credit carry forwards of approximately $4.6 million and $4.8 million available to reduce future taxable income, if any, for federal and California state income tax purposes, respectively. The federal R&D credit carry forwards expire starting 2019 and California credits can be carried forward indefinitely. In December 2014, Congress voted to retroactively extend the Federal R&D tax credit for the tax year 2014.
	Based on the weight of available evidence, including cumulative losses since inception and expected future losses, the Company has determined that it is more likely than not that the deferred tax asset amount will not be realized and therefore a full valuation allowance has been provided on net deferred tax assets.
	As of December 31, 2014 and 2013, the Company had deferred tax assets of approximately $111.3million and $108.5 million, respectively, which have been fully offset by a valuation allowance. The net valuation allowance increased by approximately $2.8 million in the year ended December 31, 2014 and decreased by approximately $0.7 million during the year ended December 31, 2013. Deferred tax assets primarily relate to net operating loss and research tax credit carry forwards.
	The tax effects of temporary differences and carry forwards that give rise to deferred tax assets are as follows (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Accruals and reserves	$	1,348		$	1,694
	Fixed assets		2,168			2,338
	Deferred research expense		2,306			3,667
	Stock options		3,970			3,822
	Net operating loss carryforwards		93,676			89,306
	Research tax credit carryforwards		7,784			7,664
	Other		12			9
	Total deferred tax assets		111,264			108,500
	Less: Valuation allowance		(111,264	)		(108,500	)
	Net deferred tax assets	$	—		$	—
	Under the provisions of Sections 382 and 383 of the Internal Revenue Code, a change of control, as defined, may impose an annual limitation on the amount of the Company’s net operating loss and tax credit carry forwards, and other tax attributes, that can be used to reduce future tax liabilities. As a result of the Reverse Merger, certain of the Company’s Old diaDexus tax attributes are subject to an annual limitation of $240,000 for federal and state purposes.
	We revised our previously reported disclosure to reduce the 2013 deferred tax credit carryforwards, uncertain tax positions and valuation allowance by $877,000. This error was not material to the prior financial statements and the correction had no impact on our Statements of Comprehensive Loss, Balance Sheets, Statements of Cash Flows or Statements of Stockholders’ Equity for any period presented.
	Uncertain Tax Positions
	Effective January 1, 2009, the Company adopted ASC 740-10 (formerly known as FIN 48), Accounting for Income Taxes, guidance that addresses the recognition, measurement, and disclosure of uncertain tax positions. The Company performed a full analysis of uncertain tax positions at December 31, 2010. The Company has no new uncertain tax positions for 2014.
	As of December 31, 2013, the Company had approximately $2.5 million of unrecognized tax benefits relating to the reserve on R&D credits. In 2014, this amount was increased by $39 thousand as a result of a reserve placed on R&D credits generated during the current year. As the Company has not utilized any of these credits, no reserve is recorded on the financial statements.
	The following table reflects the changes in the gross unrecognized tax benefits for the years ended December 31 (in thousands):
		2014			2013
	Balance at January 1	$	2,461		$	2,269
	Increase related to gross up state positions		—			251
	Increase related to current year positions		39			34
	Decrease related to expiration of credits		—			(93	)
	Balance at December 31	$	2,500		$	2,461
	The Company is currently not subject to any income tax examinations. Due to the Company’s losses, generally all years remain open.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events
	None

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
	The accompanying financial statements have been prepared in accordance with US generally accepted accounting principles (“GAAP”). Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, stockholders’ equity or cash flow.
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets, including assets held for sale, and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results may differ significantly from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with original maturities of 90 days or less to be cash equivalents. Cash equivalents consist primarily of money market accounts.
Restricted Cash	Restricted Cash
	Restricted cash represents term deposits, which expire in December 2016, held at one financial institution as collateral for the lease of the Company’s facilities in South San Francisco.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts
	The Allowance for Doubtful Accounts reflects our best estimate of probable losses inherent in the accounts receivable balance. We determine the allowance based on known troubled accounts, historical experience, and other currently available evidence. Activity in the allowance for doubtful accounts was as follows:
		2014		2013
	Balance, beginning of the period	$                             5		$                            -
	Charges to costs	1		5
	Write offs	—		—
	Balance, end of the period	$                             6		$                             5
Inventory	Inventory
	Inventories are stated as the lower of cost or market. Cost is determined using the first in, first out method. Market value is determined as the lower of replacement cost or net realizable value.
Property and Equipment	Property and Equipment
	Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Laboratory equipment, computers, software, and office furniture are depreciated over three years. Leasehold improvements are recorded at cost and amortized over the term of the lease or their useful life, whichever is shorter. Maintenance and repairs are expensed as incurred.
Segments	Segments
	The Company has one reportable segment and uses one measurement of profitability to manage its business. All long-lived assets are maintained in the United States of America.
	Revenues by geography are based on the billing address of the customer. The following table sets forth revenues by geographic area (in thousands):
		Years Ended December 31,
		2014			2013
	United States	$	26,043		$	24,316
	Europe		302			330
	Rest of the world		78			238
		$	26,423		$	24,884
Revenue Recognition	Revenue Recognition
	Revenues are generated from product sales, royalties earned, license fees and contract service arrangements, and recorded net of customer and distributor discounts. Revenue is recognized when the four basic criteria of revenue recognition are met: (i) a contractual agreement exists; (ii) delivery of product has occurred and risk of loss and title has transferred, transfer of technology (intellectual property) has been completed or services have been rendered; (iii) the fee is fixed or determinable; and (iv) collectability is reasonably assured. Service revenue is recognized as the contractually obligated services are performed, provided that the fee is fixed and determinable and collectability is reasonably assured.
	License fee revenue including nonrefundable upfront fees, is deferred and recognized over the term of the underlying agreements. Royalty revenue is recognized when reportable product sales are confirmed. Revenue from technology licenses or other payments under collaborative agreements where the Company has a continuing obligation to perform is recognized as revenue over the expected period of the continuing performance obligation. The term of these underlying agreements ranges from two to ten years.
	Starting in January 2013, the Company includes excise tax collected from customer product sales. The Company recognized $311,000 and $354,000 in charged excise tax within product revenue and product costs, respectively, for the year ended December 31, 2014. For the year ended December 31, 2013, there was $402,000 and $455,000 excise tax recognized within product revenue and product costs.
Accruals	Accruals
	In connection with the process of preparing financial statements, the Company estimates accrued expenses. This process involves communicating with our applicable personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of our service providers invoice us monthly in arrears for services performed. The Company makes estimates of accrued expenses as of each balance sheet date in the financial statements based on known facts and circumstances. The Company periodically confirms the accuracy of estimates with selected service providers and makes adjustments, if necessary.
Research and Development	Research and Development
	Research and development expenses include internal and external costs. Internal costs include product development, regulatory support for technology, laboratory materials and supply costs and other technical support costs, including salaries and consultant fees. External expenses consist of sponsored research studies and investigator sponsored trials. Research and development costs are expensed as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	In accordance with Accounting Standards Codification (“ASC”) Subtopic ASC 360-10, impairment of long-lived assets is measured or assessed when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. 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. Long-lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
Stock-Based Compensation	Stock-Based Compensation
	The Company recognizes stock-based compensation expense for all stock-based payment awards in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all stock-based payments made to employees and directors including employee stock option awards, based on estimated fair value. Stock-based compensation expense for expected-to-vest stock-based awards is valued under the single-option approach and amortized on a straight-line basis, net of estimated forfeitures. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s statements of operations for all periods presented.
	The assumptions used in computing the fair value of stock-based awards reflect the Company’s best estimates, but involve uncertainties relating to market and other conditions, many of which are outside of the Company’s control. In addition, the Company’s estimate of future stock-based compensation expense will be affected by a number of items including the Company’s stock price, the number of stock options the Company’s board of directors may grant in future periods, as well as a number of complex and subjective valuation adjustments and the related tax effect.
	The fair value of nonvested restricted stock units (“RSUs”) is based on the Company’s closing stock price on the date of grant.
	The net loss for the years ended December 31, 2014 and 2013 include employee stock-based compensation expense of $839,000 and $632,000, respectively. As of December 31, 2014, the total unrecorded stock-based compensation expense for unvested stock options, net of expected forfeitures, was $2.0 million, which is expected to be amortized over a weighted-average period of 2.85 years.
Fair Value Measurements	Fair Value Measurements
	In accordance with ASC Subtopic 820-10 the carrying amounts of certain financial instruments of the Company, including cash equivalents, marketable securities and liabilities, continue to be valued at fair value. ASC Subtopic 820-10 defines fair value and provides guidance for using fair value to measure assets and liabilities and is applicable whenever assets or liabilities are required or permitted to be measured at fair value.
	The fair value estimates presented reflect the information available to the Company as of December 31, 2014. See Note 4, “Fair Value Measurements.”
Deferred Rent	Deferred Rent
	Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the buildings the Company leases. The leases provide for fixed increases in minimum annual rental payments and the total amount of rental payments due over the lease terms are being charged to rent expense ratably over the life of the leases.
Comprehensive Income (Loss)	Comprehensive Income (Loss)
	Comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from investments or contributions by stockholders. The Company’s unrealized gains on available-for-sale securities represent the component of comprehensive income (loss) excluded from the Company’s net loss.
Income Taxes	Income Taxes
	The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	On January 1, 2009, the Company adopted ASC 740-10-25. For the years ended December 31, 2014 and 2013, the Company did not have any additional unrecognized tax benefits and there was no effect on its financial condition or results of operations as a result of adopting ASC 740-10-25. The Company’s practice is to recognize interest and/or penalties related to income tax matters in interest expense as incurred.
	. ,
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In July 2013, Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-11, “Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carry forward, a Similar Tax Loss, or a Tax Credit Carry forward Exists (a consensus of the FASB Emerging Issues Task Force).” The amendments in this ASU provide guidance on the financial statements presentation of an unrecognized tax benefit when a net operating loss carry forward, a similar tax loss, or a tax credit carry forward exists. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carry forward, a similar tax loss, or a tax credit carry forward with certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU do not require new recurring disclosures and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The company does not believe that this requirement will have any substantial impact on the presentation of its reporting of our  financial operating results.
	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” The amendment in this ASU provides guidance on the revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The core principle of this update provides guidance to identify the performance obligations under the contract(s) with a customer and how to allocate the transactions proceeds to the performance obligations in the contract. It further provides guidance to recognize revenue when (or as) the entity satisfies a performance obligation. The company is currently assessing the future impact of this ASU on its financial statements.
	In August 2014 the FASB issued Accounting Standards Update No 2014-15: Presentation of Financial Statement Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). The update sets forth a requirement for management to evaluate whether there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U,S, auditing standards. Specifically, the amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation every reporting period, including interim periods, (3) provide principles for considering the mitigating effect of management’s plans.,(4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans. (5) require an express statement of other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date the financial statements are issued (or available to be issued). ASU will be effective for the Company in fiscal year 2016. The Company is currently assessing the future impact of this ASU date on its financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Allowance for Doubtful Accounts	Activity in the allowance for doubtful accounts was as follows:
		2014		2013
	Balance, beginning of the period	$                             5		$                            -
	Charges to costs	1		5
	Write offs	—		—
	Balance, end of the period	$                             6		$                             5
Schedule of Revenues by Geographic Area	The following table sets forth revenues by geographic area (in thousands):
		Years Ended December 31,
		2014			2013
	United States	$	26,043		$	24,316
	Europe		302			330
	Rest of the world		78			238
		$	26,423		$	24,884

Cash_and_Cash_Equivalents_Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
	Dec. 31, 2014
Cash And Cash Equivalents [Abstract]
Cash, and Cash Equivalents	The following is a summary of cash, and cash equivalents, as of December 31, 2014 and 2013 (in thousands):
		31-Dec-14
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	10,894	$	—	$	—	$	10,894
	Money market funds		4,052		—		—		4,052
	Total cash and cash equivalents	$	14,946	$	—	$	—	$	14,946
		31-Dec-13
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	12,800	$	—	$	—	$	12,800
	Money market funds		4,047		—		—		4,047
	Total cash and cash equivalents	$	16,847	$	—	$	—	$	16,847

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of December 31, 2014 and 2013 (in thousands):
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2014		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level 1		Level 2
	Assets:
	Cash	$	10,894	$	10,894	$	—	$	—
	Money market funds		4,052		4,052		—		—
	Restricted cash		1,400		—		1,400		—
		$	16,346	$	14,946	$	1,400	$	—
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2013		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level 1		Level 2
	Assets:
	Cash	$	12,800	$	12,800	$	—	$	—
	Money market funds		4,047		4,047		—		—
	Restricted cash		1,400		—		1,400		—
		$	18,247	$	16,847	$	1,400	$	—

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventory	Inventory consists of the following (in thousands):
		December 31,		December 31,
		2014		2013
	Finished goods	$	234	$	361
	Work in process		271		-
	Raw materials		73		99
		$	578	$	460

Assets_Held_for_Sale_Tables

Assets Held for Sale (Tables)

12 Months Ended

Dec. 31, 2014

Property Plant And Equipment Assets Held For Sale Disclosure [Abstract]

Assets Held for Sale

Total assets held for sale are as follows (in thousands):

Fair Value Measurements Using

Description

December 31,

Quoted

Significant

Significant

Year Ended

2014

Prices in

Other

Unobservable

December 31,

Active

Observable

Inputs

2014

Markets for

Inputs

(Level 3)

Total

Identical

(Level 2)

Gains (Losses)

Assets

(Level 1)

Assets held for sale

—

—

—

—

$

5

Fair Value Measurements Using

Description

December 31,

Quoted

Significant

Significant

Year Ended

2013

Prices in

Other

Unobservable

December 31,

Active

Observable

Inputs

2013

Markets for

Inputs

(Level 3)

Total

Identical

(Level 2)

Gains (Losses)

Assets

(Level 1)

Assets held for sale

$

—

$

—

$

—

$

—

$

340

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Schedule of Estimated Useful Lives for Significant Property and Equipment	The estimated useful lives for significant property and equipment categories are as follows:
	Office and laboratory equipment	3 years
	Computer equipment and software	3 years
	Leasehold improvements	Term of lease agreement
Property and Equipment at Cost Less Accumulated Depreciation	The following is a summary of property and equipment at cost less accumulated depreciation as of December 31, 2014 and 2013 (in thousands):
		December 31,			December 31,
		2014			2013
	Laboratory equipment	$	2,402		$	2,299
	Leasehold improvements		616			616
	Computer and software		336			299
	Furniture and fixtures		101			81
	Construction in progress		49			149
			3,504			3,444
	Less: Accumulated depreciation and amortization		(2,867	)		(2,476	)
		$	637		$	968

Total_Accrued_and_Other_Curren1

Total Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables And Accruals [Abstract]
Schedule of Total Accrued and Other Current Liabilities	Other current liabilities include the following as of December 31, 2014 and 2013 (in thousands):
		December 31,		December 31,
		2014		2013
	Accrued payroll and related expenses	$	1,084	$	1,481
	Accrued collaborative research obligations		612		46
	Accrued restructuring charges		736		—
	Accrued Board of Director fees		248		115
	Accrued property and equipment		—		11
	Other current liabilities		394		550
	Total accrued and other current liabilities	$	3,074	$	2,203

Concentration_of_Credit_Risk_T

Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2014
Risks And Uncertainties [Abstract]
Revenues from Customers	Below are the top five customers that constitute the noted percentages of our revenues and accounts receivable for 2013 and 2014.
		Revenue						Accounts Receivable
		December 31,			December 31,			December 31,			December 31,
		2014			2013			2014			2013
	Customer A		29	%		44	%		7	%		36	%
	Customer B		19	%		4	%		61	%		2	%
	Customer C		15	%		14	%		4	%		10	%
	Customer D		11	%		10	%		3	%		15	%
	Customer E		3	%		6	%		1	%		11	%
	Total		77	%		78	%		76	%		74	%

Notes_Payable_Tables

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2014
Notes Payable [Abstract]
Future Minimum Payments for Notes Payable	Future minimum payments for the notes payable are as follows (in thousands):
	2015	$	2,170
	2016		5,554
	2017		5,554
	2018		5,665
	Total minimum payments		18,943
	Less: Amount representing interest		(3,943	)
	Present value of minimum payments		15,000
	Less: Unamortized debt discount		(252	)
	Notes payable, net		14,748
	Less: Notes payable, current portion		(957	)
	Non-current portion of notes payable	$	13,791

Basic_and_Diluted_Loss_per_Sha

Basic and Diluted Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Outstanding Securities Considered Anti-Dilutive, and Therefore Excluded from Computation of Diluted Net Loss Per Share	The effect of the options and warrants was anti-dilutive for the years ended December 31, 2014 and 2013. The following table shows the total outstanding securities considered anti-dilutive and therefore, excluded from the computation of diluted net loss per share (in thousands):
		As of December 31,
		2014		2013
	Options to purchase common stock		10,797		9,705
	Warrants to purchase common stock		1,175		266
	Restricted stock units		—		42
	Total		11,972		10,013

Stock_Based_Compensation_Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Nonvested Restricted Stock Units
		Shares of			Average Grant			Weighted		Aggregate
		Underlying			Date Fair Value			Remaining Vesting		Intrinsic
		RSUs			Price per Share			Period		Value
								(In years)
	Nonvested as of December 31, 2012		-			-
	Granted		41,708		$	1.33			0.5	$	37,537
	Vested and released		-			-					-
	Nonvested as of December 31, 2013		41,708		$	1.33			0.5	$	37,537
	Granted		-			-					-
	Vested and released		(41,708	)	$	1.33			0.5	$	(37,537	)
	Nonvested as of December 31, 2014		—			—			—		—
Summary of Stock Compensation Expense Related to Employee Stock Options and Employee Stock Based Compensation	The following table summarizes stock compensation expense related to employee stock options and employee stock-based compensation expense for the years ended December 31, 2014 and 2013 which were incurred as follows (in thousands):
		Years Ended December 31,
		2014			2013
	Stock-based compensation expense:
	General and administrative	$	623		$	361
	Research and development		61			135
	Sales and marketing		125			113
	Product costs		29			23
	Total stock-based compensation expense	$	838		$	632
Weighted Average Assumptions Used with Regard to Stock Option	The weighted average assumptions used were as follows:
		Years ended December 31,
		2014			2013
	Dividend yield		0	%		0	%
	Risk-free interest rate		1.5	%		0.9	%
	Expected volatility		98.4	%		84.7	%
	Forfeiture rate		15	%		13.9	%
	Expected term (years)		4.15			4.06
	Fair value per share at grant date	$	0.37		$	0.61
Schedule of Stock Option Activity	The table below presents information related to stock option activity, net of options previously exercised:
		Number of			Weighted-			Weighted-		Aggregate
		Options			Average			Average		Intrinsic
		Outstanding			Exercise			Remaining		Value
					Price			Contractual
								Term
								(In years)
	Outstanding as of December 31, 2012		8,963,226		$	0.47
	Options granted		1,563,910			1
	Options exercised		(664,568	)		0.26
	Options cancelled/forfeited/expired		(157,484	)		4.53
	Outstanding as of December 31, 2013		9,705,084			0.5			7.92		5,112,805
	Options granted		5,789,500			0.51
	Options exercised		(2,432,239	)		0.28
	Options cancelled/forfeited/expired		(2,265,664	)		0.89
	Outstanding as of December 31, 2014		10,796,681		$	0.45			6.35	$	1,264,881
	Exercisable as of December 31, 2014		5,167,878		$	0.42			4.57	$	869,314
	Vested and expected to vest as of December 31, 2014		9,411,926		$	0.45			6.13	$	1,166,624
Summary of Information Relating to Stock Options Outstanding	The following table summarizes information relating to stock options outstanding as of December 31, 2014:
		Options Outstanding								Options Exercisable
	Range of Exercise Price	Number			Weighted			Weighted		Number			Weighted
		Outstanding			Average			Average		Exercisable			Average
					Remaining			Exercise					Exercise
					Contractual			Price					Price
					Life (In Years)
	0.14		51,000			6.95		$	0.14		40,250		$	0.14
	0.25		1,288,083			0.23		$	0.25		1,287,333		$	0.25
	0.26-- 0.29		1,597,225			3.99		$	0.27		1,568,317		$	0.27
	0.33--0.36		1,587,018			7.88		$	0.35		917,021		$	0.35
	0.39		330,000			6.05		$	0.39		323,125		$	0.39
	0.41		3,078,000			9.96		$	0.41		1,666		$	0.41
	0.44--0.68		1,257,312			1.92		$	0.63		60,437		$	0.44
	0.72--0.75		1,082,918			9.05		$	0.73		500,022		$	0.74
	0.77--1.19		195,125			6.88		$	0.92		139,707		$	0.96
	1.32		330,000			8.6		$	1.32		330,000		$	1.32
	$0.14 – $1.32		10,796,681			6.35		$	0.45		5,167,878		$	0.42
Reserved Shares of Common Stock for Future Issuance	The Company had reserved shares of common stock for future issuance as of December 31, 2014 and 2013 as follows:
		As of December 31,
		2014			2013
	Options to purchase common stock		10,796,681			9,705,084
	Warrants to purchase common stock		1,174,694			265,604
	Restricted stock units		—			41,708
	Shares available for option grants		2,821,781			2,345,617
	Total		14,793,156			12,358,013

Stock_Warrants_Tables

Stock Warrants (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Summarized Information about All Warrants Outstanding	The following table summarizes information about all warrants outstanding as of December 31, 2014:
		Warrants Outstanding and Exercisable
	Exercise Price	Number		Weighted		Weighted
		Outstanding		Average		Average
				Remaining		Exercise
				Contractual		Price
				Life (In Years)
	0.37		168,919		4.7	$	0.37
	0.66		909,090		6.62	$	0.66
	1.81		96,685		5.8	$	1.81
			1,174,694		6.25	$	0.71

Leases_Commitments_and_Conting1

Leases, Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Summary of Changes in Asset Retirement Obligation Liability of Company	The following table describes changes to the Company’s asset retirement obligation liability for the years ended December 31, 2014 and 2013 (in thousands):
		Years Ended December 31,
		2014		2013
	Asset retirement obligation, beginning of year	$	334	$	302
	Accretion expense		35		32
	Asset retirement obligation, end of year	$	369	$	334
Future Minimum Lease Payments under Non-Cancelable Operating Leases	At December 31, 2014, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating
		Leases
	2015		2,658
	2016		2,738
	Total minimum lease payments	$	5,396

Restructuring_and_Other_Charge1

Restructuring and Other Charges (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring And Other Charges [Abstract]
Summary of Changes in Restructuring Accrual	The following table summarizes changes in the restructuring accrual for the twelve months ended December 31, 2014.
		For 12 months Ended December 31, 2014
		Employee	Other	Total
		Severance Costs	Costs
	Beginning balance	$                          —	$                          —	$                          —
	Charges	1,238	60	1,298
	Payments	-550	-12	-562
	Ending  Balance	$                         688	$                           48	$                         736

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Summary of US Federal and California State Tax Returns and Tax Provision	The Company files US Federal and California state tax returns and the tax provision is composed as follows (in thousands):
		December 31,
		2014			2013
	Current Tax Expense:
	Federal	$	0		$	—
	State		15			5
	Total current tax expense		15			5
	Deferred Tax Expense:
	Federal		—			—
	State		—			—
	Total deferred tax expense		—			—
	Net tax provision (benefit)	$	15		$	5
Differences between US Statutory Tax Rate and Company's Effective Tax Rate	The differences between the US statutory tax rate and the Company’s effective tax rate are as follows:
		December 31,
		2014			2013
	Statutory rate		34	%		34	%
	State taxes, net of Federal benefit		4.6			11.5
	Change in state rate		(3.4	)		(22.9	)
	R&D credit		(1.4	)		(7.3	)
	Permanent differences		(0.7	)		(3.6	)
	State minimum taxes		(0.1	)		(0.3	)
	Change in valuation allowance		(32.7	)		(13.5	)
	Other		(0.5	)		1.9
	Effective tax rate		(0.2	)%		(0.2	)%
Summary of Tax Effects of Temporary Differences and Carry forwards That Give Rise to Deferred Tax Assets	The tax effects of temporary differences and carry forwards that give rise to deferred tax assets are as follows (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Accruals and reserves	$	1,348		$	1,694
	Fixed assets		2,168			2,338
	Deferred research expense		2,306			3,667
	Stock options		3,970			3,822
	Net operating loss carryforwards		93,676			89,306
	Research tax credit carryforwards		7,784			7,664
	Other		12			9
	Total deferred tax assets		111,264			108,500
	Less: Valuation allowance		(111,264	)		(108,500	)
	Net deferred tax assets	$	—		$	—
Summary of Changes in Gross Unrecognized Tax Benefits	The following table reflects the changes in the gross unrecognized tax benefits for the years ended December 31 (in thousands):
		2014			2013
	Balance at January 1	$	2,461		$	2,269
	Increase related to gross up state positions		—			251
	Increase related to current year positions		39			34
	Decrease related to expiration of credits		—			(93	)
	Balance at December 31	$	2,500		$	2,461

Business_Overview_Additional_I

Business Overview - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Aug. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure - Business Overview - Additional Information (Detail) [Line Items]
Accumulated deficit	($208,363,000)		($199,896,000)
Working capital	14,000,000
Stockholders' equity	846,000		7,520,000	8,855,000
Proceeds from bank debt	14,748,000
Interest rate on loan		6.95%
Date of incorporation	30-Nov-95
Oxford
Disclosure - Business Overview - Additional Information (Detail) [Line Items]
Proceeds from bank debt		15,000,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Schedule of Allowance For Doubtful Accounts (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Balance, beginning of the period	$5
Charges to costs	1	5
Balance, end of the period	$6	$5

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	Segment
Significant Accounting Policies [Line Items]
Property plant and equipment useful life	3 years
Number of reportable segment	1
Excise tax recognized in product revenue	$311,000	$402,000
Excise tax recognized in product costs	354,000	455,000
Employee stock-based compensation expense	839,000	632,000
Total unrecorded stock-based compensation expense	2,000,000
Unrecorded stock-based compensation expense, weighted average amortization period	2 years 10 months 6 days
Unrecognized tax benefits	$0	$0
Minimum [Member]
Significant Accounting Policies [Line Items]
License fee agreement period	2 years
Maximum [Member]
Significant Accounting Policies [Line Items]
License fee agreement period	10 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Schedule of Revenues by Geographic Area (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Revenues	$26,423	$24,884
United States [Member]
Revenue, Major Customer [Line Items]
Revenues	26,043	24,316
Europe [Member]
Revenue, Major Customer [Line Items]
Revenues	302	330
Rest of the world [Member]
Revenue, Major Customer [Line Items]
Revenues	$78	$238

Cash_and_Cash_Equivalents_Addi

Cash and Cash Equivalents - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Cash And Cash Equivalents [Abstract]
Investments considered cash and cash equivalents, maturity period	90 days or less

Cash_and_Cash_Equivalents_Cash

Cash and Cash Equivalents - Cash, and Cash Equivalents (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Cost Basis	$14,946	$16,847	$12,851
Cash and cash equivalents, Estimated Fair Value	14,946	16,847
Cash [Member]
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Cost Basis	10,894	12,800
Cash and cash equivalents, Estimated Fair Value	10,894	12,800
Money market funds [Member]
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Cost Basis	4,052	4,047
Cash and cash equivalents, Estimated Fair Value	$4,052	$4,047

Fair_Value_Measurements_Fair_V

Fair Value Measurements - Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis (Detail) (Fair value, measurements, recurring [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	$16,346	$18,247
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	14,946	16,847
Significant other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	1,400	1,400
Cash [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	10,894	12,800
Cash [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	10,894	12,800
Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	4,052	4,047
Money market funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	4,052	4,047
Restricted cash [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	1,400	1,400
Restricted cash [Member] | Significant other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Measurements	$1,400	$1,400

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Notes payable face value	$15

Inventory_Inventory_Detail

Inventory - Inventory (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Finished goods	$234	$361
Work in process	271
Raw materials	73	99
Total inventory	$578	$460

Assets_Held_For_Sale_Assets_He

Assets Held For Sale - Assets Held for Sale (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value Measurements Using	$5	$340

Assets_Held_for_Sale_Additiona

Assets Held for Sale - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property Plant And Equipment Assets Held For Sale Disclosure [Abstract]
Committed sales price for assets held for sale			$695,000
Gains (losses) on sale of assets	$5,000	$340,000

Property_Plant_and_Equipment_S

Property, Plant and Equipment - Schedule of Estimated Useful Lives for Significant Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	3 years
Office and laboratory equipment [Member]
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	3 years
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	3 years
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Leasehold improvements	Term of lease agreement

Property_Plant_and_Equipment_P

Property, Plant and Equipment - Property and Equipment at Cost Less Accumulated Depreciation (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property Plant And Equipment [Line Items]
Gross property and equipment	$3,504	$3,444
Less: Accumulated depreciation and amortization	-2,867	-2,476
Total Property, Plant and Equipment	637	968
Laboratory equipment [Member]
Property Plant And Equipment [Line Items]
Gross property and equipment	2,402	2,299
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Gross property and equipment	616	616
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Gross property and equipment	336	299
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Gross property and equipment	101	81
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Gross property and equipment	$49	$149

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$509	$531

Total_Accrued_and_Other_Curren2

Total Accrued and Other Current Liabilities - Schedule of Total Accrued and Other Current Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]
Accrued payroll and related expenses	$1,084	$1,481
Accrued collaborative research obligations	612	46
Accrued restructuring charges	736
Accrued Board of Director fees	248	115
Accrued property and equipment		11
Other current liabilities	394	550
Total accrued and other current liabilities	$3,074	$2,203

Total_Accrued_and_Other_Curren3

Total Accrued and Other Current Liabilities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Accrued Expenses And Other Liabilities [Line Items]
Restructuring charges	$1,298,000
Payments for restructuring	-562,000
Accrued restructuring charges	736,000
License and Supply Agreement [Member]
Accrued Expenses And Other Liabilities [Line Items]
Accrued research obligations	$612,000

Concentration_of_Credit_Risk_A

Concentration of Credit Risk - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Customer
Risks And Uncertainties [Abstract]
Number of customers that constitute the noted percentage of revenues	5

Concentration_of_Credit_Risk_R

Concentration of Credit Risk - Revenues from Customers (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	77.00%	78.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	76.00%	74.00%
Customer A [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	29.00%	44.00%
Customer A [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	7.00%	36.00%
Customer B [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	19.00%	4.00%
Customer B [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	61.00%	2.00%
Customer C [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	15.00%	14.00%
Customer C [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	4.00%	10.00%
Customer D [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	11.00%	10.00%
Customer D [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	3.00%	15.00%
Customer E [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	3.00%	6.00%
Customer E [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue and Accounts Receivable	1.00%	11.00%

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)	1 Months Ended		12 Months Ended
	Aug. 31, 2014	Sep. 30, 2011	Dec. 31, 2014	Dec. 31, 2013
			Installment
Debt Instrument [Line Items]
Proceeds from bank debt			$14,748,000
Interest rate on loan	6.95%
Period for monthly installment			monthly
Date of debt first payable installments			31-Oct-14
Initial period for payment of interest only			31-Oct-14
Closing period for payment of interest only			30-Sep-15
Minimum trailing six month revenues to continue making interest only payments through September 2016 followed by 24 months of equal principal and interest payments	15,000,000
Description of loan and security agreement			The obligations under the Loan Agreement are payable in 48 monthly installments which began in October 2014, with interest only payments to be made from October 2014 to September 2015, followed by 36 months of equal principal and interest payments. If the Company’s trailing six month revenues equal or exceed $15 million at the end of the fiscal month ending July 31, 2015, the Company may continue to make interest only payments through September 2016 followed by 24 months of equal principal and interest payments.
Debt instrument number of installments			48
Debt instrument number of installments with interest only payments			24
Debt instrument number of equal principal and interest payments interest only payments			36
Loan processing fee	150,000		224,000	50,000
Additional fee required	1,500,000
Advance notice period to the bank	10 days
Warrant issued to purchase common stock	909,090	480,769
Debt instrument, restrictive covenants			The Loan Agreement contains a number of customary representations and warranties and customary covenants, including covenants regarding delivery of financial statements, maintenance of inventory, payment of taxes, maintenance of insurance, dispositions of property, business combinations or acquisitions, incurrence of additional indebtedness and transactions with affiliates. The Company is also restricted from paying dividends or making other distributions or payments of its capital stock except for repurchases of stock pursuant to employee stock purchase plans, employee restricted stock agreements, stockholder rights plans, director or consultant stock option plans, or similar plans, provided such repurchases do not exceed $250,000 in the aggregate per fiscal year. If the Company breaches any of these covenants or it is unable to make a required payment of principal or interest, or it experiences a material adverse change to its business, it could result in a default under the Loan and Security Agreement and the amount of the loan balance, plus accrued and unpaid interest, and final payment, and the prepayment fee, and other obligations due the lender would be come immediately payable. As of December 31, 2014, the Company was in compliance with all the covenants.
Debt instrument financial covenants	250,000
Debt discount	470,000		252,000
Repayments of loan with Comerica Bank	8,400,000
Amortization of debt discounts	132,000		471,000	140,000
Amortization of debt issuance costs	82,000
Balloon payments expensed on early repayment of loan	117,000
Loss from extinguishment of debt	-81,000
Oxford
Debt Instrument [Line Items]
Proceeds from bank debt	$15,000,000

Notes_Payable_Future_Minimum_P

Notes Payable - Future Minimum Payments for Notes Payable (Detail) (USD $)	Dec. 31, 2014	Aug. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
2015	$2,170,000
2016	5,554,000
2017	5,554,000
2018	5,665,000
Total minimum payments	18,943,000
Less: Amount representing interest	-3,943,000
Present value of minimum payments	15,000,000
Less: Unamortized debt discount	-252,000	-470,000
Notes payable, net	14,748,000
Less: Notes payable, current portion	-957,000		-2,763,000
Non-current portion of notes payable	$13,791,000		$7,047,000

Basic_and_Diluted_Loss_per_Sha1

Basic and Diluted Loss per Share - Outstanding Securities Considered Anti-Dilutive, and Therefore Excluded from Computation of Diluted Net Loss Per Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	11,972	10,013
Options to purchase common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	10,797	9,705
Warrants to purchase common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	1,175	266
Restricted stock units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		42

Stock_Based_Compensation_Addit

Stock Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended		0 Months Ended	1 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Aug. 06, 2013	Oct. 31, 2004	Sep. 30, 2011	Oct. 31, 2011	Feb. 01, 2012	Dec. 31, 2012	17-May-12
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non Employee Stock Options Vesting Period	1 year
Options outstanding	10,796,681	9,705,084						8,963,226
Shares available for grant	2,821,781	2,345,617
Condition for stock option expiry	Option terms expire no later than 10 years from the date of grant, or 5 years from the date the option is granted to a greater than 10% stockholder.
Condition for stock options exercisable	The stock options are exercisable at not less than the fair market value of the stock at the date of grant, or not less than 110% of the fair market value of the stock at the date of grant if granted to a greater than 10% stockholder.
Stock option plans, exercise price per share	$0.28	$0.26
Intrinsic value of options exercised	$446,000
Stock-based compensation, total remaining unrecognized expense	2,000,000
Stock-based compensation expenses recognition period	2 years 10 months 6 days
Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	0
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units awarded, outstanding	0	41,708
Shares of Underlying RSUs, Vested and released	41,708
Restricted Stock Units (RSUs) [Member] | Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units awarded to directors			41,708
Restricted Stock Units, grant-date fair value			$55,000
RSU entitles the recipient to receive share of the Company's common stock upon vesting	1
Shares of Underlying RSUs, Vested and released	0
2012 Equity Incentive Award Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuable upon exercise of options vest	4 years
Options outstanding	7,410,373
Shares available for grant	2,821,781
2012 Equity Incentive Award Plan [Member] | Options to purchase common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock authorized for issuance	3,000,000
2012 Equity Incentive Award Plan [Member] | Options to purchase common stock [Member] | Principal Owner [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options exercisable as percentage of fair market value of stock at date of grant	110.00%
2012 Equity Incentive Award Plan [Member] | Options to purchase common stock [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options expire from the date of grant	10 years
2012 Equity Incentive Award Plan [Member] | Options to purchase common stock [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options expire from the date of grant	5 years
1996 Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	2,104,225								6,398,904
Determination of Non qualified stock options exercise price fair market value of stock minimum percentage	85.00%
Shares transferred form prior plans available for issuance under the plan									1,555,492
1996 Stock Option Plan [Member] | Options to purchase common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock authorized for issuance	4,750,000
Issuable upon exercise of options vest	4 years
Options expire from the date of grant	10 years
Percentage increased by the number of issued and outstanding common stock	3.50%
Period between grant date and vesting period start date	1 year
1998 Director Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding									170,000
Shares transferred form prior plans available for issuance under the plan									130,000
1998 Director Stock Option Plan [Member] | Options to purchase common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock authorized for issuance	300,000
Non-Plan Grants [Member] | Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	0
Shares available for grant				30,000
Stock option plans, exercise price per share				$12.27
Non-Plan Grants [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	1,282,083
Shares available for grant					1,530,000
Stock option plans, exercise price per share					$0.25
Non-Plan Grants [Member] | Chief Business Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	0
Shares available for grant						1,130,000
Stock option plans, exercise price per share						$0.26
Non-Plan Grants [Member] | Chief Financial Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding	0
Shares available for grant							1,060,000
Stock option plans, exercise price per share							$0.28

Stock_Based_Compensation_Summa

Stock Based Compensation - Summary of Nonvested Restricted Stock Units (Detail) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of Underlying RSUs, Nonvested, Beginning balance	41,708
Shares of Underlying RSUs, Granted		41,708
Shares of Underlying RSUs, Vested and released	-41,708
Shares of Underlying RSUs, Nonvested, Ending balance	0	41,708
Average Grant Date Fair Value Per Share, Nonvested, Beginning balance	$1.33
Average Grant Date Fair Value Per Share, Granted		$1.33
Average Grant Date Fair Value Per Share, vested and released	$1.33
Average Grant Date Fair Value Per Share, Nonvested, Ending balance		$1.33
Weighted Remaining Vesting Period, Nonvested, Granted		0 years 6 months
Weighted Remaining Vesting Period		0 years 6 months
Weighted Remaining Vesting Period, Nonvested, Vested and released	0 years 6 months
Aggregate Intrinsic Value Nonvested, Beginning balance	$37,537
Aggregate Intrinsic Value Nonvested, Granted		37,537
Aggregate Intrinsic Value Nonvested, Vested and released	-37,537
Aggregate Intrinsic Value Nonvested, Ending balance		$37,537

Stock_Based_Compensation_Summa1

Stock Based Compensation - Summary of Stock Compensation Expense Related to Employee Stock Options and Employee Stock Based Compensation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Stock-based compensation expense:
Stock-based compensation	$838	$632
General and administrative [Member]
Stock-based compensation expense:
Stock-based compensation	623	361
Sales and marketing [Member]
Stock-based compensation expense:
Stock-based compensation	61	135
Research and development [Member]
Stock-based compensation expense:
Stock-based compensation	125	113
Product costs [Member]
Stock-based compensation expense:
Stock-based compensation	$29	$23

Stock_Based_Compensation_Weigh

Stock Based Compensation - Weighted Average Assumptions Used with Regard to Stock Option (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Dividend yield	0.00%	0.00%
Risk-free interest rate	1.50%	0.90%
Expected volatility	98.40%	84.70%
Forfeiture rate	15.00%	13.90%
Expected term (years)	4 years 1 month 24 days	4 years 22 days
Fair value per share at grant date	$0.37	$0.61

Stock_Based_Compensation_Sched

Stock Based Compensation - Schedule of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options Outstanding, Beginning balance	9,705,084	8,963,226
Number of Options Outstanding, Options granted	5,789,500	1,563,910
Number of Options Outstanding, Options exercised	-2,432,239	-664,568
Number of Options Outstanding, Options cancelled/forfeited/expired	-2,265,664	-157,484
Number of Options Outstanding, Ending balance	10,796,681	9,705,084
Number of Options Outstanding, Exercisable, Ending balance	5,167,878
Number of Options Outstanding, Vested and expected to vest, Ending balance	9,411,926
Weighted-Average Exercise Price, Outstanding Beginning balance	$0.50	$0.47
Weighted-Average Exercise Price, Options granted	$0.51	$1
Weighted-Average Exercise Price, Options exercised	$0.28	$0.26
Weighted-Average Exercise Price, Options cancelled/forfeited/expired	$0.89	$4.53
Weighted-Average Exercise Price, Outstanding Ending balance	$0.45	$0.50
Weighted-Average Exercise Price, Exercisable, Ending balance	$0.42
Weighted-Average Exercise Price, Vested and expected to vest, Ending balance	$0.45
Weighted-Average Remaining Contractual Term, Outstanding, Ending balance	6 years 4 months 6 days	7 years 11 months 1 day
Weighted-Average Remaining Contractual Term, Outstanding, Ending balance	6 years 4 months 6 days	7 years 11 months 1 day
Weighted-Average Remaining Contractual Term, Exercisable, Ending balance	4 years 6 months 26 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest, Ending balance	6 years 1 month 17 days
Aggregate Intrinsic Value, Outstanding, Ending balance	$5,112,805
Aggregate Intrinsic Value, Outstanding, Ending balance	1,264,881	5,112,805
Aggregate Intrinsic Value, Exercisable, Ending balance	869,314
Aggregate Intrinsic Value, Vested and expected to vest, Ending balance	$1,166,624

Stock_Based_Compensation_Summa2

Stock Based Compensation - Summary of Information Relating to Stock Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Range One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.14
Number Outstanding, Options Outstanding	51,000
Weighted Average Remaining Contractual Life, Options Outstanding	6 years 11 months 12 days
Weighted Average Exercise Price, Options Outstanding	$0.14
Number Exercisable, Options Exercisable	40,250
Weighted Average Exercise Price, Options Exercisable	$0.14
Range Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.25
Number Outstanding, Options Outstanding	1,288,083
Weighted Average Remaining Contractual Life, Options Outstanding	2 months 23 days
Weighted Average Exercise Price, Options Outstanding	$0.25
Number Exercisable, Options Exercisable	1,287,333
Weighted Average Exercise Price, Options Exercisable	$0.25
Range Three [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.26
Exercise Price Upper Limit	$0.29
Number Outstanding, Options Outstanding	1,597,225
Weighted Average Remaining Contractual Life, Options Outstanding	3 years 11 months 27 days
Weighted Average Exercise Price, Options Outstanding	$0.27
Number Exercisable, Options Exercisable	1,568,317
Weighted Average Exercise Price, Options Exercisable	$0.27
Range Four [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.33
Exercise Price Upper Limit	$0.36
Number Outstanding, Options Outstanding	1,587,018
Weighted Average Remaining Contractual Life, Options Outstanding	7 years 10 months 17 days
Weighted Average Exercise Price, Options Outstanding	$0.35
Number Exercisable, Options Exercisable	917,021
Weighted Average Exercise Price, Options Exercisable	$0.35
Range Five [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.39
Number Outstanding, Options Outstanding	330,000
Weighted Average Remaining Contractual Life, Options Outstanding	6 years 18 days
Weighted Average Exercise Price, Options Outstanding	$0.39
Number Exercisable, Options Exercisable	323,125
Weighted Average Exercise Price, Options Exercisable	$0.39
Range Six [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.41
Number Outstanding, Options Outstanding	3,078,000
Weighted Average Remaining Contractual Life, Options Outstanding	9 years 11 months 16 days
Weighted Average Exercise Price, Options Outstanding	$0.41
Number Exercisable, Options Exercisable	1,666
Weighted Average Exercise Price, Options Exercisable	$0.41
Range Seven [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.44
Exercise Price Upper Limit	$0.68
Number Outstanding, Options Outstanding	1,257,312
Weighted Average Remaining Contractual Life, Options Outstanding	1 year 11 months 1 day
Weighted Average Exercise Price, Options Outstanding	$0.63
Number Exercisable, Options Exercisable	60,437
Weighted Average Exercise Price, Options Exercisable	$0.44
Range Eight [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.72
Exercise Price Upper Limit	$0.75
Number Outstanding, Options Outstanding	1,082,918
Weighted Average Remaining Contractual Life, Options Outstanding	9 years 18 days
Weighted Average Exercise Price, Options Outstanding	$0.73
Number Exercisable, Options Exercisable	500,022
Weighted Average Exercise Price, Options Exercisable	$0.74
Range Nine [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.77
Exercise Price Upper Limit	$1.19
Number Outstanding, Options Outstanding	195,125
Weighted Average Remaining Contractual Life, Options Outstanding	6 years 10 months 17 days
Weighted Average Exercise Price, Options Outstanding	$0.92
Number Exercisable, Options Exercisable	139,707
Weighted Average Exercise Price, Options Exercisable	$0.96
Range Ten [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$1.32
Number Outstanding, Options Outstanding	330,000
Weighted Average Remaining Contractual Life, Options Outstanding	8 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding	$1.32
Number Exercisable, Options Exercisable	330,000
Weighted Average Exercise Price, Options Exercisable	$1.32
Range Eleven [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Lower Limit	$0.14
Exercise Price Upper Limit	$1.32
Number Outstanding, Options Outstanding	10,796,681
Weighted Average Remaining Contractual Life, Options Outstanding	6 years 4 months 6 days
Weighted Average Exercise Price, Options Outstanding	$0.45
Number Exercisable, Options Exercisable	5,167,878
Weighted Average Exercise Price, Options Exercisable	$0.42

Stock_Based_Compensation_Reser

Stock Based Compensation - Reserved Shares of Common Stock for Future Issuance (Detail)	Dec. 31, 2014	Dec. 31, 2013
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Options to purchase common stock	14,793,156	12,358,013
Warrants to purchase common stock	1,174,694	265,604
Shares available for option grants	2,821,781	2,345,617
Options to purchase common stock [Member]
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Options to purchase common stock	10,796,681	9,705,084
Restricted Stock Units (RSUs) [Member]
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Options to purchase common stock		41,708

Stock_Warrants_Additional_Info

Stock Warrants - Additional Information (Detail) (USD $)	1 Months Ended			12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Sep. 30, 2011	Dec. 31, 2014	Dec. 31, 2013
Class Of Warrant Or Right [Line Items]
Warrant issued to purchase common stock	909,090		480,769
Warrants Outstanding and Exercisable, Weighted Average Exercise Price		$0.26	$0.26	$0.71
Volatility			88.03%
Risk-free interest rate			1.36%
Expected life of warrant			7 years
Issuance of warrants			$94,000	$470,000	$136,000
Discount being amortized to interest expense			48 months
Warrant expiry date			2018-09
Common stock issued		386,784
Warrants Outstanding and Exercisable, Number				1,174,694
Aggregate exercise price				800,000
Warrant 0.37 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Weighted Average Exercise Price				$0.37
Warrants Outstanding and Exercisable, Number				168,919
Warrant 0.37 [Member] | First Amended Loan and Security Agreement [Member]
Class Of Warrant Or Right [Line Items]
Warrant issued to purchase common stock				168,919
Warrants Outstanding and Exercisable, Weighted Average Exercise Price				$0.37
Volatility				89.87%
Risk-free interest rate				1.03%
Expected life of warrant				7 years
Issuance of warrants				48,000
Warrant expiry date				2019-09
Warrant 1.81 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Weighted Average Exercise Price				$1.81
Warrants Outstanding and Exercisable, Number				96,685
Warrant 1.81 [Member] | Second Amended Loan and Security Agreement [Member]
Class Of Warrant Or Right [Line Items]
Warrant issued to purchase common stock				96,685
Warrants Outstanding and Exercisable, Weighted Average Exercise Price				$1.81
Volatility				89.01%
Risk-free interest rate				2.05%
Expected life of warrant				7 years
Issuance of warrants				136,000
Warrant expiry date				2020-10
Warrant 0.66 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Weighted Average Exercise Price				$0.66
Warrants Outstanding and Exercisable, Number				909,090
Warrant 0.66 [Member] | Loan And Security Agreement
Class Of Warrant Or Right [Line Items]
Warrant issued to purchase common stock	909,090
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	0.66			$0.66
Volatility	90.29%
Risk-free interest rate	2.06%
Expected life of warrant	7 years
Issuance of warrants	470,000
Warrant expiry date	2021-08
Loan, maturity date	30-Sep-18

Stock_Warrants_Summarized_Info

Stock Warrants - Summarized Information about All Warrants Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Aug. 31, 2013	Sep. 30, 2011
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Number	1,174,694
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	6 years 3 months
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	$0.71	$0.26	$0.26
Warrant 0.37 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Number	168,919
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	4 years 8 months 12 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	$0.37
Warrant 0.66 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Number	909,090
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	6 years 7 months 13 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	$0.66
Warrant 1.81 [Member]
Class Of Warrant Or Right [Line Items]
Warrants Outstanding and Exercisable, Number	96,685
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	5 years 9 months 18 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	$1.81

Leases_Commitments_and_Conting2

Leases, Commitments and Contingencies - Additional Information (Detail)	12 Months Ended			1 Months Ended		3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2010	Apr. 30, 2014	Dec. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
	USD ($)	USD ($)	USD ($)	License and Supply Agreement [Member]	License and Supply Agreement [Member]	License and Supply Agreement [Member]	License and Supply Agreement [Member]
				EUR (€)	EUR (€)	Development and regulatory milestones [Member]	Post-launch commercial milestones [Member]
						Potential [Member]	Potential [Member]
						Maximum [Member]	Maximum [Member]
						EUR (€)	EUR (€)
Commitments Contingencies And Litigation [Line Items]
Lease expiration date	2016-12
Unfavorable lease obligation expense			$4,100,000
Net of accumulated amortization	1,800,000
Rent expense	1,800,000	1,900,000
Deferred rent	336,000	387,000
Payment under License and Supply Agreement				750,000		500,000	1,000,000
Upfront milestone to be settled					€ 500,000

Leases_Commitments_and_Conting3

Leases, Commitments and Contingencies - Summary of Changes in Asset Retirement Obligation Liability of Company (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligation, beginning of year	$334	$302
Accretion expense	35	32
Asset retirement obligation, end of year	$369	$334

Leases_Commitments_and_Conting4

Leases, Commitments and Contingencies - Future Minimum Lease Payments under Non-Cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]
2015	$2,658
2016	2,738
Total minimum lease payments	$5,396

Restructuring_and_Other_Charge2

Restructuring and Other Charges - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$1,298,000
Payments for restructuring	562,000
Restructuring reserve	736,000
Employee Severance Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	1,238,000
Payments for restructuring	550,000
Restructuring reserve	688,000
Employee Severance Costs [Member] | Forecast [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0
Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	60,000
Payments for restructuring	12,000
Restructuring reserve	$48,000

Restructuring_and_Other_Charge3

Restructuring and Other Charges - Summary of Changes in Restructuring Accrual (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Restructuring Cost And Reserve [Line Items]
Charges	$1,298,000
Payments	-562,000
Ending Balance	736,000
Employee Severance Costs [Member]
Restructuring Cost And Reserve [Line Items]
Charges	1,238,000
Payments	-550,000
Ending Balance	688,000
Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Charges	60,000
Payments	-12,000
Ending Balance	$48,000

Income_Taxes_Summary_of_US_Fed

Income Taxes - Summary of US Federal and California State Tax Returns and Tax Provision (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current Tax Expense:
Federal	$0
State	15	5
Total current tax expense	15	5
Deferred Tax Expense:
Federal	0	0
State	0	0
Total deferred tax expense	0	0
Net tax provision (benefit)	$15	$5

Income_Taxes_Differences_betwe

Income Taxes - Differences between US Statutory Tax Rate and Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory rate	34.00%	34.00%
State taxes, net of Federal benefit	4.60%	11.50%
Change in state rate	-3.40%	-22.90%
R&D credit	-1.40%	-7.30%
Permanent differences	-0.70%	-3.60%
State minimum taxes	-0.10%	-0.30%
Change in valuation allowance	-32.70%	-13.50%
Other	-0.50%	1.90%
Effective tax rate	-0.20%	-0.20%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Tax credit carry forwards expire starting period	2019
Deferred tax assets	$111,264,000	$108,500,000
Net valuation allowance	2,800,000	-700,000
Merger tax attribute annual limitations for federal and state purpose	240,000
Change in deferred tax asset, credit carryforwards	877,000
Uncertain tax positions	0
Unrecognized tax benefits	2,500,000	2,461,000	2,269,000
California Franchise Tax Board
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards	162,000,000
Expiration period of net operating loss carry forwards	2016
Credit carry forwards	4,800,000
Unrecognized tax benefits increased amount, Gross	39
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards	244,000,000
Expiration period of net operating loss carry forwards	2019
Credit carry forwards	4,600,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards	$27,000,000
Expiration period of net operating loss carry forwards	2015

Income_Taxes_Summary_of_Tax_Ef

Income Taxes - Summary of Tax Effects of Temporary Differences and Carry forwards That Give Rise to Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Accruals and reserves	$1,348	$1,694
Fixed assets	2,168	2,338
Deferred research expense	2,306	3,667
Stock options	3,970	3,822
Net operating loss carryforwards	93,676	89,306
Research tax credit carryforwards	7,784	7,664
Other	12	9
Total deferred tax assets	111,264	108,500
Less: Valuation allowance	-111,264	-108,500
Net deferred tax assets	$0	$0

Income_Taxes_Summary_of_Change

Income Taxes - Summary of Changes in Gross Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at January 1	$2,461	$2,269
Increase related to gross up state positions		251
Increase related to current year positions	39	34
Decrease related to expiration of credits		-93
Balance at December 31	$2,500	$2,461