XenoPort (XNPT) 10-Q 7 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 15, 2015
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	XNPT
Entity Registrant Name	XENOPORT INC
Entity Central Index Key	1130591
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		62,775,469

BALANCE_SHEETS

BALANCE SHEETS (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$16,898	$11,958
Short-term investments	169,220	90,098
Accounts receivable	2,887	2,895
Inventories	1,907	1,458
Prepaids and other current assets	4,002	3,185
Total current assets	194,914	109,594
Long-term investments	5,516
Property and equipment, net	2,299	2,422
Long-term inventories	8,845	9,098
Restricted investments and other assets	1,915	1,947
Total assets	213,489	123,061
Current liabilities:
Accounts payable	2,942	2,835
Accrued compensation	4,341	7,148
Accrued preclinical and clinical costs	1,772	1,554
Other accrued liabilities	5,531	5,117
Deferred revenue	1,134	1,134
Total current liabilities	15,720	17,788
Convertible senior notes, net	111,419
Deferred revenue	10,580	10,864
Other noncurrent liability	3,403	3,269
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued or outstanding
Common stock, $0.001 par value; 100,000 shares authorized; 62,772 and 62,475 shares issued and outstanding, at March 31, 2015 and December 31, 2014, respectively	63	62
Additional paid-in capital	679,467	677,924
Accumulated other comprehensive income (loss)	62	-30
Accumulated deficit	-607,225	-586,816
Total stockholders' equity	72,367	91,140
Total liabilities and stockholders' equity	$213,489	$123,061

BALANCE_SHEETS_Parenthetical

BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	62,772,000	62,475,000
Common stock, shares outstanding	62,772,000	62,475,000

STATEMENTS_OF_COMPREHENSIVE_LO

STATEMENTS OF COMPREHENSIVE LOSS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Product sales, net	$6,639	$2,957
Collaboration revenue	284	283
Royalty revenue	144	135
Total revenues	7,067	3,375
Operating expenses:
Cost of product sales	454	430
Research and development	6,384	4,657
Selling, general and administrative	20,099	18,771
Total operating expenses	26,937	23,858
Income (loss) from operations	-19,870	-20,483
Interest income	116	49
Interest expense	-655	-114
Net income (loss)	-20,409	-20,548
Other comprehensive loss:
Unrealized gains (losses) on available-for-sale securities	92	-4
Comprehensive income (loss)	($20,317)	($20,552)
Basic and diluted net income (loss) per share	($0.33)	($0.36)
Shares used to compute basic and diluted net loss per share	62,722	56,887

STATEMENTS_OF_CASH_FLOWS

STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating activities
Net loss	($20,409)	($20,548)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	134	199
Accretion of investment discounts and amortization of investment premiums, net	311	216
Amortization of discount and debt issuance costs on convertible senior notes	73
Stock-based compensation expense	2,671	2,684
Changes in assets and liabilities:
Accounts receivable	8	-292
Prepaids and other current and noncurrent assets	-785	-519
Inventories	-196	53
Accounts payable	107	3,048
Accrued compensation	-2,807	314
Accrued preclinical and clinical costs	218	106
Other accrued liabilities, current and noncurrent	548	2,501
Deferred revenue, current and noncurrent	-284	-283
Net cash used in operating activities	-20,411	-12,521
Investing activities
Purchases of investments	-111,524	-90,148
Proceeds from maturities of investments	26,668	23,357
Purchases of property and equipment	-11
Net cash used in investing activities	-84,867	-66,791
Financing activities
Proceeds from issuance of convertible senior notes, net of discount and debt issuance costs	111,345
Net cash proceeds provided by (used in) issuance of common stock and exercise of stock options	-1,127	76,546
Net cash provided by financing activities	110,218	76,546
Net increase (decrease) in cash and cash equivalents	4,940	-2,766
Cash and cash equivalents at beginning of period	11,958	20,584
Cash and cash equivalents at end of period	$16,898	$17,818

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies
	Nature of Operations
	XenoPort, Inc., or the Company, was incorporated in the state of Delaware on May 19, 1999. The Company is a biopharmaceutical company focused on developing and commercializing a portfolio of internally discovered product candidates for the potential treatment of neurological and other disorders. The Company is currently commercializing HORIZANT® (gabapentin enacarbil) Extended-Release Tablets in the United States and developing its novel fumaric acid ester product candidate, XP23829, as a potential treatment for psoriasis and potentially for relapsing forms of multiple sclerosis, or MS. The Company’s other product candidates are: arbaclofen placarbil, or AP, which is licensed to Indivior PLC (formerly Reckitt Benckiser Pharmaceuticals, Inc.) and XP21279. Effective June 2014, the Company granted to Indivior exclusive, world-wide rights to develop and commercialize pharmaceutical products containing AP and other prodrugs of baclofen or R-baclofen, or collectively, the AP Products, for all indications, subject to the Company’s right of first negotiation with Indivior to collaborate to develop and commercialize AP Products for non-addiction indications (See Note 2 for more information). XP21279 is a potential treatment for patients with advanced idiopathic Parkinson’s disease. The Company may develop it further, to the extent that its resources permit, or it may enter into collaboration, partnership, licensing and other similar forms of revenue-generating transactions with third-party business partners for such development. HORIZANT and the Company’s product candidates are prodrugs that are typically created by modifying the chemical structure of currently marketed drugs, referred to as parent drugs, and are designed to correct limitations in the oral absorption, distribution and/or metabolism of the parent drug. HORIZANT and each of the Company’s product candidates are orally-available, patented molecules that address potential markets with unmet medical needs. The Company’s facilities are located in Santa Clara, California.
	Basis of Preparation
	The accompanying financial statements as of March 31, 2015, and for the three months ended March 31, 2015 and 2014, are unaudited. These unaudited financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of March 31, 2015 and comprehensive loss for the three months ended March 31, 2015 and 2014, and cash flows for the three months ended March 31, 2015 and 2014. The Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or the Codification, is the single source of authoritative U.S. generally accepted accounting principles, or GAAP. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015, or for any other interim period or any other future year. For more complete financial information, these financial statements, and the notes hereto, should be read in conjunction with the audited financial statements for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 27, 2015.
	Recent Accounting Pronouncements
	In May 2014, the FASB issued Accounting Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09), which creates a single source of revenue guidance under GAAP for all companies in all industries. The core principle of ASU 2014-09 is that revenue should be recognized in a manner that depicts 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. ASU 2014-09 defines a five-step process in order to achieve this core principle, which may require the use of judgment and estimates. ASU 2014-09 also requires expanded qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers, including significant judgments and estimates used. ASU 2014-09 will be effective for the Company in the first quarter of fiscal 2017, and early adoption is not permitted. The Company may adopt ASU 2014-09 either by way of a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. On April 1, 2015, the FASB voted to propose a delay in the effective date of ASU No. 2014-09. The proposed new effective date will be annual reporting periods beginning after December 15, 2017, and the interim periods within that year and will allow early adoption for all entities as of the original effective date for public business entities, which was annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the impact that ASU 2014-09 will have on its financial statements and has not yet determined which transition method it will apply.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 requires management to assess 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 and other disclosures when substantial doubt is not alleviated; and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 will be effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, with early adoption permitted. ASU 2014-15 will be effective for the Company beginning with its annual report for fiscal 2016 and interim periods thereafter. The Company is currently evaluating the impact that ASU 2014-15 will have on its financial statements.
	In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. Debt issuance costs are specified incremental costs, other than those paid to the lender, that are directly attributable to issuing a debt instrument (i.e., third party costs). Prior to this standard, debt issuance costs were required to be presented in the balance sheet as a deferred charge (i.e., an asset). This presentation differed from the presentation for a debt discount, which is a direct adjustment to the carrying value of the debt (i.e., a contra liability). These different balance sheet presentation requirements created unnecessary complexity. This new standard requires that all costs incurred to issue debt be presented in the balance sheet as a direct deduction from the carrying value of the debt. This new standard does not affect the recognition and measurement of debt issuance costs. Therefore, the amortization of such costs should continue to be calculated using the interest method and reported as interest expense. ASU No. 2015-03 is effective for the Company in the first quarter of fiscal 2016, with early adoption permitted. The Company elected to early adopt this standard by having it be effective for the reporting period ending on March 31, 2015, and as such presented $550,000 of debt issuance costs as a direct deduction from the carrying value of the Company’s convertible senior notes.
	In April 2015, the FASB issued ASU No. 2015-05, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. This update is intended to provide guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. This update will not change a customer’s accounting for service contracts. ASU No. 2015-05 is effective for the Company in the first quarter of fiscal 2016, with early adoption permitted. The Company is currently evaluating the impact that ASU 2015-05 will have on its financial statements.

License_and_Collaboration_Arra

License and Collaboration Arrangements	3 Months Ended
	Mar. 31, 2015
License and Collaboration Arrangements	2. License and Collaboration Arrangements
	Indivior PLC
	In May 2014, the Company entered into an exclusive license agreement with Indivior, which became effective on June 19, 2014. Under the terms of this agreement, the Company granted to Indivior exclusive, world-wide rights to develop and commercialize pharmaceutical products containing AP Products for all indications, subject to its right of first negotiation with Indivior to collaborate to develop and commercialize AP Products for non-addiction indications. In exchange for these rights, the Company received an upfront, non-refundable cash payment of $20,000,000 in June 2014 and also received an additional $5,000,000 payment in July 2014 after delivery of specified materials to Indivior. The Company is also eligible to receive aggregate cash payments of up to $120,000,000 upon the achievement by Indivior of certain contingent event-based payments, of which $70,000,000 are regulatory and development-based and $50,000,000 are commercialization-based. In addition, the Company is entitled to receive tiered double-digit royalty payments of up to the mid-teens on a percentage basis on potential future net sales of the products in the United States, and high single-digit royalty payments on potential future net sales of the products outside the United States. The Company also agreed to transfer its existing AP Investigational New Drug applications, or INDs, and know-how to Indivior, and to provide supply transition assistance to facilitate the establishment of Indivior’s AP Product manufacturing capabilities pursuant to a mutually agreed supply transition plan.
	The Company assessed its transfer and assistance obligations under the Indivior agreement using the multiple-element arrangements revenue recognition guidance since those obligations involved more than one deliverable to Indivior. This analysis involved identification of the deliverables, determining if they qualify as separate units of accounting, arriving at fair value estimates for each separate unit of accounting, and allocating total consideration to each unit of accounting. The Company identified the following non-contingent deliverables under the license agreement: (1) grant of exclusive rights, or the license; (2) transfer of know-how necessary for the manufacture and development of AP Products; (3) transfer of INDs; (4) transfer of specified materials; and (5) supply of transition assistance to facilitate the establishment of Indivior’s AP Product manufacturing capabilities pursuant to a mutually agreed upon supply transition plan. The license, know-how, INDs and supply of transition assistance deliverables were combined into one unit of accounting since each of these deliverables was dependent on, and not separate from each other, and accordingly did not have stand-alone value. The transfer of specified materials represented the other unit of accounting. The total of the upfront cash payment of $20,000,000 and the additional cash payment of $5,000,000 were allocated into two units of accounting using the relative estimated selling price method. The Company developed its best estimate of selling prices for each deliverable in order to allocate the non-contingent arrangement consideration to the two units of accounting. For the license, know-how, INDs and supply of transition assistance, the Company used the discounted cash flow method to estimate the price at which it could sell them on a stand-alone basis. Embedded in the estimate were significant assumptions including: (1) probabilities of success during the development process; (2) potential customer market for the drug; (3) selling price for the drug; (4) costs to develop, maintain and manufacture the developed drug; and (5) discount rate. For the transfer of specified materials, the Company estimated the selling price based on the cost to purchase such materials from third party suppliers. Both the initial upfront cash payment of $20,000,000 and the additional cash payment of $5,000,000 were recognized as collaboration revenue upon the transfer of the deliverables to Indivior, which occurred in the third quarter of 2014.
	Astellas Pharma Inc.
	Under a December 2005 license agreement with Astellas Pharma Inc., as amended in July 2012, Astellas is commercializing gabapentin enacarbil in Japan under the trade name of REGNITE® (gabapentin enacarbil) Extended-Release Tablets. In the three months ended March 31, 2015 and 2014, the Company recognized collaboration revenue of $284,000 and $283,000, respectively, representing amortization of the up-front license payment under this agreement. For the three months ended March 31, 2015 and 2014, the Company recognized $144,000 and $135,000, respectively, in royalty revenue. As of March 31, 2015, the Company had recognized an aggregate of $54,501,000 of revenue pursuant to this agreement. At March 31, 2015, $11,714,000 of such revenue was deferred under this agreement and was being recognized on a straight-line basis over a period that the Company expects to remain obligated to provide services, of which $1,134,000 was classified within current liabilities and the remaining $10,580,000 was recorded as a noncurrent liability.

Net_Loss_per_Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2015
Net Loss per Share	3. Net Loss per Share
	Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period without consideration for potential common shares. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period plus any dilutive potential common shares for the period determined using the treasury-stock method for restricted stock units and options to purchase stock and using the if-converted method for the convertible senior notes. For purposes of this calculation, restricted stock units, options to purchase stock and convertible senior notes are considered to be potential common shares and are only included in the calculation of diluted net loss per share when their effect is dilutive.
		Three Months Ended
		March 31,
		2015			2014
		(In thousands, except
		per share amounts)
	Numerator:
	Net loss	$	(20,409	)	$	(20,548	)
	Denominator:
	Weighted-average common shares outstanding		62,722			56,887
	Basic and diluted net loss per share	$	(0.33	)	$	(0.36	)
	Outstanding securities at period end not included in the computation of diluted net loss per share as they had an anti-dilutive effect:
	Restricted stock units and options to purchase common stock		9,036			8,165
	Convertible senior notes		10,729			—
			19,765			8,165
	On January 29, 2014, the Company completed an underwritten public offering of 12,000,000 shares of its common stock at a price to the public of $6.00 per share. On February 21, 2014, the underwriters exercised in full their option to purchase 1,800,000 additional shares.
	On February 3, 2015, the Company completed a private placement of $115,000,000 aggregate principal amount of 2.50% Convertible Senior Notes due 2022, or the 2022 Notes. The 2022 Notes are convertible at an initial conversion rate of 93.2945 shares of the Company’s common stock per $1,000 principal amount of the 2022 Notes, which is equal to an initial conversion price of approximately $10.72 per share of common stock. As of March 31, 2015, 10,728,867 shares of the Company’s common stock were issuable upon conversion of the 2022 Notes (see Note 7 for more information).

Cash_and_Cash_Equivalents_Shor

Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments	3 Months Ended
	Mar. 31, 2015
Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments	4. Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments
	The following are summaries of cash and cash equivalents, short-term and long-term investments and restricted investments (in thousands):
			Cost		Gross Unrealized		Gross Unrealized			Estimated Fair
					Gains		Losses			Value
	As of March 31, 2015:
	Cash		$	2,620	$	—	$	—		$	2,620
	Money market funds			12,927		—		—			12,927
	U.S. government-sponsored agencies - current			2,000		—		(2	)		1,998
	U.S. government-sponsored agencies - noncurrent			5,000		4		—			5,004
	Corporate debt securities - current			168,513		92		(32	)		168,573
	Corporate debt securities - noncurrent			512		—		—			512
	Certificates of deposit			1,725		—		—			1,725
			$	193,297	$	96	$	(34	)	$	193,359
	Reported as:
	Cash and cash equivalents									$	16,898
	Short-term investments										169,220
	Long-term investments										5,516
	Restricted investments (1)										1,725
										$	193,359
	As of December 31, 2014:
	Cash		$	3,383	$	—	$	—		$	3,383
	Money market funds			8,576		—		—			8,576
	U.S. government-sponsored agencies			2,000		—		(2	)		1,998
	Corporate debt securities			88,127		12		(40	)		88,099
	Certificates of deposit			1,725		—		—			1,725
			$	103,811	$	12	$	(42	)	$	103,781
	Reported as:
	Cash and cash equivalents									$	11,958
	Short-term investments										90,098
	Restricted investments (1)										1,725
										$	103,781
	(1)	Included in “Restricted investments and other assets” as of March 31, 2015 and December 31, 2014.
	The Company considers all highly liquid investments with original maturities of 90 days or less at the time of purchase to be cash equivalents, which primarily consist of money market funds. Management determines the appropriate classification of securities at the time of purchase. All investments have been designated as available-for-sale. The Company classifies its available-for-sale investments as either current or noncurrent based on their maturities and the Company’s intent with regard to those investments. The Company currently views its available-for-sale investments that mature within one year as available for its current operations and classified as short-term investments, while available-for-sale investments that mature beyond one year are classified as long-term investments. All available-for-sale securities are carried at estimated fair value with unrealized gains and losses reported as a component of other comprehensive loss in the statements of comprehensive loss. No gross realized gains or losses were recognized and accordingly, there were no amounts reclassified out of accumulated other comprehensive income (loss) to earnings in the three months ended March 31, 2015 or in the same period in 2014.
	The Company’s available-for-sale investments, which include cash equivalents and short-term and long-term investments, are measured at fair value on a recurring basis and are classified at the following fair value hierarchy (in thousands):
					Fair Value Measurements at Reporting Date Using
	Description		Total As of		Quoted Prices in		Significant Other			Significant
			March 31, 2015		Active Markets for		Observable Inputs			Unobservable
					Identical Assets		(Level 2)			Inputs (Level 3)
					(Level 1)
	Money market funds		$	12,927	$	12,927	$	—		$	—
	U.S. government-sponsored agencies - current and noncurrent			7,002		—		7,002			—
	Corporate debt securities - current and noncurrent			169,085		—		169,085			—
	Certificates of deposit			1,725		—		1,725			—
	Total		$	190,739	$	12,927	$	177,812		$	—
					Fair Value Measurements at Reporting Date Using
	Description		Total As of		Quoted Prices in		Significant Other			Significant
			December 31, 2014		Active Markets for		Observable Inputs			Unobservable
					Identical Assets		(Level 2)			Inputs (Level 3)
					(Level 1)
	Money market funds		$	8,576	$	8,576	$	—		$	—
	U.S. government-sponsored agencies			1,998		—		1,998			—
	Corporate debt securities			88,099		—		88,099			—
	Certificates of deposit			1,725		—		1,725			—
	Total		$	100,398	$	8,576	$	91,822		$	—

Inventories

Inventories	3 Months Ended
	Mar. 31, 2015
Inventories	5. Inventories
	Inventories are stated at the lower of cost or market. Cost is determined on a first-in, first-out, or FIFO, basis. Inventories include active pharmaceutical ingredient, or API, contract manufacturing costs and overhead allocations. The Company regularly evaluates the Company’s inventories for excess quantities and obsolescence (expiration), taking into account such factors as historical and anticipated future sales compared to quantities on hand and the remaining shelf life of HORIZANT. Write-downs of inventories are considered to be permanent reductions in the cost basis of inventories. Inventories that are not expected to be consumed within 12 months following the balance sheet date are classified as long-term inventories.
	Inventories as of March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31,		December 31,
		2015		2014
	Raw materials	$	8,671	$	9,273
	Work in progress		1,393		517
	Finished goods		688		766
	Total inventory		10,752		10,556
	Less: Long-term inventories		8,845		9,098
	Total inventory classified as current	$	1,907	$	1,458
	Long-term inventories primarily consisted of gabapentin enacarbil API used for production of HORIZANT. The Company evaluates demand for HORIZANT and expected consumption of the API based on long-term projected sales of HORIZANT.

Other_Accrued_Liabilities

Other Accrued Liabilities	3 Months Ended
	Mar. 31, 2015
Other Accrued Liabilities	6. Other Accrued Liabilities
	Other accrued liabilities at March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31,		December 31,
		2015		2014
	Accrued product costs	$	659	$	2,009
	Accrued selling and marketing expenses		2,235		1,210
	Accrued general and administrative expenses		595		466
	Accrued rebates, allowances and returns		973		986
	Interest payable - convertible senior notes		447		—
	Other liabilities		622		446
	Total other accrued liabilities	$	5,531	$	5,117

Convertible_Senior_Notes

Convertible Senior Notes	3 Months Ended
	Mar. 31, 2015
Convertible Senior Notes	7. Convertible Senior Notes
	On February 3, 2015, the Company completed a private placement of $115,000,000 aggregate principal amount of the 2022 Notes. The net proceeds from the offering of the 2022 Notes were $111,345,000, after deducting the initial purchaser’s discount and debt issuance costs payable by the Company. Beginning on August 1, 2015, interest on the 2022 Notes will be payable semi-annually in cash in arrears on February 1 and August 1 of each year, at a rate of 2.50% per year. The 2022 Notes mature on February 1, 2022, unless earlier converted or repurchased. The 2022 Notes are not redeemable prior to the maturity date.
	Holders may convert all or any portion of their 2022 Notes at their option at any time prior to the close of business on the business day immediately preceding the maturity date. The 2022 Notes are convertible at an initial conversion rate of 93.2945 shares of the Company’s common stock per $1,000 principal amount of the 2022 Notes, subject to adjustment, which is equal to an initial conversion price of approximately $10.72 per share of common stock. Upon conversion, the 2022 Notes may be settled in shares of the Company’s common stock, together with a cash payment in lieu of delivering any fractional share. The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that may occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its 2022 Notes in connection with such a corporate event in certain circumstances. If the Company undergoes a fundamental change, which would include specified change of control transactions, or liquidation or dissolution or the Company’s common stock ceasing to be listed or quoted on specified national securities exchanges, and the fundamental change occurs prior to the maturity date of the 2022 Notes, holders of the 2022 Notes may require the Company to repurchase all or part of their 2022 Notes at a repurchase price equal to 100% of the principal amount of the 2022 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. As of March 31, 2015, the outstanding principal balance on the 2022 Notes was $115,000,000 and 10,728,867 shares of the Company’s common stock were issuable upon conversion of the 2022 Notes.
	The 2022 Notes are accounted for in accordance with ASC Subtopic 470-20, Debt with Conversion and Other Options. Pursuant to ASC Subtopic 470-20, the Company evaluated the features embedded in the 2022 Notes, and concluded that the 2022 Notes are not required to be bifurcated and accounted for separately from the host debt instrument.
	The Company incurred $550,000 in debt issuance costs in connection with the issuance of the 2022 Notes, which are being amortized through the maturity date through the application of the interest method and reported as interest expense. In accordance with ASU No. 2015-03, the Company has presented debt issuance costs as a direct deduction from the carrying value of the 2022 Notes.
	As of March 31, 2015, the 2022 Notes were reported at their current carrying value which approximated fair value based on Level 3 unobservable inputs involving discounted cash flows and the estimated market rate of borrowing that could be obtained by companies with credit risk similar to the Company’s credit risk.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation	8. Stock-Based Compensation
	The Company’s employee non-cash stock-based compensation expense was as follows (in thousands):
		Three Months Ended
		March 31,
		2015		2014
		(In thousands)
	Research and development	$	382	$	702
	Selling, general and administrative		2,289		1,982
		$	2,671	$	2,684

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Basis of Preparation	Basis of Preparation
	The accompanying financial statements as of March 31, 2015, and for the three months ended March 31, 2015 and 2014, are unaudited. These unaudited financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of March 31, 2015 and comprehensive loss for the three months ended March 31, 2015 and 2014, and cash flows for the three months ended March 31, 2015 and 2014. The Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or the Codification, is the single source of authoritative U.S. generally accepted accounting principles, or GAAP. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015, or for any other interim period or any other future year. For more complete financial information, these financial statements, and the notes hereto, should be read in conjunction with the audited financial statements for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 27, 2015.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the FASB issued Accounting Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09), which creates a single source of revenue guidance under GAAP for all companies in all industries. The core principle of ASU 2014-09 is that revenue should be recognized in a manner that depicts 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. ASU 2014-09 defines a five-step process in order to achieve this core principle, which may require the use of judgment and estimates. ASU 2014-09 also requires expanded qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers, including significant judgments and estimates used. ASU 2014-09 will be effective for the Company in the first quarter of fiscal 2017, and early adoption is not permitted. The Company may adopt ASU 2014-09 either by way of a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. On April 1, 2015, the FASB voted to propose a delay in the effective date of ASU No. 2014-09. The proposed new effective date will be annual reporting periods beginning after December 15, 2017, and the interim periods within that year and will allow early adoption for all entities as of the original effective date for public business entities, which was annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the impact that ASU 2014-09 will have on its financial statements and has not yet determined which transition method it will apply.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 requires management to assess 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 and other disclosures when substantial doubt is not alleviated; and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 will be effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, with early adoption permitted. ASU 2014-15 will be effective for the Company beginning with its annual report for fiscal 2016 and interim periods thereafter. The Company is currently evaluating the impact that ASU 2014-15 will have on its financial statements.
	In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. Debt issuance costs are specified incremental costs, other than those paid to the lender, that are directly attributable to issuing a debt instrument (i.e., third party costs). Prior to this standard, debt issuance costs were required to be presented in the balance sheet as a deferred charge (i.e., an asset). This presentation differed from the presentation for a debt discount, which is a direct adjustment to the carrying value of the debt (i.e., a contra liability). These different balance sheet presentation requirements created unnecessary complexity. This new standard requires that all costs incurred to issue debt be presented in the balance sheet as a direct deduction from the carrying value of the debt. This new standard does not affect the recognition and measurement of debt issuance costs. Therefore, the amortization of such costs should continue to be calculated using the interest method and reported as interest expense. ASU No. 2015-03 is effective for the Company in the first quarter of fiscal 2016, with early adoption permitted. The Company elected to early adopt this standard by having it be effective for the reporting period ending on March 31, 2015, and as such presented $550,000 of debt issuance costs as a direct deduction from the carrying value of the Company’s convertible senior notes.
	In April 2015, the FASB issued ASU No. 2015-05, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. This update is intended to provide guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. This update will not change a customer’s accounting for service contracts. ASU No. 2015-05 is effective for the Company in the first quarter of fiscal 2016, with early adoption permitted. The Company is currently evaluating the impact that ASU 2015-05 will have on its financial statements.

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Net Loss Per Share
		Three Months Ended
		March 31,
		2015			2014
		(In thousands, except
		per share amounts)
	Numerator:
	Net loss	$	(20,409	)	$	(20,548	)
	Denominator:
	Weighted-average common shares outstanding		62,722			56,887
	Basic and diluted net loss per share	$	(0.33	)	$	(0.36	)
	Outstanding securities at period end not included in the computation of diluted net loss per share as they had an anti-dilutive effect:
	Restricted stock units and options to purchase common stock		9,036			8,165
	Convertible senior notes		10,729			—
			19,765			8,165

Cash_and_Cash_Equivalents_Shor1

Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments	The following are summaries of cash and cash equivalents, short-term and long-term investments and restricted investments (in thousands):
			Cost		Gross Unrealized		Gross Unrealized			Estimated Fair
					Gains		Losses			Value
	As of March 31, 2015:
	Cash		$	2,620	$	—	$	—		$	2,620
	Money market funds			12,927		—		—			12,927
	U.S. government-sponsored agencies - current			2,000		—		(2	)		1,998
	U.S. government-sponsored agencies - noncurrent			5,000		4		—			5,004
	Corporate debt securities - current			168,513		92		(32	)		168,573
	Corporate debt securities - noncurrent			512		—		—			512
	Certificates of deposit			1,725		—		—			1,725
			$	193,297	$	96	$	(34	)	$	193,359
	Reported as:
	Cash and cash equivalents									$	16,898
	Short-term investments										169,220
	Long-term investments										5,516
	Restricted investments (1)										1,725
										$	193,359
	As of December 31, 2014:
	Cash		$	3,383	$	—	$	—		$	3,383
	Money market funds			8,576		—		—			8,576
	U.S. government-sponsored agencies			2,000		—		(2	)		1,998
	Corporate debt securities			88,127		12		(40	)		88,099
	Certificates of deposit			1,725		—		—			1,725
			$	103,811	$	12	$	(42	)	$	103,781
	Reported as:
	Cash and cash equivalents									$	11,958
	Short-term investments										90,098
	Restricted investments (1)										1,725
										$	103,781
	(1)	Included in “Restricted investments and other assets” as of March 31, 2015 and December 31, 2014.
Available-For-Sale Investments Measured at Fair Value
					Fair Value Measurements at Reporting Date Using
	Description		Total As of		Quoted Prices in		Significant Other			Significant
			March 31, 2015		Active Markets for		Observable Inputs			Unobservable
					Identical Assets		(Level 2)			Inputs (Level 3)
					(Level 1)
	Money market funds		$	12,927	$	12,927	$	—		$	—
	U.S. government-sponsored agencies - current and noncurrent			7,002		—		7,002			—
	Corporate debt securities - current and noncurrent			169,085		—		169,085			—
	Certificates of deposit			1,725		—		1,725			—
	Total		$	190,739	$	12,927	$	177,812		$	—
					Fair Value Measurements at Reporting Date Using
	Description		Total As of		Quoted Prices in		Significant Other			Significant
			December 31, 2014		Active Markets for		Observable Inputs			Unobservable
					Identical Assets		(Level 2)			Inputs (Level 3)
					(Level 1)
	Money market funds		$	8,576	$	8,576	$	—		$	—
	U.S. government-sponsored agencies			1,998		—		1,998			—
	Corporate debt securities			88,099		—		88,099			—
	Certificates of deposit			1,725		—		1,725			—
	Total		$	100,398	$	8,576	$	91,822		$	—

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory	Inventories as of March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31,		December 31,
		2015		2014
	Raw materials	$	8,671	$	9,273
	Work in progress		1,393		517
	Finished goods		688		766
	Total inventory		10,752		10,556
	Less: Long-term inventories		8,845		9,098
	Total inventory classified as current	$	1,907	$	1,458

Other_Accrued_Liabilities_Tabl

Other Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Other Accrued Liabilities	Other accrued liabilities at March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31,		December 31,
		2015		2014
	Accrued product costs	$	659	$	2,009
	Accrued selling and marketing expenses		2,235		1,210
	Accrued general and administrative expenses		595		466
	Accrued rebates, allowances and returns		973		986
	Interest payable - convertible senior notes		447		—
	Other liabilities		622		446
	Total other accrued liabilities	$	5,531	$	5,117

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Employee Non-Cash Stock-Based Compensation	The Company’s employee non-cash stock-based compensation expense was as follows (in thousands):
		Three Months Ended
		March 31,
		2015		2014
		(In thousands)
	Research and development	$	382	$	702
	Selling, general and administrative		2,289		1,982
		$	2,671	$	2,684

License_and_Collaboration_Arra1

License and Collaboration Arrangements - Additional Information (Detail) (USD $)	3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2014	Jul. 31, 2014	Dec. 31, 2014	31-May-14
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$284,000	$283,000
Royalty revenue	144,000	135,000
Revenue recognized	7,067,000	3,375,000
Deferred revenue, current	1,134,000					1,134,000
Deferred revenue, non-current	10,580,000					10,864,000
Licensing Agreements | Indivior PLC | Upfront, non-refundable cash payment
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue, initial up-front license payment and payment for specified materials received			20,000,000
Collaboration revenue				20,000,000
Licensing Agreements | Indivior PLC | Additional payment for specified materials
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue, initial up-front license payment and payment for specified materials received					5,000,000
Collaboration revenue				5,000,000
Licensing Agreements | Indivior PLC | Achievement of certain predefined milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payments, maximum amount							120,000,000
Licensing Agreements | Indivior PLC | Regulatory and development-based milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payments, maximum amount							70,000,000
Licensing Agreements | Indivior PLC | Commercialization-based milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payments, maximum amount							50,000,000
Licensing Agreements | Astellas Pharma Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenue	144,000	135,000
Revenue recognized	54,501,000
Deferred revenue	11,714,000
Deferred revenue, current	1,134,000
Deferred revenue, non-current	10,580,000
Licensing Agreements | Astellas Pharma Inc. | Upfront, non-refundable cash payment
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$284,000	$283,000

Net_Loss_Per_Share_Detail

Net Loss Per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net loss	($20,409)	($20,548)
Denominator:
Weighted-average common shares outstanding	62,722	56,887
Basic and diluted net loss per share	($0.33)	($0.36)
Outstanding securities at period end not included in the computation of diluted net loss per share as they had an anti-dilutive effect:
Outstanding securities not included in the computation of diluted net loss per share	19,765	8,165
Restricted stock units and options to purchase common stock
Outstanding securities at period end not included in the computation of diluted net loss per share as they had an anti-dilutive effect:
Outstanding securities not included in the computation of diluted net loss per share	9,036	8,165
Convertible Senior Notes
Outstanding securities at period end not included in the computation of diluted net loss per share as they had an anti-dilutive effect:
Outstanding securities not included in the computation of diluted net loss per share	10,729

Net_Loss_Per_Share_Additional_

Net Loss Per Share - Additional Information (Detail) (USD $)	0 Months Ended
	Feb. 03, 2015	Jan. 29, 2014	Feb. 21, 2014	Mar. 31, 2015
Computation of Earnings Per Share [Line Items]
Underwriters exercised the full option to purchase additional shares			1,800,000
Convertible Senior Notes Due 2022
Computation of Earnings Per Share [Line Items]
Convertible senior notes, principal offer amount	$115,000,000			$115,000,000
Convertible senior notes, stated interest rate	2.50%
Convertible senior notes, due date	2022
Convertible senior notes, conversion share per 1000 principal amount	93.2945
Convertible senior notes, initial conversion price	$10.72
Common stock issuable upon conversion cf convertible senior notes				10,728,867
Underwritten Public Offering
Computation of Earnings Per Share [Line Items]
Common stock issued in underwritten public offering		12,000,000
Common stock price		$6

Cash_and_Cash_Equivalents_Shor2

Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Cost	$193,297		$103,811
Gross Unrealized Gains	96		12
Gross Unrealized Losses	-34		-42
Estimated Fair Value	193,359		103,781
Cash
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	2,620		3,383
Available-for-sale investments	2,620		3,383
Money market funds
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	12,927		8,576
Available-for-sale investments	12,927		8,576
Certificates of deposit
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Restricted Cost	1,725		1,725
Restricted Fair Value	1,725		1,725
Cash and cash equivalents
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available-for-sale investments	16,898		11,958
Short-term investments
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available-for-sale investments	169,220		90,098
Restricted investments
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Restricted Fair Value	1,725	[1]	1,725	[1]
US Government Sponsored Enterprises Debt Securities Current
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	2,000		2,000
Gross Unrealized Losses	-2		-2
Available-for-sale investments	1,998		1,998
US Government Sponsored Enterprises Debt Securities Noncurrent
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	5,000
Gross Unrealized Gains	4
Available-for-sale investments	5,004
Corporate Debt Securities Current
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	168,513		88,127
Gross Unrealized Gains	92		12
Gross Unrealized Losses	-32		-40
Available-for-sale investments	168,573		88,099
Corporate Debt Securities Noncurrent
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available for Sale Securities Cost	512
Available-for-sale investments	512
Long Term Investments
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Available-for-sale investments	$5,516
[1]	Included in "Restricted investments and other assets" as of March 31, 2015 and December 31, 2014.

Cash_and_Cash_Equivalents_Shor3

Cash and Cash Equivalents, Short-Term and Long-Term Investments and Restricted Investments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash Cash Equivalents Short And Long Term Investments and Restricted Investments [Line Items]
Gross realized gains or losses recognized	$0	$0
Amounts reclassified out of accumulated other comprehensive loss to earnings	$0	$0

AvailableForSale_Investments_M

Available-For-Sale Investments Measured at Fair Value (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	$193,359	$103,781
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	12,927	8,576
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Fair Value	1,725	1,725
Fair Value Measurements, Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	190,739	100,398
Fair Value Measurements, Recurring basis | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	12,927	8,576
Fair Value Measurements, Recurring basis | U.S. government-sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	7,002	1,998
Fair Value Measurements, Recurring basis | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	169,085	88,099
Fair Value Measurements, Recurring basis | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Fair Value	1,725	1,725
Fair Value Measurements, Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	12,927	8,576
Fair Value Measurements, Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	12,927	8,576
Fair Value Measurements, Recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	177,812	91,822
Fair Value Measurements, Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. government-sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	7,002	1,998
Fair Value Measurements, Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	169,085	88,099
Fair Value Measurements, Recurring basis | Significant Other Observable Inputs (Level 2) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Fair Value	$1,725	$1,725

Inventory_Detail

Inventory (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$8,671	$9,273
Work in progress	1,393	517
Finished goods	688	766
Total inventory	10,752	10,556
Less: Long-term inventories	8,845	9,098
Total inventory classified as current	$1,907	$1,458

Other_Accrued_Liabilities_Deta

Other Accrued Liabilities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]
Accrued product costs	$659	$2,009
Accrued selling and marketing expenses	2,235	1,210
Accrued general and administrative expenses	595	466
Accrued rebates, allowances and returns	973	986
Interest payable - convertible senior notes	447
Other liabilities	622	446
Total other accrued liabilities	$5,531	$5,117

Convertible_Senior_Notes_Addit

Convertible Senior Notes - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	Feb. 03, 2015	Mar. 31, 2015	Feb. 03, 2015
Debt Instrument [Line Items]
Proceeds from issuance of convertible senior notes, net of discount and debt issuance costs		$111,345,000
Convertible Senior Notes Due 2022
Debt Instrument [Line Items]
Convertible senior notes, principal offer amount	115,000,000	115,000,000	115,000,000
Convertible senior notes, due date	2022
Proceeds from issuance of convertible senior notes, net of discount and debt issuance costs		111,345,000
Convertible senior notes, repayment terms	Beginning on August 1, 2015, interest on the 2022 Notes will be payable semi-annually in cash in arrears on February 1 and August 1 of each year, at a rate of 2.50% per year.
Convertible senior notes, interest payment commencement date	1-Aug-15
Convertible senior notes, maturity date	1-Feb-22
Convertible senior notes, stated interest rate	2.50%		2.50%
Convertible senior notes, conversion share per 1000 principal amount	93.2945
Convertible senior notes, initial conversion price	$10.72		$10.72
Repurchase price of principal amount	100.00%
Common stock issuable upon conversion of notes		10,728,867
Debt issuance cost		$550,000

Employee_NonCash_StockBased_Co

Employee Non-Cash Stock-Based Compensation (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Non-cash stock-based compensation	$2,671	$2,684
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Non-cash stock-based compensation	382	702
Selling, general and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Non-cash stock-based compensation	$2,289	$1,982