Omeros (OMER) 10-K 16 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Mar. 07, 2017	Jun. 30, 2016
Document Documentand Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	OMER
Entity Registrant Name	OMEROS CORP
Entity Central Index Key	1,285,819
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		43,822,133
Entity Public Float			$ 386,370,281

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 2,224	$ 1,365
Short-term investments	43,107	26,898
Receivables	12,037	6,517
Inventory	1,128	472
Prepaid expense	1,766	1,894
Total current assets	60,262	37,146
Property and equipment, net	1,181	951
Restricted cash and investments	5,835	10,679
Other assets	0	219
Total assets	67,278	48,995
Current liabilities:
Accounts payable	2,519	6,428
Accrued expenses	13,354	9,752
Current portion of lease financing obligations	198	73
Total current liabilities	16,071	16,253
Notes payable and lease financing obligations, net	79,512	49,769
Deferred rent	9,142	9,207
Commitments and contingencies (Note 8)
Shareholders’ deficit:
Preferred stock, par value $0.01 per share, 20,000,000 authorized and none issued at December 31, 2016 and 2015.	0	0
Common Stock, par value $0.01 per share, 150,000,000 shares authorized at December 31, 2016 and 2015; 43,819,133 and 38,040,891 issued and outstanding at December 31, 2016 and December 31, 2015, respectively.	438	380
Additional paid-in capital	432,002	376,528
Accumulated deficit	(469,887)	(403,142)
Total shareholders’ deficit	(37,447)	(26,234)
Total liabilities and shareholders’ deficit	$ 67,278	$ 48,995

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value (USD per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	20,000,000	20,000,000
Preferred stock, Issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, authorized shares	150,000,000	150,000,000
Common stock, Issued shares	43,819,133	38,040,891
Common stock, outstanding shares	43,819,133	38,040,891

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Product sales, net	$ 41,444	$ 13,264	$ 0
Grant revenue	173	245	539
Total revenue	41,617	13,509	539
Costs and expenses:
Cost of product sales	1,412	1,041	0
Research and development	50,699	48,379	47,946
Selling, general and administrative	43,782	35,327	22,601
Total costs and expenses	95,893	84,747	70,547
Loss from operations	(54,276)	(71,238)	(70,008)
Interest expense	(7,819)	(3,573)	(3,470)
Loss on early extinguishment of debt	(5,595)	(1,315)	0
Other income (expense), net	945	1,030	(195)
Net loss	(66,745)	(75,096)	(73,673)
Comprehensive loss	$ (66,745)	$ (75,096)	$ (73,673)
Basic and diluted net loss per share (in dollars per share)	$ (1.65)	$ (2)	$ (2.22)
Weighted-average shares used to compute basic and diluted net loss per share (in shares)	40,446,410	37,560,257	33,234,294

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' DEFICIT - USD ($) $ in Thousands	Total	JonesTrading, ATM Agreement	Common Stock	Common StockJonesTrading, ATM Agreement	Additional Paid-in Capital	Additional Paid-in CapitalJonesTrading, ATM Agreement	Accumulated Deficit
Balance (in shares) at Dec. 31, 2013			30,359,508
Balance at Dec. 31, 2013	$ (18,384)		$ 304		$ 235,685		$ (254,373)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (in shares)			3,500,000
Issuance of stock	37,754		$ 35		37,719
Issuance of common stock utilizing At-The-Market Agreement, net of commissions (in shares)			28,653
Issuance of common stock utilizing At-The Market Agreement, net of commissions	68		$ 0		68
Issuance of common stock upon exercise of stock options for cash (in shares)			297,303
Issuance of common stock upon exercise of stock options for cash	1,800		$ 3		1,797
Stock-based compensation	8,918				8,918
Issuance of common stock warrants/warrant modification	863				863
Net loss	(73,673)						(73,673)
Balance (in shares) at Dec. 31, 2014			34,185,464
Balance at Dec. 31, 2014	(42,654)		$ 342		285,050		(328,046)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (in shares)			3,444,831
Issuance of stock	79,076		$ 34		79,042
Issuance of common stock utilizing At-The-Market Agreement, net of commissions (in shares)			133,240
Issuance of common stock utilizing At-The Market Agreement, net of commissions	1,436		$ 1		1,435
Issuance of common stock upon exercise of stock options for cash (in shares)			277,356
Issuance of common stock upon exercise of stock options for cash	1,423		$ 3		1,420
Stock-based compensation	9,581				9,581
Net loss	(75,096)						(75,096)
Balance (in shares) at Dec. 31, 2015			38,040,891
Balance at Dec. 31, 2015	(26,234)		$ 380		376,528		(403,142)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (in shares)			3,478,260	64,565
Issuance of stock	37,314	$ 725	$ 35	$ 1	37,279	$ 724
Issuance of common stock utilizing At-The-Market Agreement, net of commissions (in shares)			749,250
Issuance of common stock utilizing At-The Market Agreement, net of commissions	$ 7		$ 7		0
Issuance of common stock upon exercise of stock options for cash (in shares)	1,486,167		1,486,167
Issuance of common stock upon exercise of stock options for cash	$ 3,146		$ 15		3,131
Stock-based compensation	13,582				13,582
Issuance of common stock warrants/warrant modification	758				758
Net loss	(66,745)						(66,745)
Balance (in shares) at Dec. 31, 2016			43,819,133
Balance at Dec. 31, 2016	$ (37,447)		$ 438		$ 432,002		$ (469,887)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net loss	$ (66,745)	$ (75,096)	$ (73,673)
Adjustments to reconcile net loss to net cash used in operating activities:
Loss on early extinguishment of debt	5,595	1,315	0
Depreciation and amortization	300	209	317
Stock-based compensation expense	13,582	9,581	8,918
Non-cash interest expense	1,461	1,045	738
Conversion of accrued interest to notes payable	516	0	0
Warrant modification expense	0	0	863
Changes in operating assets and liabilities:
Receivables	(5,520)	(6,125)	(13)
Inventory	(656)	96	(568)
Prepaid expenses and assets	347	(586)	(987)
Accounts payable and accrued expenses	(319)	4,195	5,459
Deferred rent	(65)	157	902
Net cash used in operating activities	(51,504)	(65,209)	(58,044)
Investing activities:
Purchases and sales of property and equipment, net	(126)	(240)	(28)
Purchases of investments	(73,966)	(91,766)	(58,849)
Proceeds from the sale and maturities of investments	57,757	71,400	65,034
Net cash provided by (used in) investing activities	(16,335)	(20,606)	6,157
Financing activities:
Proceeds from issuance of common stock and pre-funded warrants, net	38,039	79,076	37,754
Proceeds from borrowings under notes payable	100,000	50,000	32,000
Repayments on notes payable and lease financing obligations	(70,137)	(32,000)	(20,000)
Payments for debt prepayment and extinguishment costs	(5,700)	(2,673)	(521)
Payments for debt issuance costs	(1,501)	(436)	(244)
Decrease (increase) in restricted investments	4,844	(10,000)	0
Proceeds upon exercise of stock options and warrants	3,153	2,859	1,868
Net cash provided by financing activities	68,698	86,826	50,857
Net increase (decrease) in cash and cash equivalents	859	1,011	(1,030)
Cash and cash equivalents at beginning of period	1,365	354	1,384
Cash and cash equivalents at end of period	2,224	1,365	354
Supplemental cash flow information
Cash paid for interest	5,293	4,236	2,674
Issuance of warrants in connection with amendment to notes payable	758	0	0
Property acquired under capital lease	$ 404	$ 137	$ 200

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Organization We are a biopharmaceutical company committed to discovering, developing and commercializing both small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system. Our first drug product OMIDRIA has been approved by the United States (U.S.) Food and Drug Administration (FDA) for use during cataract surgery or intraocular lens (IOL) replacement. We launched OMIDRIA in the U.S. in the second quarter of 2015. Basis of Presentation Our consolidated financial statements include the financial position and results of operations of Omeros Corporation (Omeros) and our wholly owned subsidiaries. All inter-company transactions have been eliminated. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). Segments We operate in one segment. Management uses cash flow as the primary measure to manage our business and does not segment our business for internal reporting or decision-making. Use of Estimates 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. Significant items subject to such estimates include revenue recognition, stock-based compensation expense and accruals for clinical trials, manufacturing of drug product and clinical drug supply and contingencies. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances; however, actual results could differ from these estimates. Reclassifications Certain reclassifications have been made to prior periods in the consolidated balance sheets, the statements of cash flows and the accompanying notes to conform with the current presentation. None of these reclassifications impacted our net loss or working capital as they pertained to the presentation of debt matters including issuance costs, extinguishment losses, early payments and proceeds. Going Concern As of December 31, 2016 , we adopted the provisions of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 205-40, Presentation of Financial Statements - Going Concern (ASC 205-40), which requires management to assess our ability to continue as a going concern for one year after the date the financial statements are issued. Under ASC 205-40, management has the responsibility to evaluate whether conditions and/or events raise substantial doubt about our ability to meet our future financial obligations as they become due within one year after the date that the financial statements are issued. As required by this standard, management’s evaluation shall initially not take into consideration the potential mitigating effects of management’s plans that have not been fully implemented as of the date the financial statements are issued. In performing the first step of this assessment, we concluded that the following conditions raise substantial doubt about our ability to meet our financial obligations as they become due. We have a history of net losses ( $66.7 million in 2016 ) and cash used in operating activities ( $51.5 million in 2016 ). As of December 31, 2016 , we had $45.3 million in cash, cash equivalents and short-term investments available to fund operations and debt service costs. We expect to continue to incur negative cash flows until such time as OMIDRIA or other sources of revenue generate sufficient cash inflows to finance our operations and debt service (which will be at least $6.8 million in 2017). In addition, we also considered that pass-through reimbursement for our commercial product, OMIDRIA, is currently due to expire on January 1, 2018 . In performing the second step of this assessment, we are required to evaluate whether our plans to mitigate the conditions above alleviate the substantial doubt about our ability to meet our obligations as they become due within one year after the date that the financial statements are issued. Our future plans include securing continued separate reimbursement (or equivalent reimbursement treatment) for OMIDRIA, establishing corporate partnerships, establishing collaboration and licensing revenue agreements, and issuing public or private equity securities, including selling common stock through our at-the-market facility (ATM) with JonesTrading Institutional Services LLC (JonesTrading) (see Note 9 for further detail) or securing additional borrowings including potentially accessing the $45.0 million that is contingently available under the CRG Loan Agreement (see Note 7 for further detail). These sources of working capital are not currently assured, and consequently do not sufficiently mitigate the risks and uncertainties disclosed above. We have therefore concluded there is substantial doubt about our ability to continue as a going concern through March 16, 2018 . The accompanying consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The accompanying consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from uncertainty related to our ability to continue as a going concern.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Cash and Cash Equivalents, Short-Term Investments and Restricted Cash and Investments Cash and cash equivalents include highly liquid investments with a maturity of three months or less on the date of purchase. Short-term investment securities are classified as available-for-sale and are carried at fair value. Unrealized gains and losses, if any, are reported as a separate component of shareholders’ deficit. Amortization, accretion, interest and dividends, realized gains and losses and declines in value judged to be other-than-temporary are included in other income (expense), net. The cost of securities sold is based on the specific-identification method. Investments in securities with maturities of less than one year, or those for which management intends to use the investments to fund current operations, are included in current assets. We evaluate whether an investment is other-than-temporarily impaired based on the specific facts and circumstances. Factors that are considered in determining whether an other-than-temporary decline in value has occurred include: the market value of the security in relation to its cost basis; the financial condition of the investee; and the intent and ability to retain the investment for a sufficient period of time to allow for recovery in the market value of the investment. Restricted cash and investments are held in certificates of deposit and money-market funds. Inventory Inventory is stated at the lower of cost or market determined on a specific identification basis in a manner which approximates the first-in, first-out (FIFO) method. Costs include amounts related to third party manufacturing, transportation and internal labor and overhead. Capitalization of costs as inventory begins when the product candidate receives regulatory approval in the U.S. or the European Union (EU), which for OMIDRIA began upon U.S. regulatory approval in May 2014. We expense inventory costs related to product candidates as research and development expenses prior to receiving regulatory approval in the respective territory. Inventory is reduced to net realizable value for excess and obsolete inventories based on forecasted demand. Receivables Receivables relate primarily to sales of OMIDRIA to wholesalers and include reductions for estimated chargebacks and product returns which are expected to be settled through reductions in receivables. Remaining receivables consist of amounts from subleases for space in The Omeros Building and, as of December 31, 2015 , amounts related to grants from the National Institutes of Health (NIH). Considering the nature and historic collectability of our receivables, we concluded an allowance for doubtful accounts is not necessary as of December 31, 2016 and 2015 . Property and Equipment, net Property and equipment are stated at cost and depreciation is calculated using the straight-line method over the estimated useful life of the assets, which is generally three to 10 years. Equipment financed under capital leases is recorded as property and equipment and is amortized over the shorter of the useful lives of the related assets or the lease term. Expenditures for equipment purchased with grant funds are recorded as a reduction to the cost of the applicable equipment. Expenditures for repairs and maintenance are expensed as incurred. Impairment of Long-Lived Assets The carrying amount of long-lived assets is reviewed whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Recoverability of these assets is measured by comparing the carrying value to future undiscounted cash flows the asset is expected to generate. If the asset is considered to be impaired, the amount of any impairment will be reflected in the results of operations in the period of impairment. We have not recognized any impairment losses for the years ending December 31, 2016 , 2015 and 2014 . Deferred Rent We recognize rent expense on a straight-line basis over the noncancelable term of The Omeros Building operating lease and, accordingly, record the difference between cash rent payments and the recognition of rent expense as an increase or decrease in deferred rent liability. We also record landlord-funded lease incentives, such as reimbursable leasehold improvements, as an increase in deferred rent liability which is amortized as a reduction of rent expense over the noncancelable terms of The Omeros Building operating lease. Revenue Recognition Our revenues are comprised of product sales of OMIDRIA and amounts earned for services under grants from third parties. Revenue is recognized when there is persuasive evidence that an arrangement exists, product title and risk of loss is passed to the customer or the service has been provided, the price is fixed or determinable and collection is reasonably assured. Product Sales, Net We record revenue from product sales when the product is delivered to our wholesalers. Product sales to a wholesaler are not recorded if we determine that the wholesaler’s on-hand OMIDRIA inventory, based on sell-through and inventory information we regularly receive from our wholesalers, exceeds approximately eight weeks of projected demand. Product sales are recorded net of chargebacks, wholesaler distribution fees, estimated product returns and rebates. Accruals or allowances are established for these deductions in the same period when revenue is recognized, and actual amounts incurred are offset against the applicable accruals or allowances. We reflect each of these accruals or allowances as either a reduction in the related account receivable or as an accrued liability, depending on how the amount is expected to be settled. Provisions for chargebacks are determined utilizing historical and projected payer mix and sale-through and inventory on-hand information received directly from wholesalers. Chargebacks are generally settled within four weeks of recording product sales revenue. We provide reimbursement support services and financial assistance in the form of reimbursement to certain patients whose commercial insurance is inadequate to cover the full cost of OMIDRIA. We apply our historical rebate ratio to product sales to determine the rebate accrual. This ratio is reviewed and updated periodically to reflect actual results. We provide rebate payments for which ambulatory surgery centers (ASCs) qualify by meeting or exceeding purchase volumes of OMIDRIA under a purchase volume discount program. Rebate accruals and payments under this program are determined based on contractual volume achievement. We allow for the return of product up to 12 months past its expiration date or for product that is damaged. In estimating product returns, we take into consideration our return experience to date, the remaining shelf life of product we have previously sold, inventory in the wholesale channel and our expectation that product is typically not held by the healthcare providers based on the frequency of their reorders. We pay our wholesalers a distribution fee for services they perform on our behalf based on a contractual rate. Research and Development Research and development costs are comprised primarily of costs for personnel, including salaries, benefits and stock compensation; an allocation of our occupancy costs; clinical study costs; contracted research; manufacturing; consulting arrangements; depreciation; materials and supplies; milestones; and other expenses incurred to sustain our overall research and development programs. Research and development costs are expensed as incurred. Advance payments for goods or services that will be used or rendered for future research and development activities are deferred and then recognized as an expense as the related goods are delivered or the services are performed, or when the goods or services are no longer expected to be provided. Patents We generally apply for patent protection on processes and product candidates we or our licensors conceive or develop. Patent costs are comprised primarily of external legal fees, filing fees incurred to file patent applications, and periodic renewal fees to keep the patent in force and are expensed as incurred as a component of general and administrative expense. Selling, General and Administrative Selling, general and administrative (SG&A) expenses are comprised primarily of salaries, service fees incurred for our sales force, benefits, and stock-compensation costs for sales, marketing, and other personnel not directly engaged in research and development. Additionally, SG&A includes marketing and selling expenses, professional and legal services; patent costs; depreciation, an allocation of our occupancy costs; and other general corporate expenses. Advertising Advertising costs, which we consider to be media and marketing materials, are expensed as incurred. We incurred $672,000 and $ 885,000 in advertising expense during the years ended December 31, 2016 and December 31, 2015 , respectively. We had no similar expenses during the year ended December 31, 2014 . Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized. Stock-Based Compensation Stock-based compensation expense is recognized for all share-based payments made to employees, directors and non-employees based on estimated fair values. The fair value of our stock options is calculated using the Black-Scholes option-pricing model which requires judgmental assumptions including volatility, forfeiture rates and expected option life. For employees and directors, we use the straight-line method to allocate compensation cost to reporting periods over each optionee’s requisite service period, which is generally the vesting period. Stock options granted to non-employees are accounted for using the fair-value approach and are subject to periodic revaluation over their vesting terms as earned. Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is comprised of net loss and certain changes in equity that are excluded from net loss. There was no difference between comprehensive loss and net loss for the years ended December 31, 2016 , 2015 or 2014 . Financial Instruments and Concentrations of Credit Risk Cash and cash equivalents, receivables, accounts payable and accrued liabilities, which are recorded at invoiced amount or cost, approximate fair value based on the short-term nature of these financial instruments. The fair value of short-term investments is based on quoted market prices. Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments and receivables. Cash and cash equivalents are held by financial institutions and are federally insured up to certain limits. At times, our cash and cash equivalents balance exceeds the federally insured limits. To limit the credit risk, we invest our excess cash in high quality securities such as money market mutual funds, certificates of deposit and commercial paper. Our notes payable includes features that meet the requirements under existing accounting guidance to be bifurcated from the respective notes payable agreement and to be recorded at fair value as a derivative asset or liability on the Consolidated Balance Sheet with the corresponding change in fair value recognized in Other income (expense), net on the Consolidated Statement of Operations. As of December 31, 2016 , the fair value of the embedded derivatives was not material. Major Customers We sell OMIDRIA through a limited number of wholesalers. Each of these wholesalers, together with entities under their common control, accounted for greater than 10% of total revenues for the years ended December 31, 2016 and 2015 and greater than 10% of accounts receivable as of December 31, 2016 and 2015 as noted below. 2016 2015 Percentage of Total Revenue Percentage of Accounts Receivable Percentage of Total Revenue Percentage of Accounts Receivable Distributor A 31 % 27 % 37 % 45 % Distributor B 32 % 29 % 31 % 23 % Distributor C 28 % 24 % 28 % 27 % Distributor D * 19 % * * * Distributor did not account for greater than 10% of total revenues for the years ended December 31, 2016 and 2015 or greater than 10% of accounts receivable at December 31, 2015 Major Suppliers We use a single contract manufacturer to supply OMIDRIA and generally a single contract manufacturer to produce clinical trial material which creates a concentration of risk for us. We have a non-exclusive agreement with Hospira Worldwide, Inc. (Hospira), a wholly owned subsidiary of Pfizer, Inc., for the commercial supply of OMIDRIA, and Hospira has produced product validation batches of OMIDRIA which are currently undergoing testing prior to seeking FDA approval of the Hospira manufacturing facility. We are not permitted to sell any OMIDRIA produced by Hospira, however, until the Hospira manufacturing facility is approved by the FDA. While one source of supply is utilized for OMIDRIA and generally one source for each of our product candidates, other sources are available should we need to change suppliers. We endeavor to maintain reasonable levels of drug supply for our commercial and clinical trial use. A change in suppliers, however, could cause a delay in delivery of OMIDRIA or our clinical trial material that would adversely affect our business. Recently Adopted Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-15 related to disclosure of an entity’s ability to continue as a going concern. This standard requires management to evaluate whether substantial doubt exists regarding the entity’s ability to continue as a going concern at each reporting period for a duration of one year after the date the financial statements are issued or available to be issued. The standard establishes certain required disclosures if substantial doubt exists. On December 31, 2016 , we adopted ASU 2014-15 on a prospective basis. We concluded there is substantial doubt about our ability to continue as a going concern (see “Going Concern” in Note 1 for further discussion). For the year ended December 31, 2016 , we early adopted and applied retrospectively FASB Accounting Standards Update (ASU) No. 2016-15, related to clarifying the classification of certain cash receipts and cash payments on the statement of cash flows. The new guidance requires, among other things, cash payments for debt prepayment or debt extinguishment costs to be classified as cash outflows for financing activities. The adoption of this standard resulted in the reclassification of $2.7 million of cash payments for debt prepayment costs and debt extinguishment costs within the financing activities section of our Consolidated Statements of Cash Flows for the year ended December 31, 2015 . Recent Accounting Pronouncements In May 2014, the FASB issued amended guidance related to revenue from contracts with customers. The amended guidance introduces a new principles-based framework for revenue recognition and disclosure. Since its issuance, the FASB has issued five ASUs amending the guidance and effective date, and the SEC has rescinded certain related SEC guidance; the most recent of which was issued in December 2016. The effective date of the guidance requires us to adopt the standard at the beginning of our first quarter of fiscal 2018 with earlier application permitted. The new guidance requires either a modified retrospective method or a full retrospective method of transition. We currently anticipate adopting the guidance at the beginning of our first quarter of fiscal 2018 under the modified retrospective method. While we have not yet completed our final review of the impact of this guidance, we currently do not anticipate a material impact on our revenue recognition practices. We continue to review variable consideration, potential disclosures, and our method of adoption to complete our evaluation of the impact on our consolidated financial statements. In addition, we continue to monitor additional changes, modifications, clarifications or interpretations undertaken by the FASB, which may impact our current conclusions. In February 2016, the FASB issued ASU 2016-02 related to lease accounting. This standard requires lessees to recognize a right-of-use asset and a lease liability for most leases. This standard must be applied using a modified retrospective transition method and is effective for all annual and interim periods beginning after December 15, 2018. Earlier adoption is permitted. We are evaluating how this new standard will impact the presentation of our financial statements and related disclosures. In March 2016, the FASB issued Accounting Standards Update ASU No. 2016-09 related to stock compensation, which simplifies several aspects of the accounting for share-based payment transactions. The new guidance requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, and eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows. We will adopt the standard in the three months ended March 31, 2017. Upon adoption, we will recognize the previously unrecognized excess tax benefits through a cumulative-effect adjustment to accumulated deficit. The previously unrecognized excess tax effects will be recorded as a deferred tax asset, which will be fully offset by a valuation allowance.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Loss Per Share	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. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common share equivalents outstanding for the period, determined using the treasury-stock method. Common share equivalents are excluded from the diluted net loss per share computation if their effect is anti-dilutive. The basic and diluted net loss per share amounts for the years ended December 31, 2016 , 2015 and 2014 were computed based on the shares of common stock outstanding during the respective periods. Potentially dilutive securities excluded from the diluted loss per share calculation are as follows: Year Ended December 31, 2016 2015 2014 Outstanding options to purchase common stock 9,809,374 8,310,235 8,364,469 Warrants and pre-funded warrants to purchase common stock 100,602 749,250 551,435 Total potentially dilutive securities 9,909,976 9,059,485 8,915,904

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	12 Months Ended
	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments As of December 31, 2016 and 2015 , all investments are classified as short-term and available-for-sale on the accompanying Consolidated Balance Sheets. Investment income, which is included as a component of other income (expense), consists primarily of interest earned.

Fair-Value Measurements

Fair-Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair-Value Measurements On a recurring basis, we measure certain financial assets at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, an exit price, in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The accounting standard establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available. The following summarizes the three levels of inputs required: Level 1—Observable inputs for identical assets or liabilities, such as quoted prices in active markets; Level 2—Inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3—Unobservable inputs in which little or no market data exists, therefore they are developed using estimates and assumptions developed by us, which reflect those that a market participant would use. Our fair-value hierarchy for our financial assets measured at fair value on a recurring basis are as follows: December 31, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money-market funds classified as non-current restricted cash and investments $ 5,835 $ — $ — $ 5,835 Money-market funds classified as short-term investments 43,107 — — 43,107 Total $ 48,942 $ — $ — $ 48,942 December 31, 2015 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money-market funds classified as non-current restricted cash and investments $ 10,679 $ — $ — $ 10,679 Money-market funds classified as short-term investments 26,898 — — 26,898 Total $ 37,577 $ — $ — $ 37,577 Cash held in demand deposit accounts of $2.2 million and $1.4 million is excluded from our fair-value hierarchy disclosure as of December 31, 2016 and 2015 , respectively. There were no unrealized gains or losses associated with our short-term investments as of December 31, 2016 or 2015 . The carrying amounts reported in the accompanying Consolidated Balance Sheets for receivables, accounts payable, other current monetary assets and liabilities and notes payable and lease financing obligations approximate fair value.

Certain Balance Sheet Accounts

Certain Balance Sheet Accounts	12 Months Ended
	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Certain Balance Sheet Accounts	Certain Balance Sheet Accounts Receivables December 31, 2016 2015 (In thousands) Trade receivables $ 11,937 $ 6,208 Grant receivables — 136 Other receivables 100 173 Total receivables $ 12,037 $ 6,517 Trade accounts receivable are shown net of $297,000 and $191,000 of chargebacks and product return allowances as of December 31, 2016 and 2015 , respectively. Inventory December 31, 2016 2015 (In thousands) Raw materials $ 101 $ 93 Work-in-process 854 158 Finished goods 173 221 Total inventory cost $ 1,128 $ 472 Property and Equipment December 31, 2016 2015 (In thousands) Laboratory equipment $ 1,830 $ 1,735 Capital lease equipment 774 367 Office equipment and furniture 625 625 Computer equipment 476 482 Computer software 208 174 Total cost 3,913 3,383 Less accumulated depreciation and amortization (2,732 ) (2,432 ) Total property and equipment, net $ 1,181 $ 951 For the years ended December 31, 2016 , 2015 and 2014 , depreciation and amortization expense was $300,000 , $209,000 and $317,000 , respectively. Accrued Expenses December 31, 2016 2015 (In thousands) Employee compensation $ 4,551 $ 2,590 Contract research and development 3,030 2,973 Consulting and professional fees 2,223 2,400 Clinical trials 1,167 1,108 Other accruals 2,383 681 Total accrued liabilities $ 13,354 $ 9,752

Notes Payable and Lease Financi

Notes Payable and Lease Financing Obligations	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Notes Payable and Lease Financing Obligations	Notes Payable and Lease Financing Obligations Notes payable and lease financing obligations consist of the following: December 31, 2016 2015 (In thousands) Notes payable $ 80,516 $ 50,000 Lender facility fee payable upon maturity 4,025 3,750 Lease financing obligations 522 279 Notes payable, facility fee and lease financing obligations 85,063 54,029 Unamortized debt discount (3,958 ) (3,750 ) Unamortized debt issuance costs (1,395 ) (437 ) Current portion of lease financing obligations (198 ) (73 ) Notes payable and lease financing obligations, net $ 79,512 $ 49,769 2014 Oxford/MidCap Loan Agreement In March 2014, we entered into a Loan and Security Agreement (the Oxford/MidCap Loan Agreement) with Oxford and MidCap Financial SBIC, LP (MidCap) pursuant to which we borrowed $32.0 million . We used $19.1 million of the loan proceeds to repay all of the amounts owed by us under our previously outstanding loan agreement and, after deducting loan initiation costs, we received $12.7 million in net proceeds. The Oxford/MidCap Loan Agreement provided for interest-only payments at an annual rate of 9.25% through March 1, 2015 with principal and interest payments of $1.0 million commencing April 1, 2015 through its maturity date of March 1, 2018. In addition, the Oxford/MidCap Loan Agreement required a $2.2 million loan maturity fee payment upon full repayment of the loan and a prepayment fee equal to 1.0% of the then-outstanding principal balance if we paid the loan prior to the maturity date. These costs were being amortized to interest expense using the effective interest method over the term of the Oxford/MidCap Loan Agreement. 2015 Oxford/EWB Loan Agreement In December 2015, we entered into a Loan and Security Agreement (the Oxford/EWB Loan Agreement) with Oxford and East West Bank (EWB) pursuant to which we borrowed $50.0 million . In addition, we could borrow an additional $20.0 million contingent upon the satisfaction of certain conditions including minimum net revenues from OMIDRIA. We used $27.3 million of the loan proceeds to repay all of the amounts owed by us under the Oxford/Midcap Loan Agreement including the outstanding principal of $24.8 million , the loan maturity fee of $2.2 million and the prepayment fee of $248,000 . After deducting all loan initiation costs and outstanding interest on the Oxford/MidCap Loan Agreement, we received $22.3 million in net proceeds. We accounted for the termination of the Oxford/Midcap Loan Agreement as a debt extinguishment and, accordingly, incurred a loss of $1.3 million associated with the unamortized loan maturity fee and the prepayment fee. The Oxford/EWB Loan Agreement also required a $3.8 million loan maturity fee upon full repayment of the initial $50.0 million borrowed and $525,000 for each additional $10.0 million borrowed. We had the option to prepay the outstanding principal balance in its entirety at any time if we pay a prepayment equal to 1.0% of the then-outstanding principal balance. The Oxford/EWB Loan Agreement contained covenants that required us to, among other provisions, maintain $10.0 million in restricted cash and certain eligible term investments, and to establish an at-the-market (ATM) equity facility (see Note 9 for further discussion of the ATM equity facility). In May 2016 , we entered into the First Amendment to the Oxford/EWB Loan Agreement (the Amendment) whereby we accelerated the borrowing of the additional $20.0 million available to us under the Oxford/EWB Loan Agreement. After deducting all loan initiation costs, we received $19.9 million in net proceeds. The Amendment did not modify the interest rate or any terms or covenants of the Loan Agreement except to increase the final payment fee rate applicable to the additional $20.0 million borrowed from 5.25% to 6.25% reflecting the accelerated draw-down of the additional loan. In connection with the Amendment, we issued warrants to purchase an aggregate of 100,602 shares of Omeros common stock (the Warrants) to Oxford and EWB at the then current market price of $9.94 per share. We accounted for the Warrants as a discount to our notes payable (see Note 9 for further discussion of the Warrants). We accounted for the Amendment as a debt modification and, accordingly, the unamortized discount and debt issuance costs associated with the Loan Agreement were being amortized to interest expense using the effective interest method over the remaining term of the Loan Agreement. 2016 CRG Loan Agreement In October 2016 , we entered into the CRG Loan Agreement with CRG Servicing LLC, which requires interest-only payments through December 31, 2020 and, subject to the achievement of certain milestones, potentially through the maturity date of September 30, 2022 . We initially borrowed $80.0 million and may borrow up to an additional $45.0 million in two tranches of $25.0 million and $20.0 million , respectively, contingent upon achievement of certain conditions on or before June 30, 2017 and December 31, 2017 , respectively. To borrow the $25.0 million under the first tranche, we must achieve OMIDRIA net product sales of at least $18.0 million during any consecutive three month period or an average market capitalization of at least $700.0 million for any consecutive three month period, in each case ending on or prior to June 30, 2017 , and the borrowing must occur on or prior to September 19, 2017 . To borrow the $20.0 million under the second tranche, we must achieve OMIDRIA net product sales of at least $25.0 million during any consecutive three month period or an average market capitalization of at least $1.0 billion for any consecutive three month period, in each case ending on or prior to December 31, 2017 , and the borrowing must occur on or prior to March 21, 2018 . We used $75.7 million of the initial loan proceeds to repay all amounts owed by us under our then-outstanding Oxford/EWB Loan Agreement including the outstanding principal of $70.0 million , the loan maturity fee of $5.0 million and the prepayment fee of $700,000 . After deducting the loan initiation costs and related fees on the CRG Loan Agreement, we received $3.0 million in net proceeds. We accounted for the termination of the Oxford/EWB Loan Agreement as a debt extinguishment and, accordingly, incurred a loss of 5.6 million associated with the unamortized loan maturity fee, loan initiation costs and the prepayment fee. The CRG Loan Agreement accrues interest at an annual rate of 12.25% ( 4.00% of which can be deferred at our option during the interest-only period by adding such amount to the aggregate principal amount) and is interest only for a minimum of four years and, subject to the achievement of certain milestones, potentially through the maturity date. If an OMIDRIA net revenue milestone is satisfied during the 12-month period ending on December 31, 2019 , the interest rate may be reduced to 11.50% , 3.50% of which may be deferred at our option and added to the principal amount outstanding. In addition, if either the OMIDRIA net revenue milestone is satisfied during such period or a market capitalization milestone is achieved during the fourth quarter of 2020 , the loan would convert to interest-only until the September 30, 2022 maturity. The CRG Loan Agreement requires us to maintain cash and cash equivalents of $5.0 million during the term of the agreement which is recorded as restricted cash and investments in our Consolidated Balance Sheet. We are also required to pay the Lenders a facility fee equal to 5.00% of the aggregate principal amount borrowed (including principal additions related to deferred interest) on repayment of the CRG Loan Agreement. The $4.0 million related to the facility fee is being accreted to notes payable using the effective interest method over the term of the loan agreement. We may prepay all or a portion of the outstanding principal under the CRG Loan Agreement at any time upon prior notice to the Lenders subject to a prepayment fee through September 30, 2019 , with no prepayment fee thereafter. In certain circumstances, including a change of control and certain asset sales or licensing transactions, we are required to prepay all or a portion of the loan, including the applicable prepayment premium of on the amount of the outstanding principal to be prepaid. The CRG Loan Agreement also requires us to achieve either (a) certain minimum net revenue amounts through the end of 2021 , which are $35.0 million , $55.0 million and $65.0 million for the 2016 , 2017 and 2018 calendar years, respectively, or (b) a minimum market capitalization threshold equal to the product of 6.4 multiplied by the aggregate principal amount of loans outstanding under the CRG Loan Agreement determined as of the fifth business day following announcement of earnings results for the applicable year. If we are unable to satisfy the minimum annual revenue requirement or the market capitalization threshold for any given year, we may avoid a related default by repaying the shortfall between actual revenues and the minimum revenue requirement for such year using proceeds generated by an equity or subordinated debt issuance. We exceeded the OMIDRIA minimum revenue requirement for 2016. The CRG Loan Agreement also includes customary events of default that include, among other things, non-payment, inaccuracy of representations and warranties, covenant breaches, cross default to material indebtedness or material agreements, bankruptcy and insolvency, material judgments and a change of control. An event of default under the CRG Loan Agreement also includes the occurrence of any material adverse effect upon our business, condition (financial or otherwise), operations, performance or property taken as a whole. If there is an event of default under the CRG Loan Agreement, the lenders may have the right to accelerate all of our repayment obligations under the CRG Loan Agreement and to take control of our pledged assets, which include substantially all of our assets including our intellectual property. Under certain circumstances, a default interest rate of an additional 4.00% per annum will apply on all outstanding obligations during the existence of an event of default under the Loan Agreement. On December 31, 2016 , as allowed under the CRG Loan Agreement, we deferred $516,000 of interest due on December 31, 2016 by increasing the principal amount outstanding. As of December 31, 2016 , we were not in default under the CRG Loan Agreement. Lease Financing Obligations We have capital leases for certain lab and office equipment which have lease terms expiring between October 2017 and December 2021 . Equipment costs related to these capital leases of $774,000 and $367,000 is included in our property and equipment as of December 31, 2016 and December 31, 2015 , respectively and the accumulated depreciation on this equipment was $230,000 and $98,000 , respectively. The remaining principal payments under these capital leases totaled $522,000 and $281,000 as of December 31, 2016 and 2015 , respectively. Future Principal Payments Future principal payments as of December 31, 2016 under the CRG Loan Agreement and our capital equipment financing leases, based on stated contractual maturities, are as follows: Year Ending December 31, Notes Payable Lease Financing Obligations Total (In thousands) 2017 $ — $ 198 $ 198 2018 — 199 199 2019 — 89 89 2020 — 31 31 2021 46,009 5 46,014 Thereafter 34,507 — 34,507 Total future principal payments $ 80,516 $ 522 $ 81,038 The principal payments reflected in the table above exclude the $4.0 million lender’s facility fee due on repayment of the CRG Loan Agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Real Estate and Equipment Lease Obligations We lease office and laboratory spaces in The Omeros Building. The initial term of the real estate lease ends in November 2027 and we have two options to extend the lease term, each by five years. As of December 31, 2016 , the remaining aggregate non-cancelable rent under the initial terms of the real estate, excluding common area maintenance and related operating expenses, was $50.5 million . The deferred rent balance of $9.2 million relates to rent deferrals and landlord funded lease incentives since the inception of our lease and is being amortized to research and development and selling, general and administrative expense on a straight-line basis through the initial term of the lease. Rent expense, including the amortization of lease incentives and rent deferrals, totaled $4.4 million , $4.5 million and $4.5 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. We periodically sublease unused office and laboratory space in The Omeros Building to third-party tenants. Rental income received under these subleases was $737,000 , $889,000 and $568,000 for the years ended December 31, 2016 , 2015 and 2014 , respectively. Rental income is recorded as other income (expense), net in the accompanying Consolidated Statements of Operations and Comprehensive Loss. We rent equipment and fleet vehicles for our sales force under various operating lease agreements which have remaining aggregate non-cancellable rent of $1.1 million at December 31, 2016 . Future minimum payments related to our leases at December 31, 2016 , are as follows: Year Ending December 31, Lease Sublease Net Lease (In thousands) 2017 $ 4,474 $ 663 $ 3,811 2018 4,545 663 3,882 2019 4,632 597 4,035 2020 4,690 335 4,355 2021 4,552 — 4,552 Thereafter 28,712 — 28,712 Total $ 51,605 $ 2,258 $ 49,347 Contracts We have various agreements with third parties that collectively require payment of termination fees totaling $2.2 million as of December 31, 2016 if we cancel the work within specific time frames, either prior to commencing or during performance of the contracted services. This is in addition to fees associated with the CRG Loan Agreement as described within Note 7 and within the Contractual Obligations and Commitments and Financial Condition - Liquidity and Capital Resources sections of Management’s Discussion and Analysis. Development Milestones and Product Royalties Phosphodiesterase 10 (PDE10) inhibitors - In connection with a funding agreement with The Stanley Medical Research Institute entered into in December 2006, beginning the first calendar year after commercial sales of any therapeutic product that inhibits or modulates PDE10 (including for schizophrenia or Huntington’s disease), we are obligated to pay royalties based on net income of the product, as defined in the agreement. Based on the amount of grant funding received, the maximum amount of royalties payable by us is $12.8 million . For the years ended December 31, 2016 , 2015 and 2014 , we did not owe any royalties. Peroxisome proliferators activated receptor gamma (PPARγ) - In February 2009, we entered into a patent assignment agreement whereby we acquired all intellectual property rights, including patent applications, related to PPARγ agonists for the treatment and prevention of addictions to substances of abuse, as well as other compulsive behaviors. In February 2011, we amended the patent assignment agreement to include all intellectual property rights, including patent applications, related to dietary supplements that increase PPARγ activity. We will be required to make payments up to $3.8 million in total, for both PPARγ agonists and dietary supplements that increase PPARγ activity, upon achievement of certain development events, such as the initiation of clinical trials and receipt of marketing approval. In addition, we are obligated to pay a low single-digit percentage royalty on any net sales of drug products that are covered by the patent assignment agreement. For the years ended December 31, 2016 , 2015 and 2014 , we did not owe any development milestones or royalties. Phosphodiesterase 7 (PDE7) inhibitors - Under a license agreement with Daiichi Sankyo Co., Ltd. (Daiichi Sankyo) we hold an exclusive license to phosphodiesterase 7 (PDE7) inhibitors owned by Daiichi Sankyo for use in (1) the treatment of movement disorders and other specified indications; (2) addiction and compulsive disorders; and (3) all other indications except those related to dermatologic conditions. We will be required to make milestone payments to Daiichi Sankyo of up to $33.5 million upon the achievement of certain events, such as successful completion of certain preclinical toxicology studies; dosing of human subjects in Phase 1, 2 and 3 clinical trials; receipt of marketing approval of a PDE7 inhibitor product; and reaching specified sales milestones. However, if only one of the three indications is advanced through each milestone, the total milestone payments would be $23.5 million . In addition, we are obligated to pay Daiichi Sankyo a low single-digit percentage royalty on any net sales of a PDE7 inhibitor licensed under the agreement provided that if the sales are made by a sublicensee, the amount payable by us to Daiichi Sankyo is capped at a low double-digit percentage of all royalty and specified milestone payments that we receive from the sublicensee. For the year ended December 31, 2013, we paid $50,000 upon execution of an amendment which was recognized as research and development expense. For the years ended December 31, 2016 , 2015 and 2014 , we did not owe any development milestones or royalties. Mannan-binding lectin-associated serine protease-2 (MASP-2) - In April 2010, we entered into an exclusive license agreement with Helion Biotech ApS (Helion), pursuant to which we received a royalty bearing, worldwide exclusive license to all of Helion’s intellectual property rights related to MASP-2 antibodies, polypeptides and methods in the field of inhibition of mannan-binding lectin-mediated activation of the complement system for the prevention, treatment or diagnosis of any disease or condition. We will be required to make development and sales milestone payments to Helion of up to $6.1 million upon the achievement of certain events, such as the filing of an Investigational New Drug Application (IND) with the FDA; initiation of Phase 2 and 3 clinical trials; receipt of marketing approval; and reaching specified sales milestones. We are obligated to pay Helion a low single-digit percentage royalty on net sales of a MASP-2 inhibitor product covered by the patents licensed under the agreement. For the year ended December 31, 2016 and 2015, we did not owe any development milestones or royalties. For the year ended December 31, 2014 , we incurred development milestone costs of $300,000 under this agreement which was recognized as research and development expense. G protein-coupled receptor (GPCR) - In October 2010, we entered into funding agreements for our GPCR program with Vulcan and LSDF. In connection with the funding agreements, we agreed to pay Vulcan and LSDF tiered percentages of the net proceeds derived from the GPCR program. The percentage rates decrease as the cumulative net proceeds reach specified thresholds, and the blended percentage rate in the aggregate is in the mid-teens with respect to approximately the first $1.5 billion of cumulative net proceeds. If we receive cumulative net proceeds in excess of approximately $1.5 billion , the percentage rate decreases to one percent. Pursuant to the agreement with Vulcan, we may pay a portion of Vulcan’s share of the one percent of net proceeds to a life sciences initiative (LSI) to be established in accordance with the LSDF agreement. The LSI will be a non-profit, tax-exempt organization with a mission to advance life sciences in the State of Washington. Net proceeds are generally defined in the Vulcan and LSDF agreements as (1) all consideration received by us in any form relating directly to the GPCR program less (2) all expenses and expenditures in excess of $25.0 million incurred by us in connection with the GPCR program. Any consideration that we receive (a) from government entities (subject to specified exceptions), (b) from third parties that have designated such consideration for the purpose of funding research and development expenses and related overhead or (c) in the form of grants, as well as any expenses or expenditures that we incur that are paid for with such consideration, are excluded for purposes of determining net proceeds. Under our agreement with Vulcan, we granted Vulcan a security interest in our personal property related to the GPCR program, other than intellectual property, which security interest is junior to any existing or future security interests granted in connection with a financing transaction and which will be automatically released after Vulcan receives $25.0 million under the agreement. We also agreed not to grant any liens on intellectual property related to the GPCR program. The term of our agreement with Vulcan is 35 years , provided that the term will automatically extend until the cumulative net proceeds that we receive from the GPCR program are approximately $1.5 billion . Under our agreement with LSDF, after LSDF receives $25.0 million , any remaining amounts that would be payable to LSDF will be paid to LSI. Our obligations with respect to LSI are limited to creating LSI’s charter documents, incorporating LSI, selecting directors and applying for tax exempt status, all in consultation with LSDF. The term of our agreement with LSDF expires on the six-month anniversary following the last date that we deliver a report related to our incurrence of grant-funded expenses described in the agreement. The term of our payment obligations to LSDF is the same as that under our agreement with Vulcan. As of December 31, 2016 , we have not derived any net proceeds as defined in the Vulcan and LSDF agreements from our GPCR program. Litigation In July 2015, we received a Paragraph IV Notice Letter from Par Pharmaceutical, Inc. and its subsidiary, Par Sterile Products, LLC, (collectively, Par) stating that Par filed an Abbreviated New Drug Application (ANDA) seeking approval from the FDA to market a generic version of OMIDRIA prior to the expiration of three patents listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) for OMIDRIA (the Orange Book Patents). Following receipt of the Paragraph IV Notice Letter, in September 2015 we filed a patent infringement lawsuit under the Hatch-Waxman Act against Par. In April 2016, August 2016 and November 2016, we amended the lawsuit to assert additional OMIDRIA patents. Par has stipulated to infringement of each of the currently asserted patents, and the court entered a partial judgment that Par’s filing of its ANDA constitutes an act of infringement of each of the currently asserted patents, subject to Par’s continued invalidity defenses and any challenge to enforceability. The filing of our suit against Par triggered a 30-month stay of the FDA’s approval of Par’s ANDA, which is expected to remain in effect until late January 2018. We have reviewed the invalidity assertions in Par’s Paragraph IV Notice Letter and defenses and counterclaims and believe they do not have merit, and we intend to defend our patents vigorously in the litigation against Par.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity Common Stock As of December 31, 2016 , we had reserved shares of common stock for the following purposes: Options granted and outstanding 9,809,374 Options available for future grant 524,145 Common stock warrants 100,602 Total shares reserved 10,434,121 Options Available for Future Grant - On January 1, 2017 , an additional 1,785,714 shares became available for future issuance under the 2008 Equity Incentive Plan (the 2008 Plan) in accordance with the annual increase provisions of the 2008 Plan. These additional shares are not included in the table above. At Market Issuance Sales Agreement - In January 2016, we entered into an At Market Issuance Sales Agreement (the ATM Agreement) with JonesTrading Institutional Services LLC (JonesTrading) pursuant to which we may direct JonesTrading to sell shares of our common stock directly on The Nasdaq Global Market, through a market maker other than on an exchange or in negotiated transactions. Any sales made under the ATM Agreement are based solely on our instructions and JonesTrading will receive a 1.7% commission from the gross proceeds. The ATM Agreement may be terminated by either party at any time upon 10 days ' notice to the other party or by JonesTrading at any time in certain circumstances including the occurrence of a material adverse effect to Omeros. During the year ended December 31, 2016 , we sold 64,565 shares of our common stock at an average price of $11.41 per share under the ATM Agreement and received net proceeds of $724,000 . We currently may sell shares of our common stock having an aggregate offering price of up to $50.0 million under the ATM Agreement. Securities Offerings - In August 2016 , we sold 3.5 million shares of our common stock at a public offering price of $11.50 per share. After deducting underwriter discounts and offering expenses, we received net proceeds from the offering of $37.3 million . In February 2015, we sold 3.4 million shares of our common stock at a public offering price of $20.03 and sold pre-funded warrants to purchase up to 749,250 shares of our common stock at a public offering price of $20.02 per pre-funded warrant share. The public offering price for the pre-funded warrants was equal to the public offering price of the common stock, less the $0.01 per share exercise price of each pre-funded warrant. After deducting underwriter discounts and offering expenses of $4.9 million , we received net proceeds from the transaction of $79.1 million . In March 2014, we sold 3.5 million shares of our common stock at a public offering price of $11.50 per share. After deducting underwriter discounts and offering expenses of $2.5 million , we received net proceeds from the transaction of $37.8 million . Warrants The following table summarizes our outstanding warrants at December 31, 2016 : Outstanding At Expiration Date Exercise Price 100,602 May 18, 2023 $9.94 In connection with an amendment to the Oxford/EWB Loan Agreement in May 2016 , we issued warrants to purchase an aggregate of 100,602 shares of our common stock to Oxford and EWB (the Warrants). We evaluated the terms of the Warrants and determined that the Warrants should be recorded as permanent equity. The aggregate fair value of the Warrants on the issue date was $758,000 , which we recorded as a discount to our notes payable. We were amortizing the Warrants over the remaining term of the Oxford/EWB Loan Agreement using the effective interest method. On October 26, 2016 , in connection with our repayment of the Oxford/EWB Loan Agreement (see Note 7), the unamortized discount to our notes payable was expensed as a loss on early extinguishment of debt in our Consolidated Statement of Operations and Comprehensive Loss. The Warrants remain outstanding and exercisable through May 18, 2023 at an exercise price per share of $9.94 per share. In March 2016, we received cash proceeds of approximately $7,500 upon the cash exercise of our then-outstanding pre-funded warrants referenced above. The warrants had a weighted average exercise price of $0.01 per share, and the exercise resulted in the issuance of 749,250 shares of our common stock. In March 2009, we issued warrants with an exercise price of $12.25 per share to brokers who assisted us in our Series E financing (the Series E Warrants). In both March and September 2014, we extended the expiration dates of the Series E Warrants by six months. We evaluated the fair value of the Series E Warrants before and after each modification, and we recorded $863,000 change in fair value as other income (expense), net in our Consolidated Statement of Operations and Comprehensive Loss for the year ended December 31, 2014 . For the year ending December 31, 2014, Series E Warrants were exercised, through cash and cashless net exercise, resulting in cash proceeds of $68,000 and the issuance of 28,653 shares of our common stock. Additionally, for the year ended December 31, 2015, we received cash proceeds of $1.4 million upon the cash and cashless exercise of Series E Warrants which resulted in the issuance of 133,240 shares of our common stock.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The 2008 Plan provides for the grant of incentive and non-statutory stock options, restricted stock, stock appreciation rights, performance units and performance shares to employees, directors and consultants and subsidiary corporations’ employees and consultants. Options are granted with exercise prices equal to the closing fair market value of the common stock on the date of the grant. The terms of options may not exceed 10 years and options generally vest over a four -year period. The 2008 Plan also allows any shares returned under our Amended and Restated 1998 Stock Option Plan (the 1998 Plan), as a result of cancellation of options or repurchase of shares issued pursuant to the 1998 Plan, to be issued under the 2008 Plan. In addition, the 2008 Plan provides for annual increases in the number of shares available for issuance thereunder on the first day of each year, equal to the lower of: • five percent of the outstanding shares of our common stock on the last day of the preceding year; • 1,785,714 shares; or • such other amount as our board of directors may determine. As of December 31, 2016 , a total of 10,333,519 shares were reserved for issuance under our stock plans, of which 524,145 were available for future grants. On January 1, 2017 , an additional 1,785,714 shares became available for future issuance under our 2008 Plan in accordance with the annual increase. In February 2017, options exercisable for up to 1,434,250 shares were granted to employees related to 2016 annual performance grants. Compensation cost for stock options granted to employees and directors is based on the grant-date fair value and is recognized over the vesting period of the applicable option on a straight-line basis. Stock-based compensation expense is based on options ultimately expected to vest, and therefore has been reduced for estimated forfeitures. We estimate forfeitures based on our historical experience; separate groups of employees that have similar historical forfeiture behavior are considered separately for expense recognition. The fair value of each option grant to employees and directors is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions were applied to employee and director stock option grants during the periods ended: Year Ended December 31, 2016 2015 2014 Estimated weighted-average fair value $ 6.89 $ 11.31 $ 7.39 Weighted-average assumptions: Expected volatility 74 % 71 % 73 % Expected term, in years 5.7 6.0 5.8 Risk-free interest rate 1.63 % 1.68 % 1.87 % Expected dividend yield — % — % — % The risk-free interest rates are based on the implied yield currently available in U.S. Treasury securities at maturity with an equivalent term. For purposes of determining the expected term of the awards in the absence of sufficient historical data relating to stock-option exercises, we apply a simplified approach in which the expected term of an award is presumed to be the mid-point between the vesting date and the expiration date of the award. We have not declared or paid any dividends and do not currently expect to do so in the foreseeable future. Since October 2014, we have has based our expected volatility on our own trading history which is roughly equivalent to the average expected term of our options and we do not anticipate future volatility will differ significantly from the past. Stock options granted to non-employees are accounted for using the fair-value approach. The fair value of non-employee option grants is estimated using the Black-Scholes option-pricing model and are re-measured over the vesting term as earned. The estimated fair value is charged to expense over the applicable service period. During the years ended December 31, 2016 , 2015 and 2014 , we granted to non-employees options to purchase 38,000 shares, 4,200 shares and 86,000 shares of common stock, respectively. Stock-based compensation expense includes amortization of stock options granted to employees and non-employees and has been reported in our Consolidated Statements of Operations and Comprehensive Loss as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Research and development $ 6,304 $ 4,977 $ 4,754 Selling, general and administrative 7,278 4,604 4,164 Total stock-based compensation expense $ 13,582 $ 9,581 $ 8,918 In connection with the non-employee options, we recognized expense of $ 313,000 , $ 492,000 and $289,000 during the years ended December 31, 2016 , 2015 and 2014 , respectively. Stock option activity for all stock plans is as follows: Options Outstanding Weighted- Average Exercise Price per Share Remaining Contractual Life (in years) Aggregate Intrinsic Value (In thousands) Balance at December 31, 2015 8,310,235 $ 7.97 Granted 3,128,567 10.72 Exercised (1,486,167 ) 2.12 Forfeited and expired (143,261 ) 12.92 Balance at December 31, 2016 9,809,374 $ 9.66 7.12 $ 11,162 Vested and expected to vest at December 31, 2016 9,483,392 $ 9.60 7.05 $ 11,155 Exercisable at December 31, 2016 6,568,859 $ 8.87 6.17 $ 11,087 The total intrinsic value of options exercised during the years ended December 31, 2016 , 2015 and 2014 was $13.6 million , $3.9 million and $2.9 million , respectively. At December 31, 2016 , there were 3,240,515 unvested options outstanding that will vest over a weighted-average period of 2.4 years. Excluding non-employee stock options, the remaining estimated compensation expense to be recognized in connection with these options is $19.0 million .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We have a history of losses and therefore have made no provision for income taxes. Deferred income taxes reflect the tax effect of net operating loss and tax credit carryforwards and the net temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of deferred income taxes are as follows: December 31, 2016 2015 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 126,410 $ 110,092 Tax credit carryforwards 18,741 14,758 Stock-based compensation 11,102 8,136 Deferred rent 3,318 3,324 Other 4,401 2,744 Total deferred tax assets 163,972 139,054 Less valuation allowance (163,972 ) (139,054 ) Net deferred tax assets $ — $ — As of December 31, 2016 and 2015 , we had federal net operating loss carryforwards of approximately $378.9 million and $325.9 million , respectively, state net operating losses of approximately $50.0 million and $30.6 million , respectively, and tax credit carryforwards of approximately $18.7 million and $14.8 million , respectively. Approximately $13.3 million of our net operating loss carryforwards relate to tax deductible stock-based compensation in excess of amounts recognized for financial statement purposes. To the extent that net operating loss carryforwards, if realized, relate to stock-based compensation, the resulting tax benefits will be recorded to shareholders’ equity, rather than to the results of operations. In certain circumstances, due to ownership changes, our net operating loss and tax credit carryforwards may be subject to limitations under Section 382 of the Internal Revenue Code. To date, we have not completed a Section 382 study. Unless previously utilized, our net operating loss and research and development tax credit carryforwards expire between 2018 and 2036 . We have established a 100% valuation allowance due to the uncertainty of our ability to generate sufficient taxable income to realize the deferred tax assets. Our valuation allowance increased $24.9 million , $30.4 million and $25.8 million in 2016 , 2015 and 2014 , respectively, primarily due to net operating losses incurred during these periods. Reconciliation of income tax computed at federal statutory rates to the reported provisions for income taxes is as follows: Year ended December 31, 2016 2015 2014 Federal statutory tax rate (34 )% (34 )% (34 )% State tax rates (2 )% (2 )% — % Other permanent differences 3 % 1 % 2 % Change in valuation allowance 37 % 41 % 35 % Tax credits (4 )% (5 )% (4 )% Other — % (1 )% 1 % Effective tax rate — % — % — % We file federal and certain state income tax returns, which provides varying statutes of limitations on assessments. However, because of net operating loss carryforwards, substantially all of our tax years remain open to federal and state tax examination. The guidance for accounting for uncertainties in income taxes requires that we recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. As of December 31, 2016 , 2015 and 2014 , we maintained an uncertain tax position of $212,000 related to a reduction of our research and development credit deferred tax asset. Further, there were no unrecognized tax benefits that, if recognized, would impact our effective tax rate. We recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense. To date, there have been no interest or penalties charged to us in relation to the underpayment of income taxes.

401k Retirement Plan

401k Retirement Plan	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
401(k) Retirement Plan	401(k) Retirement Plan We have adopted a 401(k) plan. To date, we have not matched employee contributions or made discretionary contributions to the plan. Starting in 2017, the plan will provide for an annual company match on employee contributions, initially set at a maximum of 4.0% of each participating employee’s contributions, with a maximum company match of $4,000 per employee per year. All employees are eligible to participate, provided they meet the requirements of the plan.

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Information (Unaudited)	Quarterly Information (Unaudited) The following table summarizes the unaudited statements of operations and comprehensive loss for each quarter of 2016 and 2015 (in thousands, except per share amounts): 2016 For the Quarter Ended March 31, June 30, September 30, December 31, Revenue $ 7,419 $ 10,004 $ 11,289 $ 12,905 Total operating expenses 26,871 20,933 23,327 24,762 Loss from operations (19,452 ) (10,929 ) (12,038 ) (11,857 ) Net loss (20,539 ) (12,612 ) (13,962 ) (19,632 ) Basic and diluted net loss per share $ (0.54 ) $ (0.32 ) $ (0.34 ) $ (0.45 ) 2015 For the Quarter Ended March 31, June 30, September 30, December 31, Revenue $ 388 $ 3,187 $ 3,259 $ 6,675 Total operating expenses 18,318 19,154 22,560 24,715 Loss from operations (17,930 ) (15,967 ) (19,301 ) (18,040 ) Net loss (18,669 ) (16,680 ) (19,921 ) (19,826 ) Basic and diluted net loss per share $ (0.51 ) $ (0.44 ) $ (0.53 ) $ (0.52 )

Significant Accounting Polici20

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Organization	Organization We are a biopharmaceutical company committed to discovering, developing and commercializing both small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system.
Basis of Presentation	Basis of Presentation Our consolidated financial statements include the financial position and results of operations of Omeros Corporation (Omeros) and our wholly owned subsidiaries. All inter-company transactions have been eliminated. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP).
Segments	Segments We operate in one segment. Management uses cash flow as the primary measure to manage our business and does not segment our business for internal reporting or decision-making.
Use of Estimates	Use of Estimates 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. Significant items subject to such estimates include revenue recognition, stock-based compensation expense and accruals for clinical trials, manufacturing of drug product and clinical drug supply and contingencies. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances; however, actual results could differ from these estimates.
Reclassification	Reclassifications Certain reclassifications have been made to prior periods in the consolidated balance sheets, the statements of cash flows and the accompanying notes to conform with the current presentation. None of these reclassifications impacted our net loss or working capital as they pertained to the presentation of debt matters including issuance costs, extinguishment losses, early payments and proceeds.
Cash and Cash Equivalents, Short-Term Investments and Restricted Cash and Investments	Cash and Cash Equivalents, Short-Term Investments and Restricted Cash and Investments Cash and cash equivalents include highly liquid investments with a maturity of three months or less on the date of purchase. Short-term investment securities are classified as available-for-sale and are carried at fair value. Unrealized gains and losses, if any, are reported as a separate component of shareholders’ deficit. Amortization, accretion, interest and dividends, realized gains and losses and declines in value judged to be other-than-temporary are included in other income (expense), net. The cost of securities sold is based on the specific-identification method. Investments in securities with maturities of less than one year, or those for which management intends to use the investments to fund current operations, are included in current assets. We evaluate whether an investment is other-than-temporarily impaired based on the specific facts and circumstances. Factors that are considered in determining whether an other-than-temporary decline in value has occurred include: the market value of the security in relation to its cost basis; the financial condition of the investee; and the intent and ability to retain the investment for a sufficient period of time to allow for recovery in the market value of the investment. Restricted cash and investments are held in certificates of deposit and money-market funds.
Inventory	Inventory Inventory is stated at the lower of cost or market determined on a specific identification basis in a manner which approximates the first-in, first-out (FIFO) method. Costs include amounts related to third party manufacturing, transportation and internal labor and overhead. Capitalization of costs as inventory begins when the product candidate receives regulatory approval in the U.S. or the European Union (EU), which for OMIDRIA began upon U.S. regulatory approval in May 2014. We expense inventory costs related to product candidates as research and development expenses prior to receiving regulatory approval in the respective territory. Inventory is reduced to net realizable value for excess and obsolete inventories based on forecasted demand.
Receivables	Receivables Receivables relate primarily to sales of OMIDRIA to wholesalers and include reductions for estimated chargebacks and product returns which are expected to be settled through reductions in receivables. Remaining receivables consist of amounts from subleases for space in The Omeros Building and, as of December 31, 2015 , amounts related to grants from the National Institutes of Health (NIH). Considering the nature and historic collectability of our receivables, we concluded an allowance for doubtful accounts is not necessary as of December 31, 2016 and 2015 .
Property and Equipment, net	Property and Equipment, net Property and equipment are stated at cost and depreciation is calculated using the straight-line method over the estimated useful life of the assets, which is generally three to 10 years. Equipment financed under capital leases is recorded as property and equipment and is amortized over the shorter of the useful lives of the related assets or the lease term. Expenditures for equipment purchased with grant funds are recorded as a reduction to the cost of the applicable equipment. Expenditures for repairs and maintenance are expensed as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The carrying amount of long-lived assets is reviewed whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Recoverability of these assets is measured by comparing the carrying value to future undiscounted cash flows the asset is expected to generate. If the asset is considered to be impaired, the amount of any impairment will be reflected in the results of operations in the period of impairment. We have not recognized any impairment losses for the years ending December 31, 2016 , 2015 and 2014 .
Deferred Rent	Deferred Rent We recognize rent expense on a straight-line basis over the noncancelable term of The Omeros Building operating lease and, accordingly, record the difference between cash rent payments and the recognition of rent expense as an increase or decrease in deferred rent liability. We also record landlord-funded lease incentives, such as reimbursable leasehold improvements, as an increase in deferred rent liability which is amortized as a reduction of rent expense over the noncancelable terms of The Omeros Building operating lease.
Revenue Recognition	Revenue Recognition Our revenues are comprised of product sales of OMIDRIA and amounts earned for services under grants from third parties. Revenue is recognized when there is persuasive evidence that an arrangement exists, product title and risk of loss is passed to the customer or the service has been provided, the price is fixed or determinable and collection is reasonably assured. Product Sales, Net We record revenue from product sales when the product is delivered to our wholesalers. Product sales to a wholesaler are not recorded if we determine that the wholesaler’s on-hand OMIDRIA inventory, based on sell-through and inventory information we regularly receive from our wholesalers, exceeds approximately eight weeks of projected demand. Product sales are recorded net of chargebacks, wholesaler distribution fees, estimated product returns and rebates. Accruals or allowances are established for these deductions in the same period when revenue is recognized, and actual amounts incurred are offset against the applicable accruals or allowances. We reflect each of these accruals or allowances as either a reduction in the related account receivable or as an accrued liability, depending on how the amount is expected to be settled. Provisions for chargebacks are determined utilizing historical and projected payer mix and sale-through and inventory on-hand information received directly from wholesalers. Chargebacks are generally settled within four weeks of recording product sales revenue. We provide reimbursement support services and financial assistance in the form of reimbursement to certain patients whose commercial insurance is inadequate to cover the full cost of OMIDRIA. We apply our historical rebate ratio to product sales to determine the rebate accrual. This ratio is reviewed and updated periodically to reflect actual results. We provide rebate payments for which ambulatory surgery centers (ASCs) qualify by meeting or exceeding purchase volumes of OMIDRIA under a purchase volume discount program. Rebate accruals and payments under this program are determined based on contractual volume achievement. We allow for the return of product up to 12 months past its expiration date or for product that is damaged. In estimating product returns, we take into consideration our return experience to date, the remaining shelf life of product we have previously sold, inventory in the wholesale channel and our expectation that product is typically not held by the healthcare providers based on the frequency of their reorders. We pay our wholesalers a distribution fee for services they perform on our behalf based on a contractual rate.
Research and Development	Research and Development Research and development costs are comprised primarily of costs for personnel, including salaries, benefits and stock compensation; an allocation of our occupancy costs; clinical study costs; contracted research; manufacturing; consulting arrangements; depreciation; materials and supplies; milestones; and other expenses incurred to sustain our overall research and development programs. Research and development costs are expensed as incurred. Advance payments for goods or services that will be used or rendered for future research and development activities are deferred and then recognized as an expense as the related goods are delivered or the services are performed, or when the goods or services are no longer expected to be provided.
Patents	Patents We generally apply for patent protection on processes and product candidates we or our licensors conceive or develop. Patent costs are comprised primarily of external legal fees, filing fees incurred to file patent applications, and periodic renewal fees to keep the patent in force and are expensed as incurred as a component of general and administrative expense.
Selling, General and Administrative	Selling, General and Administrative Selling, general and administrative (SG&A) expenses are comprised primarily of salaries, service fees incurred for our sales force, benefits, and stock-compensation costs for sales, marketing, and other personnel not directly engaged in research and development. Additionally, SG&A includes marketing and selling expenses, professional and legal services; patent costs; depreciation, an allocation of our occupancy costs; and other general corporate expenses.
Advertising	Advertising Advertising costs, which we consider to be media and marketing materials, are expensed as incurred. We incurred $672,000 and $ 885,000 in advertising expense during the years ended December 31, 2016 and December 31, 2015 , respectively. We had no similar expenses during the year ended December 31, 2014 .
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense is recognized for all share-based payments made to employees, directors and non-employees based on estimated fair values. The fair value of our stock options is calculated using the Black-Scholes option-pricing model which requires judgmental assumptions including volatility, forfeiture rates and expected option life. For employees and directors, we use the straight-line method to allocate compensation cost to reporting periods over each optionee’s requisite service period, which is generally the vesting period. Stock options granted to non-employees are accounted for using the fair-value approach and are subject to periodic revaluation over their vesting terms as earned.
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is comprised of net loss and certain changes in equity that are excluded from net loss. There was no difference between comprehensive loss and net loss for the years ended December 31, 2016 , 2015 or 2014 .
Financial Instruments and Concentrations of Credit Risk	Financial Instruments and Concentrations of Credit Risk Cash and cash equivalents, receivables, accounts payable and accrued liabilities, which are recorded at invoiced amount or cost, approximate fair value based on the short-term nature of these financial instruments. The fair value of short-term investments is based on quoted market prices. Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments and receivables. Cash and cash equivalents are held by financial institutions and are federally insured up to certain limits. At times, our cash and cash equivalents balance exceeds the federally insured limits. To limit the credit risk, we invest our excess cash in high quality securities such as money market mutual funds, certificates of deposit and commercial paper. Our notes payable includes features that meet the requirements under existing accounting guidance to be bifurcated from the respective notes payable agreement and to be recorded at fair value as a derivative asset or liability on the Consolidated Balance Sheet with the corresponding change in fair value recognized in Other income (expense), net on the Consolidated Statement of Operations.
Major Customers	Major Customers We sell OMIDRIA through a limited number of wholesalers.
Major Suppliers	Major Suppliers We use a single contract manufacturer to supply OMIDRIA and generally a single contract manufacturer to produce clinical trial material which creates a concentration of risk for us. We have a non-exclusive agreement with Hospira Worldwide, Inc. (Hospira), a wholly owned subsidiary of Pfizer, Inc., for the commercial supply of OMIDRIA, and Hospira has produced product validation batches of OMIDRIA which are currently undergoing testing prior to seeking FDA approval of the Hospira manufacturing facility. We are not permitted to sell any OMIDRIA produced by Hospira, however, until the Hospira manufacturing facility is approved by the FDA. While one source of supply is utilized for OMIDRIA and generally one source for each of our product candidates, other sources are available should we need to change suppliers. We endeavor to maintain reasonable levels of drug supply for our commercial and clinical trial use. A change in suppliers, however, could cause a delay in delivery of OMIDRIA or our clinical trial material that would adversely affect our business.
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-15 related to disclosure of an entity’s ability to continue as a going concern. This standard requires management to evaluate whether substantial doubt exists regarding the entity’s ability to continue as a going concern at each reporting period for a duration of one year after the date the financial statements are issued or available to be issued. The standard establishes certain required disclosures if substantial doubt exists. On December 31, 2016 , we adopted ASU 2014-15 on a prospective basis. We concluded there is substantial doubt about our ability to continue as a going concern (see “Going Concern” in Note 1 for further discussion). For the year ended December 31, 2016 , we early adopted and applied retrospectively FASB Accounting Standards Update (ASU) No. 2016-15, related to clarifying the classification of certain cash receipts and cash payments on the statement of cash flows. The new guidance requires, among other things, cash payments for debt prepayment or debt extinguishment costs to be classified as cash outflows for financing activities. The adoption of this standard resulted in the reclassification of $2.7 million of cash payments for debt prepayment costs and debt extinguishment costs within the financing activities section of our Consolidated Statements of Cash Flows for the year ended December 31, 2015 . Recent Accounting Pronouncements In May 2014, the FASB issued amended guidance related to revenue from contracts with customers. The amended guidance introduces a new principles-based framework for revenue recognition and disclosure. Since its issuance, the FASB has issued five ASUs amending the guidance and effective date, and the SEC has rescinded certain related SEC guidance; the most recent of which was issued in December 2016. The effective date of the guidance requires us to adopt the standard at the beginning of our first quarter of fiscal 2018 with earlier application permitted. The new guidance requires either a modified retrospective method or a full retrospective method of transition. We currently anticipate adopting the guidance at the beginning of our first quarter of fiscal 2018 under the modified retrospective method. While we have not yet completed our final review of the impact of this guidance, we currently do not anticipate a material impact on our revenue recognition practices. We continue to review variable consideration, potential disclosures, and our method of adoption to complete our evaluation of the impact on our consolidated financial statements. In addition, we continue to monitor additional changes, modifications, clarifications or interpretations undertaken by the FASB, which may impact our current conclusions. In February 2016, the FASB issued ASU 2016-02 related to lease accounting. This standard requires lessees to recognize a right-of-use asset and a lease liability for most leases. This standard must be applied using a modified retrospective transition method and is effective for all annual and interim periods beginning after December 15, 2018. Earlier adoption is permitted. We are evaluating how this new standard will impact the presentation of our financial statements and related disclosures. In March 2016, the FASB issued Accounting Standards Update ASU No. 2016-09 related to stock compensation, which simplifies several aspects of the accounting for share-based payment transactions. The new guidance requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, and eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows. We will adopt the standard in the three months ended March 31, 2017. Upon adoption, we will recognize the previously unrecognized excess tax benefits through a cumulative-effect adjustment to accumulated deficit. The previously unrecognized excess tax effects will be recorded as a deferred tax asset, which will be fully offset by a valuation allowance.

Significant Accounting Polici21

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments	We sell OMIDRIA through a limited number of wholesalers. Each of these wholesalers, together with entities under their common control, accounted for greater than 10% of total revenues for the years ended December 31, 2016 and 2015 and greater than 10% of accounts receivable as of December 31, 2016 and 2015 as noted below. 2016 2015 Percentage of Total Revenue Percentage of Accounts Receivable Percentage of Total Revenue Percentage of Accounts Receivable Distributor A 31 % 27 % 37 % 45 % Distributor B 32 % 29 % 31 % 23 % Distributor C 28 % 24 % 28 % 27 % Distributor D * 19 % * * * Distributor did not account for greater than 10% of total revenues for the years ended December 31, 2016 and 2015 or greater than 10% of accounts receivable at December 31, 2015

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Calculation of Historical Outstanding Dilutive Securities Not Included in Diluted Loss per Share	Potentially dilutive securities excluded from the diluted loss per share calculation are as follows: Year Ended December 31, 2016 2015 2014 Outstanding options to purchase common stock 9,809,374 8,310,235 8,364,469 Warrants and pre-funded warrants to purchase common stock 100,602 749,250 551,435 Total potentially dilutive securities 9,909,976 9,059,485 8,915,904

Fair-Value Measurements (Tables

Fair-Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	Our fair-value hierarchy for our financial assets measured at fair value on a recurring basis are as follows: December 31, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money-market funds classified as non-current restricted cash and investments $ 5,835 $ — $ — $ 5,835 Money-market funds classified as short-term investments 43,107 — — 43,107 Total $ 48,942 $ — $ — $ 48,942 December 31, 2015 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money-market funds classified as non-current restricted cash and investments $ 10,679 $ — $ — $ 10,679 Money-market funds classified as short-term investments 26,898 — — 26,898 Total $ 37,577 $ — $ — $ 37,577

Certain Balance Sheet Accounts

Certain Balance Sheet Accounts (Tables)	12 Months Ended
	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Receivables	Receivables December 31, 2016 2015 (In thousands) Trade receivables $ 11,937 $ 6,208 Grant receivables — 136 Other receivables 100 173 Total receivables $ 12,037 $ 6,517
Inventory	Inventory December 31, 2016 2015 (In thousands) Raw materials $ 101 $ 93 Work-in-process 854 158 Finished goods 173 221 Total inventory cost $ 1,128 $ 472
Property and Equipment	Property and Equipment December 31, 2016 2015 (In thousands) Laboratory equipment $ 1,830 $ 1,735 Capital lease equipment 774 367 Office equipment and furniture 625 625 Computer equipment 476 482 Computer software 208 174 Total cost 3,913 3,383 Less accumulated depreciation and amortization (2,732 ) (2,432 ) Total property and equipment, net $ 1,181 $ 951
Accrued Expenses	Accrued Expenses December 31, 2016 2015 (In thousands) Employee compensation $ 4,551 $ 2,590 Contract research and development 3,030 2,973 Consulting and professional fees 2,223 2,400 Clinical trials 1,167 1,108 Other accruals 2,383 681 Total accrued liabilities $ 13,354 $ 9,752

Notes Payable and Lease Finan25

Notes Payable and Lease Financing Obligations (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of notes payable and lease financing obligations	Notes payable and lease financing obligations consist of the following: December 31, 2016 2015 (In thousands) Notes payable $ 80,516 $ 50,000 Lender facility fee payable upon maturity 4,025 3,750 Lease financing obligations 522 279 Notes payable, facility fee and lease financing obligations 85,063 54,029 Unamortized debt discount (3,958 ) (3,750 ) Unamortized debt issuance costs (1,395 ) (437 ) Current portion of lease financing obligations (198 ) (73 ) Notes payable and lease financing obligations, net $ 79,512 $ 49,769
Contractual Obligation, Fiscal Year Maturity Schedule	Future principal payments as of December 31, 2016 under the CRG Loan Agreement and our capital equipment financing leases, based on stated contractual maturities, are as follows: Year Ending December 31, Notes Payable Lease Financing Obligations Total (In thousands) 2017 $ — $ 198 $ 198 2018 — 199 199 2019 — 89 89 2020 — 31 31 2021 46,009 5 46,014 Thereafter 34,507 — 34,507 Total future principal payments $ 80,516 $ 522 $ 81,038

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Payments Related Operating Lease	Future minimum payments related to our leases at December 31, 2016 , are as follows: Year Ending December 31, Lease Sublease Net Lease (In thousands) 2017 $ 4,474 $ 663 $ 3,811 2018 4,545 663 3,882 2019 4,632 597 4,035 2020 4,690 335 4,355 2021 4,552 — 4,552 Thereafter 28,712 — 28,712 Total $ 51,605 $ 2,258 $ 49,347

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Reserved Shares of Common Stock	As of December 31, 2016 , we had reserved shares of common stock for the following purposes: Options granted and outstanding 9,809,374 Options available for future grant 524,145 Common stock warrants 100,602 Total shares reserved 10,434,121
Schedule of Stockholders' Equity Note, Warrants or Rights	The following table summarizes our outstanding warrants at December 31, 2016 : Outstanding At Expiration Date Exercise Price 100,602 May 18, 2023 $9.94

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Weighted Average Assumptions For Employee Stock Option Grants	The fair value of each option grant to employees and directors is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions were applied to employee and director stock option grants during the periods ended: Year Ended December 31, 2016 2015 2014 Estimated weighted-average fair value $ 6.89 $ 11.31 $ 7.39 Weighted-average assumptions: Expected volatility 74 % 71 % 73 % Expected term, in years 5.7 6.0 5.8 Risk-free interest rate 1.63 % 1.68 % 1.87 % Expected dividend yield — % — % — %
Stock-Based Compensation Expense	Stock-based compensation expense includes amortization of stock options granted to employees and non-employees and has been reported in our Consolidated Statements of Operations and Comprehensive Loss as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Research and development $ 6,304 $ 4,977 $ 4,754 Selling, general and administrative 7,278 4,604 4,164 Total stock-based compensation expense $ 13,582 $ 9,581 $ 8,918
Stock Option Activity and Related Information	Stock option activity for all stock plans is as follows: Options Outstanding Weighted- Average Exercise Price per Share Remaining Contractual Life (in years) Aggregate Intrinsic Value (In thousands) Balance at December 31, 2015 8,310,235 $ 7.97 Granted 3,128,567 10.72 Exercised (1,486,167 ) 2.12 Forfeited and expired (143,261 ) 12.92 Balance at December 31, 2016 9,809,374 $ 9.66 7.12 $ 11,162 Vested and expected to vest at December 31, 2016 9,483,392 $ 9.60 7.05 $ 11,155 Exercisable at December 31, 2016 6,568,859 $ 8.87 6.17 $ 11,087

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Significant Components of Deferred Tax Assets	Significant components of deferred income taxes are as follows: December 31, 2016 2015 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 126,410 $ 110,092 Tax credit carryforwards 18,741 14,758 Stock-based compensation 11,102 8,136 Deferred rent 3,318 3,324 Other 4,401 2,744 Total deferred tax assets 163,972 139,054 Less valuation allowance (163,972 ) (139,054 ) Net deferred tax assets $ — $ —
Reconciliation of Federal Statutory Tax Rate to Effective Income Tax	econciliation of income tax computed at federal statutory rates to the reported provisions for income taxes is as follows: Year ended December 31, 2016 2015 2014 Federal statutory tax rate (34 )% (34 )% (34 )% State tax rates (2 )% (2 )% — % Other permanent differences 3 % 1 % 2 % Change in valuation allowance 37 % 41 % 35 % Tax credits (4 )% (5 )% (4 )% Other — % (1 )% 1 % Effective tax rate — % — % — %

Quarterly Information (Unaudi30

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary of Unaudited Statements of Operations	The following table summarizes the unaudited statements of operations and comprehensive loss for each quarter of 2016 and 2015 (in thousands, except per share amounts): 2016 For the Quarter Ended March 31, June 30, September 30, December 31, Revenue $ 7,419 $ 10,004 $ 11,289 $ 12,905 Total operating expenses 26,871 20,933 23,327 24,762 Loss from operations (19,452 ) (10,929 ) (12,038 ) (11,857 ) Net loss (20,539 ) (12,612 ) (13,962 ) (19,632 ) Basic and diluted net loss per share $ (0.54 ) $ (0.32 ) $ (0.34 ) $ (0.45 ) 2015 For the Quarter Ended March 31, June 30, September 30, December 31, Revenue $ 388 $ 3,187 $ 3,259 $ 6,675 Total operating expenses 18,318 19,154 22,560 24,715 Loss from operations (17,930 ) (15,967 ) (19,301 ) (18,040 ) Net loss (18,669 ) (16,680 ) (19,921 ) (19,826 ) Basic and diluted net loss per share $ (0.51 ) $ (0.44 ) $ (0.53 ) $ (0.52 )

Organization and Basis of Pre31

Organization and Basis of Presentation - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)segment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 26, 2016USD ($)
Accounting Policies [Abstract]
Number of operating segments | segment									1
Net loss	$ (19,632)	$ (13,962)	$ (12,612)	$ (20,539)	$ (19,826)	$ (19,921)	$ (16,680)	$ (18,669)	$ (66,745)	$ (75,096)	$ (73,673)
Net cash used in operating activities									(51,504)	$ (65,209)	$ (58,044)
Cash, cash equivalents and marketable securities	$ 45,300								$ 45,300
CRG Loan
Debt Instrument [Line Items]
Line of credit facility, additional advances limit												$ 45,000

Significant Accounting Polici32

Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Advertising expense	$ 672	$ 885
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	10 years

Significant Accounting Polici33

Significant Accounting Policies - Major Customers and Major Suppliers (Details) - supplier	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Number of suppliers	1
Customer Concentration Risk | Distributor A | Percentage of Total Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	31.00%	37.00%
Customer Concentration Risk | Distributor A | Percentage of Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	27.00%	45.00%
Customer Concentration Risk | Distributor B | Percentage of Total Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	32.00%	31.00%
Customer Concentration Risk | Distributor B | Percentage of Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	29.00%	23.00%
Customer Concentration Risk | Distributor C | Percentage of Total Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	28.00%	28.00%
Customer Concentration Risk | Distributor C | Percentage of Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	24.00%	27.00%
Customer Concentration Risk | Distributor D | Percentage of Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%

Significant Accounting Polici34

Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncement, Early Adoption [Line Items]
Net cash provided by financing activities	$ 68,698	$ 86,826	$ 50,857
Accounting Standards Update 2016-15 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncement, Early Adoption [Line Items]
Net cash provided by financing activities		$ 2,700

Net Loss Per Share - Calculatio

Net Loss Per Share - Calculation of Historical Outstanding Dilutive Securities Not Included in Diluted Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding dilutive securities not included in diluted loss per share calculation	9,909,976	9,059,485	8,915,904
Outstanding options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding dilutive securities not included in diluted loss per share calculation	9,809,374	8,310,235	8,364,469
Warrants and pre-funded warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding dilutive securities not included in diluted loss per share calculation	100,602	749,250	551,435

Fair-Value Measurements - Finan

Fair-Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total	$ 48,942	$ 37,577
Non Current
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as restricted cash	5,835	10,679
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as short-term investments	43,107	26,898
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total	48,942	37,577
Fair Value, Inputs, Level 1 | Non Current
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as restricted cash	5,835	10,679
Fair Value, Inputs, Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as short-term investments	43,107	26,898
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total	0	0
Fair Value, Inputs, Level 2 | Non Current
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as restricted cash	0	0
Fair Value, Inputs, Level 2 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as short-term investments	0	0
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total	0	0
Fair Value, Inputs, Level 3 | Non Current
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as restricted cash	0	0
Fair Value, Inputs, Level 3 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money-market funds classified as short-term investments	$ 0	$ 0

Fair-Value Measurements - Narra

Fair-Value Measurements - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Cash excluded from fair value hierarchy disclosure	$ 2,200,000	$ 1,400,000
Unrealized gain (loss) on investments	$ 0	$ 0

Certain Balance Sheet Account38

Certain Balance Sheet Accounts - Grant and Other Receivables (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Trade receivables	$ 11,937	$ 6,208
Grant receivables	0	136
Other receivables	100	173
Total receivables	12,037	6,517
Deferred Discounts, Finance Charges and Interest Included in Receivables	$ 297	$ 191

Certain Balance Sheet Account39

Certain Balance Sheet Accounts - Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 101	$ 93
Work-in-process	854	158
Finished goods	173	221
Total inventory cost	$ 1,128	$ 472

Certain Balance Sheet Account40

Certain Balance Sheet Accounts - Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,913	$ 3,383
Less accumulated depreciation and amortization	(2,732)	(2,432)
Total property and equipment, net	1,181	951
Depreciation and amortization	300	209	$ 317
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,830	1,735
Capital lease equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	774	367
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Property and equipment, gross	625	625
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	476	482
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 208	$ 174

Certain Balance Sheet Account41

Certain Balance Sheet Accounts - Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Employee compensation	$ 4,551	$ 2,590
Contract research and development	3,030	2,973
Consulting and professional fees	2,223	2,400
Clinical trials	1,167	1,108
Other accruals	2,383	681
Total accrued liabilities	$ 13,354	$ 9,752

Notes Payable and Lease Finan42

Notes Payable and Lease Financing Obligations - Schedule of Notes Payable and Lease Financing Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Notes payable	$ 80,516	$ 50,000
Lender facility fee payable upon maturity	4,025	3,750
Lease financing obligations	522	279
Notes payable, facility fee and lease financing obligations	85,063	54,029
Unamortized debt discount	(3,958)	(3,750)
Unamortized debt issuance costs	(1,395)	(437)
Current portion of lease financing obligations	(198)	(73)
Notes payable and lease financing obligations, net	$ 79,512	$ 49,769

Notes Payable and Lease Finan43

Notes Payable and Lease Financing Obligations - Additional Information (Detail)	Oct. 26, 2016USD ($)tranche	Mar. 11, 2014USD ($)	May 31, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Mar. 31, 2016$ / shares	Feb. 28, 2015shares	Mar. 04, 2014USD ($)	Mar. 31, 2009$ / shares
Debt Instrument [Line Items]
Final payment fee, amount	$ 5,000,000
Payments of debt extinguishment costs	700,000			$ 248,000		$ 5,700,000	$ 2,673,000	$ 521,000
Gain (loss) on early extinguishment of debt						(5,595,000)	(1,315,000)	0
Proceeds from debt issuance						$ 100,000,000	50,000,000	$ 32,000,000
Shares of common stock to purchase by warrant (in shares) | shares						100,602						749,250
Exercise price of warrants (in USD per share) | $ / shares						$ 9.94					$ 0.01			$ 12.25
Outstanding balance	70,000,000					$ 80,516,000
Lender facility fee payable upon maturity				3,750,000		4,025,000	3,750,000
Capital Leased Assets, Gross				367,000		774,000	367,000
Capital lease, accumulated depreciation				98,000		230,000	98,000
Capital lease, future minimum payments due				281,000		522,000	$ 281,000
Unamortized balance of debt discount						$ 4,000,000
Oxford Midcap Loan
Debt Instrument [Line Items]
Loan and security agreement, existing outstanding indebtedness													$ 32,000,000
Repayments of debt		$ 19,100,000		24,800,000
Proceeds from long-term debt					$ 12,700,000
Accrued interest rate						9.25%
Principal and interest payment amount						$ 1,000,000
Final payment fee, amount													$ 2,200,000
Prepayment fee as percentage of outstanding principal amount						1.00%
Debt extinguished				27,300,000
Oxford EWB Loan
Debt Instrument [Line Items]
Loan and security agreement, existing outstanding indebtedness						$ 50,000,000
Repayments of debt	$ 75,700,000
Proceeds from long-term debt				22,300,000
Final payment fee, amount						$ 3,800,000
Prepayment fee as percentage of outstanding principal amount						1.00%
Line of credit facility, additional advances limit						$ 20,000,000
Gain (loss) on early extinguishment of debt				$ (1,300,000)
Fee for each additional $10 million advance						525,000
Line of credit facility, additional advances, increase per tranche						10,000,000
Debt instrument, covenant compliance, minimum restricted cash and certain eligible term investments threshold						10,000,000
Proceeds from debt issuance			$ 19,900,000
Maturity fee, as a percent			5.25%
Maturity fee on amended balance, as a percent			6.25%
CRG Loan
Debt Instrument [Line Items]
Accrued interest rate	12.25%
Line of credit facility, additional advances limit	$ 45,000,000
Gain (loss) on early extinguishment of debt	$ (5,600,000)
Maturity fee, as a percent	5.00%
Debt issued	$ 80,000,000
Additional borrowing capacity, number of tranches | tranche	2
Additional borrowing capacity, tranche one	$ 25,000,000
Additional borrowing capacity, tranche two	20,000,000
Debt instrument, covenant compliance, product sales revenues required over consecutive 3 month period, tranche one	18,000,000
Debt instrument, covenant compliance, average market capitalization, tranche one	700,000,000
Debt instrument, covenant compliance, product sales revenues required over consecutive 3 month period, tranche two	25,000,000
Debt instrument, covenant compliance, average market capitalization, tranche two	1,000,000,000
Net proceeds from issuance of debt	$ 3,000,000
Deferred interest rate percentage	4.00%
Debt instrument, covenant compliance, minimum restricted cash and cash equivalents	$ 5,000,000
Debt instrument, potential future interest rate if revenue milestone is satisfied	11.50%
Debt instrument, potential future deferred interest rate if revenue milestone is satisfied	3.50%
Debt instrument, covenant compliance, minimum net revenue amount						35,000,000
Debt instrument, covenant compliance, minimum market capitalization threshold multiplier	6.4
Increase in interest rate if an event of default occurs	4.00%
Increase in principal amount of debt outstanding from deferred interest						$ 516,000
CRG Loan | Scenario, Forecast
Debt Instrument [Line Items]
Debt instrument, covenant compliance, minimum net revenue amount									$ 65,000,000	$ 55,000,000
Minimum
Debt Instrument [Line Items]
Capital lease expiration date						Oct. 1, 2017
Maximum
Debt Instrument [Line Items]
Capital lease expiration date						Dec. 1, 2021

Notes Payable and Lease Finan44

Notes Payable and Lease Financing Obligations - Future Minimum Payment Related Lease (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Oct. 26, 2016	Dec. 31, 2015
Notes Payable
2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	46,009
Thereafter	34,507
Total future principal payments	80,516	$ 70,000
Lease Financing Obligations
2,017	198
2,018	199
2,019	89
2,020	31
2,021	5
Thereafter	0
Total future principal payments	522		$ 281
Total
2,017	198
2,018	199
2,019	89
2,020	31
2,021	46,014
Thereafter	34,507
Total future principal payments	$ 81,038

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Oct. 31, 2010USD ($)	Dec. 31, 2016USD ($)lease_extension	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Commitments and Contingencies Disclosure [Line Items]
Remaining aggregate non-cancelable rent due		$ 51,605,000
Liabilities subject to compromise, early contract termination fee		2,200,000
Research and development		50,699,000	$ 48,379,000	$ 47,946,000
Maximum | Individual
Commitments and Contingencies Disclosure [Line Items]
Potential future payments		3,800,000
Stanley Medical Research Institute | Maximum
Commitments and Contingencies Disclosure [Line Items]
Potential future payments		12,800,000
Daiichi Sankyo Company Limited | One Indication
Commitments and Contingencies Disclosure [Line Items]
Potential future payments		23,500,000
Research and development					$ 50,000
Daiichi Sankyo Company Limited | Maximum
Commitments and Contingencies Disclosure [Line Items]
Potential future payments		33,500,000
Helion Biotech ApS
Commitments and Contingencies Disclosure [Line Items]
Research and development		0	0	300,000
Helion Biotech ApS | Maximum
Commitments and Contingencies Disclosure [Line Items]
Potential future payments		$ 6,100,000
Vulcan and Life Sciences Discovery Fund Authority
Commitments and Contingencies Disclosure [Line Items]
Potential future net proceeds	$ 1,500,000,000
Eligible expenses and expenditures deducted for computation of net proceeds	25,000,000
Vulcan Incorporated
Commitments and Contingencies Disclosure [Line Items]
Amount payable under agreement	$ 25,000,000
Term of agreement	35 years
Life Sciences Discovery Fund Authority
Commitments and Contingencies Disclosure [Line Items]
Amount payable under agreement	$ 25,000,000
Building
Commitments and Contingencies Disclosure [Line Items]
Number of Options to extend the lease term | lease_extension		2
Options to extend the lease term, number of options		5 years
Remaining aggregate non-cancelable rent due		$ 50,500,000
Deferred rent		9,200,000
Rent expense		4,400,000	4,500,000	4,500,000
Sublease revenue		737,000	$ 889,000	$ 568,000
Equipment
Commitments and Contingencies Disclosure [Line Items]
Remaining aggregate non-cancelable rent due		$ 1,100,000

Commitments and Contingencies46

Commitments and Contingencies - Future Minimum Payment Related Lease (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Lease Payments
2,017	$ 4,474
2,018	4,545
2,019	4,632
2,020	4,690
2,021	4,552
Thereafter	28,712
Total	51,605
Sublease Receipts
2,017	663
2,018	663
2,019	597
2,020	335
2,021	0
Thereafter	0
Total sublease income receivable	2,258
Net Lease Payments
2,017	3,811
2,018	3,882
2,019	4,035
2,020	4,355
2,021	4,552
Thereafter	28,712
Net operating lease payments	$ 49,347

Shareholders' Equity - Reserved

Shareholders' Equity - Reserved Share of Common Stock (Detail)	Dec. 31, 2016shares
Reserved Common Stock [Line Items]
Total shares reserved	10,434,121
Options granted and outstanding
Reserved Common Stock [Line Items]
Total shares reserved	9,809,374
Options available for future grant
Reserved Common Stock [Line Items]
Total shares reserved	524,145
Common stock warrants
Reserved Common Stock [Line Items]
Total shares reserved	100,602

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($)	Jan. 01, 2017	Aug. 31, 2016	Aug. 21, 2016	Mar. 31, 2016	Jan. 31, 2016	Feb. 28, 2015	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	May 31, 2016	Mar. 31, 2009
Class of Stock [Line Items]
Issuance of stock (in shares)			3,500,000			3,400,000	3,500,000
Share price (in USD per share)		$ 11.50				$ 20.03	$ 11.50
Proceeds from issuance of common stock and pre-funded warrants, net		$ 37,300,000				$ 79,100,000	$ 37,800,000	$ 38,039,000	$ 79,076,000	$ 37,754,000
Shares of common stock to purchase by warrant (in shares)						749,250		100,602
Exercise price of warrants (in USD per share)				$ 0.01				$ 9.94				$ 12.25
Payment of stock issuance costs						$ 4,900,000	$ 2,500,000
Warrant fair value											$ 758,000
Warrant expiration date								May 18, 2023
Proceeds from warrant exercises				$ 8,000					1,400,000
Fair value adjustment of warrants										(863,000)
Issuance of common stock utilizing At-The Market Agreement, net of commissions								$ 7,000	$ 1,436,000	$ 68,000
Stock Issued During Period, Shares, Other										28,653
Pre-funded warrants
Class of Stock [Line Items]
Share price (in USD per share)						$ 20.02
Exercise price of warrants (in USD per share)						$ 0.01
At The Market (ATM) Program
Class of Stock [Line Items]
Stock offering program, commission percent					1.70%
Stock offering program, notice period for termination					10 days
Issuance of stock (in shares)								64,565
Proceeds from issuance of common stock and pre-funded warrants, net								$ 724,000
Stock offering program, aggregate offering price					$ 50,000,000
At The Market (ATM) Program | Weighted Average
Class of Stock [Line Items]
Share price (in USD per share)								$ 11.41
Equity Option | Subsequent Event | Equity Incentive Plan 2008
Class of Stock [Line Items]
Increase in authorized shares	1,785,714
Common Stock
Class of Stock [Line Items]
Issuance of stock (in shares)								3,478,260	3,444,831	3,500,000
Issuance of common stock utilizing At-The-Market Agreement (in shares)								749,250	133,240	28,653
Issuance of common stock utilizing At-The Market Agreement, net of commissions								$ 7,000	$ 1,000	$ 0
Additional Paid-in Capital
Class of Stock [Line Items]
Issuance of common stock utilizing At-The Market Agreement, net of commissions								$ 0	$ 1,435,000	$ 68,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2017	Feb. 28, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, maximum term			5 years 8 months 12 days	5 years 11 months 15 days	5 years 10 months 3 days
Shares granted in period			3,128,567
Non-employee options granted (in shares)			38,000	4,200	86,000
Issuance of warrants in connection with amendment to notes payable			$ 313	$ 492	$ 289,000
Total intrinsic value of options exercised			$ 13,600	$ 3,900	$ 2,900
Unvested options outstanding (in shares)			3,240,515
Unvested options outstanding, vesting period			2 years 4 months 24 days
Unrecognized compensation expense			$ 19,000
Equity Incentive Plan 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, average vesting period			4 years
Annual increase provision, allowable percentage			5.00%
Annual increase provision, maximum allowable shares			1,785,714
Shares reserved for issuance			10,333,519
Shares available for grant			524,145
Equity Incentive Plan 2008 | Equity Option | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in authorized shares	1,785,714
Equity Incentive Plan 2008 | Performance Shares | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in period		1,434,250
Equity Incentive Plan 2008 | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, maximum term			10 years

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Employee Option Grant Estimated on Date of Grant (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Weighted-Average Assumptions
Estimated weighted-average fair value (in dollars per share)	$ 6.89	$ 11.31	$ 7.39
Expected volatility	74.00%	71.00%	73.00%
Expected term, in years	5 years 8 months 12 days	5 years 11 months 15 days	5 years 10 months 3 days
Risk-free interest rate	1.63%	1.68%	1.87%
Expected dividend yield	0.00%	0.00%	0.00%

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 13,582	$ 9,581	$ 8,918
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	6,304	4,977	4,754
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 7,278	$ 4,604	$ 4,164

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity and Related Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Options Outstanding
Beginning balance (in shares) | shares	8,310,235
Granted (in shares) | shares	3,128,567
Exercised (in shares) | shares	(1,486,167)
Forfeited and expired (in shares) | shares	(143,261)
Ending balance (in shares) | shares	9,809,374
Vested and expected to vest (in shares) | shares	9,483,392
Exercisable at December 31, 2016 (in shares) | shares	6,568,859
Weighted-Average Exercise Price per Share
Beginning balance (in dollars per share) | $ / shares	$ 7.97
Granted (in dollars per share) | $ / shares	10.72
Exercised (in dollars per share) | $ / shares	2.12
Forfeited and expired (in dollars per share) | $ / shares	12.92
Ending balance (in dollars per share) | $ / shares	9.66
Vested and expected to vest (in dollars per share) | $ / shares	9.60
Exercisable at December 31, 2016 (in dollars per share) | $ / shares	$ 8.87
Weighted- Average Remaining Contractual Life
Balance at December 31, 2016	7 years 1 month 13 days
Vested and expected to vest at December 31, 2016	7 years 19 days
Exercisable at December 31, 2016	6 years 1 month 30 days
Aggregate Intrinsic Value
Balance at December 31, 2016 | $	$ 11,162
Vested and expected to vest at December 31, 2016 | $	11,155
Exercisable at December 31, 2016 | $	$ 11,087

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carryforwards	$ 126,410	$ 110,092
Tax credit carryforwards	18,741	14,758
Stock-based compensation	11,102	8,136
Deferred rent	3,318	3,324
Other	4,401	2,744
Total deferred tax assets	163,972	139,054
Less valuation allowance	(163,972)	(139,054)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 378,900	$ 325,900
Operating loss carryforward, state	50,000	30,600
Research and development tax credit	$ 18,741	14,758
Beginning year of net operating loss expiration	2,018
Ending year of net operating loss expiration	2,036
Deferred tax assets, percentage of valuation allowance	100.00%
Increase in deferred tax valuation allowance	$ 24,900	30,400	$ 25,800
Unrecognized Tax Benefits	212	$ 212	$ 212
Share Based Compensation
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 13,300

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Federal Statutory Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal statutory tax rate	(34.00%)	(34.00%)	(34.00%)
State tax rates	(2.00%)	(2.00%)	(0.00%)
Other permanent differences	3.00%	1.00%	2.00%
Change in valuation allowance	37.00%	41.00%	35.00%
Tax credits	(4.00%)	(5.00%)	(4.00%)
Other	(0.00%)	(1.00%)	1.00%
Effective tax rate	0.00%	0.00%	0.00%

401k Retirement Plan - Narrativ

401k Retirement Plan - Narrative (Details)	12 Months Ended
	Dec. 31, 2016USD ($)
Compensation and Retirement Disclosure [Abstract]
Maximum percent of each employee's contributions matched by employer	4.00%
Maximum amount of each employee's contributions matched by employer	$ 4,000

Quarterly Information (Unaudi57

Quarterly Information (Unaudited) - Quarterly Unaudited Statements of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 12,905	$ 11,289	$ 10,004	$ 7,419	$ 6,675	$ 3,259	$ 3,187	$ 388	$ 41,617	$ 13,509	$ 539
Total operating expenses	24,762	23,327	20,933	26,871	24,715	22,560	19,154	18,318	95,893	84,747	70,547
Loss from operations	(11,857)	(12,038)	(10,929)	(19,452)	(18,040)	(19,301)	(15,967)	(17,930)	(54,276)	(71,238)	(70,008)
Net loss	$ (19,632)	$ (13,962)	$ (12,612)	$ (20,539)	$ (19,826)	$ (19,921)	$ (16,680)	$ (18,669)	$ (66,745)	$ (75,096)	$ (73,673)
Basic and diluted net loss per share (in dollars per share)	$ (0.45)	$ (0.34)	$ (0.32)	$ (0.54)	$ (0.52)	$ (0.53)	$ (0.44)	$ (0.51)	$ (1.65)	$ (2)	$ (2.22)