Kubota Pharmaceutical (KBBTF) 10-K 11 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Mar. 03, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	ACUCELA INC.
Entity Central Index Key	1,400,482
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		37,644,582
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 106.1

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 5,088	$ 18,778
Investments	106,922	85,008
Accounts receivable from collaborations	6,140	5,285
Deferred tax asset	0	61
Prepaid expenses and other current assets	2,051	2,582
Total current assets	120,201	111,714
Property and equipment, net	920	742
Long-term investments	54,515	84,033
Long-term deferred tax asset	0	42
Other assets	314	435
Total assets	175,950	196,966
Current liabilities:
Accounts payable	207	441
Accrued liabilities	3,138	4,176
Accrued compensation	2,457	1,683
Deferred revenue from collaborations	2,467	6,231
Deferred rent and lease incentives	143	25
Total current liabilities	$ 8,412	$ 12,556
Commitments and contingencies (Note 13)
Long-term deferred rent, lease incentives, and others	$ 1,104	$ 47
Total long-term liabilities	1,104	47
Shareholders’ equity:
Common stock, no par value, 100,000 shares authorized as of December 31, 2015 and December 31, 2014; 36,517 and 35,809 shares issued and outstanding as of December 31, 2015 and December 31, 2014	191,696	186,589
Additional paid-in capital	6,288	3,601
Accumulated other comprehensive loss	(575)	(361)
Accumulated deficit	(30,975)	(5,466)
Total shareholders’ equity	166,434	184,363
Total liabilities and shareholders’ equity	$ 175,950	$ 196,966

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	36,517,000	35,809,000
Common stock, shares outstanding	36,517,000	35,809,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue from collaborations	$ 24,067	$ 35,396	$ 52,947
Expenses:
Research and development	22,636	25,582	36,405
General and administrative	27,987	10,002	9,548
Total expenses	50,623	35,584	45,953
Income (loss) from operations	(26,556)	(188)	6,994
Other income (expense), net:
Interest income	1,117	519	122
Interest expense	0	(15)	(116)
Other income (expense), net	(20)	37	182
Total other income, net	1,097	541	188
Income (loss) before income tax	(25,459)	353	7,182
Income tax benefit (expense)	(50)	(2,359)	(2,883)
Net income (loss)	(25,509)	(2,006)	4,299
Net income attributable to participating securities	0	0	3,138
Net income (loss) attributable to common shareholders	$ (25,509)	$ (2,006)	$ 1,161
Net income (loss) per share attributable to common shareholders
Basic (in dollars per share)	$ (0.71)	$ (0.06)	$ 0.10
Diluted (in dollars per share)	$ (0.71)	$ (0.06)	$ 0.09
Weighted average shares used to compute net income (loss) per share attributable to common shareholders:
Basic (shares)	35,972	32,869	11,964
Diluted (shares)	35,972	32,869	12,355

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (25,509)	$ (2,006)	$ 4,299
Other comprehensive income (loss):
Net unrealized loss on securities	(214)	(354)	(7)
Comprehensive income (loss)	$ (25,723)	$ (2,360)	$ 4,292

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Preferred StockConvertible	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance (in shares) at Dec. 31, 2012		32,441	11,910
Balance at Dec. 31, 2012	$ 25,607	$ 28,209	$ 3,192	$ 1,965	$ 0	$ (7,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	667			667
Excess net tax provision related to share-based awards	96			96
Common stock issued in connection with stock option exercises (in shares)			30
Common stock issued in connection with stock option exercises	6		$ 6
Common stock issued in connection with the restricted stock purchase agreement (in shares)			31
Common stock issued in connection with the restricted stock purchase agreement	456		$ 456
Net income (loss)	4,299					4,299
Unrealized loss on marketable securities available for sale	(7)				(7)
Balance (in shares) at Dec. 31, 2013		32,441	11,971
Balance at Dec. 31, 2013	31,124	$ 28,209	$ 3,654	2,728	(7)	(3,460)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	516			516
Excess net tax provision related to share-based awards	(64)			(64)
Common stock issued in connection with stock option exercises (in shares)			188
Common stock issued in connection with stock option exercises	682		$ 682
Net income (loss)	(2,006)					(2,006)
Unrealized loss on marketable securities available for sale	(354)				(354)
Common stock issued in connection with IPO offering, net of issuance costs of $7,093 (in shares)			9,200
Common stock issued in connection with IPO offering, net of issuance costs of $7,093	142,044		$ 142,044
Common stock issued in connection with conversion of convertible preferred stock upon IPO (in shares)		(32,441)	10,814
Common stock issued in connection with conversion of convertible preferred stock upon IPO		$ (28,209)	$ 28,209
Common stock issued in connection with conversion of contingently convertible notes upon IPO (in shares)			3,636
Common stock issued in connection with conversion of contingently convertible notes upon IPO	12,000		$ 12,000
Excess net tax benefit related to IPO costs	421			421
Balance (in shares) at Dec. 31, 2014		0	35,809
Balance at Dec. 31, 2014	184,363	$ 0	$ 186,589	3,601	(361)	(5,466)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	8,940			8,940
Common stock issued in connection with stock option exercises (in shares)			11
Common stock issued in connection with stock option exercises	5		$ 17	(12)
Net income (loss)	(25,509)					(25,509)
Unrealized loss on marketable securities available for sale	(214)				(214)
Issuance of restricted shares of common stock (in shares)			904
RSUs withheld for employee payroll taxes (in shares)			(207)
RSUs withheld for employee payroll taxes	(1,165)			(1,165)
Excess net tax benefit related to IPO costs	14			14
Vesting of restricted stock and exercise of options			$ 5,090	(5,090)
Balance (in shares) at Dec. 31, 2015		0	36,517
Balance at Dec. 31, 2015	$ 166,434	$ 0	$ 191,696	$ 6,288	$ (575)	$ (30,975)

CONSOLIDATED STATEMENTS OF SHA7

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 7,093

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income (loss)	$ (25,509)	$ (2,006)	$ 4,299
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	381	501	531
Stock-based compensation	8,940	516	1,123
Amortization net of premium/discount on marketable securities	2,290	1,175	332
Deferred taxes	103	2,349	2,274
Excess net tax provision related to share-based awards	0	(64)	0
Loss on disposal of fixed assets	30	0	0
Changes in operating assets and liabilities:
Accounts receivable from collaborations	(855)	4,977	(1,562)
Prepaid expenses and other current assets	815	401	(443)
Accounts payable	(234)	(313)	(102)
Accrued liabilities	(1,038)	(2,403)	2,650
Accrued compensation	774	(1,586)	856
Deferred rent and lease incentives	1,075	(250)	(264)
Deferred revenue from collaborations	(3,764)	6,231	(2,570)
Other assets	121	(86)	122
Net cash (used in) provided by operating activities	(16,871)	9,442	7,246
Cash flows from investing activities
Purchases of marketable securities available for sale	(86,590)	(201,732)	(23,217)
Maturities of marketable securities available for sale	91,420	48,931	17,136
Net additions to property and equipment	(489)	(131)	(500)
Net cash provided by (used in) investing activities	4,341	(152,932)	(6,581)
Cash flows from financing activities
Repurchase of restricted stock units related to tax withholdings	(1,165)	0	0
Proceeds from issuance of common stock	17	149,819	6
Sale of stock, net	(12)	0	0
Payments for deferred offering costs	0	(1,545)	(3,412)
Excess tax benefit from stock-based compensation	0	0	96
Net cash (used in) provided by financing activities	(1,160)	148,274	(3,310)
Increase (decrease) in cash and cash equivalents	(13,690)	4,784	(2,645)
Cash and cash equivalents—beginning of period	18,778	13,994	16,639
Cash and cash equivalents—end of period	5,088	18,778	13,994
Supplemental disclosure
Cash paid for income taxes	$ 0	60	828
Unpaid deferred offering costs		5,548	937
Restriction of investment as collateral	$ 0	0	(5,759)
Conversion of convertible preferred stock upon IPO	0	28,209	0
Conversion of contingently convertible debt, related party, upon IPO	$ 0	$ 12,000	$ 0

Business and Basis of Presentat

Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Business Acucela Inc. and its subsidiary ("the Company", “we,” “our” and “us”) are clinical stage ophthalmology companies that specialize in identifying and developing novel therapeutics to treat and slow the progression of sight-threatening ophthalmic diseases affecting millions of people worldwide. In 2008 , we and Otsuka Pharmaceutical Co., Ltd. (“Otsuka”) entered into a definitive agreement to co-develop Emixustat hydrochloride ("Emixustat"), our lead investigational compound which is currently being evaluated in a Phase 2b/3 clinical trial in patients with geographic atrophy associated with dry age-related macular degeneration ("AMD"). Basis of Presentation Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Acucela Japan KK, which was organized under the laws of Japan on December 11, 2015. Through December 31, 2015, Acucela Japan KK has not commenced operations. We eliminate all intercompany balances and transactions in consolidation. Presentation of the cash flow Prior year presentation of cash flows includes a re-classification to conform with the current year presentation of purchased interest on marketable securities. 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. Actual results could differ from these estimates. Segments We operate in one segment, pharmaceutical product development. All of our significant assets are located in the United States. During the years ended December 31, 2015 , 2014 , and 2013 , all revenue was generated in the United States.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Revenue Recognition Our business strategy includes entering into collaboration agreements with pharmaceutical companies for the development and commercialization of our product candidates. The terms of the agreements may include nonrefundable license fees, funding of research and development activities, payments based upon achievement of development milestones, payments based upon achievement of revenue milestones, or royalties on product sales. We recognize revenue when four basic criteria have been met: (a) persuasive evidence of an arrangement exists; (b) delivery has occurred or services rendered; (c) the fee is fixed or determinable; and (d) collectability is reasonably assured. Revenue recognized for the years ended December 31, 2015 , 2014 , and 2013 consists entirely of amounts derived from our collaboration agreements with Otsuka (See Note 10). Multiple Element Arrangements Our collaboration agreements are multiple element arrangements that must be analyzed to identify the deliverables included in the agreements and to determine if the deliverables qualify as separate units of accounting. Deliverables are considered a separate unit of accounting when all of the following criteria are met: (i) the delivered item has value to the customer on a standalone basis and (ii) if the arrangement includes a general right of return relative to the delivered item, and the delivery or performance of the undelivered item is considered probable and substantially within our control. There are no rights of return in our collaboration agreements. Arrangement consideration is allocated to the separate units of accounting based on their relative selling prices. We follow a hierarchy to determine the selling price for each unit of accounting, determining first if there is vendor-specific objective evidence (“VSOE”) of fair value (the price at which the goods or services are regularly sold by us on a standalone basis). If VSOE of fair value is not available, third-party evidence (“TPE”) of vendors selling similar goods or services to similarly situated customers on a standalone basis is used to establish fair value. If neither VSOE nor TPE of fair value exists, we use our best estimate of the selling price (“BESP”) for that unit of accounting. Our BESP represents the price at which we would transact if we regularly sold the unit of accounting on a standalone basis. We consider market conditions and entity-specific factors when estimating the selling price. Once the selling price for each unit of accounting has been established, the consideration received is allocated among the units of accounting based on their relative selling price, and the applicable revenue recognition criteria are applied to each of the separate units. The amount of arrangement consideration allocable to a delivered item that is a separate unit of accounting is limited to arrangement consideration that is fixed or determinable. Payments that are contingent upon the occurrence of future events that are not exclusively within our control are excluded from the allocable arrangement consideration until the contingency is resolved. When we have continuing performance obligations, revenue is recognized using one of two methods. Where we are able to estimate the total amount of services under a unit of accounting and such performance obligations are provided on a best-efforts basis, revenue is recognized using a proportional performance model. Costs incurred to date compared to total expected costs are used to determine proportional performance, as this is considered to be representative of the delivery of outputs. Changes in estimates of total expected costs are accounted for prospectively as a change in estimates. When we cannot reasonably estimate the total amount of service that is to be performed, but can reasonably estimate when the performance obligation ceases or becomes inconsequential, a time-based method is used to recognize revenue. Under the time-based method, revenue is recognized ratably over the estimated performance period of the unit of accounting, but not before the removal of any contingencies. If we cannot reasonably estimate when our performance obligation either ceases or becomes inconsequential and perfunctory, then revenue is not recognized until we can reasonably estimate when the performance obligation ceases or becomes inconsequential and perfunctory. Revenue is then recognized over the remaining estimated period of performance. Significant management judgment is required in determining the level of effort required and the period over which we are expected to complete our performance obligations under each unit of accounting. Substantive Milestone Payments Our collaboration agreements contain substantive milestones. A substantive milestone is defined as an event that meets the following conditions: (i) there is substantive uncertainty on the date the arrangement is entered into about whether the event will be achieved; (ii) achievement of the event is based in whole, or in part, on either our performance or a specific outcome resulting from our performance; and (iii) achievement of the event results in additional payment due to us. For a milestone to be considered substantive, the payment associated with our achievement must have all of the following characteristics: (i) relate solely to our past performance; (ii) be reasonable relative to all of the deliverables and payment terms in the arrangement; and (iii) be commensurate with either our effort required to achieve the milestone or the enhanced value of the delivered item(s) as a result of the milestone achievement. Substantive milestone payments are recognized as revenue upon achievement of the milestone only if all of the previous conditions are met and the milestone payments are nonrefundable. Determination as to whether a payment meets the aforementioned conditions involves management’s judgment. If any of the aforementioned conditions are not met, the resulting payment would not be considered a substantive milestone and, therefore, the resulting payment would be determined to be part of the allocable arrangement consideration and would be recognized as revenue as such performance obligations are performed under either the proportional performance or time-based methods, as applicable, and in accordance with the policies as described above. Deferred Revenue Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue. Cash and Cash Equivalents and Investments We consider investments in highly liquid instruments purchased with an original maturity at purchase of three months or less to be cash equivalents. The amounts are recorded at cost, which approximates fair value. Our cash equivalents consist of cash and money market funds. We have classified our entire investment portfolio, which consists of corporate debt securities, commercial paper and certificates of deposit, as available-for-sale. Available-for-sale securities are stated at fair value as of each balance sheet date based on market quotes, and unrealized gains and losses are reflected as a net amount under the caption of accumulated other comprehensive loss. Premiums or discounts arising at acquisition are amortized into earnings. We periodically evaluate whether declines in fair values of our investments below their cost are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss, as well as whether it is more likely than not that we will hold the investment until recovery of its amortized cost basis. Realized gains and losses are calculated using the specific identification method. Realized gains and losses and declines in value judged to be other-than-temporary are recorded within the statements of income under the caption other income (expense). We consider an investment with a maturity greater than twelve months from the balance sheet date as long-term and a maturity less than twelve months as short-term at the balance sheet date. Concentration of Credit Risk Our accounts receivable, as of December 31, 2015 and December 31, 2014, consist of amounts due from our collaborations with Otsuka. There was no allowance for doubtful accounts for the periods presented, as we believe all outstanding amounts will be paid based on our contractual arrangements with Otsuka and history of successful collections thereunder and collateral is not required. Revenue recognized for the years ended December 31, 2015 , 2014 , and 2013 consist of amounts derived from our collaboration agreements with Otsuka. Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation. We provide for depreciation of equipment on a straight-line basis over an estimated useful life of five years, except leasehold improvements which are amortized on a straight-line basis over the shorter of the lease term or estimated useful life of the assets. Expenditures for maintenance and repairs are expensed as incurred. Long-lived assets held for use are subject to an impairment assessment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the carrying value is no longer recoverable based upon the undiscounted future cash flows of the asset, the amount of the impairment is the difference between the carrying amount and the fair value of the asset. We have recorded no impairment charges for the periods presented. Fair Value We measure and report at fair value our cash equivalents and investment securities. 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. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. The carrying amounts reflected in the balance sheets for accounts receivable and accounts payable approximate fair value due to their short-term nature. Stock-Based Compensation Stock-based compensation cost is estimated at the grant date based on the award’s fair value and is recognized on a straight line basis as expense, less estimated forfeitures, over the requisite service period, which is generally the vesting period. The fair value of stock options under our equity-based incentive plans (the "Equity Plans") are calculated using the Black-Scholes option pricing model. This model requires us to make assumptions to determine expected risk‑free interest rates, stock price volatility, dividend yield, and weighted‑average option term. We recognize stock‑based compensation expense over the period from the date of grant to the date when the award is no longer contingent on either the employee providing additional services to the Company or the market price of the Company’s common stock reaching a certain level for a specified minimum period of time (the vesting period). Any unexercised options expire in ten years. We estimate the fair value of each grant as a single award and amortize that value on a straight‑line basis into compensation expense over the option’s vesting period. The fair value of restricted stock units and restricted stock awards is equal to the market price of Acucela's stock on the date of grant. We amortize that value on a straight line basis into compensation expense over the restricted share’s vesting period. Research and Development Costs Research and development costs include salaries paid to clinical development staff and scientists, fees paid to external service providers and to contract research organizations to conduct research and development activities. Costs may also include laboratory supplies, license fees, consulting, travel, fees paid to third parties involved in research and development activities, and an allocated portion of certain general and administrative costs. Research and development costs are currently expensed as incurred. Deferred Offering Costs External costs we incurred directly attributable to our public offering were deferred and recorded as noncurrent assets and were offset against the proceeds of our 2014 initial public offering. Income Taxes We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have already been recognized in the financial statements or tax returns. Excess tax benefits associated with stock option exercises and other equity awards are credited to shareholders' equity. Deferred tax liabilities and assets are based on the difference between financial statement carrying amounts and the tax basis of assets and liabilities, operating loss, and tax credit carryforwards and are measured using enacted tax rates expected to be in effect in the years the differences or carryforwards are anticipated to be recovered or settled. A valuation allowance is established when we believe that it is more likely than not that benefits of the deferred tax assets will not be realized.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements On May 28, 2014, the Financial Accounting Standards Board ("FASB") and the International Accounting Standards Board ("IASB") issued a converged standard on revenue recognition from contracts with customers, ASU 2014-09 (Topic 606 and IFRS 15). This standard will supersede nearly all existing revenue recognition guidance. Under the new revenue recognition model, a company will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The ASU was delayed to permit adoption one year later and is effective in the first quarter of 2017. Early adoption is not permitted. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. We are currently evaluating the impact this guidance will have on our financial condition, results of operations and cash flows. In June 2014, the FASB issued ASU No. 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period ("ASU 2014-12"). ASU 2014-12 requires that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. This update further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The amendments in this ASU are effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. We are currently evaluating the impact this guidance on our financial condition, results of operations and cash flows. In November 2015, the FASB issued ASU No. 2015-17—Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes that simplified the presentation of deferred income taxes. The amendment in this update requires that deferred tax liabilities and assets be classified as noncurrent in the balance sheet. For public business entities, the amendments are effective for financial statements issued for annual periods beginning after December 15, 2016 and interim periods within those annual periods. Other than noted above, we do not expect the adoption of recently issued accounting pronouncements to have a significant impact on our results of operations, financial position or cash flow.

Cash and Cash Equivalents and I

Cash and Cash Equivalents and Investments	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Cash and Cash Equivalents and Investments	Cash and Cash Equivalents and Investments Cash, cash equivalents and investments at December 31, 2015 and 2014 include all cash, money market funds, corporate debt securities, commercial paper and certificates of deposit. We consider our investments as available-for-sale. Available-for-sale securities are stated at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. To increase the comparability of fair value measures, the following hierarchy prioritizes the inputs to valuation methodologies used to measure fair value: Level 1—Quoted prices in active markets for identical assets and liabilities, Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities, and Level 3—Unobservable inputs in which there is little or no market data available, which requires us to develop our own assumptions. We measure the fair value of money market funds based on quoted prices in active markets for identical assets or liabilities. All other financial instruments were valued either based on recent trades of securities in inactive markets or based on quoted market prices of similar instruments and other significant inputs derived from or corroborated by observable market data. We did not hold any financial instruments categorized as Level 3 as of December 31, 2015 or 2014 . Cash and cash equivalents and investments as of December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 Amortized Cost Gross Unrealized Fair Value Holding Gains Holding Losses < 12 mos Holding Losses > 12 mos Cash $ 3,856 $ — $ — $ — $ 3,856 Level 1 Securities: Money market funds 1,232 — — — 1,232 Level 2 Securities: U.S. government agencies 10,020 — (37 ) — 9,983 Corporate debt securities 144,352 — (435 ) (96 ) 143,821 Certificates of deposit 7,640 1 (7 ) (1 ) 7,633 $ 167,100 $ 1 $ (479 ) $ (97 ) $ 166,525 December 31, 2014 Amortized Cost Gross Unrealized Fair Value Holding Gains Holding Losses < 12 mos Holding Losses > 12 mos Cash $ 767 $ — $ — $ — $ 767 Level 1 Securities: Money market funds 17,771 — — — 17,771 Level 2 Securities: Commercial paper 15,992 2 (1 ) — 15,993 Corporate debt securities 131,586 — (398 ) — 131,188 Certificates of deposit 22,115 4 (19 ) — 22,100 $ 188,231 $ 6 $ (418 ) $ — $ 187,819 As of December 31, 2015 , $1.4 million of certificates of deposit, $43.1 million of corporate debt securities and $10.0 million of U.S. government mortgage-backed securities mature in greater than one year, but less than two years. All other investment securities held at December 31, 2015 mature within 12 months. We do not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of our amortized cost basis, which may be maturity. Market values were determined for each individual security in the investment portfolio. The declines in value of certain of these investments are primarily related to changes in interest rates and are considered to be temporary in nature. We evaluate, among other things, the duration and extent to which the fair value of a security is less than its cost, the financial condition of the issuer, and our intent to sell, or whether it is more likely than not we will be required to sell the security before recovery of the amortized cost basis. We do not consider these investments to be other-than-temporarily impaired as of December 31, 2015 .

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment as of December 31, 2015 and 2014 consist of the following (in thousands): December 31, 2015 2014 Laboratory and computer equipment $ 2,981 $ 2,910 Leasehold improvements 1,423 1,812 Office furniture and equipment 366 497 4,770 5,219 Less accumulated depreciation and amortization (3,850 ) (4,477 ) Property and equipment, net $ 920 $ 742

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Common Stock Our articles of incorporation, as amended and restated, authorize us to issue 100,000,000 shares of common stock without par value. In February 2014 , upon the closing of our initial public offering ("IPO"), all shares of our outstanding convertible preferred stock automatically converted into 10,813,867 shares of common stock. We issued 9,200,000 shares of common stock for aggregate proceeds of $142.0 million from the IPO, net of underwriters’ discounts and commissions, and offering expenses. In addition, upon the closing of the IPO, $12.0 million of outstanding principal underlying convertible notes that we issued to affiliates of SBI Holdings, Inc. in May 2006 automatically converted into 3,636,365 shares of common stock, after an intermediate conversion into Series C preferred shares. The number of shares issued upon conversion was determined by dividing the principal of the note by $3.30 . Changes in Accumulated Other Comprehensive Loss (in thousands): Years Ended December 31, 2015 2014 2013 Beginning balance $ (361 ) $ (7 ) $ — Current period other comprehensive gain (loss), net of tax (214 ) (354 ) (7 ) Ending balance $ (575 ) $ (361 ) $ (7 ) The changes in accumulated other comprehensive loss relate to unrealized holding gains and losses in available-for-sale securities.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation Equity-Based Incentive Plans As of December 31, 2015, we have three equity incentive plans under which equity awards are outstanding: the 2014 Equity Incentive Plan, as amended, the 2012 Equity Incentive Plan (the "2012 Plan"), and the 2002 Stock Option and Restricted Stock Plan (the "2002 Plan"), collectively (the "Equity Plans"). We record compensation expense based on the fair value for all stock-based awards, which amounted to $8.9 million , $0.5 million , and $1.1 million for the years ended December 31, 2015, 2014, and 2013, respectively. As of December 31, 2015 , 30,425 shares of common stock were reserved to be issued in conjunction with the Equity Plans. The Equity Plans allow for the granting of various types of awards, including stock options, restricted stock units ("RSUs"), restricted stock awards and performance based awards which may be granted to employees, board members, and consultants. Incentive stock options may only be granted to employees. On December 18, 2015, the compensation committee of our Board of Directors (the “Compensation Committee”) approved granting 458,100 options to employees. The Company granted 64,500 shares to new hires and 393,600 shares to existing employees in place of a $0.6 million cash retention bonus pool. The vesting schedules for all outstanding awards as of December 31, 2015 are: Type of Award Vesting Schedule (1) Group Stock Options 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis All Stock Options 20% vested annually for five years Executives Stock Options 25% vested annually for four years Executives Restricted Awards 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis Executives RSUs 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis Executives RSUs 20% vested annually for five years Executives RSUs 25% vested annually for four years Employees (1) Former board of directors' vesting schedules range from 12 to 48 months. Stock options have a term of ten years. Any unexercised options expire at the end of the term. Amendments to Equity Incentive Plans and Share-based Awards On March 24, 2015, our Board of Directors (the "Board") approved amendments to outstanding equity awards granted under the Equity Plans to our employees, executive officers and non-employee members of our Board. The amendments provided that for employees and executive officers, if their employment is terminated without Cause or for Good Reason (as such terms are defined in the Change in Control Agreements) following a qualifying change in control of the Company, then any unvested portion of the awards held by such terminated employees and executives will become immediately vested. It was determined that the events of the Company's May 1, 2015 special shareholders meeting constituted a Qualifying Change in Control as defined in the Equity Plans. Prior to the Qualifying Change in Control event, employees, executive officers and non-employee members of our Board were permitted to exercise their awards up to three months after termination. The Qualifying Change in Control changed the allowable post-termination exercise period from three to twelve months. The resulting modification resulted in $0.1 million of additional expense and affected 27 employees and one non-employee member of our Board. The Qualifying Change in Control event on May 1, 2015 accelerated the vesting of options previously granted to our former non-employee directors as well as options and RSUs granted to our former President and Chief Executive Officer (see Note 13). Equity Awards During the year, we granted 1,509,872 of RSUs, 477,061 of restricted stock awards, and 1,500,903 of options to employees and senior executives of the Company. These awards are subject to a four -year vesting, with 25% vesting on the first year anniversary of the grant date and the remaining 75% on a monthly pro-rata basis over the ensuing three years. Option Activity The following is a summary of our stock options outstanding and exercisable under the Company's Equity Plans as of December 31, 2015 and 2014 : Year Ended December 31, 2015 Stock options: Shares Underlying Options Weighted Average Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Term (in years) Outstanding at beginning of period 375,956 $ 8.45 $ 397 Granted 1,500,903 5.76 Exercised (10,500 ) 1.60 45 Forfeited (5,104 ) 10.33 Expired (7,225 ) 10.33 Outstanding at end of period 1,854,030 6.30 2,244 4.2 Vested and expected to vest at end of period 1,783,811 6.32 2,162 4.0 Vested and exercisable at end of period 1,151,837 6.63 1,430 0.8 Year Ended December 31, 2014 Stock options: Options Weighted Average Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Term (in years) Outstanding at beginning of period 696,878 $ 7.21 Granted 101,000 7.78 Exercised (187,007 ) 3.64 Forfeited (167,699 ) 8.27 Expired (67,216 ) 8.42 Outstanding at end of period 375,956 8.45 397 6.5 Vested and exercisable at end of period 263,929 6.18 381 5.8 Supplemental Information 2015 2014 2013 Stock options: Weighted average grant date fair value per share - granted $ 3.57 $ 5.00 $ 8.09 Total intrinsic value of options exercised (in thousands) $ 45 $ 886 $ 307 Total fair value of options vested (in thousands) $ 3,768 $ 482 $ 625 The fair value of stock options granted for the years ended December 31, 2015 , 2014 , and 2013 was calculated using the Black-Scholes option-pricing model and applied the following assumptions: Years ended December 31, 2015 2014 2013 Risk-free interest rate 1.3%-1.8% 1.5%–2.5% 1.2%–2.1% Expected term 6.3 years 6.2 years 6.3 years Dividend yield —% —% —% Expected volatility 67% 70% 50% Risk-Free Interest Rate. We base the risk-free interest rate used in our option-pricing model on the implied yield currently available on U.S. Treasuries issued with an equivalent term. Where the expected term of our stock-based awards does not correspond with the term for which an interest rate is quoted, we perform a straight-line interpolation to determine the rate from the available term maturities. Expected Term. The expected term used in our option-pricing model represents the period that our stock-based awards are expected to be outstanding and is determined based on the simplified method. The simplified method uses a simple average of the vesting and original contractual terms of the option. We use the simplified method to determine the expected option term, since our stock option exercise experience does not provide a reasonable basis upon which to estimate the expected option term. Dividend Yield. We have never paid cash dividends and have no present intention to pay cash dividends in the future. Accordingly, the expected dividend used in our option-pricing model is zero . Expected Volatility. The volatility factor used in our option-pricing model is estimated using comparable public company stock volatility. RSU and Restricted Stock Award Activity The following is a summary of our RSU and restricted stock award activity under the Company's Equity Plans as of December 31, 2015 and 2014 : Years Ended December 31, 2015 2014 RSUs and restricted stock awards: Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Outstanding at beginning of period 10,000 $ 7.46 — $ — Granted 1,986,933 5.65 10,000 7.46 Vested (785,902 ) 5.73 — — Forfeited (15,100 ) 5.71 — — Outstanding at end of period 1,195,931 $ 5.61 10,000 $ 7.46 As of December 31, 2015 , there was unrecognized compensation cost related to non-vested options of $2.2 million and unrecognized compensation cost related to RSUs and restricted stock awards of $6.0 million granted under the Equity Plans, respectively. The cost is expected to be recognized over a weighted average period of 3.8 years and 3.5 years, respectively. Vesting of RSUs During the year ended December 31, 2015 , employees became vested in 427,210 shares of RSUs.

Strategic Restructuring

Strategic Restructuring	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Strategic Restructuring	Strategic Restructuring In October 2013 , we announced a plan to reduce expenses, including a workforce reduction, as a result of the termination of the Rebamipide Agreement (see Note 10). The plan resulted in a reduction in force of approximately 35% of our total workforce, or approximately 30 employees, effective January 1, 2014 . As a result of this workforce reduction, we recorded a $1.0 million charge in 2013 in general and administrative expense, related to severance, other termination benefits, and outplacement services. The cash outlays related to this charge primarily took place in the first six months of 2014 and activities were complete as of June 30, 2014. The following table summarizes the utilization of the restructuring liability (in thousands): Severance and Other Termination Benefits Balance, December 31, 2013 $ 966 Adjustments (8 ) Cash payments (958 ) Balance, December 31, 2014 $ —

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Due to our continuing losses, we had an effective tax rate of (0.2)% for the year ended December 31, 2015, which differed from the U.S. federal statutory tax rate of 34% , due to a full valuation allowance against our deferred tax assets. In the year ended December 31, 2014, our effective tax rate was 667.7% . The difference between the U.S. federal statutory rate and our effective tax rate in 2014 was due primarily to the provision of a partial valuation allowance which related to deferred tax assets for which we do not anticipate future realization and permanent differences in book and tax earnings for stock options, meals and entertainment, and other miscellaneous items. Deferred tax assets arise from temporary differences between financial and tax reporting. We established a valuation allowance because it is more likely than not that the deferred tax assets will expire before we are able to realize their benefits or the future deductibility is uncertain. Periodically, the valuation allowance is reviewed and adjusted based on management’s assessments of the realizability of deferred tax assets. During the year ended December 31, 2015, we recorded a full valuation allowance of $10.9 million against our net operating loss for a net increase of $8.6 million from the previous year. During the year ended December 31, 2014, we recorded a partial valuation allowance of $2.3 million , against our deferred tax assets. This increase in our valuation allowance was due to expected future losses as a result of our new strategic plan. Our Board approved a new strategic plan that includes commencement of development of certain proprietary preclinical programs or in-license opportunities. Because these opportunities will be developed independently, our development expenditures on these programs will initially not be funded by collaborative partners and we expect that our total research and development expenses will increase and that we will incur net losses from our operating activities. Deferred tax assets for the years ended December 31, 2015 and 2014 , are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 6,050 $ 7 Research & development tax credit carry forwards 1,029 925 Deferred rent 427 25 Property & equipment 140 224 Compensation 2,810 774 Alternative minimum tax credits 259 334 Other 7 (4 ) Unrealized losses 141 142 Total $ 10,863 $ 2,427 Less: valuation allowance (10,863 ) (2,324 ) Net deferred tax asset $ — $ 103 Reported as: Current deferred income tax asset $ — $ 61 Current deferred income tax liability (16,962 ) — Long term deferred income tax asset 16,962 42 Net deferred income tax asset $ — $ 103 At December 31, 2015 the company had federal research and development tax credit and net operating loss carryforwards of $1.0 million and $17.7 million , respectively. Use of the carryforwards is limited based on the future income of the company. The research and development tax credit carryforward will begin expiring in 2028, and the net operating loss carryforward will begin expiring in 2035. Approximately $0.3 million of the research and development tax credit carryforward relates to tax deductible stock-based compensation in excess of amounts recognized for financial statement purpose. To the extent that research and development tax credit carryforwards, if realized, relate to stock-based compensation, the resulting tax benefits will be recorded to shareholders' equity, rather than to results of operations. The components of the tax provisions are as follows (in thousands): Years Ended December 31, 2015 2014 2013 Federal: Current $ (2 ) $ (79 ) $ 575 Deferred 43 2,400 2,295 41 2,321 2,870 State: Current $ — $ 19 $ 34 Deferred 9 19 (21 ) 9 38 13 Total $ 50 $ 2,359 $ 2,883 The reconciliation of the statutory federal income tax rate to the Company's effective tax rate is as follows: Years Ended December 31, 2015 2014 2013 Federal Statutory rate 34.0 % 34.0 % 34.0 % State income taxes 0.2 6.8 — Stock compensation (0.8 ) (7.8 ) — Other permanent items (0.1 ) 5.5 — Meals and entertainment — 7.1 — Loss carryforward adjustment — — 3.7 Return to provision items — (6.0 ) — Unrealized losses — 0.6 — IPO costs — — — Other, net — (4.2 ) 2.1 Valuation allowance (33.5 ) 631.7 — Effective tax rate (0.2 )% 667.7 % 39.8 % We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. However, there are no material unrecognized tax benefits as of December 31, 2015 , 2014 , and 2013 . Furthermore, we do not anticipate any significant changes in our unrecognized tax benefits over the next 12 months. We recognize interest and penalties related to our liabilities for uncertain tax positions in income tax expense. However, during the years ended December 31, 2015 , 2014 , and 2013 , we did not have any accrued interest or penalties associated with any unrecognized tax benefits.

Collaboration and License Agree

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2015
Revenue Recognition [Abstract]
Collaboration and License Agreements	Collaboration and License Agreements Emixustat Collaboration In 2008 , we entered into a definitive agreement with Otsuka to co-develop and commercialize Emixustat, our compound, for the dry form of AMD and for other potential indications in the United States, Canada, and Mexico (“Shared Territory”). Under the agreement, we retained all rights in Europe, South America, Central America, the Caribbean, and Africa (“Acucela Territory”), and Otsuka acquired the exclusive development and commercialization rights to the compound in Asia, the Middle East, and selected markets in the rest of the world (“Otsuka Territory”). Otsuka paid us a $5.0 million nonrefundable up-front license fee upon its entry into the agreement. Under the agreement, Otsuka agreed to fund all development activities in the Shared Territory through Phase 2, up to $40.0 million . If the Phase 2 development costs exceed $40.0 million , Otsuka could have, at its sole discretion, either (i) terminated the agreement or (ii) continued the agreement and share equally with us all Phase 2 development costs in excess of $40.0 million . In 2012, the cost of development activities exceeded $40.0 million and Otsuka agreed to continue the agreement and equally share development costs with us. Phase 3 costs are to be shared equally by Otsuka and us under the agreement. In addition, under the agreement, we have the potential to receive development milestones totaling $82.5 million . The co-development portion of the agreement is governed by a Joint Development Committee (“JDC”). We may earn development milestones as follows: i. Initial Indication— $55.0 million a. $5.0 million upon initiation of a Phase 2b/3 clinical trial in the United States (received in the year ending December 31, 2013) b. $5.0 million upon initiation of a Phase 3 clinical trial in the United States, or the filing of a New Drug Application (“NDA”) with the FDA in the United States, if a second Phase 3 clinical trial is not needed c. $15.0 million upon filing of a NDA with the FDA in the United States d. $20.0 million upon receipt of approval by the FDA of an NDA in the United States e. $10.0 million upon receipt of approval by the regulatory authority of a marketing approval application in Japan ii. Second Indication— $27.5 million a. $5.0 million upon initiation of a Phase 3 clinical trial in the United States b. $7.5 million upon filing of an NDA with the FDA in the United States c. $10.0 million upon receipt of approval by the FDA of an NDA in the United States d. $5.0 million upon receipt of approval by the regulatory authority of a marketing approval application in Japan Under the agreement, Otsuka will fund our share of the Phase 2 and Phase 3 development costs in the form of a secured promissory note. The promissory note provides that (a) interest will accrue daily and be calculated on the basis of 360 days per year and be payable on all amounts advanced to us from the date of advance until paid in full; (b) unpaid interest will compound annually; and (c) the applicable interest rate will be adjusted quarterly to reflect the then-effective rate equal to the three-month London InterBank Offered Rate (“LIBOR”) in the “Money Rates” column of The Wall Street Journal as of the first business day of each calendar quarter, plus 3% ; and (d) all amounts are payable in U.S. dollars. The agreement includes a security interest agreement that grants Otsuka a first priority interest on our interests in net profits and royalty payments, and on our interests in ownership of the related collaboration compounds and collaboration products and the underlying intellectual property rights, both in the Shared Territory and the Acucela Territory. The loan is repayable only in the event that proceeds are generated by any future product sales under the collaboration agreement or by the sale or license of collaboration compounds and collaboration products developed under the agreement outside North America and Otsuka’s sole territory. As the agreement contains elements of funded development, we evaluated the agreement to determine if our obligation to Otsuka under the secured promissory note should be accounted for as a liability to repay a loan or as an obligation to perform contractual services. To conclude that a liability to repay a loan does not exist, the transfer of the financial risk involved with research and development from us to Otsuka must be substantive and genuine. We have determined that our obligation to Otsuka should be accounted for as an obligation to perform contractual services because repayment depends solely on the results of development having future economic benefit. Consequently, amounts received from Otsuka for our share of development costs under the agreement are recognized as revenue. For the years ended December 31, 2015 , 2014 , and 2013 , we have recognized cumulative revenue of approximately $61.5 million , $49.7 million , and $32.4 million respectively, which is contingently repayable as described above. As of December 31, 2015 and 2014 , the contingently repayable funding has accrued $4.6 million and $2.5 million of interest, respectively, which is contingently repayable along with the above. Upon commercialization, we may exercise our option to co-promote in the Shared Territory on a country-by-country basis. In markets where we opt to co-promote the product, Otsuka and we equally share all expenses and profits from sales of the product in the Shared Territory. If we do not elect to co-promote in a country or countries in the Shared Territory, Otsuka shall pay us royalties on the annual aggregate net sales of collaboration products in the country or countries in the Shared Territory for which we did not elect to participate in co-promotion. Each party shall pay the other party a royalty of 2% on annual aggregate net sales of collaboration products in their sole territories. In addition, we have the potential to receive net sales milestones totaling $175.0 million . The co-promotion arrangement is governed by a Joint Commercialization Committee (“JCC”). The milestones are as follows: i. All Indications a. $25.0 million upon reaching $250.0 million in aggregate annual worldwide sales of all collaboration products b. $50.0 million upon reaching $500.0 million in aggregate annual worldwide sales of all collaboration products c. $100.0 million upon reaching $1.0 billion in aggregate annual worldwide sales of all collaboration products The agreement also includes a three-year research program (the “Research Program”), the purpose of which was to identify a second indication for the lead collaborative compound and to conduct development on a backup compound for the collaborative compound. During the three years of the Research Program, which ended in 2011, Otsuka paid us $5.0 million per year, payable on a quarterly basis. The agreement also provides Otsuka with a right of first negotiation to license new compounds discovered or developed by us (independent of the collaboration activities) during the agreement term. Our agreement with Otsuka is a multiple element arrangement, and we have determined that the elements within the arrangement consist of the license, the Research Program, and research and development services. The license granted to Otsuka was determined to be a separate unit of accounting because it has value to Otsuka on a standalone basis. Because Otsuka may license and develop the intellectual property independent of the development or research program services that are to be provided by us, we conducted a net present value valuation of the license, and it was determined that the estimated standalone selling price for the license at inception of the agreement exceeded the arrangement consideration received for the license fee. Since the value assigned to a delivered element cannot exceed the arrangement consideration, the arrangement consideration of $5.0 million due and paid upon execution of the agreement was assigned to the license. We have determined that the activities associated with development meet the criterion for a separate unit of accounting, since these services have value to Otsuka on a standalone basis. BESP is based on the Company’s analysis of the value of the services provided and consideration of the fees charged by third party vendors for similar development services and represent our BESP. Revenue from development efforts is recognized as services are performed. In the years ended December 31, 2015 , 2014 , and 2013 , we recognized $24.1 million , $35.4 million and $39.2 million , respectively, of revenue associated with development activities. We have determined that the activities associated with the Research Program meet the criterion for a separate unit of accounting, since these services have value to Otsuka on a standalone basis. The types of services contemplated under the Research Program may be performed by a third party. We have determined that the fees charged for the research services are competitive with the price other third-party vendors charge for similar research services. Our BESP of the selling price for the Research Program was $15.0 million , which equals the agreement consideration. Revenue from the research activities was recognized under a proportional performance model. We evaluated the development and net sales milestones in the arrangement and determined that they each meet the criteria of a milestone under ASC 605-28, Revenue Recognition-Milestone Method . We recognize consideration that is contingent upon achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. During the year ended December 31, 2013, we received and recognized as revenue the $5.0 million milestone payment associated with the initiation of the Phase 2b/3 clinical trial. No development or net sales milestones were achieved during the years ended December 31, 2015 or 2014. In the fourth quarter of 2015 , we were in negotiations with Otsuka regarding the amount of indirect cost applicable in 2015 . This negotiation resulted in a settlement of approximately $2.6 million , which was issued as a credit to Otsuka for development expenses that had been recognized as revenue in 2015 and has been recorded as a reduction to revenue for the year ended December 31, 2015 . OPA-6566 Collaboration In 2010, Otsuka and we entered into a definitive agreement to develop OPA-6566, Otsuka’s proprietary compound for the treatment of glaucoma. The agreement grants us an opt-in right to co-develop and co-promote OPA-6566 in the United States. Until we exercise our opt-in right, Otsuka will have responsibility for directing development activities and costs. Upon our exercise of the opt-in right, Otsuka will grant us additional opt-in rights, which include: (1) the right to co-develop and co-promote OPA-6566 for ophthalmological indications in the United States other than for glaucoma; (2) the right to co-develop and co-promote new formulations of OPA-6566 for glaucoma in the United States; and (3) a right of first negotiation to co-develop and co-promote other adenosine A2a receptor agonist compounds for the treatment of ophthalmologic diseases in the United States. We evaluated the agreement and determined that the development activities under the agreement represented the only deliverable under the arrangement. Revenue from development activities is recognized as services are performed. During the years ended December 31, 2015 , 2014 , and 2013 , we recognized $0 , $0 , and $1.5 million respectively, of revenues in performance of the agreement. Rebamipide Collaboration In 2008, Otsuka and we entered into a definitive agreement to co-develop rebamipide, Otsuka’s proprietary compound for the treatment of dry eye. Under the agreement, the parties agreed to collaborate in the clinical development efforts for rebamipide in the United States. Otsuka paid us a $2.0 million up-front payment and, under the agreement, we had the potential to receive clinical development milestones and royalties on net sales of the product in the United States and the European Union. Under the agreement, Otsuka was responsible for all clinical development and commercialization expenses. We evaluated the agreement and determined that the clinical development activities represented the only deliverable under the arrangement. Revenue from clinical development efforts is recognized as services are performed. During the years ended December 31, 2015 , 2014 , and 2013 we recognized $0 , $0 , and $12.3 million , respectively, of revenue associated with the rebamipide clinical development activities. We evaluated the development milestones under the agreement and determined that they each meet the criteria of a substantive milestone. We recognize consideration that is contingent upon achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. No development milestones were achieved during the year ended December 31, 2015. In 2012, we received and recognized as revenue the $5.0 million milestone payment associated with the initiation of the Phase 3 clinical trial. In September 2013, Otsuka elected to end its rebamipide co-development agreement with us. As a result, we recognized as revenue, in the year ended December 31, 2013, $2.0 million upfront payment from Otsuka that had been deferred due to refund provisions. These refund provisions expired with the end of the co-development agreement.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share Net income (loss) per share attributable to common shareholders is presented in conformity with the two-class method required for participating securities for periods in which we have net income. Prior to the IPO, all series of convertible preferred stock were considered to be participating securities, as the holders were entitled to participate in any dividends prior and in preference to dividends declared or paid on the common stock. Undistributed earnings allocated to these participating securities were subtracted from net income in determining net income attributable to common shareholders. Immediately prior to the closing of our IPO, all outstanding shares of preferred stock were converted to common stock. We issued 9,200,000 shares of common stock in the IPO. In addition, 3,636,365 shares of common stock were issued upon the conversion of the contingently convertible debt held by a related party. As a result, as of December 31, 2015 , common stock is our only outstanding class of capital stock. Basic net income (loss) per share is calculated by dividing net income by the weighted average number of shares outstanding for the period. Diluted net income (loss) per share is calculated by dividing net income (loss) by the weighted average number of shares of the common stock outstanding and other dilutive securities outstanding during the period. The potential dilutive shares of our common stock include the exercise of outstanding stock options that are dilutive and the vesting RSUs and restricted stock awards. The following tables reconcile the numerator and denominator used to calculate diluted net income per share for the periods presented (in thousands): Years Ended December 31, 2015 2014 2013 Numerator: Net income (loss) attributable to common shareholders $ (25,509 ) $ (2,006 ) $ 1,161 Denominator: Weighted-average shares outstanding—basic (shares) 35,972 32,869 11,964 Dilutive effect of stock options, RSUs and restricted stock awards — — 391 Weighted average shares outstanding—diluted (shares) 35,972 32,869 12,355 For the years ended December 31, 2015 and 2014 , equity awards of 96,683 and 185,551 were excluded from the calculation of diluted net income (loss) per share because the impact was anti-dilutive.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	Retirement Plans We provide a 401(k) retirement savings plan (the “401(k) Plan”) to all employees. The 401(k) Plan allows participants to defer eligible compensation on a pre-tax and post-tax basis subject to certain Internal Revenue Code maximum amounts. Beginning in 2015, the Company began matching 50% of the employee’s contribution to the 401(k) Plan up to 6% of their total compensation, not exceed a ceiling of 3% of an employee's total compensation. Employees are always 100.0% vested in their own contributions and vest in our contributions at the end of each year. In January 2015, the Board also authorized a non-elective discretionary employer contribution of $0.4 million to be allocated to participant accounts which vests over a four -year period based on employee hire dates. Such amounts are included in general and administrative and research and development expenses in the accompanying consolidated statements of operations.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases We lease laboratory and corporate office space under operating leases. On June 26, 2014, we entered into an agreement for the lease of approximately 38,723 square feet of office space in our headquarters building in Seattle, Washington. The term of the lease commenced on January 1, 2015 and, subject to the terms of the lease, will expire on November 30, 2021. We received a tenant leasehold improvement allowance of $1.2 million in connection with the commencement of this lease in 2015. On September 19, 2014, we entered into an amendment of our lease agreement for the lease of approximately 17,488 square feet of laboratory and office space in Bothell, Washington. The amendment extended the expiration date of the original lease from February 28, 2015 to February 28, 2017 and reduced the basic annual rent to approximately $0.4 million , subject to adjustment pursuant to the terms of the lease. Lease incentives are recognized as deferred rent liabilities and amortized to rent expense over the term of the lease. Minimum rent payments under operating leases are recognized on a straight-line basis over the term of the lease, including any periods of free rent and reduced rent. Future minimum lease payments under operating leases (with initial or remaining lease terms in excess of one year) as of December 31, 2015 are as follows (in thousands): Payments Due by Period 2016 2017 2018 2019 2020 Thereafter Total Operating lease obligations 1,328 997 968 1,007 1,046 994 6,340 Total 1,328 997 968 1,007 1,046 994 6,340 Rent expense was $2.0 million , $1.0 million , and $1.0 million , respectively, in the years ended December 31, 2015 , 2014 , and 2013 . Severance and Change in Effective Control Agreements On March 24, 2015, our Board of Directors approved the terms of the Severance and Change in Effective Control Agreements entered into with each member of our then current management team and certain other employees (the "Change in Control Agreements"). The Change in Control Agreements provide that if the employee terminates for any reason or for no reason (including disability), voluntarily resigns for good reason (as defined in the agreement), or the employee dies, and the termination occurs within the six month period following a Qualifying Change in Effective Control (as defined in the Change in Control Agreements), the employee will be entitled to an amount equal to the sum of six months of his or her monthly base salary, plus 50% of the employee’s annual target bonus for 2015, plus the premiums required to continue the employee’s group health care coverage for a period of six months following termination, which will be “grossed up” to cover taxes. The Change in Control Agreements terminated upon the earlier of November 1, 2015 or the employee’s termination date (unless the termination is within six months following a Qualifying Change in Effective Control). On May 1, 2015, as a result of the actions taken by our shareholders at a special meeting of shareholders, a Qualifying Change in Effective Control was deemed to have taken place under the terms of the Change in Control Agreements. As of December 31, 2015 , payments totaling $1.9 million have been made under this plan and payments totaling an additional $0.4 million were accrued. Litigation From time to time, we may be subject to legal proceedings and claims in the ordinary course of business. We are not currently a party to any material legal proceedings, and to our knowledge none is threatened. There can be no assurance that future legal proceedings arising in the ordinary course of business or otherwise will not have a material adverse effect on our financial position, results of operations or cash flows.

Former CEO and COO Severance

Former CEO and COO Severance	12 Months Ended
	Dec. 31, 2015
Former CEO Severance [Abstract]
Former CEO and COO Severance	Former CEO and COO Severance Under Mr. O'Callaghan's employment agreement, dated October 14, 2014, as amended, the termination of Mr. O’Callaghan’s employment without Cause or for Good Reason (as such terms were defined in his employment agreement), entitled him to receive 18 months of salary, up to 18 months of the premiums for health benefit coverage provided under our COBRA program, and a pro-rated portion of his annual bonus (“the CEO severance amounts”). Mr. O'Callaghan resigned his position as our President and Chief Executive Officer, effective on May 3, 2015. The CEO severance amounts, totaling approximately $0.9 million in cash, were paid on May 11, 2015. In addition, pursuant to the terms of the 2014 Equity Incentive Plan, as amended, the vesting of his 712,480 options and 356,410 RSUs was accelerated such that all of his equity awards were fully vested as of May 3, 2015. In April 2015, Mr. O'Callaghan's 712,480 options were modified to extend the post-termination exercise period from three months to twelve months. The Company recognized stock-based compensation expense of $2.7 million related to the accelerated vesting of his options in connection with his termination. In addition, pursuant to the terms of the 2014 Equity Incentive Plan, as amended, the vesting of his 356,410 RSUs was accelerated such that these equity awards were fully vested as of May 3, 2015. We recognized general and administrative expense of approximately $2.1 million related to these RSUs during the twelve months ended December 31, 2015. Under Mr. Tarr's employment agreement, dated May 1, 2015, the termination of Mr. Tarr's employment without Cause or for Good reason, entitled him to receive 9 months of salary and 9 months of health benefit coverage under our COBRA program. Mr. Tarr resigned his position as our Chief Operating Officer, effective November 18, 2015. The COO severance amounts, totaling $0.3 million in cash, will be paid through August 2016. In addition, pursuant to the terms of the 2014 Equity Incentive Plan, as amended, the vesting of his 358,692 restricted stock was accelerated such that all of his equity awards were fully vested as of November 18, 2015. The Company recognized stock-based compensation expense of $1.8 million related to the accelerated vesting of his restricted stock in connection with his termination which was recorded to general and administrative expense.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions Peter Kresel, M.B.A., a former member of the Board, received payments from us for consulting services and reimbursement of direct expenses. This consulting relationship terminated in January 2014. Mr. Kresel’s payments for consulting services and expense reimbursements were $0 , $0 , and $0.3 million during 2015 , 2014 , and 2013 respectively. SBI Holdings, Inc. (a related party), one of our shareholders, was the holder for our contingently convertible debt. In connection with our IPO, the contingently convertible debt automatically converted into 3,636,365 shares of common stock. The number of shares issued upon conversion was determined by dividing the principal of the note by $3.30 , which was subject to adjustment for any subsequent recapitalizations, stock combinations, stock dividends, or stock splits. On December 22, 2015, the Company filed an S-3 Registration Statement for the resale of up to 7,752,425 shares of our common stock that may be offered and sold from time to time by SBI Holdings, Inc. The shares of common stock were initially issued in private sales not registered under the Securities Act. We will not receive any of the proceeds from the sale of the shares of our common stock being sold. Dr. Kubota and SBI Holdings, Inc., our two largest shareholders, incurred certain fees and expenses totaling approximately $0.8 million in preparation for the May 1, 2015 Special Shareholders' meeting. Our Board appointed a special committee (the "Special Committee") consisting entirely of independent directors to evaluate these expenses to determine if the expenses, or a portion thereof, should be reimbursed by the Company. The Special Committee met on June 8, 2015 and concluded that the reimbursement of these expenses was appropriate.

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Information (Unaudited)	Quarterly Information (Unaudited) The following tables set forth our unaudited quarterly statement of operations data for each of the last eight quarters in the period ended December 31, 2015 . The unaudited quarterly statement of operations data below have been prepared on the same basis as the audited financial statements included elsewhere in this Form 10-K and reflect all necessary adjustments, consisting only of normal recurring adjustments, that we believe are necessary for a fair statement of this information. The results of historical quarters are not necessarily indicative of the results of operations for a full year or any future period: (unaudited) (In thousands, except per share amounts) March 31 June 30 September 30 December 31 2015 Revenue from collaborations $ 7,215 $ 7,181 $ 7,128 $ 2,543 (1) Net income (loss) (3,940 ) (9,738 ) (3,550 ) (8,281 ) Basic net income (loss) per share $ (0.11 ) $ (0.27 ) $ (0.10 ) $ (0.23 ) Diluted net income (loss) per share $ (0.11 ) $ (0.27 ) $ (0.10 ) $ (0.23 ) March 31 June 30 September 30 December 31 2014 Revenue from collaborations $ 10,546 $ 9,086 $ 8,119 $ 7,645 Net income (loss) 54 71 (1,536 ) (2) (595 ) Basic net income (loss) per share $ — $ — $ (0.04 ) $ (0.02 ) Diluted net income (loss) per share $ — $ — $ (0.04 ) $ (0.02 ) (1) In the fourth quarter of 2015, we were in negotiations with Otsuka regarding the amount of indirect cost applicable in 2015. This negotiation resulted in a settlement of approximately $2.6 million , which was issued as a credit to Otsuka for development expenses that had been recognized as revenue in 2015and has been recorded as a reduction to revenue for the year ended December 31, 2015. (2) In the third quarter of 2014, we recorded a valuation allowance against our deferred tax assets of $1.6 million due to expected future losses as a result of our new strategic plan.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 6, 2016, an additional 1,460,684 shares were reserved for issuance under the Evergreen provision of the 2014 Equity Incentive Plan, as amended. On January 21, 2016, the Board approved the grant of 900,000 options, including 780,000 options to Dr. Kubota, our CEO, and 30,000 options to each of the four non-employee directors of the Board. The grant of options to Dr. Kubota included 390,000 options that will vest over a three -year period, with 33% vesting after one year and 67% vesting monthly thereafter. Dr. Kubota's remaining 390,000 options are performance based awards which will vest incrementally based on the closing market price of the Company's shares of common stock on the Tokyo Stock Exchange which 33% will vest upon the stock price of ¥1,102 trading for thirty consecutive calendar days, 33% will vest upon the stock price of ¥1,470 trading for thirty consecutive calendar days, and the remaining will vest upon the stock price of ¥1,837 trading for thirty consecutive calendar days. The board member option grants vest in equal monthly installments over four years from the vesting commencement date of May 1, 2015 when they were elected Board of Directors of the Company.

Significant Accounting Polici26

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Acucela Japan KK, which was organized under the laws of Japan on December 11, 2015. Through December 31, 2015, Acucela Japan KK has not commenced operations. We eliminate all intercompany balances and transactions in consolidation.
Presentation of the cash flow	Prior year presentation of cash flows includes a re-classification to conform with the current year presentation of purchased interest on marketable securities.
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. Actual results could differ from these estimates.
Segments	We operate in one segment, pharmaceutical product development. All of our significant assets are located in the United States. During the years ended December 31, 2015 , 2014 , and 2013 , all revenue was generated in the United States.
Revenue Recognition	Our business strategy includes entering into collaboration agreements with pharmaceutical companies for the development and commercialization of our product candidates. The terms of the agreements may include nonrefundable license fees, funding of research and development activities, payments based upon achievement of development milestones, payments based upon achievement of revenue milestones, or royalties on product sales. We recognize revenue when four basic criteria have been met: (a) persuasive evidence of an arrangement exists; (b) delivery has occurred or services rendered; (c) the fee is fixed or determinable; and (d) collectability is reasonably assured.
Revenue Recognition, Multiple Element Arrangements	Our collaboration agreements are multiple element arrangements that must be analyzed to identify the deliverables included in the agreements and to determine if the deliverables qualify as separate units of accounting. Deliverables are considered a separate unit of accounting when all of the following criteria are met: (i) the delivered item has value to the customer on a standalone basis and (ii) if the arrangement includes a general right of return relative to the delivered item, and the delivery or performance of the undelivered item is considered probable and substantially within our control. There are no rights of return in our collaboration agreements. Arrangement consideration is allocated to the separate units of accounting based on their relative selling prices. We follow a hierarchy to determine the selling price for each unit of accounting, determining first if there is vendor-specific objective evidence (“VSOE”) of fair value (the price at which the goods or services are regularly sold by us on a standalone basis). If VSOE of fair value is not available, third-party evidence (“TPE”) of vendors selling similar goods or services to similarly situated customers on a standalone basis is used to establish fair value. If neither VSOE nor TPE of fair value exists, we use our best estimate of the selling price (“BESP”) for that unit of accounting. Our BESP represents the price at which we would transact if we regularly sold the unit of accounting on a standalone basis. We consider market conditions and entity-specific factors when estimating the selling price. Once the selling price for each unit of accounting has been established, the consideration received is allocated among the units of accounting based on their relative selling price, and the applicable revenue recognition criteria are applied to each of the separate units. The amount of arrangement consideration allocable to a delivered item that is a separate unit of accounting is limited to arrangement consideration that is fixed or determinable. Payments that are contingent upon the occurrence of future events that are not exclusively within our control are excluded from the allocable arrangement consideration until the contingency is resolved. When we have continuing performance obligations, revenue is recognized using one of two methods. Where we are able to estimate the total amount of services under a unit of accounting and such performance obligations are provided on a best-efforts basis, revenue is recognized using a proportional performance model. Costs incurred to date compared to total expected costs are used to determine proportional performance, as this is considered to be representative of the delivery of outputs. Changes in estimates of total expected costs are accounted for prospectively as a change in estimates. When we cannot reasonably estimate the total amount of service that is to be performed, but can reasonably estimate when the performance obligation ceases or becomes inconsequential, a time-based method is used to recognize revenue. Under the time-based method, revenue is recognized ratably over the estimated performance period of the unit of accounting, but not before the removal of any contingencies. If we cannot reasonably estimate when our performance obligation either ceases or becomes inconsequential and perfunctory, then revenue is not recognized until we can reasonably estimate when the performance obligation ceases or becomes inconsequential and perfunctory. Revenue is then recognized over the remaining estimated period of performance. Significant management judgment is required in determining the level of effort required and the period over which we are expected to complete our performance obligations under each unit of accounting.
Revenue Recognition, Substantive Milestone Payments	Our collaboration agreements contain substantive milestones. A substantive milestone is defined as an event that meets the following conditions: (i) there is substantive uncertainty on the date the arrangement is entered into about whether the event will be achieved; (ii) achievement of the event is based in whole, or in part, on either our performance or a specific outcome resulting from our performance; and (iii) achievement of the event results in additional payment due to us. For a milestone to be considered substantive, the payment associated with our achievement must have all of the following characteristics: (i) relate solely to our past performance; (ii) be reasonable relative to all of the deliverables and payment terms in the arrangement; and (iii) be commensurate with either our effort required to achieve the milestone or the enhanced value of the delivered item(s) as a result of the milestone achievement. Substantive milestone payments are recognized as revenue upon achievement of the milestone only if all of the previous conditions are met and the milestone payments are nonrefundable. Determination as to whether a payment meets the aforementioned conditions involves management’s judgment. If any of the aforementioned conditions are not met, the resulting payment would not be considered a substantive milestone and, therefore, the resulting payment would be determined to be part of the allocable arrangement consideration and would be recognized as revenue as such performance obligations are performed under either the proportional performance or time-based methods, as applicable, and in accordance with the policies as described above.
Revenue Recognition, Deferred Revenue	Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue.
Cash and Cash Equivalents	We consider investments in highly liquid instruments purchased with an original maturity at purchase of three months or less to be cash equivalents. The amounts are recorded at cost, which approximates fair value. Our cash equivalents consist of cash and money market funds.
Investments	We have classified our entire investment portfolio, which consists of corporate debt securities, commercial paper and certificates of deposit, as available-for-sale. Available-for-sale securities are stated at fair value as of each balance sheet date based on market quotes, and unrealized gains and losses are reflected as a net amount under the caption of accumulated other comprehensive loss. Premiums or discounts arising at acquisition are amortized into earnings. We periodically evaluate whether declines in fair values of our investments below their cost are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss, as well as whether it is more likely than not that we will hold the investment until recovery of its amortized cost basis. Realized gains and losses are calculated using the specific identification method. Realized gains and losses and declines in value judged to be other-than-temporary are recorded within the statements of income under the caption other income (expense). We consider an investment with a maturity greater than twelve months from the balance sheet date as long-term and a maturity less than twelve months as short-term at the balance sheet date.
Concentration of Credit Risk	Our accounts receivable, as of December 31, 2015 and December 31, 2014, consist of amounts due from our collaborations with Otsuka. There was no allowance for doubtful accounts for the periods presented, as we believe all outstanding amounts will be paid based on our contractual arrangements with Otsuka and history of successful collections thereunder and collateral is not required. Revenue recognized for the years ended December 31, 2015 , 2014 , and 2013 consist of amounts derived from our collaboration agreements with Otsuka.
Property and Equipment	Property and equipment are recorded at cost, less accumulated depreciation. We provide for depreciation of equipment on a straight-line basis over an estimated useful life of five years, except leasehold improvements which are amortized on a straight-line basis over the shorter of the lease term or estimated useful life of the assets. Expenditures for maintenance and repairs are expensed as incurred. Long-lived assets held for use are subject to an impairment assessment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the carrying value is no longer recoverable based upon the undiscounted future cash flows of the asset, the amount of the impairment is the difference between the carrying amount and the fair value of the asset. We have recorded no impairment charges for the periods presented.
Fair Value	We measure and report at fair value our cash equivalents and investment securities. 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. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. The carrying amounts reflected in the balance sheets for accounts receivable and accounts payable approximate fair value due to their short-term nature.
Share-Based Compensation	Stock-based compensation cost is estimated at the grant date based on the award’s fair value and is recognized on a straight line basis as expense, less estimated forfeitures, over the requisite service period, which is generally the vesting period. The fair value of stock options under our equity-based incentive plans (the "Equity Plans") are calculated using the Black-Scholes option pricing model. This model requires us to make assumptions to determine expected risk‑free interest rates, stock price volatility, dividend yield, and weighted‑average option term. We recognize stock‑based compensation expense over the period from the date of grant to the date when the award is no longer contingent on either the employee providing additional services to the Company or the market price of the Company’s common stock reaching a certain level for a specified minimum period of time (the vesting period). Any unexercised options expire in ten years. We estimate the fair value of each grant as a single award and amortize that value on a straight‑line basis into compensation expense over the option’s vesting period. The fair value of restricted stock units and restricted stock awards is equal to the market price of Acucela's stock on the date of grant. We amortize that value on a straight line basis into compensation expense over the restricted share’s vesting period.
Research and Development Cost	Research and development costs include salaries paid to clinical development staff and scientists, fees paid to external service providers and to contract research organizations to conduct research and development activities. Costs may also include laboratory supplies, license fees, consulting, travel, fees paid to third parties involved in research and development activities, and an allocated portion of certain general and administrative costs. Research and development costs are currently expensed as incurred.
Deferred Offering Costs	External costs we incurred directly attributable to our public offering were deferred and recorded as noncurrent assets and were offset against the proceeds of our 2014 initial public offering.
Income Taxes	We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have already been recognized in the financial statements or tax returns. Excess tax benefits associated with stock option exercises and other equity awards are credited to shareholders' equity. Deferred tax liabilities and assets are based on the difference between financial statement carrying amounts and the tax basis of assets and liabilities, operating loss, and tax credit carryforwards and are measured using enacted tax rates expected to be in effect in the years the differences or carryforwards are anticipated to be recovered or settled. A valuation allowance is established when we believe that it is more likely than not that benefits of the deferred tax assets will not be realized.
Recent Accounting Pronouncements	On May 28, 2014, the Financial Accounting Standards Board ("FASB") and the International Accounting Standards Board ("IASB") issued a converged standard on revenue recognition from contracts with customers, ASU 2014-09 (Topic 606 and IFRS 15). This standard will supersede nearly all existing revenue recognition guidance. Under the new revenue recognition model, a company will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The ASU was delayed to permit adoption one year later and is effective in the first quarter of 2017. Early adoption is not permitted. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. We are currently evaluating the impact this guidance will have on our financial condition, results of operations and cash flows. In June 2014, the FASB issued ASU No. 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period ("ASU 2014-12"). ASU 2014-12 requires that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. This update further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The amendments in this ASU are effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. We are currently evaluating the impact this guidance on our financial condition, results of operations and cash flows. In November 2015, the FASB issued ASU No. 2015-17—Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes that simplified the presentation of deferred income taxes. The amendment in this update requires that deferred tax liabilities and assets be classified as noncurrent in the balance sheet. For public business entities, the amendments are effective for financial statements issued for annual periods beginning after December 15, 2016 and interim periods within those annual periods. Other than noted above, we do not expect the adoption of recently issued accounting pronouncements to have a significant impact on our results of operations, financial position or cash flow.

Cash and Cash Equivalents and27

Cash and Cash Equivalents and Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Cash and Cash Equivalents and Investments	Cash and cash equivalents and investments as of December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 Amortized Cost Gross Unrealized Fair Value Holding Gains Holding Losses < 12 mos Holding Losses > 12 mos Cash $ 3,856 $ — $ — $ — $ 3,856 Level 1 Securities: Money market funds 1,232 — — — 1,232 Level 2 Securities: U.S. government agencies 10,020 — (37 ) — 9,983 Corporate debt securities 144,352 — (435 ) (96 ) 143,821 Certificates of deposit 7,640 1 (7 ) (1 ) 7,633 $ 167,100 $ 1 $ (479 ) $ (97 ) $ 166,525 December 31, 2014 Amortized Cost Gross Unrealized Fair Value Holding Gains Holding Losses < 12 mos Holding Losses > 12 mos Cash $ 767 $ — $ — $ — $ 767 Level 1 Securities: Money market funds 17,771 — — — 17,771 Level 2 Securities: Commercial paper 15,992 2 (1 ) — 15,993 Corporate debt securities 131,586 — (398 ) — 131,188 Certificates of deposit 22,115 4 (19 ) — 22,100 $ 188,231 $ 6 $ (418 ) $ — $ 187,819

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment as of December 31, 2015 and 2014 consist of the following (in thousands): December 31, 2015 2014 Laboratory and computer equipment $ 2,981 $ 2,910 Leasehold improvements 1,423 1,812 Office furniture and equipment 366 497 4,770 5,219 Less accumulated depreciation and amortization (3,850 ) (4,477 ) Property and equipment, net $ 920 $ 742

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Changes in Accumulated Other Comprehensive Loss	Changes in Accumulated Other Comprehensive Loss (in thousands): Years Ended December 31, 2015 2014 2013 Beginning balance $ (361 ) $ (7 ) $ — Current period other comprehensive gain (loss), net of tax (214 ) (354 ) (7 ) Ending balance $ (575 ) $ (361 ) $ (7 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Award Vesting Period	The vesting schedules for all outstanding awards as of December 31, 2015 are: Type of Award Vesting Schedule (1) Group Stock Options 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis All Stock Options 20% vested annually for five years Executives Stock Options 25% vested annually for four years Executives Restricted Awards 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis Executives RSUs 25% after the first year and the remaining 75% of award vesting on a monthly pro rata basis Executives RSUs 20% vested annually for five years Executives RSUs 25% vested annually for four years Employees
Schedule of Share-based Compensation, Stock Options, Activity	The following is a summary of our stock options outstanding and exercisable under the Company's Equity Plans as of December 31, 2015 and 2014 : Year Ended December 31, 2015 Stock options: Shares Underlying Options Weighted Average Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Term (in years) Outstanding at beginning of period 375,956 $ 8.45 $ 397 Granted 1,500,903 5.76 Exercised (10,500 ) 1.60 45 Forfeited (5,104 ) 10.33 Expired (7,225 ) 10.33 Outstanding at end of period 1,854,030 6.30 2,244 4.2 Vested and expected to vest at end of period 1,783,811 6.32 2,162 4.0 Vested and exercisable at end of period 1,151,837 6.63 1,430 0.8 Year Ended December 31, 2014 Stock options: Options Weighted Average Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Term (in years) Outstanding at beginning of period 696,878 $ 7.21 Granted 101,000 7.78 Exercised (187,007 ) 3.64 Forfeited (167,699 ) 8.27 Expired (67,216 ) 8.42 Outstanding at end of period 375,956 8.45 397 6.5 Vested and exercisable at end of period 263,929 6.18 381 5.8
Schedule of Share-based Compensation, Supplemental Information	Supplemental Information 2015 2014 2013 Stock options: Weighted average grant date fair value per share - granted $ 3.57 $ 5.00 $ 8.09 Total intrinsic value of options exercised (in thousands) $ 45 $ 886 $ 307 Total fair value of options vested (in thousands) $ 3,768 $ 482 $ 625
Schedule of Fair Value of Stock Options Granted	The fair value of stock options granted for the years ended December 31, 2015 , 2014 , and 2013 was calculated using the Black-Scholes option-pricing model and applied the following assumptions: Years ended December 31, 2015 2014 2013 Risk-free interest rate 1.3%-1.8% 1.5%–2.5% 1.2%–2.1% Expected term 6.3 years 6.2 years 6.3 years Dividend yield —% —% —% Expected volatility 67% 70% 50%
Schedule of Restricted Stock and Restricted Stock Units Activity	The following is a summary of our RSU and restricted stock award activity under the Company's Equity Plans as of December 31, 2015 and 2014 : Years Ended December 31, 2015 2014 RSUs and restricted stock awards: Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Outstanding at beginning of period 10,000 $ 7.46 — $ — Granted 1,986,933 5.65 10,000 7.46 Vested (785,902 ) 5.73 — — Forfeited (15,100 ) 5.71 — — Outstanding at end of period 1,195,931 $ 5.61 10,000 $ 7.46

Strategic Restructuring (Tables

Strategic Restructuring (Tables)	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Summary of the Utilization of the Restructuring Liability	The following table summarizes the utilization of the restructuring liability (in thousands): Severance and Other Termination Benefits Balance, December 31, 2013 $ 966 Adjustments (8 ) Cash payments (958 ) Balance, December 31, 2014 $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets	Deferred tax assets for the years ended December 31, 2015 and 2014 , are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 6,050 $ 7 Research & development tax credit carry forwards 1,029 925 Deferred rent 427 25 Property & equipment 140 224 Compensation 2,810 774 Alternative minimum tax credits 259 334 Other 7 (4 ) Unrealized losses 141 142 Total $ 10,863 $ 2,427 Less: valuation allowance (10,863 ) (2,324 ) Net deferred tax asset $ — $ 103 Reported as: Current deferred income tax asset $ — $ 61 Current deferred income tax liability (16,962 ) — Long term deferred income tax asset 16,962 42 Net deferred income tax asset $ — $ 103
Schedule of Components of Income Tax Expense (Benefit)	The components of the tax provisions are as follows (in thousands): Years Ended December 31, 2015 2014 2013 Federal: Current $ (2 ) $ (79 ) $ 575 Deferred 43 2,400 2,295 41 2,321 2,870 State: Current $ — $ 19 $ 34 Deferred 9 19 (21 ) 9 38 13 Total $ 50 $ 2,359 $ 2,883
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation of the statutory federal income tax rate to the Company's effective tax rate is as follows: Years Ended December 31, 2015 2014 2013 Federal Statutory rate 34.0 % 34.0 % 34.0 % State income taxes 0.2 6.8 — Stock compensation (0.8 ) (7.8 ) — Other permanent items (0.1 ) 5.5 — Meals and entertainment — 7.1 — Loss carryforward adjustment — — 3.7 Return to provision items — (6.0 ) — Unrealized losses — 0.6 — IPO costs — — — Other, net — (4.2 ) 2.1 Valuation allowance (33.5 ) 631.7 — Effective tax rate (0.2 )% 667.7 % 39.8 %

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following tables reconcile the numerator and denominator used to calculate diluted net income per share for the periods presented (in thousands): Years Ended December 31, 2015 2014 2013 Numerator: Net income (loss) attributable to common shareholders $ (25,509 ) $ (2,006 ) $ 1,161 Denominator: Weighted-average shares outstanding—basic (shares) 35,972 32,869 11,964 Dilutive effect of stock options, RSUs and restricted stock awards — — 391 Weighted average shares outstanding—diluted (shares) 35,972 32,869 12,355

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments Under Noncancelable Operating Leases	Future minimum lease payments under operating leases (with initial or remaining lease terms in excess of one year) as of December 31, 2015 are as follows (in thousands): Payments Due by Period 2016 2017 2018 2019 2020 Thereafter Total Operating lease obligations 1,328 997 968 1,007 1,046 994 6,340 Total 1,328 997 968 1,007 1,046 994 6,340

Quarterly Information (Unaudi35

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The results of historical quarters are not necessarily indicative of the results of operations for a full year or any future period: (unaudited) (In thousands, except per share amounts) March 31 June 30 September 30 December 31 2015 Revenue from collaborations $ 7,215 $ 7,181 $ 7,128 $ 2,543 (1) Net income (loss) (3,940 ) (9,738 ) (3,550 ) (8,281 ) Basic net income (loss) per share $ (0.11 ) $ (0.27 ) $ (0.10 ) $ (0.23 ) Diluted net income (loss) per share $ (0.11 ) $ (0.27 ) $ (0.10 ) $ (0.23 ) March 31 June 30 September 30 December 31 2014 Revenue from collaborations $ 10,546 $ 9,086 $ 8,119 $ 7,645 Net income (loss) 54 71 (1,536 ) (2) (595 ) Basic net income (loss) per share $ — $ — $ (0.04 ) $ (0.02 ) Diluted net income (loss) per share $ — $ — $ (0.04 ) $ (0.02 ) (1) In the fourth quarter of 2015, we were in negotiations with Otsuka regarding the amount of indirect cost applicable in 2015. This negotiation resulted in a settlement of approximately $2.6 million , which was issued as a credit to Otsuka for development expenses that had been recognized as revenue in 2015and has been recorded as a reduction to revenue for the year ended December 31, 2015. (2) In the third quarter of 2014, we recorded a valuation allowance against our deferred tax assets of $1.6 million due to expected future losses as a result of our new strategic plan.

Business and Basis of Present36

Business and Basis of Presentation (Details)	12 Months Ended
	Dec. 31, 2015segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	1

Cash and Cash Equivalents and37

Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash	$ 3,856	$ 767
Amortized Cost	167,100	188,231
Gross Unrealized Holding Gains	1	6
Gross Unrealized Holding Losses Less than 12 mos	(479)	(418)
Gross Unrealized Holding Losses 12 mos or Longer	(97)	0
Fair Value	166,525	187,819
Level 1 Securities | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	1,232	17,771
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses Less than 12 mos	0	0
Gross Unrealized Holding Losses 12 mos or Longer	0	0
Fair Value	1,232	17,771
Level 2 Securities | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		15,992
Gross Unrealized Holding Gains		2
Gross Unrealized Holding Losses Less than 12 mos		(1)
Gross Unrealized Holding Losses 12 mos or Longer		0
Fair Value		15,993
Level 2 Securities | US Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	10,020
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses Less than 12 mos	(37)
Gross Unrealized Holding Losses 12 mos or Longer	0
Fair Value	9,983
Level 2 Securities | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	144,352	131,586
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses Less than 12 mos	(435)	(398)
Gross Unrealized Holding Losses 12 mos or Longer	(96)	0
Fair Value	143,821	131,188
Level 2 Securities | Certificates of deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	7,640	22,115
Gross Unrealized Holding Gains	1	4
Gross Unrealized Holding Losses Less than 12 mos	(7)	(19)
Gross Unrealized Holding Losses 12 mos or Longer	(1)	0
Fair Value	$ 7,633	$ 22,100

Cash and Cash Equivalents and38

Cash and Cash Equivalents and Investments (Narrative) (Details) $ in Millions	Dec. 31, 2015USD ($)
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Securities maturing from year one to year two	$ 1.4
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Securities maturing from year one to year two	43.1
US Government agencies
Schedule of Available-for-sale Securities [Line Items]
Securities maturing from year one to year two	$ 10

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,770	$ 5,219
Less accumulated depreciation and amortization	(3,850)	(4,477)
Property and equipment, net	920	742
Laboratory and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,981	2,910
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,423	1,812
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 366	$ 497

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2015
Conversion of Stock [Line Items]
Common stock, shares authorized		100,000,000	100,000,000
IPO | Affiliated Entity | Convertible Debt
Conversion of Stock [Line Items]
Convertible debt face amount	$ 12
Debt conversion price	$ 3.30
Common Stock
Conversion of Stock [Line Items]
IPO, shares issued	9,200,000	9,200,000
Proceeds from IPO	$ 142
Common Stock | IPO
Conversion of Stock [Line Items]
Number of shares issued on conversion of preferred stock	10,813,867
Common Stock | IPO | Affiliated Entity
Conversion of Stock [Line Items]
Number of shares issued through debt conversion	3,636,365

Shareholders' Equity (Changes i

Shareholders' Equity (Changes in AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (361)	$ (7)	$ 0
Current period other comprehensive gain (loss), net of tax	(214)	(354)	(7)
Ending balance	$ (575)	$ (361)	$ (7)

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) $ in Thousands	Dec. 18, 2015shares	Dec. 31, 2015USD ($)planEmployeeshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)	Feb. 24, 2015USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | plan		3
Stock-based compensation | $		$ 8,940	$ 516	$ 1,123
Common stock reserved for future issuance		30,425
Cash retention pool bonus, amount | $					$ 600
Share-based compensation, vesting period		4 years
Exercise period after termination		3 months
New exercise period after termination		12 months
Compensation cost | $		$ 100
Plan modification, number of employees affected | Employee		27
Options granted		1,500,903	101,000
Dividend yield		0.00%	0.00%	0.00%
Unrecognized compensation cost related to nonvested share-based compensation awards | $		$ 6,000
On the First Employment Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
On a Monthly Pro Rata Basis Over the Next Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		75.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments, granted		1,509,872
Unrecognized compensation cost related to nonvested share-based compensation awards, weighted average period of recognition		3 years 6 months
Vested units		427,210
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments, granted		477,061
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting period		10 years
Unrecognized compensation cost related to nonvested share-based compensation awards | $		$ 2,200
Unrecognized compensation cost related to nonvested share-based compensation awards, weighted average period of recognition		3 years 9 months 18 days
Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	458,100
New Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	64,500
Existing Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	393,600
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan modification, number of employees affected | Employee		1
Employees and Senior Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted		1,500,903

Share-Based Compensation (Vesti

Share-Based Compensation (Vesting Schedule) (Details)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting period	4 years
On the First Employment Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
On a Monthly Pro Rata Basis Over the Next Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	75.00%
Stock Options | On the First Employment Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Stock Options | On a Monthly Pro Rata Basis Over the Next Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	75.00%
Executives | Stock Options | Vested Annually for Four Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Share-based compensation, vesting period	4 years
Executives | Stock Options | Vested Annually for Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Share-based compensation, vesting period	5 years
Executives | Restricted Stock | On the First Employment Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Executives | Restricted Stock | On a Monthly Pro Rata Basis Over the Next Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	75.00%
Executives | Restricted Stock Units (RSUs) | On the First Employment Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Executives | Restricted Stock Units (RSUs) | On a Monthly Pro Rata Basis Over the Next Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	75.00%
Executives | Restricted Stock Units (RSUs) | Vested Annually for Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Share-based compensation, vesting period	5 years
Employees | Restricted Stock Units (RSUs) | Vested Annually for Four Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Share-based compensation, vesting period	4 years
Former Board of Directors | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting period	12 months
Former Board of Directors | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting period	48 months

Share-Based Compensation (Stock

Share-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
Shares Underlying Options
Outstanding at beginning of period	375,956	696,878
Granted	1,500,903	101,000
Exercised	(10,500)	(187,007)
Forfeited	(5,104)	(167,699)
Expired	(7,225)	(67,216)
Outstanding at end of period	1,854,030	375,956	696,878
Vested and expected to vest at end of period				1,783,811
Vested and exercisable at end of period		263,929		1,151,837
Weighted Average Exercise Price
Outstanding at beginning of period	$ 8.45	$ 7.21
Granted	5.76	7.78
Exercised	1.60	3.64
Forfeited	10.33	8.27
Expired	10.33	8.42
Outstanding at end of period	$ 6.30	8.45	$ 7.21
Vested and expected to vest at end of period				$ 6.32
Vested and exercisable at end of period		$ 6.18		$ 6.63
Aggregate Intrinsic Value
Outstanding at beginning of period	$ 397
Exercised	45	$ 886	$ 307
Outstanding at end of period	$ 397	397		$ 2,244
Aggregate Intrinsic Value, Vested and expected to vest at end of period				2,162
Aggregate Intrinsic Value, Vested and exercisable at end of period		$ 381		$ 1,430
Weighted Average Remaining Contractual Term, Outstanding at end of period	4 years 2 months 12 days	6 years 6 months
Weighted Average Remaining Contractual Term, Vested and expected to vest at end of period	4 years
Weighted Average Remaining Contractual Term, Vested and exercisable at end of period	9 months 18 days	5 years 9 months 18 days

Share-Based Compensation (Suppl

Share-Based Compensation (Supplemental Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average grant date fair value per share - granted	$ 3.57	$ 5	$ 8.09
Exercised	$ 45	$ 886	$ 307
Total fair value of options vested	$ 3,768	$ 482	$ 625

Share-Based Compensation (Fair

Share-Based Compensation (Fair Value of Stock Options Granted) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected term	6 years 3 months 18 days	6 years 2 months 12 days	6 years 3 months 18 days
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	67.00%	70.00%	50.00%
Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	1.30%	1.50%	1.20%
Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	1.80%	2.50%	2.10%

Share-Based Compensation (RSU a

Share-Based Compensation (RSU and Restricted Stock Award Activity) (Details) - RSUs and Restricted Stock - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Shares
Outstanding at beginning of period	10,000	0
Granted	1,986,933	10,000
Vested	(785,902)	0
Forfeited	(15,100)	0
Outstanding at end of period	1,195,931	10,000
Weighted Average Grant Date Fair Value
Outstanding at beginning of period	$ 7.46	$ 0
Granted	5.65	7.46
Vested	5.73	0
Forfeited	5.71	0
Outstanding at end of period	$ 5.61	$ 7.46

Strategic Restructuring (Narrat

Strategic Restructuring (Narrative) (Details) - Employee Severance $ in Millions	1 Months Ended
	Oct. 31, 2013Employee	Dec. 31, 2013USD ($)
Restructuring Cost and Reserve [Line Items]
Workforce reduction, percentage	35.00%
Number of positions eliminated | Employee	30
Restructuring costs | $		$ 1

Strategic Restructuring (Detail

Strategic Restructuring (Details) - Employee Severance $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Restructuring Reserve [Roll Forward]
Balance, December 31, 2013	$ 966
Adjustments	(8)
Cash payments	(958)
Balance, December 31, 2014	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Operating Loss Carryforwards [Line Items]
Effective tax rate	(0.20%)	667.70%	39.80%
Federal Statutory rate	34.00%	34.00%	34.00%
Deferred tax assets, valuation allowance	$ 10,863	$ 2,324		$ 1,600
Valuation allowance, deferred tax asset, increase, amount	8,600
Tax credit carryforwards, research and development	1,000
Operating loss carryforwards	$ 17,700
Income tax examination, likelihood of being realized upon ultimate settlement	50.00%
Share-based Compensation [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards, research and development	$ 300

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2014
Deferred tax assets:
Net operating loss carryforwards	$ 6,050	$ 7
Research & development tax credit carry forwards	1,029	925
Deferred rent	427	25
Property & equipment	140	224
Compensation	2,810	774
Alternative minimum tax credits	259	334
Other	7	(4)
Unrealized losses	141	142
Total	10,863	2,427
Less: valuation allowance	(10,863)	(2,324)	$ (1,600)
Net deferred tax asset	0	103
Reported as:
Current deferred income tax asset	0	61
Current deferred income tax liability	(16,962)	0
Long term deferred income tax asset	16,962	42
Net deferred income tax asset	$ 0	$ 103

Income Taxes (Components of Tax

Income Taxes (Components of Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Federal:
Current	$ (2)	$ (79)	$ 575
Deferred	43	2,400	2,295
Federal income tax expense (benefit)	41	2,321	2,870
State:
Current	0	19	34
Deferred	9	19	(21)
State income tax expense (benefit)	9	38	13
Total	$ 50	$ 2,359	$ 2,883

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Statutory Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal Statutory rate	34.00%	34.00%	34.00%
State income taxes	0.20%	6.80%	0.00%
Stock compensation	(0.80%)	(7.80%)	(0.00%)
Other permanent items	(0.10%)	5.50%	0.00%
Meals and entertainment	0.00%	7.10%	0.00%
Loss carryforward adjustment	0.00%	0.00%	3.70%
Return to provision items	0.00%	(6.00%)	0.00%
Unrealized losses	0.00%	0.60%	0.00%
IPO costs	0.00%	0.00%	0.00%
Other, net	0.00%	(4.20%)	2.10%
Valuation allowance	(33.50%)	631.70%	0.00%
Effective tax rate	(0.20%)	667.70%	39.80%

Collaboration and License Agr54

Collaboration and License Agreements (Details) - USD ($)

3 Months Ended

12 Months Ended

72 Months Ended

84 Months Ended

96 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2008

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2015

Revenue Recognition, Milestone Method [Line Items]

Revenue from collaborations

$ 7,645,000

$ 8,119,000

$ 9,086,000

$ 10,546,000

$ 24,067,000

$ 35,396,000

$ 52,947,000

Deferred revenue from collaborations

$ 2,467,000

6,231,000

2,467,000

6,231,000

$ 6,231,000

$ 2,467,000

Reduction of Indirect Charges Billed Earlier

Revenue Recognition, Milestone Method [Line Items]

Revenue from collaborations

2,600,000

Collaborative Arrangement, Product | Emixustat

Revenue Recognition, Milestone Method [Line Items]

Nonrefundable up-front license fee received

$ 5,000,000

Funded amount, Phase 1

40,000,000

Potential to receive development milestones

$ 82,500,000

Milestone method, revenue recognized

$ 0

$ 5,000,000

Number of days used as base for calculating accrued interest

360 days

Percent of royalty paid on annual aggregate net sales for each party

2.00%

Revenue from collaborations

$ 32,400,000

49,700,000

61,500,000

Contingently repayable funding, accrued interest

$ 4,600,000

$ 2,500,000

$ 4,600,000

2,500,000

$ 2,500,000

$ 4,600,000

Collaborative Arrangement, Product | Emixustat | Secured Promissory Note | Three-month LIBOR

Revenue Recognition, Milestone Method [Line Items]

Stated percentage

3.00%

3.00%

3.00%

Collaborative Arrangement, Product | Emixustat | Initial Indication

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

$ 55,000,000

Collaborative Arrangement, Product | Emixustat | Second Indication

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

27,500,000

Collaborative Arrangement, Product | Emixustat | All Indications

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

175,000,000

Collaborative Arrangement, Product | Emixustat | All Indications | Aggregate Annual Worldwide Sales of 250 million

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

25,000,000

Benchmark for aggregate annual worldwide sales of all collaboration products

250,000,000

Collaborative Arrangement, Product | Emixustat | All Indications | Aggregate Annual Worldwide Sales of 500 million

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

50,000,000

Benchmark for aggregate annual worldwide sales of all collaboration products

500,000,000

Collaborative Arrangement, Product | Emixustat | All Indications | Aggregate Annual Worldwide Sales of 1 billion

Revenue Recognition, Milestone Method [Line Items]

Potential to receive development milestones

100,000,000

Benchmark for aggregate annual worldwide sales of all collaboration products

1,000,000,000

Collaborative Arrangement, Product | Development Activities

Revenue Recognition, Milestone Method [Line Items]

Selling price for research program

$ 15,000,000

$ 15,000,000

$ 15,000,000

Revenue from collaborations

24,100,000

35,400,000

39,200,000

Collaborative Arrangement, Product | Development Activities | Initial Indication | Upon Initiation of a Phase 2b/3 | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

5,000,000

Collaborative Arrangement, Product | Development Activities | Initial Indication | Upon Initiation of a Phase 3 | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

5,000,000

Collaborative Arrangement, Product | Development Activities | Initial Indication | Upon Filing of a NDA with the FDA | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

15,000,000

Collaborative Arrangement, Product | Development Activities | Initial Indication | Upon Receipt of Approval by the FDA of an NDA | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

20,000,000

Collaborative Arrangement, Product | Development Activities | Initial Indication | Upon Receipt of Approval by Regulatory Authority of a Marketing Approval | JAPAN

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

10,000,000

Collaborative Arrangement, Product | Development Activities | Second Indication | Upon Filing of a NDA with the FDA | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

7,500,000

Collaborative Arrangement, Product | Development Activities | Second Indication | Upon Receipt of Approval by the FDA of an NDA | UNITED STATES

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

10,000,000

Collaborative Arrangement, Product | Development Activities | Second Indication | Upon Receipt of Approval by Regulatory Authority of a Marketing Approval | JAPAN

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

$ 5,000,000

Collaborative Arrangement, Product | OPA-6566

Revenue Recognition, Milestone Method [Line Items]

Revenue from collaborations

0

0

1,500,000

Collaborative Arrangement, Product | Rebamipide

Revenue Recognition, Milestone Method [Line Items]

Milestone method, revenue recognized

2,000,000

$ 5,000,000

Revenue from collaborations

$ 0

$ 0

$ 12,300,000

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				12 Months Ended
	Feb. 28, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Net income (loss) attributable to common shareholders		$ (8,281)	$ (3,550)	$ (9,738)	$ (3,940)	$ (25,509)	$ (2,006)	$ 1,161
Weighted-average shares outstanding—basic (shares)						35,972,000	32,869,000	11,964,000
Dilutive effect of stock options, RSUs and restricted stock awards						0	0	391,000
Weighted average shares outstanding—diluted (shares)						35,972,000	32,869,000	12,355,000
Antidilutive securities excluded from the calculation of diluted net income (loss) per share						96,683	185,551
Common Stock
Class of Stock [Line Items]
IPO, shares issued	9,200,000						9,200,000
Common Stock | Affiliated Entity | IPO
Class of Stock [Line Items]
Number of shares issued through debt conversion	3,636,365

Retirement Plans (Details)

Retirement Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Compensation and Retirement Disclosure [Abstract]
Employer matching contribution, percent	50.00%
Employee contribution, percent	6.00%
Ceiling of an employee's total compensation, percent	3.00%
Percent of vesting of employees in their contributions	100.00%
Contributions by employer	$ 0.4
Defined contribution plan, vesting period	4 years

Commitments and Contingencies57

Commitments and Contingencies (Narrative) (Details) $ in Millions	Mar. 24, 2015	Sep. 19, 2014USD ($)ft²	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Jan. 02, 2015USD ($)	Jun. 26, 2014ft²
Related Party Transaction [Line Items]
Reduction in rent expense		$ 0.4
Rent expense			$ 2	$ 1	$ 1
Percent of employee’s annual target bonus for 2015	50.00%
Payments under equity award agreement			1.9
Accrued payments under equity award agreement			$ 0.4
Office Building
Related Party Transaction [Line Items]
Net rentable area of leased property | ft²							38,723
Tenant leasehold improvement allowance						$ 1.2
Laboratory and Office Space
Related Party Transaction [Line Items]
Net rentable area of leased property | ft²		17,488

Commitments and Contingencies58

Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 1,328
2,017	997
2,018	968
2,019	1,007
2,020	1,046
Thereafter	994
Operating lease obligations	$ 6,340

Former CEO and COO Severance (D

Former CEO and COO Severance (Details) - USD ($) $ in Thousands	Nov. 18, 2015	May. 03, 2015	May. 01, 2015	Oct. 14, 2014	Apr. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2016	May. 11, 2015
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vested options						1,783,811
Incremental compensation cost						$ 100
General and administrative expense						$ 27,987	$ 10,002	$ 9,548
Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vested units						427,210
General and administrative expense						$ 2,100
Chief Executive Officer
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance term				18 months
Severance benefit term				18 months
Severance escrow, funded amount										$ 900
Vested options		712,480
Options modified					712,480
Incremental compensation cost					$ 2,700
Chief Executive Officer | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vested units		356,410
Chief Operating Officer
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance term			9 months
Severance benefit term			9 months
Incremental compensation cost	$ 1,800
Chief Operating Officer | Scenario, Forecast
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance escrow, funded amount									$ 300
Chief Operating Officer | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vested units	358,692

Related-Party Transactions (Det

Related-Party Transactions (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 22, 2015
Common Stock
Related Party Transaction [Line Items]
Release of shares					7,752,425
Management
Related Party Transaction [Line Items]
Expenses from transactions with related party		$ 0	$ 0	$ 0.3
Affiliated Entity | Common Stock | IPO
Related Party Transaction [Line Items]
Number of shares issued through debt conversion	3,636,365
Dr. Kubota and SBI Holding
Related Party Transaction [Line Items]
Costs and expenses, related party		$ 0.8

Quarterly Information (Unaudi61

Quarterly Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue from collaborations					$ 7,645	$ 8,119	$ 9,086	$ 10,546	$ 24,067	$ 35,396	$ 52,947
Net income (loss)	$ 2,543	$ 7,128	$ 7,181	$ 7,215	$ (595)	$ (1,536)	$ 71	$ 54	(25,509)	(2,006)	4,299
Net income (loss) attributable to common shareholders	$ (8,281)	$ (3,550)	$ (9,738)	$ (3,940)					$ (25,509)	$ (2,006)	$ 1,161
Basic net income (loss) per share (in dollars per share)	$ (0.23)	$ (0.10)	$ (0.27)	$ (0.11)	$ (0.02)	$ (0.04)	$ 0	$ 0	$ (0.71)	$ (0.06)	$ 0.10
Diluted net income (loss) per share (in dollars per share)	$ (0.23)	$ (0.10)	$ (0.27)	$ (0.11)	$ (0.02)	$ (0.04)	$ 0	$ 0	$ (0.71)	$ (0.06)	$ 0.09
Deferred tax assets, valuation allowance	$ 10,863				$ 2,324	$ 1,600			$ 10,863	$ 2,324
Reduction of Indirect Charges Billed Earlier
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue from collaborations	$ 2,600

Subsequent Events (Details)

Subsequent Events (Details) - ¥ / shares	Jan. 21, 2016	Dec. 31, 2015	Jan. 06, 2016
Subsequent Event [Line Items]
Common stock reserved for future issuance		30,425
Share-based compensation, vesting period		4 years
On the First Employment Anniversary
Subsequent Event [Line Items]
Vesting percentage		25.00%
On a Monthly Pro Rata Basis Over the Next Three Years
Subsequent Event [Line Items]
Vesting percentage		75.00%
Subsequent Event
Subsequent Event [Line Items]
Options granted	900,000
Subsequent Event | Chief Executive Officer
Subsequent Event [Line Items]
Options granted	780,000
Share-based compensation, vesting period	3 years
Subsequent Event | Each of our Board of Directors
Subsequent Event [Line Items]
Options granted	30,000
Subsequent Event | Over Three Years | Chief Executive Officer
Subsequent Event [Line Items]
Options granted	390,000
Subsequent Event | On the First Employment Anniversary | Chief Executive Officer
Subsequent Event [Line Items]
Vesting percentage	33.00%
Subsequent Event | On a Monthly Pro Rata Basis Over the Next Three Years | Chief Executive Officer
Subsequent Event [Line Items]
Vesting percentage	67.00%
Subsequent Event | Incrementally on the Closing Market Price of the Common Shares on the Tokyo Stock Exchange | Chief Executive Officer
Subsequent Event [Line Items]
Options granted	390,000
Subsequent Event | Vest upon Stock Price of ¥1,102 | Chief Executive Officer
Subsequent Event [Line Items]
Vesting percentage	33.00%
Price per share	¥ 1,102
Subsequent Event | Vest upon Stock Price of ¥1,470 | Chief Executive Officer
Subsequent Event [Line Items]
Vesting percentage	33.00%
Price per share	¥ 1,470
Subsequent Event | Vest upon Stock Price of ¥1,837 | Chief Executive Officer
Subsequent Event [Line Items]
Price per share	¥ 1,837
Subsequent Event | Equity Plans
Subsequent Event [Line Items]
Common stock reserved for future issuance			1,460,684