IVERIC bio (ISEE) 10-K11 Mar 142013 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 28, 2014
Document and Entity Information	'	'
Entity Registrant Name	'Ophthotech Corp.	'
Entity Central Index Key	'0001410939	'
Document Type	'10-K	'
Document Period End Date	31-Dec-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'No	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Public Float	$327.50	'
Entity Common Stock, Shares Outstanding	'	33,318,575
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'FY	'

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets	'	'
Cash and cash equivalents	$210,596	$4,304
Prepaid expenses and other current assets	6,804	44
Other Assets	'	331
Security deposits	'	158
Total current assets	217,400	4,837
Property, plant and equipment, net	27	42
Security deposits	255	'
Total assets	217,682	4,879
Current liabilities	'	'
Accrued clinical drug supplies and trial costs	2,485	1,013
Accounts payable and accrued expenses	3,810	1,391
Notes payable	'	11,040
Warrant liability	'	966
Total current liabilities	6,295	14,410
Royalty purchase liability	41,667	'
Total liabilities	47,962	14,410
Preferred Stock, Convertible and Redeemable:	'	'
Total Preferred Stock, Convertible and Redeemable	'	113,939
Stockholders' equity (deficit)	'	'
Common stock - $0.001 par value, 200,000,000 shares authorized, 31,413,208 shares issued and outstanding at December 31, 2013; 155,864,851 shares authorized, 1,469,798 shares issued and outstanding at December 31, 2012	31	1
Additional paid-in capital	352,739	'
Deficit accumulated during development stage	-183,050	-126,471
Total stockholders' equity (deficit)	169,720	-123,470
Total liabilities and stockholders' equity (deficit)	217,682	4,879
Series A	'	'
Preferred Stock, Convertible and Redeemable:	'	'
Total Preferred Stock, Convertible and Redeemable	'	69,471
Series A-1	'	'
Preferred Stock, Convertible and Redeemable:	'	'
Total Preferred Stock, Convertible and Redeemable	'	8,460
Series B	'	'
Preferred Stock, Convertible and Redeemable:	'	'
Total Preferred Stock, Convertible and Redeemable	'	35,456
Series B-1	'	'
Preferred Stock, Convertible and Redeemable:	'	'
Total Preferred Stock, Convertible and Redeemable	'	552
Junior Series A Convertible Preferred Stock	'	'
Stockholders' equity (deficit)	'	'
Preferred Stock	'	3,000
Preferred stock	'	'
Stockholders' equity (deficit)	'	'
Preferred Stock	'	'

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	200,000,000	155,864,851
Common stock, shares issued	31,413,208	1,469,798
Common stock, shares outstanding	31,413,208	1,469,798
Series A	'	'
Preferred Stock, Convertible and Redeemable, par value (in dollars per share)	'	$0.00
Preferred Stock, Convertible and Redeemable, shares authorized	'	73,094,000
Preferred Stock, Convertible and Redeemable, shares issued	'	51,790,000
Preferred Stock, Convertible and Redeemable, shares outstanding	'	51,790,000
Series A-1	'	'
Preferred Stock, Convertible and Redeemable, par value (in dollars per share)	'	$0.00
Preferred Stock, Convertible and Redeemable, shares authorized	'	18,480,000
Preferred Stock, Convertible and Redeemable, shares issued	'	6,000,000
Preferred Stock, Convertible and Redeemable, shares outstanding	'	6,000,000
Series B	'	'
Preferred Stock, Convertible and Redeemable, par value (in dollars per share)	'	$0.00
Preferred Stock, Convertible and Redeemable, shares authorized	'	42,320,200
Preferred Stock, Convertible and Redeemable, shares issued	'	30,000,000
Preferred Stock, Convertible and Redeemable, shares outstanding	'	30,000,000
Series B-1	'	'
Preferred Stock, Convertible and Redeemable, par value (in dollars per share)	'	$0.00
Preferred Stock, Convertible and Redeemable, shares authorized	'	700,000
Preferred Stock, Convertible and Redeemable, shares issued	'	500,000
Preferred Stock, Convertible and Redeemable, shares outstanding	'	500,000
Junior Series A Convertible Preferred Stock	'	'
Preferred stock, par value (in dollars per share)	'	$0.00
Preferred stock, shares authorized	'	3,000,000
Preferred stock, shares issued	'	3,000,000
Preferred stock, shares outstanding	'	3,000,000
Preferred Stock	'	'
Preferred stock, par value (in dollars per share)	$0.00	'
Preferred stock, shares authorized	5,000,000	'
Preferred stock, shares issued	0	'
Preferred stock, shares outstanding	0	'

Statement_of_Operations

Statement of Operations (USD $)	12 Months Ended			84 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Costs and expenses:	'	'	'	'
Research and development	$33,215	$6,792	$13,896	$108,107
General and administrative	14,210	6,889	5,738	41,559
Total costs and expenses	47,425	13,681	19,634	149,666
Loss from operations	-47,425	-13,681	-19,634	-149,666
Interest (expense) income	-1,454	-507	2	-1,482
Loss on extinguishment of debt	-1,091	'	'	-1,091
Other loss	-1,175	-374	-30	-1,546
Change in fair value related to investor rights liability	'	'	'	683
Net loss before income tax benefit	-51,145	-14,562	-19,662	-153,102
Income tax benefit	'	'	1,029	1,327
Net loss	-51,145	-14,562	-18,633	-151,775
Add: accretion of preferred stock dividends	-5,891	-7,063	-6,838	-33,046
Net loss attributable to common stockholders	($57,036)	($21,625)	($25,471)	($184,821)
Net loss attributable to common stockholders per share :	'	'	'	'
Basic and diluted (in dollars per share)	($6.34)	($14.89)	($18.27)	'
Weighted average common shares outstanding:	'	'	'	'
Basic and diluted (in shares)	9,003	1,452	1,394	'

Statement_of_Stockholders_Equi

Statement of Stockholders' Equity (Deficit) (USD $)	Total	Junior Series A Preferred Stock	Common stock	Additional paid-in Capital	Deficit Accumulated During the Development Stage
In Thousands, except Share data, unless otherwise specified	Total	Junior Series A Preferred Stock	Common stock	Additional paid-in Capital	Deficit Accumulated During the Development Stage
Balance at Jan. 04, 2007	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	$55	'	$1	$54	'
Issuance of common stock (in shares)	'	'	932,000	'	'
Issuance of Junior Series A Preferred Stock	3,000	3,000	'	'	'
Issuance of Junior Series A Preferred Stock (in shares)	'	3,000,000	'	'	'
Preferred Stock dividends	-646	'	'	-54	-592
Net loss	-14,417	'	'	'	-14,417
Balance at Dec. 31, 2007	-12,008	3,000	1	'	-15,009
Balance (in shares) at Dec. 31, 2007	'	3,000,000	932,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	11	'	'	11	'
Issuance of common stock (in shares)	'	'	97,000	'	'
Share-based compensation	14	'	'	14	'
Preferred Stock dividends	-2,597	'	'	-25	-2,572
Net loss	-20,556	'	'	'	-20,556
Balance at Dec. 31, 2008	-35,136	3,000	1	'	-38,137
Balance (in shares) at Dec. 31, 2008	'	3,000,000	1,029,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	13	'	'	13	'
Issuance of common stock (in shares)	'	'	107,000	'	'
Share-based compensation	58	'	'	58	'
Preferred Stock dividends	-4,188	'	'	-71	-4,117
Net loss	-13,514	'	'	'	-13,514
Balance at Dec. 31, 2009	-52,767	3,000	1	'	-55,768
Balance (in shares) at Dec. 31, 2009	'	3,000,000	1,136,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	39	'	'	39	'
Issuance of common stock (in shares)	'	'	290,000	'	'
Share-based compensation	231	'	'	231	'
Preferred Stock dividends	-5,823	'	'	-270	-5,553
Net loss	-18,948	'	'	'	-18,948
Balance at Dec. 31, 2010	-77,268	3,000	1	'	-80,269
Balance (in shares) at Dec. 31, 2010	'	3,000,000	1,426,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	4	'	'	4	'
Issuance of common stock (in shares)	'	'	25,000	'	'
Share-based compensation	248	'	'	248	'
Preferred Stock dividends	-6,838	'	'	-252	-6,586
Net loss	-18,633	'	'	'	-18,633
Balance at Dec. 31, 2011	-102,487	3,000	1	'	-105,488
Balance (in shares) at Dec. 31, 2011	'	3,000,000	1,451,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock	2	'	'	2	'
Issuance of common stock (in shares)	'	'	19,000	'	'
Share-based compensation	640	'	'	640	'
Preferred Stock dividends	-7,063	'	'	-642	-6,421
Net loss	-14,562	'	'	'	-14,562
Balance at Dec. 31, 2012	-123,470	3,000	1	'	-126,471
Balance (in shares) at Dec. 31, 2012	'	3,000,000	1,470,000	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'
Issuance of common stock upon conversion of Series A, A-1, B, B-1 and C preferred stock	174,331	'	21	174,310	'
Issuance of common stock upon conversion of Series A, A-1, B, B-1 and C preferred stock (in shares)	'	'	21,038,000	'	'
Issuance of common stock from initial public offering, net	175,555	'	9	175,546	'
Issuance of common stock from initial public offering, net (in shares)	'	'	8,740,000	'	'
Issuance of common stock upon conversion of Junior Series A Preferred Stock	-3,000	-3,000	'	'	'
Issuance of common stock upon conversion of Junior Series A Preferred Stock (in shares)	'	-3,000,000	'	'	'
Reclassification of warrant liability	2,179	'	'	2,179	'
Reclassification of preferred stock issuance costs	-1,804	'	'	-1,804	'
Exercise of stock options/warrants	94	'	'	94	'
Exercise of stock options/warrants (in shares)	'	'	165,000	'	'
Share-based compensation	2,871	'	'	2,871	'
Preferred Stock dividends	-5,891	'	'	-457	-5,434
Net loss	-51,145	'	'	'	-51,145
Balance at Dec. 31, 2013	$169,720	'	$31	$352,739	($183,050)
Balance (in shares) at Dec. 31, 2013	'	'	31,413,000	'	'

Statement_of_Cash_Flows

Statement of Cash Flows (USD $)	12 Months Ended			84 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Operating Activities	'	'	'	'
Net loss	($51,145)	($14,562)	($18,633)	($151,775)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'	'	'
Depreciation	20	31	32	174
Amortization of debt issuance costs	88	47	'	135
Accretion of debt discount	87	59	'	146
Non-cash change in fair value of warrant liability	1,181	366	7	1,563
Non-cash change in fair value of investor rights liability	'	'	'	-683
Loss on extinguishment of debt	1,091	'	'	1,091
Share-based compensation	2,871	640	248	4,061
Series A-1, Series B-1 and Junior Preferred Stock issued for acquired technology and licenses	'	'	500	9,500
Accrued interest expense converted to Series A Preferred Stock	'	'	'	2
Changes in operating assets and liabilities:	'	'	'	'
Prepaid expense and other current assets	-6,761	21	135	-6,804
Other receivables	'	1,036	-738	'
Security deposits	-96	'	'	-255
Accrued clinical drug supplies and trial costs	1,472	-485	-822	2,485
Accounts payable and accrued expenses	2,375	-235	172	3,754
Deferred rent	42	-22	-24	42
Net cash used in operating activities	-48,775	-13,104	-19,123	-136,564
Investing Activities	'	'	'	'
Purchase of marketable securities	'	'	'	-4,238
Maturities of marketable securities	'	'	3,400	4,250
Purchase of property, equipment	-5	'	-4	-201
Net cash used in investing activities	-5	'	3,396	-189
Financing Activities	'	'	'	'
Payment of debt issuance costs	-43	-377	'	-421
Proceeds from issuance of common stock	94	2	4	218
Proceeds from initial public offering, net	175,555	'	'	175,555
(Repayments on) Proceeds from issuance of notes payable, net	-11,900	11,387	'	-302
Proceeds from issuance of preferred stock, net	49,699	'	14,990	130,632
Proceeds from royalty purchase agreement	41,667	'	'	41,667
Net cash provided by financing activities	255,072	11,012	14,994	347,349
Net change in cash and cash equivalents	206,292	-2,092	-733	210,596
Cash and cash equivalents	'	'	'	'
Beginning of period	4,304	6,396	7,129	'
End of period	210,596	4,304	6,396	210,596
Supplemental disclosure of cash paid	'	'	'	'
Interest	1,523	437	'	1,964
Income Taxes	0	'	'	'
Supplemental disclosures of cash flow information	'	'	'	'
Conversion of preferred stock to common stock upon completion of IPO	174,310	'	'	174,310
Accreted dividends on Series A, Series A-1, Series of B, B-1 and Series C Preferred Stock	5,891	7,063	6,838	33,046
Notes payable and accrued interest converted to Series A Preferred Stock	'	'	'	$212

Business

Business	12 Months Ended
Business	Dec. 31, 2013
Business	'
Business	'

	1. Business

	Description of Business and Organization

	Ophthotech Corporation (the "Company" or "Ophthotech") was incorporated on January 5, 2007, in Delaware. The Company is a biopharmaceutical company specializing in the development of novel therapeutics to treat diseases of the back of the eye, with a focus on developing therapeutics for age-related macular degeneration, or AMD. The Company's operations since inception have been limited to organizing and staffing the Company, acquiring rights to product candidates, business planning, raising capital and developing its product candidates. Accordingly, the Company is considered to be in the development stage as defined by Financial Accounting Standards Board Accounting Standards Codification ("ASC") 915, Development Stage Entities. The Company operates in one business segment.

	Capitalized terms not otherwise defined herein are defined in their respective agreements.

	Liquidity

	Since the Company's inception, it has incurred significant operating losses. The Company reported a net losses of $51.1 million for the year ended December 31, 2013, $14.6 million for the year ended December 31, 2012 and $18.6 million for the year ended December 31, 2011. As of December 31, 2013, the Company had a deficit accumulated during the development stage of $183.1 million. To date, the Company has not generated any revenues and has financed its operations primarily through private placements of its preferred stock, venture debt borrowings, its royalty purchase and sale agreement with Novo A/S and its initial public offering ("IPO"), which closed on September 30, 2013. The Company issued and sold an aggregate of 8,740,000 shares of common stock in its IPO at a public offering price of $22.00 per share, including 1,140,000 shares pursuant to the exercise by the underwriters of an over-allotment option. The Company received net proceeds from the IPO of $175.6 million, after deducting underwriting discounts and commissions and other offering expenses. The Company has devoted substantially all of its financial resources and efforts to research and development and expects to continue to incur significant expenses and increasing operating losses over the next several years. The Company's net losses may fluctuate significantly from quarter to quarter and year to year.

	To fully execute its business plan, the Company will need to complete certain research and development activities and clinical trials. Further, the Company's product candidates will require regulatory approval prior to commercialization. These activities may span many years and require substantial expenditures to complete and may ultimately be unsuccessful. Any delays in completing these activities could adversely impact the Company. The Company plans to meet its capital requirements primarily through a combination of equity and debt financings, collaborations, strategic alliances and marketing distribution or licensing arrangements and in the longer term, revenue from potential product sales. There can be no assurance that such funds will be available, or if available, on terms favorable to the Company. The Company faces the normal risks associated with a development stage company, including but not limited to the risk that the Company's research and development activities will not be successfully completed, that adequate patent protection for the Company's technology will not be obtained, that any products developed will not obtain necessary government regulatory approval and that any approved products will not be commercially viable. In addition, the Company operates in an environment of rapid change in technology, substantial competition from pharmaceutical and biotechnology companies and is dependent upon the services of its employees and its consultants. The Company's capital requirements will depend on many factors, including the success of its development and commercialization of its product candidates and whether it pursues the development of additional product candidates. Even if the Company succeeds in developing and commercializing one or more of its product candidates, it may never achieve sufficient sales revenue to achieve or maintain profitability.

Significant_Accounting_Policie

Significant Accounting Policies

12 Months Ended

Dec. 31, 2013

Significant Accounting Policies

2. Significant Accounting Policies

Basis of Presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States and include all adjustments necessary for the fair presentation of the Company's financial position for the periods presented.

Use of Estimates

The preparation of financial statements and related disclosures in conformity with accounting principles generally accepted in the United States requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company's Balance Sheets and the amount of expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, accounting for share-based compensation and accounting for research and development costs. Actual results could differ from those estimates.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. The carrying amounts reported in the Balance Sheets for cash and cash equivalents are valued at cost, which approximates their fair value.

Concentration of Credit Risk

The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents. The Company maintains its cash in bank accounts, which, at times, exceed federally insured limits. The Company also maintains cash equivalents in money market funds that invest primarily in U.S. Treasury securities. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on its cash and cash equivalents.

Foreign Currency Translation

The Company maintains a bank account in a foreign currency. The Company considers the U.S. dollar to be its functional currency. Expenses are translated at the exchange rate on the date the expense is incurred. The effect of exchange rate fluctuations on translating foreign currency assets and liabilities into U.S. dollars is included in the Statements of Operations. Foreign exchange transaction gains and losses are included in the results of operations and are not material in the Company's financial statements.

Financial Instruments

The carrying amounts of the Company's financial instruments, which include cash and cash equivalents, accounts payable and accrued expenses approximate their respective fair value due to their short maturities.

Property and Equipment

Property and equipment, which consist mainly of computers and other equipment, are carried at cost less accumulated depreciation. Depreciation is computed over the estimated useful lives of the respective assets, generally five to seven years, using the straight-line method.

Research and Development

Research and development expenses consist of costs associated with the development and clinical testing of Fovista, an anti-PDGF aptamer the Company is developing for use in combination with anti-VEGF drugs for treatment of wet age-related macular degeneration, or wet AMD, and the Company's other product candidates. Research and development expenses consist of:

•

external research and development expenses incurred under arrangements with third parties, such as contract research organizations, ("CROs") and other vendors, contract manufacturing organizations and consultants; and

•

employee-related expenses, including salaries, benefits, travel and share-based compensation expense.

Research and development costs also include costs of acquired product licenses and related technology rights where there is no alternative future use, prototypes used in research and development, consultant fees and amounts paid to collaborative partners.

All research and development costs are charged to operations as incurred in accordance with ASC 730 Research and Development. The Company accounts for non-refundable advance payments for goods and services that will be used in future research and development activities as expenses when the service has been performed or when the goods have been received, rather than when the payment is made.

Income Taxes

The Company utilizes the liability method of accounting for deferred income taxes, as set forth in ASC 740-10, Income Taxes-Overall. Under this method, deferred tax liabilities and assets are recognized for the expected future tax consequences of temporary differences between the carrying amounts and the tax basis of assets and liabilities. A valuation allowance is established against net deferred tax assets because, based on the weight of available evidence, it is more likely than not that some or all of the net deferred tax assets will not be realized. The Company maintains a full valuation allowance on its deferred tax assets. Accordingly, the Company has not recorded a benefit or provision for income taxes other than for the sale of a portion of its unused New Jersey State operating loss carryforwards through a program sponsored by the State of New Jersey and the New Jersey Economic Development Authority in 2011. The Company's U.S. federal net operating losses have occurred since inception and as such, tax years subject to potential tax examination could apply from that date because carrying back net operating loss opens the relevant year to audit.

Share-Based Compensation

The Company follows the provisions of ASC 718, Compensation—Stock Compensation which requires the measurement and recognition of compensation expense for all share-based payment awards made to employees and non-employee directors, including employee stock options. Share-based compensation expense is based on the grant date fair value estimated in accordance with the provisions of ASC 718 and is generally recognized as an expense over the requisite service period.

For stock options granted as consideration for services rendered by non-employees, the Company recognizes expense in accordance with the requirements of ASC 505-50, Equity Based Payments to Non-Employees. Non-employee option grants that do not vest immediately upon grant are recorded as an expense over the vesting period of the underlying stock options. At the end of each financial reporting period prior to vesting, the value of these options, as calculated using the Black-Scholes option-pricing model, will be re-measured using the fair value of the Company's common stock and the non-cash expense recognized during the period will be adjusted accordingly. Since the fair value of options granted to non-employees is subject to change in the future, the amount of the future expense will include fair value re-measurements until the stock options are fully vested.

Prior to the Company's initial public offering, the Company determined the estimated fair value of the common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector and the prices at which the Company sold shares of its common stock.

Due to the lack of trading history, the Company's computation of stock-price volatility is based on the volatility rates of comparable publicly held companies over a period equal to the expected term of the options granted by the Company. The Company's computation of expected term was determined using the "simplified" method which is the midpoint between the vesting date and the end of the contractual term. The Company believes that it does not have sufficient reliable exercise data in order to justify the use of a method other than the "simplified" method of estimating the expected exercise term of employee stock option grants. The Company has paid no dividends to stockholders. The risk-free interest rate is based on the zero-coupon U.S. Treasury yield at the date of grant for a term equivalent to the expected term of the option. Share-based compensation expense includes stock options granted to employees and non-employees and has been reported in the Company's statements of operations as follows:

Years ended

December 31,

2013

2012

2011

(in thousands)

Research and development

2,062

412

159

General and administrative

809

228

Total

2,871

640

248

The Company had no shares of unvested restricted common stock granted to employees at December 31, 2013 or at December 31, 2012, respectively.

JOBS Act

As an "emerging growth company" under the Jumpstart Our Business Startups Act of 2012, the Company can take advantage of an extended transition period for complying with new or revised accounting standards. This allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. The Company has elected to delay the adoption of such new or revised accounting standards. As a result of this election, the Company's financial statements may not be comparable to the financial statements of other public companies. There are, however, no standards for which adoption has been delayed that would have a significant impact on the financial statements of the Company.

Recent Accounting Pronouncements

In May 2011, the Financial Accounting Standards Board issued guidance that changed the requirement for presenting "Comprehensive Income" in the financial statements. The update requires an entity to present the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The currently available option to disclose the components of other comprehensive income within the statement of stockholders' equity will no longer be available. The update is effective for fiscal years, and interim periods within those years, beginning after December 15, 2011, and should be applied retrospectively. The Company did not incur any components of comprehensive income for the periods presented and therefore did not include a statement of comprehensive income in the financial statements.

In February 2013, the FASB issued Accounting Standards Update ("ASU") 2013-02, Comprehensive Income: Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02"). ASU 2013-02 requires an entity to present the effect of certain significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. The amendments in the ASU do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. ASU 2013-02 is effective for public companies on a prospective basis for fiscal years beginning after December 15, 2012. As an emerging growth company as defined by the JOBS Act, the Company has delayed adoption of this pronouncement. However, the Company has not incurred any components of comprehensive income for the periods presented and the ASU requires only additional presentation, as such, there will be no impact to the Company's results of operations or financial position upon adoption.

Capitalization

Capitalization	12 Months Ended
Capitalization	Dec. 31, 2013
Capitalization	'
Capitalization	'

	3. Capitalization

	On September 9, 2013, the Company effected a one-for-5.9 reverse stock split of its common stock. All share and per share data (except par value) related to common stock, options and warrants included in these financial statements and accompanying notes have been adjusted to reflect the reverse stock split for all periods presented.

	On September 30, 2013, the Company closed its initial public offering of 8,740,000 shares of common stock at a price of $22.00 per share. The net proceeds to the Company were $175.6 million, after deducting underwriters' commissions and other offering expenses. In connection with the closing of the IPO, all of the Company's shares of redeemable convertible preferred stock outstanding at the time of the offering were automatically converted into 21,038,477 shares of common stock.

	In August 2013, the Company's Board of Directors and stockholders approved a restated certificate of incorporation which became effective following the closing of the Company's IPO on September 30, 2013. The restated certificate of incorporation increased the number of authorized shares of common stock to 200,000,000 and decreased the number of authorized shares of preferred stock to 5,000,000.

Net_Loss_Per_Common_Share

Net Loss Per Common Share	12 Months Ended
Net Loss Per Common Share	Dec. 31, 2013
Net Loss Per Common Share	'
Net Loss Per Common Share	'

	4. Net Loss Per Common Share

	Basic and diluted net loss per common share is determined by dividing net loss applicable to common stockholders by the weighted average common shares outstanding during the period. For the periods where there is a net loss attributable to common stockholders, the outstanding shares of preferred stock, stock options, unvested restricted stock, and warrants have been excluded from the calculation of diluted loss per common stockholder because their effect would be anti-dilutive.

	Therefore, the weighted average shares used to calculate both basic and diluted loss per share would be the same. The following table sets forth the computation of basic and diluted net loss per share for the periods indicated:


		Years ended December 31,
		2013			2012			2011
	Basic and diluted net loss per common share calculation:
	Net loss	$	(51,145	)	$	(14,562	)	$	(18,633	)
	Accretion of preferred stock dividends		(5,891	)		(7,063	)		(6,838	)


	Net loss attributable to common shareholders	$	(57,036	)	$	(21,625	)	$	(25,471	)




	Weighted average common shares outstanding		9,003			1,452			1,394




	Net loss per share of common stock—basic and diluted	$	(6.34	)	$	(14.89	)	$	(18.27	)





	The following potentially dilutive securities have been excluded from the computations of diluted weighted average shares outstanding for the periods presented, as they would be anti-dilutive:


		Years ended December 31,
		2013			2012			2011
	Redeemable convertible preferred stock		—			16,663			16,064
	Options outstanding		2,708			1,344			1,113
	Warrants		88			94			39


	Total		2,796			18,101			17,216

Financing_Activities

Financing Activities	12 Months Ended
Financing Activities	Dec. 31, 2013
Financing Activities	'
Financing Activities	'

	5. Financing Activities

	On June 18, 2007, the Company issued convertible promissory notes (the "Convertible Notes") totaling $0.2 million to certain investors. The Convertible Notes carried an interest rate of 8% per annum. The Convertible Notes and related accrued interest expense were converted into Series A Preferred Stock in conjunction with the Initial Closing under the Series A Agreement described below.

	On August 9, 2007, the Company entered into a Series A Preferred Stock Purchase Agreement (the "Series A Agreement") with the holders of the Notes and another investor (the "Series A Investors") which provided for the sale and issuance of the Company's Series A Preferred Stock at a price of $1.00 per share in the following tranches: (a) 9,253,101 shares at closing (the "Initial Closing"), (b) 9,217,243 shares provided that the License Agreement described in Note 7 remained in effect within 10 days of the date of the Series A Agreement (the "First Milestone Event Closing") and (c) 17,319,656 shares upon initiation of a Phase 1b study with respect to assets acquired or licensed under certain of the Product and Technology Agreements entered into by the Company in 2007 described in Note 7. As of December 31, 2007, the Company and the Series A Investors had completed the Initial Closing and the First Milestone Event Closing. On April 14, 2008, the Series A Agreement was amended and established the following tranches for the sale and issuance of Series A Preferred Stock to each of the Series A Investors at $1.00 per share: (a) 6,000,000 shares provided the Company's agreement with its collaborative partners referred to in Note 7 remained in effect on or before April 15, 2008 (the "Second Milestone Event"), (b) 13,000,000 shares upon initiation of a Phase 1b study with respect to any one of the assets (each such asset a "Milestone Asset") identified in the amendment to the Series A Agreement (the "Third Milestone Event"), (c) 4,319,656 shares upon initiation of a Phase 1b study with respect to a Milestone Asset other than the Milestone Asset relating to the Third Milestone Event (the "Fourth Milestone Event"), and (d) 7,000,000 shares upon initiation of a Phase 1b study with respect to a Milestone Asset other than the Milestone Asset relating to the Third Milestone Event or the Fourth Milestone Event (the "Fifth Milestone Event").

	In connection with the issuance of the Notes in June 2007, the Company issued 210,000 warrants to purchase Series A Preferred Stock with an exercise price of $0.01 per share. The warrants expire on June 18, 2017. The warrants provide for proportionate adjustments to be made to the number of shares purchasable and the exercise price payable under the warrants in the event of certain changes to the underlying Series A Preferred Stock, including for subdivisions, combinations and stock dividends.

	Prior to the Company's initial public offering, the Series A warrants were accounted for as a liability and were marked to market using a hybrid method of an option pricing model and a probability-weighted return methodology. During the periods prior to the initial public offering, the change in fair value of the Series A warrant liability was recorded within other loss. As of December 31, 2012, the value of the Series A warrant liability was $0.5 million as reflected in the accompanying Balance Sheets and the change in the fair value of $0.3 million for the year ended December 31, 2012, was recorded in the Statements of Operations.

	The Company and the Series A Investors closed the Second Milestone Event on April 14, 2008, and closed the Third Milestone Event on September 19, 2008, issuing 6,000,000 and 13,000,000 shares of Series A Preferred Stock, respectively.

	Under ASC 480, Distinguishing Liabilities from Equity, the Company concluded that these rights for shares in redeemable instruments represent free-standing financial instruments and should be accounted for as liabilities under ASC 480. In accordance with ASC 480, the Company adjusted the carrying value of such rights to their estimated fair value at each reporting date prior to the completion of its initial public offering. Pursuant to ASC 480, increases or decreases in the fair value of such rights were recorded in the Statements of Operations.

	The estimated fair value was determined using a valuation model which considers the probability of achieving a milestone, if any, the Company's cost of capital, the estimated period the rights will be outstanding, consideration received for the instrument with the rights, the number of shares to be issued to satisfy the rights and at what price and any changes in the fair value of the underlying instrument to the rights. The recorded liability was fulfilled in May 2009 upon the exercise of the remaining rights by investors. Since such time, there have not been, and there continue not to be, any rights outstanding.

	On September 19, 2008, the Company met the Third Milestone and issued 13,000,000 shares of Series A Preferred Stock at $1.00 per share, resulting in net proceeds to the Company of $13.0 million. As a result of the exercise of certain investor rights, the related liability amounting to $0.3 million was extinguished and recorded as an increase in Preferred Stock.

	On May 6, 2009, the Company met the Fourth Milestone and the Fifth Milestone and issued 11,319,656 shares of Series A Preferred Stock at $1.00 per share, resulting in net proceeds to the Company of $11.3 million. As a result of the exercise of certain investor rights, the related liability amounting to $0.3 million was extinguished and recorded as an increase in Preferred Stock.

	On October 14, 2009, the Series A Agreement was amended to allow for the sale and issuance of up to 3,000,000 additional shares of Series A Preferred Stock at an additional closing.

	Consequently, on October 14, 2009, the Company issued 3,000,000 shares of Series A Preferred Stock to existing Series A stockholders at a price per share of $1.00.

	In connection with certain of its Product and Technology Agreements entered into by the Company (see Note 7), the Company issued, on August 9, 2007, 2,000,000 shares of Series A-1 Preferred Stock and 3,000,000 shares of Junior Series A Preferred Stock, with each class of Preferred Stock being recorded at a fair market value of $1.00 per share based on the cash price paid by the Series A Investors for similar shares on the same date.

	In connection with a license agreement entered into by the Company on January 4, 2008 (see Note 7), the Company issued 4,000,000 shares of Series A-1 Preferred Stock. The Series A-1 Preferred Stock was valued at $1.00 per share. Accordingly, the Company charged $4.0 million to research and development expense during the year ended December 31, 2008.

	On December 11, 2009, the Company entered into a Series B Preferred Stock Purchase Agreement (the "Series B Agreement") with the Series A Investors and another investor (the "Series B Investors") which provided for the sale and issuance of the Company's Series B Preferred Stock at a price of $1.00 per share in the following tranches: (a) 15,000,000 shares at closing (the "Initial B Closing") and (b) up to an additional 15,000,000 shares based on the satisfaction of the Second Closing Conditions, as defined in the Series B Agreement.

	On March 1, 2011, the Company met the Second Closing Conditions, as defined in the Series B Agreement, and issued 15,000,000 shares of Series B Preferred Stock at $1.00 per share to the existing holders of Series B Preferred Stock.

	In June 2012, December 2012 and March 2013, the Company issued secured promissory notes (the "Notes") in the amount of $7.5 million and $4.0 million and $1.5 million, respectively, to the same lender. The Notes bore interest on the outstanding principal amount thereof from the Closing Date until paid in full at a rate per annum equal to the sum of (i) the greater of (A) the LIBOR Rate in effect for the applicable Interest Period and (B) 3.0%, plus (ii) the LIBOR Rate Margin adjusted on the first day of each Interest Period and fixed for the duration of each such Interest Period.

	In conjunction with the secured promissory note issued on June 20, 2012, the Lender received warrants to purchase 225,000 shares of Series B Preferred Stock with an exercise price of $1.00 per share. The warrants expire on June 20, 2022. In conjunction with the secured promissory note issued on December 24, 2012, the Lender received warrants to purchase 95,200 shares of Series B Preferred Stock with an exercise price of $2.50 per share. The warrants expire on December 24, 2022. In conjunction with the secured promissory note issued on March 15, 2013, the Lender received warrants to purchase 35,700 shares of Series B Preferred Stock with an exercise price of $2.50 per share. The warrants expire on March 15, 2023. The warrants provide for proportionate adjustments to be made to the number of shares purchasable and the exercise price payable under the warrants in the event of certain changes to the underlying Series B Preferred Stock, including for subdivisions, combinations and stock dividends.

	Prior to the completion of the Company's initial public offering, the Series B warrants were accounted for as a liability and were marked to market using a hybrid method of an option pricing model and a probability-weighted return methodology. The change in fair value of the Series B warrant liability was recorded within other loss. As of December 31, 2012, the value of the Series B warrant liability was $0.4 million as reflected in the accompanying Balance Sheet and the change in the fair value of $36 thousand for the year ended December 31, 2012 was recorded in the Statement of Operations.

	Upon completion of the Company's IPO on September 30, 2013, the underlying preferred stock of the Series A and Series B warrants were converted to common stock and the preferred stock warrants became exercisable for common stock. The fair value of the warrant liability was re-measured immediately prior to the completion of the Company's IPO, and the fair value of the warrant liability at that time was reclassified to additional paid-in capital. Based on the initial public offering price of $22.00 per share, the fair value of the warrant liability that was reclassified to additional paid-in capital was $2.2 million. The Company recorded a related charge of approximately $1.2 million for the year ended December 31, 2013.

Royalty_Agreement_and_Series_C

Royalty Agreement and Series C Agreement	12 Months Ended
Royalty Agreement and Series C Agreement	Dec. 31, 2013
Royalty Agreement and Series C Agreement	'
Royalty Agreement and Series C Agreement	'

	6. Royalty Agreement and Series C Agreement

	In May 2013, the Company entered into a Purchase and Sale Agreement (the "Purchase and Sale Agreement") with Novo A/S, providing for the Company to sell, and Novo A/S to purchase, the right, title, and interest in a portion of the revenues from the sale of (a) Fovista, (b) Fovista-Related Products, and (c) Other Products (as defined in the Purchase and Sale Agreement), calculated as low to mid-single digit percentages of net sales.

	The Purchase and Sale Agreement provides for up to three separate purchases for a purchase price of $41.7 million each, at a first, second and third closing, for an aggregate purchase price of $125.0 million. In each purchase, Novo A/S acquires rights to a low single digit percentage of net sales. If all royalty interests under the Purchase and Sale Agreement are purchased, Novo A/S will have a right to receive royalties on net sales at a mid-single digit percentage.

	In May 2013, the Company received cash proceeds of $41.7 million for the royalty entitlement related to the first closing on the date of the Purchase and Sale Agreement. Receipt of cash proceeds for the second and third purchases is contingent upon certain triggers and conditions detailed in the Purchase and Sale Agreement, none of which have occurred prior to the date of these financial statements.

	The royalty payment period covered by the Purchase and Sale Agreement begins on commercial launch and ends, on a product-by-product and country-by-country basis, on the latest to occur of (i) the 12th anniversary of the commercial launch, (ii) the expiration of certain patent rights and (iii) the expiration of the regulatory exclusivity for each product in each country.

	Under the terms of the Purchase and Sale Agreement, the Company is not required to reimburse or otherwise compensate Novo A/S through any means other than the agreed royalty entitlement. In addition, the Company does not, under the terms of the Purchase and Sale Agreement, have the right or obligation to prepay Novo A/S in connection with a change of control of the Company or otherwise.

	The proceeds from the first financing tranche under the Purchase and Sale Agreement were recorded as a liability on the Company's Balance Sheet as of December 31, 2013, in accordance with ASC 730. Because there is a significant related party relationship between the Company and Novo A/S, the Company is treating its obligation to make royalty payments under the Purchase and Sale Agreement as an implicit obligation to repay the funds advanced by Novo A/S. As the Company makes royalty payments in accordance with the Purchase and Sale Agreement, it will reduce the liability balance. At the time that such royalty payments become probable and estimable, and if such amounts exceed the liability balance, the Company will impute interest accordingly on a prospective basis based on such estimates, which would result in a corresponding increase in the liability balance.

	The Purchase and Sale Agreement requires the establishment of a Joint Oversight Committee in the event that Novo A/S does not continue to have a representative on the Company's board of directors. The Joint Oversight Committee would have responsibilities that include "discussion and review" of all matters related to Fovista research, development, regulatory approval and commercialization, but there is no provision either implicit or explicit that gives the Joint Oversight Committee or its members decision-making authority.

	Also in May 2013, the Company entered into a Series C Preferred Stock Purchase Agreement (the "Series C Agreement") with certain of its existing investors for the sale and issuance, upon the satisfaction of certain conditions, of an aggregate of 20,000,000 shares of the Company's Series C Preferred Stock at a price of $2.50 ($14.75 on a post-reverse stock split basis) per share. The Company issued 6,666,667 shares of Series C Preferred Stock at $2.50 ($14.75 on a post-reverse stock split basis) per share in a closing that occurred in May 2013, simultaneous with entry into the Series C Agreement. In August 2013, the Company amended the Series C Agreement to provide for the acceleration of the sale and issuance of the remaining 13,333,333 shares issuable thereunder, the purchase and sale of which closed on August 7, 2013 at $2.50 ($14.75 on a post-reverse stock split basis) per share for aggregate proceeds of $33.3 million. There are no further rights or obligations for the issuance of Series C Preferred Stock under the Series C Agreement.

	As the Series C Agreement was entered into in conjunction with the Purchase and Sale Agreement, the Company's management considered whether the consideration received for the issuance of Series C Preferred Stock or the consideration received for the sale of the royalty entitlement at the first closing under the Purchase and Sale Agreement should be allocated in the Company's financial statements in a manner different than the prices stated in the respective agreements. The Company's management, with the assistance of an outside valuation specialist, determined that the $2.50 ($14.75 on a post-reverse stock split basis) per share price approximated the fair value of a share of Series C Preferred Stock, and therefore concluded that the consideration received under the agreements should be allocated in accordance with the terms of the respective agreements. In connection with entering into the Series C Agreement, the minimum public offering price per share in an underwritten public offering of common stock required for the automatic conversion of outstanding shares of Series A Preferred Stock, Series A-1 Preferred Stock, Series B Preferred Stock, Series B-1 Preferred Stock, Series C Preferred Stock and Junior Series A Preferred Stock pursuant to the Company's certificate of incorporation was adjusted to $14.75 per share (subject to further adjustment as a result of any stock dividend, stock split, combination or similar recapitalization of the common stock).

	The Company has determined that in accordance with ASC 470-20-20, at the time of the initial closing under the Series C Agreement on May 23, 2013, there was a firm commitment from the Series C Preferred Stock investors with respect to the significant terms of the financing, including the quantity of shares to be issued, the fixed price of the shares and the timing of the transaction. In addition, the Company has concluded that the Series C Agreement and the Company's certificate of incorporation includes a disincentive feature for non-performance that was sufficiently large enough to make investor performance at subsequent closings probable. As such, the Company's measurement of any beneficial conversion feature occurred at the time of the initial closing. Based on a $10.03 per share valuation of the Company's common stock as of the date of the initial closing of the sale of the Series C Preferred Stock, as well as the fact that the Series C Preferred Stock featured a common stock conversion price of $14.75 per share (implying a one-to-one conversion into shares of common stock), the Company determined that there was no beneficial conversion feature associated with the issuance of its Series C Preferred Stock.

	The proceeds received from Novo A/S under the Purchase and Sale Agreement will be reported as revenue for income tax purposes. Notwithstanding the Company's receipt of $41.7 million in proceeds under the Purchase and Sale Agreement in May 2013, the Company has forecasted a tax loss for the 2013 tax year. Based upon the Company's cumulative history of losses and expected future losses, the Company recorded a full valuation allowance against all net federal and state deferred tax assets.

Product_and_Technology_Agreeme

Product and Technology Agreements	12 Months Ended
Product and Technology Agreements	Dec. 31, 2013
Product and Technology Agreements	'
Product and Technology Agreements	'

	7. Product and Technology Agreements

	Transferred Technology and Assumed Agreements

	Under an agreement dated July 27, 2007, the Company assumed the rights and obligations related to certain patents and know-how (the "Transferred Technology") and under certain agreements (the "Assumed Agreements") owned and/or controlled by OSI (Eyetech), Inc. (the "Transferor") for use in the Company's activities in the research, development and commercial production of a product as defined in the agreement (the "Divestiture Agreement"). In consideration for the Transferred Technology and the Assumed Agreements, the Company made an upfront payment of $4.0 million to the Transferor. In addition, on August 9, 2007, the Company issued to the Transferor 3,000,000 shares of Junior Series A Preferred Stock which was valued at $1.00 per share based upon the Original Issue Price.

	The Divestiture Agreement also entitles the Transferor to significant payments from the Company upon achievement of certain milestones, and to royalties on the Company's net sales of Products, as defined, and on terms set forth in the Divestiture Agreement.

	The Divestiture Agreement may be terminated by either party in the event of the other party's insolvency or material breach (following a specified cure period). Unless terminated earlier by the Company or the Transferor, the Divestiture Agreement will remain in effect until the Company no longer has any financial obligations to the Transferor, after which the rights granted to the Company under the Divestiture Agreement will become perpetual and fully paid-up.

	If the Company fails to satisfy its diligence obligations under the Divestiture Agreement, the Transferor may terminate the Divestiture Agreement as to particular countries with respect to which such failure has occurred, and upon such termination the Company will be obligated to transfer to the Transferor specified rights and licenses related to the product covered by the Divestiture Agreement and other related assets, and if the Company is then manufacturing such product or products, at the time of such termination, the Company may be obligated to provide transitional supply of the covered products to the Transferor, for the applicable countries.

	The Assumed Agreements include a license, manufacturing and supply agreement (the "Supply Agreement") with Nektar Therapeutics, AL (the "Supplier") for a reagent linked with the active ingredient in the Company's lead product candidate. Prior to the Company's assumption of the Supply Agreement in 2007, the Transferor paid the Supplier approximately $0.3 million under the Supply Agreement. The Company has paid the Supplier an aggregate of approximately $0.8 million under the Supply Agreement, which was charged to research and development expense during the year ended December 31, 2010. Under the Supply Agreement, the Company is obligated to make certain milestone payments to the Supplier, as well as tiered royalties based on certain percentages of net sales as well as certain other payments and revenue it may receive if it licenses certain product rights to a third party. See "Note 12—Commitments and Contingencies" below.

	The Supply Agreement, unless earlier terminated by either party, will expire upon the expiration of the Company's obligation to pay royalties to the Supplier on net sales of licensed products. The Supply Agreement may be terminated by either party in the event of the other party's material breach (following a specified cure period). The Company may terminate the Supply Agreement, without cause, effective at the end of a specified period following written notice to the Supplier, in which event the Company will be obligated to pay the Supplier specified termination fees and reimburse the Supplier for certain costs.

	License Agreements

	The Assumed Agreements also included an agreement with Archemix Corp. (the "Licensor") for the Company's acquisition of an exclusive royalty-bearing license over certain patent rights and technology owned and/or controlled by the Licensor (the "PDGF License") for use in the Company's activities in the research, development and commercial production of pharmaceutical products related to anti-PDGF aptamers (the "PDGF Licensed Products") as contemplated in the agreement (the "PDGF Agreement"). In addition, on July 31, 2007, the Company also entered into an agreement with the Licensor for the Company's acquisition of an exclusive royalty-bearing license over certain patent rights and technology owned and/or controlled by the Licensor (the "C5 License" and together with the PDGF License, the "Licenses") for use in the Company's activities in the research, development and commercial production of pharmaceutical products related to Zimura, formerly known as ARC1905 (the "C5 Licensed Product"), as contemplated in the agreement (the "C5 License Agreement" and together with the PDGF License Agreement, the "License Agreements"). In consideration of the Licenses, the Company paid the Licensor aggregate upfront fees of $1.0 million and, on August 9, 2007, issued to the Licensor an aggregate of 2,000,000 shares of Series A-1 Preferred Stock which was valued at $1.00 per share based on the cash price paid by the Series A Investors for similar shares on the same date.

	The Licensor is also entitled to certain regulatory milestone payments and sales milestone payments under the License Agreements.

	The upfront fees totaling $5.0 million and the value of the Junior Series A Preferred Stock and Series A-1 Preferred Stock issued totaling $5.0 million to the Transferor and the Licensor, under the Divestiture Agreement and the License Agreement, respectively, were charged to research and development expense during the year ended December 31, 2007.

	On January 4, 2008, the Company entered into an agreement with certain collaborative partners whereby the Company acquired an exclusive license to develop, market and promote products containing or comprising certain material upon which the collaborative partners have sole and exclusive worldwide rights to develop, market and sell. Upon the execution of the license agreement, the Company issued 4,000,000 shares of Series A-1 Preferred Stock to such partners. The Series A-1 Preferred Stock was valued at $1.00 per share based upon the Original Issue Price. Accordingly, the Company charged research and development expense for $4.0 million. Under the license agreement, the collaborative partners are entitled to certain development and sales milestone payments plus royalties on net sales. On May 3, 2012, the Company terminated such agreement.

	On September 12, 2011, the License Agreements, were amended to cover expanded licenses for all indications outside of the ophthalmic field (as defined in the amended license agreements (the "Amended License Agreements")). Upon the execution of the Amended License Agreements, the Company issued 500,000 shares of Series B-1 Preferred Stock to the Licensor. The Series B-1 Preferred Stock was valued at $1.00 per share based upon the Original Issue Price, which was deemed to be fair value as of the date of this transaction. Accordingly, the Company charged research and development expense for $0.5 million.

	Unless earlier terminated, the amended PDGF Agreement will expire upon the later of 10 years after the first commercial sale in any country of the last PDGF Licensed Product and the expiration of the last-to-expire valid claim of the PDGF licensed patents that covers a PDGF Licensed Product. Unless earlier terminated, the amended C5 Agreement will expire upon the later of 12 years after the first commercial sale in any country of the last C5 Licensed Product, the expiration of the last-to-expire valid claim of the C5 licensed patents, and the date on which no further payments of sublicensing income, if any, are to be received by the Company.

	Either of the Amended License Agreements may be terminated by either party in the event of the other party's material breach (following a specified cure period). The Licensor may also terminate each of the Amended License Agreements, or may convert the Company's exclusive licenses to non-exclusive licenses, if the Company challenges or assists a third party in challenging the validity or enforceability of any of the patents licensed under the applicable Amended License Agreement. The Company may terminate each of the Amended License Agreements at any time and for any or no reason effective at the end of a specified period following written notice to the Licensor.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
Property, Plant and Equipment	Dec. 31, 2013
Property, Plant and Equipment	'
Property, Plant and Equipment	'

	8. Property, Plant and Equipment

	Property and equipment at December 31, 2013 and 2012 were as follows:


		Useful Life		December 31,			December 31,
		(Years)		2013			2012
	Computer and other equipment		5	$	85		$	80
	Furniture and fixtures		7		117			117


					202			197
	Accumulated depreciation and amortization				(175	)		(155	)


	Property, plant and equipment, net			$	27		$	42





	For the years ended December 31, 2013, 2012 and 2011, depreciation expense was $20 thousand, $31 thousand, $32 thousand, respectively.

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2013
Income Taxes	'
Income Taxes	'

	9. Income Taxes

	The Company utilizes the liability method of accounting for deferred income taxes. Under this method, deferred tax liabilities and assets are recognized for the expected future tax consequences of temporary differences between the carrying amounts and the tax basis of assets and liabilities. A valuation allowance is established against deferred tax assets because, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company's policy is to record interest and penalties on uncertain tax positions as income tax expense. As of December 31, 2013, the Company does not believe any material uncertain tax positions are present. Accordingly, interest and penalties have not been accrued due to an uncertain tax position and the fact the Company has reported tax losses since inception.

	Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. A reconciliation of the statutory U.S. federal rate to the Company's effective tax rate is as follows:


		Years ended
		December 31,
		2013			2012			2011
	Percent of pre-tax income:
	U.S. federal staturtory income tax rate		35	%		35	%		35	%
	State taxes, net of federal benefit		—			—			3.4	%
	Permanent items		(2.2	)%		(1.0	)%		(0.6	)%
	Research and development credit		2.7	%		1	%		0.7	%
	Change in valuation allowance		(35.5	)%		(35.0	)%		(33.3	)%


	Effective income tax rate		—			—			5.2	%





	Significant components of the Company's deferred tax assets/liabilities for 2013 and 2012 consist of the following:


		December 31,
		2013			2012
	Deferred tax assets/(liabilities)
	Federal net operating loss carryforwards	$	30,084		$	29,464
	State and local net operating loss carryforwards		5,026			4,825
	License and technology payments		6,407			5,566
	Share-based compensation		1,396			476
	Depreciation		(7	)		(11	)
	Federal research and development credit carryforwards		2,966			1,562
	State research and development credit carryforwards		1,483			781


	Deferred income tax assets		47,355			42,663
	Valuation allowance		(47,355	)		(42,663	)


	Net deferred tax assets (liabilities)		—			—





	In assessing the reliability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the temporary differences representing net future deductible amounts become deductible. Due to the Company's history of losses, and lack of other positive evidence, the Company has determined that it is more likely than not that its deferred tax assets will not be realized, and therefore, the deferred tax assets are fully offset by a valuation allowance at December 31, 2013 and 2012.

	Deferred tax assets relating to employee share-based compensation deductions were reduced to reflect exercises of non-qualified stock option grants and vesting of restricted stock. Although certain of these deductions were reported on the corporate tax returns and increased net operating losses, these related tax benefits were not recognized for financial reporting purposes. The Company has unrealized excess tax benefits related to stock based compensation costs of $0.8 million that it expects to credit to stockholder's equity in future periods.

	The following table summarizes carryforwards of net operating losses and tax credits as of December 31, 2013:


		Amount			Expiration
	Federal net operating losses	$	85,955			2033
	Research and development credits	$	2,966			2033

	The federal, state, and local net operating loss carryforwards will start to expire in 2027. Utilization of the net operating losses and general business tax credits carryforwards may be subject to a substantial limitation under Sections 382 and 383 of the Internal Revenue Code of 1986 due to changes in ownership of the Company that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating losses and general business tax credits carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50 percentage points over a three-year period.

The Company believes that it had undergone at least one ownership change during 2007, but has not completed a study to determine the impact of the ownership change on its ability to utilize the aforementioned carryforwards. The amount of net operating losses and credits incurred during the year of ownership change amounted to $4.5 million and $0.1 million, respectively. As such, the net operating losses and credits at the time of the ownership change would have been no greater than $4.5 million and $0.1 million, respectively. Accordingly, the Company's ability to utilize its carryforwards may be limited. Additionally, U.S. tax laws limit the time during which these carryforwards may be applied against future taxes. Therefore, the Company may not be able to take full advantage of these carryforwards for federal or state income tax purposes. No other ownership changes have been identified in any years subsequent to 2007.

Operating_Leases

Operating Leases	12 Months Ended
Operating Leases	Dec. 31, 2013
Operating Leases	'
Operating Leases	'

	10. Operating Leases

	The Company leases office spaces located in Princeton, New Jersey and New York, New York under operating lease arrangements. The Company's Princeton, New Jersey office space lease expires in January 2019, whereas the Company's New York, New York office space lease expires in February 2020. Future minimum rental commitments under noncancelable operating leases in effect as of December 31, 2013, are as follows:


	2014	$	777
	2015		894
	2016		875
	2017		877
	2018		884
	Thereafter		740


	Total	$	5,047





	Rent expense is calculated on the straight-line basis and amounted to $0.5 million, $0.4 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.

Security_Deposits

Security Deposits	12 Months Ended
Security Deposits	Dec. 31, 2013
Security Deposits	'
Security Deposits	'

	11. Security Deposits

	Security deposits consist of amounts required to secure the Company's performance of its obligations under the operating leases for its New Jersey and New York offices. Such amounts were approximately $0.3 million and $0.2 million as of December 31, 2013 and 2012, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2013
Commitments and Contingencies	'
Commitments and Contingencies	'

	12. Commitments and Contingencies

	Under various agreements, the Company may be required to pay royalties and make milestone payments. These agreements include the following:



	•
	Under the Company's acquisition agreement with OSI (Eyetech), Inc., which agreement is now held by OSI Pharmaceuticals, Inc., ("OSI Pharmaceuticals"), a subsidiary of Astellas US, LLC, for rights to particular anti-PDGF aptamers, including Fovista, the Company is obligated to pay to OSI Pharmaceuticals future one-time payments of $12.0 million in the aggregate upon marketing approval in the United States and the European Union of a covered anti-PDGF product. The Company is also obligated to pay to OSI Pharmaceuticals a royalty at a low single-digit percentage of net sales of any covered anti-PDGF product the Company successfully commercializes.

	•
	Under a license agreement with Archemix Corp., ("Archemix"), with respect to pharmaceutical products comprised of or derived from any anti-PDGF aptamer, the Company is obligated to make future payments to Archemix of up to an aggregate of $14.0 million if the Company achieves specified clinical and regulatory milestones with respect to Fovista, up to an aggregate of $3.0 million if the Company achieves specified commercial milestones with respect to Fovista and, for each other anti-PDGF aptamer product that the Company may develop under the agreement, up to an aggregate of approximately $18.8 million if the Company achieves specified clinical and regulatory milestones and up to an aggregate of $3.0 million if the Company achieves specified commercial milestones. No royalties are payable to Archemix under this license agreement. From inception through December 31, 2013, the Company has made payments of approximately $4.8 million resulting from this agreement, including a $2.5 million payment to Archemix that was triggered by the initiation of the Company's Phase 3 clinical program for Fovista in August 2013.

	•
	Under a license agreement with Archemix with respect to pharmaceutical products comprised of or derived from anti-C5 aptamers, for each anti-C5 aptamer product that the Company may develop under the agreement, including Zimura (formerly known as ARC1905), the Company is obligated to make future payments to Archemix of up to an aggregate of $57.5 million if the Company achieves specified development, clinical and regulatory milestones and, as to all anti-C5 products under the agreement collectively, up to an aggregate of $22.5 million if the Company achieves specified commercial milestones. The Company is also obligated to pay Archemix a double-digit percentage of specified non-royalty payments the Company may receive from any sublicensee of its rights under this license agreement. No royalties are payable to Archemix under this license agreement. From inception through December 31, 2013, the Company has made payments totaling $2.0 million under this agreement.

	•
	Under a license, manufacturing and supply agreement with Nektar Therapeutics ("Nektar"), for specified pegylation reagents used to manufacture Fovista, the Company is obligated to make future payments to Nektar of up to an aggregate of $4.5 million if the Company achieves specified clinical and regulatory milestones, and an additional payment of $3.0 million if the Company achieves a specified commercial milestone with respect to Fovista. The Company is obligated to pay Nektar tiered royalties at low to mid-single-digit percentages of net sales of any licensed product the Company successfully commercializes, with the royalty percentage determined by the Company's level of licensed product sales, the extent of patent coverage for the licensed product and whether the Company has granted a third-party commercialization rights to the licensed product. The Company has agreed to pay Nektar a low double-digit percentage of any upfront payment the Company receives in connection with granting any third-party commercialization rights to a licensed product less certain milestone events the Company has previously paid, and a higher double-digit percentage of other specified amounts, such as milestone payments, the Company receives in connection with any such commercialization agreement, subject to agreed minimum and maximum amounts. From inception through December 31, 2013, the Company has made approximately $1.8 million in payments resulting from this agreement, including a $1.0 million payment to Nektar that was triggered by the initiation of the Company's Phase 3 clinical program for Fovista in August 2013.

	•
	Under the Company's royalty agreement with Novo A/S with respect to Fovista, the Company is obligated to pay Novo A/S a low to mid-single-digit percentage royalty based on worldwide sales of Fovista, with the royalty percentage determined by the amount of funding provided by Novo A/S.


	The Company also has employment agreements with certain employees which require the funding of a specific level of payments, if certain events, such as a change in control or termination without cause, occur.

	In addition, in the course of normal business operations, the Company has agreements with contract service providers to assist in the performance of the Company's research and development and manufacturing activities. Expenditures to CROs represent a significant cost in clinical development. The Company can elect to discontinue the work under these agreements at any time. The Company could also enter into additional collaborative research, contract research, manufacturing, and supplier agreements in the future, which may require upfront payments and even long-term commitments of cash.

Stock_Option_and_Compensation_

Stock Option and Compensation Plans	12 Months Ended
Stock Option and Compensation Plans	Dec. 31, 2013
Stock Option and Compensation Plans	'
Stock Option and Compensation Plans	'

	13. Stock Option and Compensation Plans

	The Company adopted its 2007 Stock Incentive Plan (the "2007 Plan") for employees and consultants for the purpose of advancing the interests of the Company stockholders by enhancing its ability to attract, retain and motivate persons who are expected to make important contributions to the Company. The 2007 Plan provided for the granting of stock option awards, restricted stock awards, and other stock-based and cash-based awards. Following the effectiveness of the 2013 Stock Incentive Plan described below in connection with the closing of the Company's initial public offering, the Company is no longer granting additional awards under the 2007 Plan.

	During the year ended December 31, 2013, the Company's Board of Directors and stockholders increased the number of shares authorized under the 2007 Plan by 1,878,343 shares. The Company's Board of Directors also adopted and the Company's stockholders also approved the 2013 stock incentive plan (the "2013 Plan"), which became effective immediately prior to the closing of the Company's initial public offering. The 2013 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, and other stock-based awards. Upon effectiveness of the 2013 Plan, the number of shares of the Company's common stock that were reserved for issuance under the 2013 Plan was the sum of (1) such number of shares (up to approximately 3,359,641 shares) as is equal to the sum of 739,317 shares (the number of shares of the common stock then available for issuance under the 2007 Plan), and such number of shares of the Company's common stock that are subject to outstanding awards under the 2007 Plan that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right plus (2) an annual increase, to be added the first day of each fiscal year, beginning with the fiscal year ending December 31, 2014 and continuing until, and including, the fiscal year ending December 31, 2023, equal to the lowest of 2,542,372 shares of the Company's common stock, 4% of the number of shares of the Company's common stock outstanding on the first day of the fiscal year and an amount determined by the Company's board of directors. The Company's employees, officers, directors, consultants and advisors are eligible to receive awards under the 2013 Plan. However, incentive stock options may only be granted to employees of the Company.

	As of December 31, 2013, the Company had approximately 2,708,000 stock options outstanding under the 2013 Plan and approximately 503,000 shares available for grant under the 2013 Plan. In connection with the evergreen provisions of the 2013 Plan, the number of shares available for issuance under the 2013 Plan was increased by approximately 1,257,000, effective as of January 1, 2014.

	Cash proceeds from, and the aggregate intrinsic value of, stock options exercised during the years ended December 31, 2013, 2012 and 2011, respectively, were as follows:


			Year ended December, 31
			2013			2012		2011
	Cash proceeds from options exercised		$	93		$	2	$	4
	Aggregate intrinsic value of options exercised		$	4,545		$	28	$	36

	A summary of the stock option activity, weighted average exercise prices, options outstanding and exercisable as of December 31, 2013 is as follows:


			For the Year ended December 31,
			2013					2012					2011
			Common			Weighted		Common			Weighted		Common			Weighted
			Stock			Average		Stock			Average		Stock			Average
			Options			Exercise		Options			Exercise		Options			Exercise
						Price					Price					Price
	Outstanding at beginning of year:			1,344		$	1.65		1,113		$	1.3		953		$	1.2
	Granted			1,583		$	14.82		250		$	3.12		184		$	1.65
	Exercised			(151	)	$	0.61		(19	)	$	0.12		(24	)	$	0.17
	Expired or forfeited			(68	)	$	1.53		—			—		—			—


	Outstanding at end of year:			2,708		$	9.41		1,344		$	1.65		1,113		$	1.3









			Year ended December 31,
			2013					2012					2011
	Options exercisable at end of year			984					823					561
	Weighted average grant date fair value (per share) of options granted during the period		$	10.48				$	1.65				$	1.18





						As of December 31, 2013
						Options Outstanding					Options Exercisable
	Range of Exercise Prices		Total			Weighted		Weighted			Number		Weighted
			Options			Average		Average			Exercisable		Average
			Outstanding			Remaining		Exercise					Exercise
						Life (Years)		Price					Price
	$0.12 - $10.03			1,800			7.8	$	4.89			969	$	2.5
	$10.04 - $20.00			604			9.5	$	13.37			10	$	13.22
	$20.01 - $33.27			304			9.8	$	28.34			5	$	32.58


				2,708								984




Aggregate Intrinsic Value		$	62,185							$	29,107

In connection with stock option awards granted to employees, the Company recognized share-based compensation expense approximately $2.2 million, $0.5 million, and $0.2 million, for the years ended December 31, 2013, 2012, and 2011, respectively. As of December 31, 2013, there was approximately $14.6 million of unrecognized compensation costs, net of estimated forfeitures, related to stock option awards to employees, which are expected to be recognized over a remaining weighted average period of 3.3 years.

In connection with stock options awards granted to consultants, the Company recognized approximately $0.7 million, $0.1 million and $0.1 million in share-based compensation expense during the years ended December 31, 2013, 2012 and 2011, respectively. As of December 31, 2013, there were approximately $1.9 million of unrecognized compensation costs, net of estimated forfeitures, related to stock option award granted to consultants which are expected to be recognized over a remaining weighted average period of 3.0 years.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2013
Employee Benefit Plan	'
Employee Benefit Plan	'

	14. Employee Benefit Plan

	The Company maintains a defined contribution 401(k) plan available to employees. Employee contributions are voluntary and are determined on an individual basis, limited by the maximum amounts allowable under federal tax regulations. The Company does not match any of the employee contributions.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2013
Fair Value Measurements	'
Fair Value Measurements	'

	15. Fair Value Measurements

	ASC 820, Fair Value Measurements and Disclosures, defines fair value as the price that would be received to sell an asset, or paid to transfer a liability, in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. The fair value standard also establishes a three-level hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.

	The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability on the measurement date. The three levels are defined as follows:



	•
	Level 1—inputs to the valuation methodology are quoted prices (unadjusted) for an identical asset or liability in an active market.

	•
	Level 2—inputs to the valuation methodology include quoted prices for a similar asset or liability in an active market or model-derived valuations in which all significant inputs are observable for substantially the full term of the asset or liability.

	•
	Level 3—inputs to the valuation methodology are unobservable and significant to the fair value measurement of the asset or liability.

	The following table presents, for each of the fair value hierarchy levels required under ASC 820, the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2013:


			Fair Value Measurement Using
			Quoted prices in			Significant other		Significant
			active markets for			observable inputs		unobservable
			identical assets			(Level 2)		inputs
			(Level 1)					(Level 3)
	Assets
	Investments in U.S. Treasury money market funds*		$	203,828		$	—	$	—
	Liabilities
	Series A Warrant Liability		$	—		$	—	$	—
	Series B Warrant Liabilty		$	—		$	—	$	—


	*
	Investments in U.S. Treasury money market funds are reflected in cash and cash equivalents in the accompanying Balance Sheets.

	The following table presents, for each of the fair value hierarchy levels required under ASC 820, the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012:


			Fair Value Measurement Using
			Quoted prices in			Significant other		Significant
			active markets for			observable inputs		unobservable
			identical assets			(Level 2)		inputs
			(Level 1)					(Level 3)
	Assets
	Investments in money market funds*		$	524		$	—	$	—
	Liabilities
	Series A Warrant Liability		$	—		$	—	$	523
	Series B Warrant Liabilty		$	—		$	—	$	443


	*
	Investments in money markets are reflected in cash and cash equivalents in the accompanying Balance Sheets.

	Level 3 Valuation

	The warrant liability was recorded in its own line item on the Company's Balance Sheets. The warrant liability was marked-to-market each reporting period with the change in fair value recorded to other loss in the Statement of Operations. The fair value of the warrant liability was estimated using a hybrid method between a probability-weighted expected return method, or PWERM, model and an option pricing model, which includes variables such as the expected volatility based on guideline public companies, the preferred stock value, and the estimated time to a liquidity event.

	The significant assumptions used in preparing the option pricing model for valuing the Company's warrants for the Series A preferred shares as of December 31, 2012, include (i) volatility (47.2% - 85.3%), (ii) risk free interest rate (0.05% - 0.62%), (iii) strike price ($0.01), (iv) fair value of Series A preferred shares ($1.22 - $4.34), (v) expected life (0.25 years to 4.5 years) and (vi) expected outcome probability weighting of three outcome scenarios: merger (65%); dissolution (20%) and an initial public offering (15%).

	The significant assumptions used in preparing the option pricing model for valuing the Company's warrants for the Series B preferred shares as of December 31, 2012, include (i) volatility (47.2% - 80.1%), (ii) risk free interest rate (0.05% - 1.68%), (iii) strike prices ($1.00 - $2.50), (iv) fair value of Series B preferred shares ($1.18 - $4.22), (v) expected life (0.25 years to 9.5 years) and (vi) expected outcome probability weighting of three outcome scenarios: merger (65%); dissolution (20%) and an initial public offering (15%).

	The table presented below is a summary of changes in the fair value of the Company's Level 3 valuation for the Series A and Series B warrant liabilities for the years ended December 31, 2013 and 2012:


		Level 3
		Series A			Series B
		Warrant Liability			Warrant Liability
Balance at December 31, 2011		$	193		$	—
Warrants issued in connection with venture debt facility			—			407
Change in fair value of warrant liability			330			36


Balance at December 31, 2012			523			443
Warrants issued in connection with venture debt facility			—			32
Change in fair value of warrant liability			379			802
Conversion of warrant liability to equity			(902	)		(1,277	)


Balance at December 31, 2013		$	—		$	—





Upon completion of the Company's IPO on September 30, 2013, the underlying preferred stock was converted to common stock and the preferred stock warrants became exercisable for common stock. The fair value of the warrant liability was re-measured immediately prior to the completion of the Company's IPO, and the fair value of the warrant liability at that time was reclassified to additional paid-in capital. Based on the initial public offering price of $22.00 per share, the fair value of the warrant liability that was reclassified to additional paid-in capital was $2.2 million. The Company recorded a related charge of approximately $1.2 million as other loss in its results of operations for the year ended December 31, 2013.

Notes_Payable

Notes Payable	12 Months Ended
Notes Payable	Dec. 31, 2013
Notes Payable	'
Notes Payable	'

	16. Notes Payable

	In June 2012, December 2012 and March 2013, the Company issued secured promissory notes (the "Notes") in the amount of $7.5 million and $4.0 million and $1.5 million, respectively, to the same lender. The Notes bore interest on the outstanding principal amount thereof from the Closing Date until paid in full at a rate per annum equal to the sum of (i) the greater of (A) the LIBOR Rate in effect for the applicable Interest Period and (B) 3.0%, plus (ii) the LIBOR Rate Margin adjusted on the first day of each Interest Period and fixed for the duration of each such Interest Period.

	The Company repaid in full the outstanding principal of the Notes, together with accrued and unpaid interest and related prepayment fees in May 2013. The repayment of the Notes resulted in a loss on extinguishment of debt in the amount of $1.1 million for the year ended December 31, 2013. In addition, the Company made payments of $0.8 million which, in accordance with the Notes, were required upon the earlier of the maturity date or the prepayment date of the Notes. These payments were recorded as interest expense for year ended December 31, 2013.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information (unaudited)	12 Months Ended
Selected Quarterly Financial Information (unaudited)	Dec. 31, 2013
Selected Quarterly Financial Information (unaudited)	'
Selected Quarterly Financial Information (unaudited)	'

	17. Selected Quarterly Financial Information (unaudited)

	The following is a summary of the quarterly results of operations for the years ended December 31, 2013 and 2012


		2013
		March 31			June 30			September 30			December 31
	Revenues	$	—		$	—		$	—		$	—
	Research and development		2,390			4,345			11,101			15,379
	General and administrative		1,738			3,241			4,166			5,065


	Loss from operations		(4,128	)		(7,586	)		(15,267	)		(20,444	)
	Net loss attributable to common shareholders	$	(6,361	)	$	(11,863	)	$	(18,424	)	$	(20,388	)
	Basic and diluted earnings per common share	$	(4.33	)	$	(8.07	)	$	(10.26	)	$	(0.65	)





		2012
		March 31			June 30			September 30			December 31
	Revenues	$	—		$	—		$	—		$	—
	Research and development		1,621			1,578			1,595			1,998
	General and administrative		1,388			1,694			2,259			1,548


	Loss from operations		(3,009	)		(3,272	)		(3,854	)		(3,546	)
	Net loss attributable to common shareholders	$	(4,765	)	$	(5,326	)	$	(5,928	)	$	(5,606	)
	Basic and diluted earnings per common share	$	(3.31	)	$	(3.68	)	$	(4.07	)	$	(3.81	)

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2013
Subsequent Events	'
Subsequent Events	'

	18. Subsequent Events

	On January 23, 2014, in connection with its royalty agreement with Novo A/S, the Company received cash proceeds of approximately $41.7 million in royalty financing in exchange for a low single-digit royalty interest in future potential worldwide sales of Fovista. The receipt of this second financing tranche under the royalty agreement was triggered as a result of the Company reaching an initial enrollment milestone of a specified number of patients in its Phase 3 clinical program for Fovista. The closing of a third potential financing tranche of approximately $41.7 million is subject to the further enrollment milestone of a specified number of patients in the Company's Phase 3 clinical program for Fovista, and the Company satisfying additional closing conditions and other obligations.

	On February 18, 2014, the Company closed a follow-on public offering of 2,628,571 shares of common stock at a public offering price of $31.50 per share of common stock. The Company sold 1,900,000 shares and 728,571 shares were sold by selling stockholders, 342,857 of which were sold by the selling stockholders upon the full exercise by the underwriters of their option to purchase additional shares in the offering. Net proceeds to the Company were approximately $55.5 million, after deducting underwriters' commissions and other offering expenses. The Company did not receive any proceeds from the sale of shares by the selling stockholders in the offering.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Significant Accounting Policies	'
Basis of Presentation	'

	Basis of Presentation

	The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States and include all adjustments necessary for the fair presentation of the Company's financial position for the periods presented.

Use of Estimates	'

	Use of Estimates

	The preparation of financial statements and related disclosures in conformity with accounting principles generally accepted in the United States requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company's Balance Sheets and the amount of expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, accounting for share-based compensation and accounting for research and development costs. Actual results could differ from those estimates.

Cash and Cash Equivalents	'

	Cash and Cash Equivalents

	The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. The carrying amounts reported in the Balance Sheets for cash and cash equivalents are valued at cost, which approximates their fair value.

Concentration of Credit Risk	'

	Concentration of Credit Risk

	The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents. The Company maintains its cash in bank accounts, which, at times, exceed federally insured limits. The Company also maintains cash equivalents in money market funds that invest primarily in U.S. Treasury securities. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on its cash and cash equivalents.

Foreign Currency Translation	'

	Foreign Currency Translation

	The Company maintains a bank account in a foreign currency. The Company considers the U.S. dollar to be its functional currency. Expenses are translated at the exchange rate on the date the expense is incurred. The effect of exchange rate fluctuations on translating foreign currency assets and liabilities into U.S. dollars is included in the Statements of Operations. Foreign exchange transaction gains and losses are included in the results of operations and are not material in the Company's financial statements.

Financial Instruments	'

	Financial Instruments

	The carrying amounts of the Company's financial instruments, which include cash and cash equivalents, accounts payable and accrued expenses approximate their respective fair value due to their short maturities.

Property and Equipment	'

	Property and Equipment

	Property and equipment, which consist mainly of computers and other equipment, are carried at cost less accumulated depreciation. Depreciation is computed over the estimated useful lives of the respective assets, generally five to seven years, using the straight-line method.

Research and Development	'

	Research and Development

	Research and development expenses consist of costs associated with the development and clinical testing of Fovista, an anti-PDGF aptamer the Company is developing for use in combination with anti-VEGF drugs for treatment of wet age-related macular degeneration, or wet AMD, and the Company's other product candidates. Research and development expenses consist of:



	•
	external research and development expenses incurred under arrangements with third parties, such as contract research organizations, ("CROs") and other vendors, contract manufacturing organizations and consultants; and

	•
	employee-related expenses, including salaries, benefits, travel and share-based compensation expense.

	Research and development costs also include costs of acquired product licenses and related technology rights where there is no alternative future use, prototypes used in research and development, consultant fees and amounts paid to collaborative partners.

	All research and development costs are charged to operations as incurred in accordance with ASC 730 Research and Development. The Company accounts for non-refundable advance payments for goods and services that will be used in future research and development activities as expenses when the service has been performed or when the goods have been received, rather than when the payment is made.

Income Taxes	'

	Income Taxes

	The Company utilizes the liability method of accounting for deferred income taxes, as set forth in ASC 740-10, Income Taxes-Overall. Under this method, deferred tax liabilities and assets are recognized for the expected future tax consequences of temporary differences between the carrying amounts and the tax basis of assets and liabilities. A valuation allowance is established against net deferred tax assets because, based on the weight of available evidence, it is more likely than not that some or all of the net deferred tax assets will not be realized. The Company maintains a full valuation allowance on its deferred tax assets. Accordingly, the Company has not recorded a benefit or provision for income taxes other than for the sale of a portion of its unused New Jersey State operating loss carryforwards through a program sponsored by the State of New Jersey and the New Jersey Economic Development Authority in 2011. The Company's U.S. federal net operating losses have occurred since inception and as such, tax years subject to potential tax examination could apply from that date because carrying back net operating loss opens the relevant year to audit.

Share-Based Compensation	'

	Share-Based Compensation

	The Company follows the provisions of ASC 718, Compensation—Stock Compensation which requires the measurement and recognition of compensation expense for all share-based payment awards made to employees and non-employee directors, including employee stock options. Share-based compensation expense is based on the grant date fair value estimated in accordance with the provisions of ASC 718 and is generally recognized as an expense over the requisite service period.

	For stock options granted as consideration for services rendered by non-employees, the Company recognizes expense in accordance with the requirements of ASC 505-50, Equity Based Payments to Non-Employees. Non-employee option grants that do not vest immediately upon grant are recorded as an expense over the vesting period of the underlying stock options. At the end of each financial reporting period prior to vesting, the value of these options, as calculated using the Black-Scholes option-pricing model, will be re-measured using the fair value of the Company's common stock and the non-cash expense recognized during the period will be adjusted accordingly. Since the fair value of options granted to non-employees is subject to change in the future, the amount of the future expense will include fair value re-measurements until the stock options are fully vested.

	Prior to the Company's initial public offering, the Company determined the estimated fair value of the common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector and the prices at which the Company sold shares of its common stock.

	Due to the lack of trading history, the Company's computation of stock-price volatility is based on the volatility rates of comparable publicly held companies over a period equal to the expected term of the options granted by the Company. The Company's computation of expected term was determined using the "simplified" method which is the midpoint between the vesting date and the end of the contractual term. The Company believes that it does not have sufficient reliable exercise data in order to justify the use of a method other than the "simplified" method of estimating the expected exercise term of employee stock option grants. The Company has paid no dividends to stockholders. The risk-free interest rate is based on the zero-coupon U.S. Treasury yield at the date of grant for a term equivalent to the expected term of the option. Share-based compensation expense includes stock options granted to employees and non-employees and has been reported in the Company's statements of operations as follows:


		Years ended
		December 31,
		2013		2012		2011
		(in thousands)
	Research and development	$	2,062	$	412	$	159
	General and administrative		809		228		89


	Total	$	2,871	$	640	$	248





	The Company had no shares of unvested restricted common stock granted to employees at December 31, 2013 or at December 31, 2012, respectively.

JOBS Act	'

	JOBS Act

	As an "emerging growth company" under the Jumpstart Our Business Startups Act of 2012, the Company can take advantage of an extended transition period for complying with new or revised accounting standards. This allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. The Company has elected to delay the adoption of such new or revised accounting standards. As a result of this election, the Company's financial statements may not be comparable to the financial statements of other public companies. There are, however, no standards for which adoption has been delayed that would have a significant impact on the financial statements of the Company.

Recent Accounting Pronouncements	'

	Recent Accounting Pronouncements

	In May 2011, the Financial Accounting Standards Board issued guidance that changed the requirement for presenting "Comprehensive Income" in the financial statements. The update requires an entity to present the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The currently available option to disclose the components of other comprehensive income within the statement of stockholders' equity will no longer be available. The update is effective for fiscal years, and interim periods within those years, beginning after December 15, 2011, and should be applied retrospectively. The Company did not incur any components of comprehensive income for the periods presented and therefore did not include a statement of comprehensive income in the financial statements.

	In February 2013, the FASB issued Accounting Standards Update ("ASU") 2013-02, Comprehensive Income: Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02"). ASU 2013-02 requires an entity to present the effect of certain significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. The amendments in the ASU do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. ASU 2013-02 is effective for public companies on a prospective basis for fiscal years beginning after December 15, 2012. As an emerging growth company as defined by the JOBS Act, the Company has delayed adoption of this pronouncement. However, the Company has not incurred any components of comprehensive income for the periods presented and the ASU requires only additional presentation, as such, there will be no impact to the Company's results of operations or financial position upon adoption.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
Significant Accounting Policies (Tables)	Dec. 31, 2013
Significant Accounting Policies	'
Schedule of share-based compensation expense including stock options granted to employees and non-employees	'




		Years ended
		December 31,
		2013		2012		2011
		(in thousands)
	Research and development	$	2,062	$	412	$	159
	General and administrative		809		228		89


	Total	$	2,871	$	640	$	248

Net_Loss_Per_Common_Share_Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
Net Loss Per Common Share (Tables)	Dec. 31, 2013
Net Loss Per Common Share	'
Schedule of computation of basic and diluted net loss per share	'




		Years ended December 31,
		2013			2012			2011
	Basic and diluted net loss per common share calculation:
	Net loss	$	(51,145	)	$	(14,562	)	$	(18,633	)
	Accretion of preferred stock dividends		(5,891	)		(7,063	)		(6,838	)


	Net loss attributable to common shareholders	$	(57,036	)	$	(21,625	)	$	(25,471	)




	Weighted average common shares outstanding		9,003			1,452			1,394




	Net loss per share of common stock—basic and diluted	$	(6.34	)	$	(14.89	)	$	(18.27	)







Schedule of potentially dilutive securities that have been excluded from the computations of diluted weighted average shares outstanding	'




		Years ended December 31,
		2013			2012			2011
	Redeemable convertible preferred stock		—			16,663			16,064
	Options outstanding		2,708			1,344			1,113
	Warrants		88			94			39


	Total		2,796			18,101			17,216

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
Property, Plant and Equipment (Tables)	Dec. 31, 2013
Property, Plant and Equipment	'
Schedule of property and equipment	'




		Useful Life		December 31,			December 31,
		(Years)		2013			2012
	Computer and other equipment		5	$	85		$	80
	Furniture and fixtures		7		117			117


					202			197
	Accumulated depreciation and amortization				(175	)		(155	)


	Property, plant and equipment, net			$	27		$	42

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2013
Income Taxes	'
Schedule of reconciliation of the statutory U.S. federal rate to the Company's effective tax rate	'




		Years ended
		December 31,
		2013			2012			2011
	Percent of pre-tax income:
	U.S. federal staturtory income tax rate		35	%		35	%		35	%
	State taxes, net of federal benefit		—			—			3.4	%
	Permanent items		(2.2	)%		(1.0	)%		(0.6	)%
	Research and development credit		2.7	%		1	%		0.7	%
	Change in valuation allowance		(35.5	)%		(35.0	)%		(33.3	)%


	Effective income tax rate		—			—			5.2	%







Schedule of significant components of the Company's deferred tax assets/liabilities	'




		December 31,
		2013			2012
	Deferred tax assets/(liabilities)
	Federal net operating loss carryforwards	$	30,084		$	29,464
	State and local net operating loss carryforwards		5,026			4,825
	License and technology payments		6,407			5,566
	Share-based compensation		1,396			476
	Depreciation		(7	)		(11	)
	Federal research and development credit carryforwards		2,966			1,562
	State research and development credit carryforwards		1,483			781


	Deferred income tax assets		47,355			42,663
	Valuation allowance		(47,355	)		(42,663	)


	Net deferred tax assets (liabilities)		—			—







Summary of carryforwards of net operating losses and tax credits	'

	The following table summarizes carryforwards of net operating losses and tax credits as of December 31, 2013:


		Amount			Expiration
	Federal net operating losses	$	85,955			2033
	Research and development credits	$	2,966			2033

Operating_Leases_Tables

Operating Leases (Tables)	12 Months Ended
Operating Leases (Tables)	Dec. 31, 2013
Operating Leases	'
Schedule of future minimum rental commitments under noncancelable operating leases	'

	Future minimum rental commitments under noncancelable operating leases in effect as of December 31, 2013, are as follows:


	2014	$	777
	2015		894
	2016		875
	2017		877
	2018		884
	Thereafter		740


	Total	$	5,047

Stock_Option_and_Compensation_1

Stock Option and Compensation Plans (Tables)	12 Months Ended
Stock Option and Compensation Plans (Tables)	Dec. 31, 2013
Stock Option and Compensation Plans	'
Schedule of cash proceeds from, and the aggregate intrinsic value of, stock options exercised	'




		Year ended December, 31
		2013			2012		2011
	Cash proceeds from options exercised	$	93		$	2	$	4
	Aggregate intrinsic value of options exercised	$	4,545		$	28	$	36



Summary of the stock option activity including weighted average exercise prices, options outstanding and exercisable	'




		For the Year ended December 31,
		2013					2012					2011
		Common			Weighted		Common			Weighted		Common			Weighted
		Stock			Average		Stock			Average		Stock			Average
		Options			Exercise		Options			Exercise		Options			Exercise
					Price					Price					Price
	Outstanding at beginning of year:		1,344		$	1.65		1,113		$	1.3		953		$	1.2
	Granted		1,583		$	14.82		250		$	3.12		184		$	1.65
	Exercised		(151	)	$	0.61		(19	)	$	0.12		(24	)	$	0.17
	Expired or forfeited		(68	)	$	1.53		—			—		—			—


	Outstanding at end of year:		2,708		$	9.41		1,344		$	1.65		1,113		$	1.3









		Year ended December 31,
		2013					2012					2011
	Options exercisable at end of year		984					823					561
	Weighted average grant date fair value (per share) of options granted during the period	$	10.48				$	1.65				$	1.18




Schedule of options outstanding and exercisable by range of exercise prices	'




					As of December 31, 2013
					Options Outstanding					Options Exercisable
	Range of Exercise Prices	Total			Weighted		Weighted			Number		Weighted
		Options			Average		Average			Exercisable		Average
		Outstanding			Remaining		Exercise					Exercise
					Life (Years)		Price					Price
	$0.12 - $10.03		1,800			7.8	$	4.89			969	$	2.5
	$10.04 - $20.00		604			9.5	$	13.37			10	$	13.22
	$20.01 - $33.27		304			9.8	$	28.34			5	$	32.58


			2,708								984




	Aggregate Intrinsic Value	$	62,185							$	29,107

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2013
Fair Value Measurements	'
Schedule of the Company's assets and liabilities that are measured at fair value on recurring basis	'

	The following table presents, for each of the fair value hierarchy levels required under ASC 820, the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2013:


		Fair Value Measurement Using
		Quoted prices in			Significant other			Significant
		active markets for			observable inputs			unobservable
		identical assets			(Level 2)			inputs
		(Level 1)						(Level 3)
	Assets
	Investments in U.S. Treasury money market funds*	$	203,828		$	—		$	—
	Liabilities
	Series A Warrant Liability	$	—		$	—		$	—
	Series B Warrant Liabilty	$	—		$	—		$	—


	*
	Investments in U.S. Treasury money market funds are reflected in cash and cash equivalents in the accompanying Balance Sheets.

	The following table presents, for each of the fair value hierarchy levels required under ASC 820, the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012:


		Fair Value Measurement Using
		Quoted prices in			Significant other			Significant
		active markets for			observable inputs			unobservable
		identical assets			(Level 2)			inputs
		(Level 1)						(Level 3)
	Assets
	Investments in money market funds*	$	524		$	—		$	—
	Liabilities
	Series A Warrant Liability	$	—		$	—		$	523
	Series B Warrant Liabilty	$	—		$	—		$	443


	*
	Investments in money markets are reflected in cash and cash equivalents in the accompanying Balance Sheets.

Summary of changes in fair value of the Company's Level 3 valuation for the Series A and Series B warrant liabilities	'




		Level 3
		Series A			Series B
		Warrant Liability			Warrant Liability
	Balance at December 31, 2011	$	193		$	—
	Warrants issued in connection with venture debt facility		—			407
	Change in fair value of warrant liability		330			36


	Balance at December 31, 2012		523			443
	Warrants issued in connection with venture debt facility		—			32
	Change in fair value of warrant liability		379			802
	Conversion of warrant liability to equity		(902	)		(1,277	)


	Balance at December 31, 2013	$	—		$	—

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Selected Quarterly Financial Information (unaudited)	'
Summary of the quarterly results of operations	'




		2013
		March 31			June 30			September 30			December 31
	Revenues	$	—		$	—		$	—		$	—
	Research and development		2,390			4,345			11,101			15,379
	General and administrative		1,738			3,241			4,166			5,065


	Loss from operations		(4,128	)		(7,586	)		(15,267	)		(20,444	)
	Net loss attributable to common shareholders	$	(6,361	)	$	(11,863	)	$	(18,424	)	$	(20,388	)
	Basic and diluted earnings per common share	$	(4.33	)	$	(8.07	)	$	(10.26	)	$	(0.65	)





		2012
		March 31			June 30			September 30			December 31
	Revenues	$	—		$	—		$	—		$	—
	Research and development		1,621			1,578			1,595			1,998
	General and administrative		1,388			1,694			2,259			1,548


	Loss from operations		(3,009	)		(3,272	)		(3,854	)		(3,546	)
	Net loss attributable to common shareholders	$	(4,765	)	$	(5,326	)	$	(5,928	)	$	(5,606	)
	Basic and diluted earnings per common share	$	(3.31	)	$	(3.68	)	$	(4.07	)	$	(3.81	)

Business_Details

Business (Details) (USD $)	0 Months Ended	12 Months Ended							84 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2013
	Sep. 30, 2013	item	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2013
Business	'	'	'	'	'	'	'	'	'
Number of business segments	'	1	'	'	'	'	'	'	'
Net loss	'	$51,145	$14,562	$18,633	$18,948	$13,514	$20,556	$14,417	$151,775
Accumulated deficit during the development stage	'	183,050	126,471	'	'	'	'	'	183,050
Common stock issued and sold in IPO (in shares)	8,740,000	'	'	'	'	'	'	'	'
Public offering price (in dollars per share)	$22	'	'	'	'	'	'	'	'
Shares issued on exercise of over-allotment option by underwriters	1,140,000	'	'	'	'	'	'	'	'
Net proceeds from IPO after deducting underwriting discounts and commissions and other offering expenses	$175,600	$175,555	'	'	'	'	'	'	$175,555

Significant_Accounting_Policie3

Significant Accounting Policies (Details)	12 Months Ended
Significant Accounting Policies (Details)	Dec. 31, 2013
Minimum	'
Property and equipment	'
Estimated useful lives	'5 years
Maximum	'
Property and equipment	'
Estimated useful lives	'7 years

Significant_Accounting_Policie4

Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Significant Accounting Policies	'	'	'
Dividends paid to stockholders	$0	'	'
Share-Based Compensation	'	'	'
Share-based compensation expense	2,871	640	248
Research and development	'	'	'
Share-Based Compensation	'	'	'
Share-based compensation expense	2,062	412	159
General and administrative	'	'	'
Share-Based Compensation	'	'	'
Share-based compensation expense	$809	$228	$89

Significant_Accounting_Policie5

Significant Accounting Policies (Details 3) (Restricted common stock, Unvested)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Restricted common stock \| Unvested	'	'
Other information	'	'
Shares of unvested restricted common stock granted to employees	0	0

Capitalization_Details

Capitalization (Details) (USD $)	0 Months Ended		12 Months Ended	84 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 09, 2013	Dec. 31, 2013	Dec. 31, 2013	Aug. 31, 2013	Dec. 31, 2012
Capitalization	'	'	'	'	'	'
Reverse stock split conversion ratio	'	5.9	'	'	'	'
Capital structure	'	'	'	'	'	'
Price of common stock issued in initial public offering (in dollars per share)	$22	'	'	'	'	'
Net proceeds from issuance of shares of common stock after deducting underwriters' commissions and other offering expenses (in dollars)	$175,600	'	$175,555	$175,555	'	'
Authorized shares of common stock	'	'	200,000,000	200,000,000	200,000,000	155,864,851
Authorized shares of preferred stock	'	'	'	'	5,000,000	'
Common stock	'	'	'	'	'	'
Capital structure	'	'	'	'	'	'
Number of shares registered in initial public offering	8,740,000	'	'	'	'	'
Price of common stock issued in initial public offering (in dollars per share)	$22	'	'	'	'	'
Net proceeds from issuance of shares of common stock after deducting underwriters' commissions and other offering expenses (in dollars)	$175,600	'	'	'	'	'
Shares issued on automatic conversion of redeemable convertible preferred stock	21,038,477	'	'	'	'	'

Net_Loss_Per_Common_Share_Deta

Net Loss Per Common Share (Details) (USD $)

3 Months Ended

12 Months Ended

84 Months Ended

In Thousands, except Per Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 30, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2013

Basic and diluted net loss per common share calculation:

Net loss

($51,145)

($14,562)

($18,633)

($18,948)

($13,514)

($20,556)

($14,417)

($151,775)

Accretion of preferred stock dividends

-5,891

-7,063

-6,838

-33,046

Net loss attributable to common stockholders

($20,388)

($18,424)

($11,863)

($6,361)

($5,606)

($5,928)

($5,326)

($4,765)

($57,036)

($21,625)

($25,471)

($184,821)

Weighted average common shares outstanding

9,003

1,452

1,394

Net loss per share of common stock - basic and diluted (in dollars per share)

($0.65)

($10.26)

($8.07)

($4.33)

($3.81)

($4.07)

($3.68)

($3.31)

($6.34)

($14.89)

($18.27)

Anti-dilutive securities

Total (in shares)

2,796

18,101

17,216

Redeemable convertible preferred stock

Anti-dilutive securities

Total (in shares)

16,663

16,064

Options outstanding

Anti-dilutive securities

Total (in shares)

2,708

1,344

1,113

Warrants

Anti-dilutive securities

Total (in shares)

Financing_Activities_Details

Financing Activities (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

84 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 30, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Jun. 18, 2007

Jan. 04, 2008

Aug. 09, 2007

Dec. 31, 2008

Aug. 09, 2007

Mar. 15, 2013

Dec. 24, 2012

Jun. 20, 2012

Apr. 14, 2008

Aug. 09, 2007

Apr. 14, 2008

Sep. 19, 2008

Apr. 14, 2008

6-May-09

Apr. 14, 2008

Oct. 14, 2009

Dec. 11, 2009

Mar. 01, 2011

Dec. 11, 2009

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Jun. 18, 2007

Series A Warrant

Series B Warrant

Series A preferred shares

Series A-1 Preferred Stock

Junior Series A Preferred Stock

Series B Preferred Stock

Series A Investors

Series B Investors

Notes

Series A Warrant

License Agreements

Divestiture Agreement

Series B Warrant

Series A preferred shares

Series B Preferred Stock

Initial Closing

First Milestone Event

Initiation of Phase 1b study of assets acquired or licensed

Second Milestone Event

Third Milestone Event

Fourth and Fifth Milestone Event

Fourth Milestone Event

Fifth Milestone Event

Additional closing

Initial Closing

Second Closing

Financing activities

Secured promissory notes issued

$1,500,000

$4,000,000

$7,500,000

$200,000

Interest rate (as a percent)

3.00%

8.00%

Share price (in dollars per share)

Shares available for sale and issuance under agreement

9,253,101

9,217,243

17,319,656

6,000,000

13,000,000

4,319,656

7,000,000

15,000,000

Period up to which the License Agreement is to be kept in effect

'10 days

Warrants issued (in shares)

210,000

35,700

95,200

225,000

Exercise price of warrants (in dollars per share)

$0.01

$2.50

Warrant Liability

966,000

500,000

400,000

Change in fair value of warrant liability

330,000

36,000

Shares issued

8,740,000

4,000,000

2,000,000

3,000,000

6,000,000

13,000,000

11,319,656

3,000,000

15,000,000

Proceeds from issuance of shares

49,699,000

14,990,000

130,632,000

13,000,000

11,300,000

Extinguishment of liability due to exercise of investor rights

300,000

Research and development expense

15,379,000

11,101,000

4,345,000

2,390,000

1,998,000

1,595,000

1,578,000

1,621,000

33,215,000

6,792,000

13,896,000

108,107,000

4,000,000

Basis of interest rate

'LIBOR

Public offering price (in dollars per share)

$22

Fair value of warrant liability reclassified to additional paid-in capital

2,200,000

Charge related to change in fair value of warrant liability

$1,181,000

$366,000

$7,000

$1,563,000

Royalty_Agreement_and_Series_C1

Royalty Agreement and Series C Agreement (Details) (USD $)	12 Months Ended	84 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	31-May-13	31-May-13
			Novo A/S	Novo A/S
			Purchase and Sale Agreement	Purchase and Sale Agreement
			Fovista, Fovista-Related Products, and Other Products	Fovista, Fovista-Related Products, and Other Products
				Maximum
				item
Royalty agreement	'	'	'	'
Number of purchases	'	'	'	3
Royalty rights purchase price	$41,667,000	$41,667,000	$41,700,000	'
Aggregate royalty rights	'	'	125,000,000	'
Proceeds from royalty purchase agreement	$41,667,000	$41,667,000	$41,700,000	'

Royalty_Agreement_and_Series_C2

Royalty Agreement and Series C Agreement (Details 2) (USD $)	12 Months Ended		84 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2013	23-May-13	Aug. 31, 2013	Aug. 07, 2013	31-May-13	23-May-13	23-May-13
				Series C Agreement	Series C Agreement	Series C Agreement	Series C Agreement	Series C Agreement	Initial Public Offering
				Series C Preferred Stock	Series C Preferred Stock	Series C Preferred Stock	Series C Preferred Stock	Common stock	Common stock
									Conversion Terms
Series C Preferred Stock Purchase Agreement	'	'	'	'	'	'	'	'	'
Shares available for sale and issuance under agreement	'	'	'	'	'	'	20,000,000	'	'
Share price (in dollars per share)	'	'	'	'	'	$2.50	$2.50	'	$14.75
Share price on a post-reverse stock split basis (in dollars per share)	'	'	'	'	'	$14.75	$14.75	'	'
Shares issued	'	'	'	'	'	13,333,333	6,666,667	'	'
Share price at fair value (in dollars per share)	'	'	'	$2.50	'	'	'	$10.03	'
Common stock conversion price (in dollars per share)	'	'	'	$14.75	'	'	'	'	'
Conversion ratio (per share of common stock)	'	'	'	'	'	'	'	1	'
Beneficial conversion feature	'	'	'	$0	'	'	'	'	'
Aggregate proceeds	$49,699,000	$14,990,000	$130,632,000	'	$33,300,000	'	'	'	'

Product_and_Technology_Agreeme1

Product and Technology Agreements (Details) (USD $)

3 Months Ended

12 Months Ended

84 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 30, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2007

Dec. 31, 2013

Dec. 31, 2012

Aug. 09, 2007

Jul. 27, 2007

Dec. 31, 2010

Dec. 31, 2008

Jan. 04, 2008

Aug. 09, 2007

Dec. 31, 2013

Jan. 04, 2008

Aug. 09, 2007

Sep. 12, 2011

Junior Series A Preferred Stock

Series A-1 Preferred Stock

Series B-1 Preferred Stock

Divestiture Agreement

Supply Agreement

License Agreements

Junior Series A Preferred Stock

Transferor

Supplier

Series A-1 Preferred Stock

PDGF Licensed Products

C5 Licensed Product

Licensor

Series A-1 Preferred Stock

Series B-1 Preferred Stock

Product and Technology Agreements

Upfront payment

$4,000,000

$1,000,000

Preferred stock issued (in shares)

3,000,000

Share price (in dollars per share)

Aggregate payment to supplier

300,000

Aggregate payment

800,000

Shares issued

6,000,000

500,000

4,000,000

2,000,000

500,000

Research and development expense related to upfront fees

5,000,000

Research and development expense related to issuance of preferred stock

5,000,000

Research and development expense

$15,379,000

$11,101,000

$4,345,000

$2,390,000

$1,998,000

$1,595,000

$1,578,000

$1,621,000

$33,215,000

$6,792,000

$13,896,000

$108,107,000

$4,000,000

$500,000

Expiration period of agreements

'10 years

'12 years

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details) (USD $)	12 Months Ended			84 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Property, plant and equipment	'	'	'	'
Property, plant and equipment, gross	$202	$197	'	$202
Accumulated depreciation and amortization	-175	-155	'	-175
Property, plant and equipment, net	27	42	'	27
Depreciation expense	20	31	32	174
Computer and other equipment	'	'	'	'
Property, plant and equipment	'	'	'	'
Useful Life	'5 years	'	'	'
Property, plant and equipment, gross	85	80	'	85
Furniture and fixtures	'	'	'	'
Property, plant and equipment	'	'	'	'
Useful Life	'7 years	'	'	'
Property, plant and equipment, gross	$117	$117	'	$117

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Percent of pre-tax income:	'	'	'
U.S. federal statutory income tax rate (as a percent)	35.00%	35.00%	35.00%
State taxes, net of federal benefit (as a percent)	'	'	3.40%
Permanent items (as a percent)	-2.20%	-1.00%	-0.60%
Research and development credit (as a percent)	2.70%	1.00%	0.70%
Change in valuation allowance (as a percent)	-35.50%	-35.00%	-33.30%
Effective income tax rate (as a percent)	'	'	5.20%
Deferred tax assets (liabilities)	'	'	'
Federal net operating loss carryforwards	$30,084	$29,464	'
State and local net operating loss carryforwards	5,026	4,825	'
License and technology payments	6,407	5,566	'
Share-based compensation	1,396	476	'
Depreciation	-7	-11	'
Federal research and development credit carryforwards	2,966	1,562	'
State research and development credit carryforwards	1,483	781	'
Deferred income tax assets	47,355	42,663	'
Valuation allowance	($47,355)	($42,663)	'

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended		84 Months Ended
	Dec. 31, 2013	Dec. 31, 2007	Dec. 31, 2013
	Dec. 31, 2013	Dec. 31, 2007	item
Income Taxes	'	'	'
Unrealized excess tax benefits related to stock based compensation costs	$800,000	'	'
Ownership change	'	'	'
Number of ownership changes undergone	'	'	0
Amount of net operating losses incurred	'	4,500,000	'
Amount of credits incurred	'	100,000	'
Minimum	'	'	'
Ownership change	'	'	'
Number of ownership changes undergone	'	1	'
Maximum	'	'	'
Ownership change	'	'	'
Amount of net operating losses incurred	'	4,500,000	'
Amount of credits incurred	'	100,000	'
Research and development	'	'	'
Carryforwards of tax credits	'	'	'
Credits	2,966,000	'	2,966,000
Federal	'	'	'
Carryforwards of net operating losses	'	'	'
Net operating losses	$85,955,000	'	85,955,000

Operating_Leases_Details

Operating Leases (Details) (USD $)	12 Months Ended
Operating Leases (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Future minimum rental commitments under noncancelable operating leases	'	'	'
2014	$777,000	'	'
2015	894,000	'	'
2016	875,000	'	'
2017	877,000	'	'
2018	884,000	'	'
Thereafter	740,000	'	'
Total	5,047,000	'	'
Rent expense	$500,000	$400,000	$400,000

Security_Deposits_Details

Security Deposits (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Security Deposits	'	'
Security deposits required to secure the Company's performance of its obligations under the operating leases	$0.30	$0.20

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)

Dec. 31, 2013

Aug. 31, 2013

Dec. 31, 2013

Aug. 31, 2013

Dec. 31, 2013

In Millions, unless otherwise specified

Acquisition agreement

License agreement

License, manufacturing and supply agreement

OSI Pharmaceuticals

Archemix

Nektar

Anti-PDGF aptamers

Fovista

Other anti-PDGF aptamer

Anti-C5 aptamers

Achievement of specified clinical and regulatory milestones

Fovista

Achievement of specified clinical and regulatory milestones

Initiation of planned Phase 3 clinical program of Fovista

Achievement of specified commercial milestones

Achievement of specified clinical and regulatory milestones

Achievement of specified commercial milestones

Achievement of specified development, clinical and regulatory milestones

Maximum

Initiation of planned Phase 3 clinical program of Fovista

Achievement of specified commercial sale milestone

Maximum

Commitments and contingencies

Amount of obligation to make one-time payments

$12

Amount to be paid on achievement of milestone

18.8

22.5

57.5

4.5

Royalty payable

Cumulative payments

$4.80

$2.50

$1.80

Stock_Option_and_Compensation_2

Stock Option and Compensation Plans (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option and Compensation Plans	'	'	'
Share-based compensation expense	$2,871	$640	$248
2007 Plan	'	'	'
Stock Option and Compensation Plans	'	'	'
Increase in number of shares authorized under the Plan	1,878,343	'	'
Number of shares of common stock available for issuance under the Plan	739,317	'	'
2013 Plan	'	'	'
Stock Option and Compensation Plans	'	'	'
Increase in number of shares authorized under the Plan	1,257,000	'	'
Number of shares of common stock available for issuance under the Plan	503,000	'	'
Annual increase in shares reserved for issuance under the Plan	2,542,372	'	'
Annual increase in shares reserved for issuance under the Plan (as a percent)	4.00%	'	'
Awards outstanding (in shares)	2,708,000	'	'
Common Stock Options	'	'	'
Outstanding at end of year: (in shares)	2,708,000	'	'
2013 Plan \| Maximum	'	'	'
Stock Option and Compensation Plans	'	'	'
Number of shares reserved for issuance under the Plan	3,359,641	'	'
Stock option	'	'	'
Stock Option and Compensation Plans	'	'	'
Awards outstanding (in shares)	2,708,000	1,344,000	1,113,000
Cash proceeds from, and the aggregate intrinsic value of, stock options exercised	'	'	'
Cash Proceeds from options exercised	93	2	4
Aggregate intrinsic value of options exercised	$4,545	$28	$36
Common Stock Options	'	'	'
Outstanding at beginning of year: (in shares)	1,344,000	1,113,000	953,000
Granted (in shares)	1,583,000	250,000	184,000
Exercised (in shares)	-151,000	-19,000	-24,000
Expired or forfeited (in shares)	-68,000	'	'
Outstanding at end of year: (in shares)	2,708,000	1,344,000	1,113,000
Weighted Average Exercise Price	'	'	'
Outstanding at beginning of year: (in dollars per share)	$1.65	$1.30	$1.20
Granted (in dollars per share)	$14.82	$3.12	$1.65
Exercised (in dollars per share)	$0.61	$0.12	$0.17
Expired or forfeited (in dollars per share)	$1.53	'	'
Outstanding at end of year: (in dollars per share)	$9.41	$1.65	$1.30
Additional disclosures	'	'	'
Options exercisable at end of year (in shares)	984,000	823,000	561,000
Weighted average grant date fair value (per share) of options granted during the period (in dollars per share)	$10.48	$1.65	$1.18

Stock_Option_and_Compensation_3

Stock Option and Compensation Plans (Details 2) (Stock option, USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013
Options Outstanding	'
Total Options Outstanding (in shares)	2,708
Aggregate Intrinsic Value	$62,185
Options Exercisable	'
Number Exercisable (in shares)	984
Aggregate Intrinsic Value	$29,107
$0.12-$10.03	'
Range of Exercise Prices	'
Exercise prices, low end of range (in dollars per share)	$0.12
Exercise prices, high end of range (in dollars per share)	$10.03
Options Outstanding	'
Total Options Outstanding (in shares)	1,800
Weighted Average Remaining Life	'7 years 9 months 18 days
Weighted Average Exercise Price (in dollars per share)	$4.89
Options Exercisable	'
Number Exercisable (in shares)	969
Weighted Average Exercise Price (in dollars per share)	$2.50
$10.04-$20.00	'
Range of Exercise Prices	'
Exercise prices, low end of range (in dollars per share)	$10.04
Exercise prices, high end of range (in dollars per share)	$20
Options Outstanding	'
Total Options Outstanding (in shares)	604
Weighted Average Remaining Life	'9 years 6 months
Weighted Average Exercise Price (in dollars per share)	$13.37
Options Exercisable	'
Number Exercisable (in shares)	10
Weighted Average Exercise Price (in dollars per share)	$13.22
$20.01-$33.27	'
Range of Exercise Prices	'
Exercise prices, low end of range (in dollars per share)	$20.01
Exercise prices, high end of range (in dollars per share)	$33.27
Options Outstanding	'
Total Options Outstanding (in shares)	304
Weighted Average Remaining Life	'9 years 9 months 18 days
Weighted Average Exercise Price (in dollars per share)	$28.34
Options Exercisable	'
Number Exercisable (in shares)	5
Weighted Average Exercise Price (in dollars per share)	$32.58

Stock_Option_and_Compensation_4

Stock Option and Compensation Plans (Details 3) (USD $)	12 Months Ended
Stock Option and Compensation Plans (Details 3) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option and Compensation Plans	'	'	'
Share-based compensation expense	$2,871,000	$640,000	$248,000
Stock options	'	'	'
Stock Option and Compensation Plans	'	'	'
Share-based compensation expense	2,200,000	500,000	200,000
Unrecognized share-based compensation costs, net of estimated forfeitures	14,600,000	'	'
Expected weighted average period to recognize share-based compensation costs	'3 years 3 months 18 days	'	'
Non-employee Options \| Consultants	'	'	'
Stock Option and Compensation Plans	'	'	'
Share-based compensation expense	700,000	100,000	100,000
Unrecognized share-based compensation costs, net of estimated forfeitures	$1,900,000	'	'
Expected weighted average period to recognize share-based compensation costs	'3 years	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012
In Thousands, unless otherwise specified		Recurring basis	Recurring basis	Recurring basis	Recurring basis
		Quoted prices in active markets for identical assets (Level 1)	Quoted prices in active markets for identical assets (Level 1)	Significant unobservable inputs (Level 3)	Significant unobservable inputs (Level 3)
		Money Market Funds	U.S. Treasury money market funds	Series A Warrant	Series B Warrant
Fair Value Measurements	'	'	'	'	'
Investments in money market funds	'	$524	$203,828	'	'
Warrant Liability	$966	'	'	$523	$443

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (Level 3, USD $)	12 Months Ended
	Dec. 31, 2012
	item
Series A Warrant	'
Level 3 Valuation	'
Strike price (in dollars per share)	$0.01
Number of scenarios for expected outcome probability weight	3
Expected outcome probability rate of merger (as a percent)	65.00%
Expected outcome probability rate of dissolution (as a percent)	20.00%
Expected outcome probability rate of initial public offering (as a percent)	15.00%
Series A Warrant \| Minimum	'
Level 3 Valuation	'
Volatility (as a percent)	47.20%
Risk free interest rate (as a percent)	0.05%
Expected life	'3 months
Series A Warrant \| Maximum	'
Level 3 Valuation	'
Volatility (as a percent)	85.30%
Risk free interest rate (as a percent)	0.62%
Expected life	'4 years 6 months
Series A Warrant \| Series A preferred shares \| Minimum	'
Level 3 Valuation	'
Fair value of shares (in dollars per share)	$1.22
Series A Warrant \| Series A preferred shares \| Maximum	'
Level 3 Valuation	'
Fair value of shares (in dollars per share)	$4.34
Series B Warrant	'
Level 3 Valuation	'
Number of scenarios for expected outcome probability weight	3
Expected outcome probability rate of merger (as a percent)	65.00%
Expected outcome probability rate of dissolution (as a percent)	20.00%
Expected outcome probability rate of initial public offering (as a percent)	15.00%
Series B Warrant \| Minimum	'
Level 3 Valuation	'
Volatility (as a percent)	47.20%
Risk free interest rate (as a percent)	0.05%
Strike price (in dollars per share)	$1
Expected life	'3 months
Series B Warrant \| Maximum	'
Level 3 Valuation	'
Volatility (as a percent)	80.10%
Risk free interest rate (as a percent)	1.68%
Strike price (in dollars per share)	$2.50
Expected life	'9 years 6 months
Series B Warrant \| Series B preferred shares \| Minimum	'
Level 3 Valuation	'
Fair value of shares (in dollars per share)	$1.18
Series B Warrant \| Series B preferred shares \| Maximum	'
Level 3 Valuation	'
Fair value of shares (in dollars per share)	$4.22

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (USD $)	0 Months Ended	12 Months Ended			84 Months Ended
Fair Value Measurements (Details 3) (USD $)	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Changes in fair value of the Company's Level 3 valuation for the Series A and Series B warrant liabilities	'	'	'	'	'
Public offering price (in dollars per share)	$22	'	'	'	'
Fair value of warrant liability reclassified to additional paid-in capital	$2,200,000	'	'	'	'
Charge related to change in fair value of warrant liability	'	1,181,000	366,000	7,000	1,563,000
Series A Warrant	'	'	'	'	'
Changes in fair value of the Company's Level 3 valuation for the Series A and Series B warrant liabilities	'	'	'	'	'
Balance at the beginning of the period	'	523,000	193,000	'	'
Change in fair value of warrant liability	'	379,000	330,000	'	'
Conversion of warrant liability to equity	'	-902,000	'	'	'
Balance at the end of the period	'	'	523,000	'	'
Series B Warrant	'	'	'	'	'
Changes in fair value of the Company's Level 3 valuation for the Series A and Series B warrant liabilities	'	'	'	'	'
Balance at the beginning of the period	'	443,000	'	'	'
Warrants issued in connection with venture debt facility	'	32,000	407,000	'	'
Change in fair value of warrant liability	'	802,000	36,000	'	'
Conversion of warrant liability to equity	'	-1,277,000	'	'	'
Balance at the end of the period	'	'	$443,000	'	'

Notes_Payable_Details

Notes Payable (Details) (USD $)	12 Months Ended	84 Months Ended	12 Months Ended					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 18, 2007	Dec. 31, 2013
			Notes	Notes	Notes	Notes	Notes	Notes
								LIBOR
Notes payable	'	'	'	'	'	'	'	'
Secured promissory notes issued	'	'	'	$1,500,000	$4,000,000	$7,500,000	$200,000	'
Fixed interest rate (as a percent)	'	'	3.00%	'	'	'	8.00%	'
Basis of interest rate	'	'	'LIBOR	'	'	'	'	'LIBOR
Margin on base rate	'	'	'	'	'	'	'	'LIBOR Rate Margin
Loss on extinguishment of debt	1,091,000	1,091,000	1,100,000	'	'	'	'	'
Payment of debt recorded as interest expense	'	'	$800,000	'	'	'	'	'

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended			84 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 30, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Selected Quarterly Financial Information (unaudited)	'	'	'	'	'	'	'	'	'	'	'	'
Research and development	$15,379	$11,101	$4,345	$2,390	$1,998	$1,595	$1,578	$1,621	$33,215	$6,792	$13,896	$108,107
General and administrative	5,065	4,166	3,241	1,738	1,548	2,259	1,694	1,388	14,210	6,889	5,738	41,559
Loss from operations	-20,444	-15,267	-7,586	-4,128	-3,546	-3,854	-3,272	-3,009	-47,425	-13,681	-19,634	-149,666
Net loss attributable to common stockholders	($20,388)	($18,424)	($11,863)	($6,361)	($5,606)	($5,928)	($5,326)	($4,765)	($57,036)	($21,625)	($25,471)	($184,821)
Basic and diluted earnings per common share (in dollars per share)	($0.65)	($10.26)	($8.07)	($4.33)	($3.81)	($4.07)	($3.68)	($3.31)	($6.34)	($14.89)	($18.27)	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	0 Months Ended	12 Months Ended			84 Months Ended	0 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Feb. 18, 2014	Jan. 23, 2014
						Subsequent event	Subsequent event
							Novo A/S
							Royalty agreement
Subsequent events	'	'	'	'	'	'	'
Cash proceeds received in exchange for a low single-digit royalty interest	'	$41,667,000	'	'	$41,667,000	'	$41,700,000
Third potential financing tranche	'	'	'	'	'	'	41,700,000
Shares of common stock offered in follow on offering	'	'	'	'	'	2,628,571	'
Offering price (in dollars per share)	'	'	'	'	'	$31.50	'
Shares sold by the company in follow on offering	8,740,000	'	'	'	'	1,900,000	'
Shares sold by selling stockholders in follow on offering	'	'	'	'	'	728,571	'
Shares sold by selling stockholders upon full exercise by underwriters of their option to purchase additional shares	'	'	'	'	'	342,857	'
Net proceeds, after deducting underwriters' commissions and other offering expense	'	$94,000	$2,000	$4,000	$218,000	$55,500,000	'