Phio Pharmaceuticals (PHIO) 10-Q13 Nov 142014 Q3 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
Document and Entity Information	Sep. 30, 2014	Nov. 07, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'RXII	'
Entity Registrant Name	'RXi Pharmaceuticals Corp	'
Entity Central Index Key	'0001533040	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Smaller Reporting Company	'
Entity Common Stock, Shares Outstanding	'	21,132,021

Condensed_Balance_Sheets_Unaud

Condensed Balance Sheets (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:	'	'
Cash and cash equivalents	$5,130	$11,390
Restricted cash	50	50
Short-term investments	5,000	3,000
Prepaid expenses and other current assets	510	303
Total current assets	10,690	14,743
Equipment and furnishings, net	193	177
Other assets	18	18
Total assets	10,901	14,938
Current liabilities:	'	'
Accounts payable	137	163
Accrued expenses and other current liabilities	958	1,795
Deferred revenue	61	118
Total current liabilities	1,156	2,076
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Preferred stock	0	0
Common stock, $0.0001 par value, 100,000,000 shares authorized; 21,132,021 and 11,788,045 shares issued and outstanding at September 30, 2014 and December 31, 2013, respectively	2	1
Additional paid-in capital	47,452	40,969
Accumulated deficit	-44,578	-38,082
Total stockholders' equity	4,723	4,942
Total liabilities, convertible preferred stock and stockholders' equity	10,901	14,938
Series A Convertible Preferred Stock [Member]	'	'
Current liabilities:	'	'
Series A convertible preferred stock, $0.0001 par value, 15,000 shares authorized; 5,022 and 7,920 shares issued and outstanding at September 30, 2014 and December 31, 2013, respectively (at liquidation value)	5,022	7,920
Series A-1 Convertible Preferred Stock [Member]	'	'
Stockholders' equity:	'	'
Preferred stock	$1,847	$2,054

Condensed_Balance_Sheets_Unaud1

Condensed Balance Sheets (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	21,132,021	11,788,045
Common stock, shares outstanding	21,132,021	11,788,045
Series A Convertible Preferred Stock [Member]	'	'
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	15,000	15,000
Preferred stock, shares issued	5,022	7,920
Preferred stock, shares outstanding	5,022	7,920
Series A-1 Convertible Preferred Stock [Member]	'	'
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	1,847	2,054
Preferred stock, shares outstanding	1,847	2,054

Condensed_Statements_of_Operat

Condensed Statements of Operations (Unaudited) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenues:	'		'		'		'
Grant revenues	$16		$92		$57		$370
Operating expenses:	'		'		'		'
Research and development expenses	1,459	[1]	1,229	[1]	4,118	[1]	16,213	[1]
General and administrative expenses	766	[1]	934	[1]	2,459	[1]	2,588	[1]
Total operating expenses	2,225		2,163		6,577		18,801
Loss from operations	-2,209		-2,071		-6,520		-18,431
Interest income, net	4		10		15		14
Other income (expense), net	-1		2		9		'
Net loss	-2,206		-2,059		-6,496		-18,417
Series A and Series A-1 convertible preferred stock dividends	-700		-1,447		-3,668		-7,393
Net loss applicable to common stockholders	($2,906)		($3,506)		($10,164)		($25,810)
Net loss per common share applicable to common stockholders (Note 1):	'		'		'		'
Basic and diluted	($0.17)		($0.30)		($0.69)		($2.64)
Weighted average common shares: basic and diluted	17,494,109		11,630,189		14,726,417		9,783,615

[1]	Non-cash share-based compensation expenses included in operating expenses are as follows: Research and development $ 216 $ 165 $ 632 $ 726 General and administrative 238 284 770 780

Condensed_Statements_of_Operat1

Condensed Statements of Operations (Unaudited) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Research and Development Expense [Member]	'	'	'	'
Non-cash share-based compensation expenses	$216	$165	$632	$726
General and Administrative Expense [Member]	'	'	'	'
Non-cash share-based compensation expenses	$238	$284	$770	$780

Condensed_Statements_of_Cash_F

Condensed Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:	'	'
Net loss	($6,496)	($18,417)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	68	78
Gain on disposal of equipment	-10	'
Non-cash share-based compensation	1,402	1,506
Fair value of common stock issued in exchange for patent and technology rights	'	12,250
Changes in operating assets and liabilities:	'	'
Prepaid expenses and other assets	-207	33
Accounts payable	-26	-239
Accrued expenses and other current liabilities	-837	251
Deferred revenue	-57	-371
Net cash used in operating activities	-6,163	-4,909
Cash flows from investing activities:	'	'
Purchases of short-term investments	-5,000	-9,000
Maturities of short-term investments	3,000	'
Cash paid for purchase of equipment and furnishings	-86	-10
Proceeds from disposal of equipment and furnishings	12	'
Net cash used in investing activities	-2,074	-9,010
Cash flows from financing activities:	'	'
Net proceeds from the issuance of common stock	1,947	15,651
Proceeds from issuance of common stock in connection with employee stock purchase plan	30	'
Proceeds from exercise of stock options	'	5
Cash paid in lieu of fractional shares for 1:30 reverse stock split	'	-12
Repayments of capital lease obligations	'	-5
Net cash provided by financing activities	1,977	15,639
Net (decrease) increase in cash and cash equivalents	-6,260	1,720
Cash and cash equivalents at the beginning of period	11,390	5,127
Cash and cash equivalents at the end of period	5,130	6,847
Supplemental disclosure of non-cash investing and financing activities:	'	'
Exchange of Series A convertible preferred stock into Series A-1 convertible preferred stock	3,000	2,000
Conversion of Series A and Series A-1 convertible preferred stock into common stock	3,582	396
Fair value of Series A and Series A-1 convertible preferred stock dividends	3,668	7,393
Series A and Series A-1 convertible preferred stock dividends	$477	$510

Condensed_Statements_of_Cash_F1

Condensed Statements of Cash Flows (Unaudited) (Parenthetical)	9 Months Ended
	Sep. 30, 2013
Statement of Cash Flows [Abstract]	'
Reverse stock split ratio	0.033

Nature_of_Business_and_Basis_o

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Nature of Business and Basis of Presentation	'

	1. Nature of Business and Basis of Presentation

	RXi Pharmaceuticals Corporation (“RXi” or the “Company”) is a biotechnology company focused on discovering, developing and commercializing innovative therapies based on its proprietary, next-generation RNAi platform. Therapeutics that use RNA interference, or “RNAi,” have great promise because of their ability to “silence,” or down-regulate, the expression of a specific gene that may be overexpressed in a disease condition. The Company’s first RNAi product candidate, RXI-109, commenced human clinical trials in 2012. RXI-109 targets connective tissue growth factor (“CTGF”), a key regulator of fibrosis and scar formation, and is initially being developed to reduce or inhibit scar formation in the skin following surgery. The Company’s pipeline includes a clinical program in anti-scarring, a preclinical program in ophthalmology and a discovery program to identify other potential sd-rxRNA® lead compounds and targets in dermatology and ophthalmology indications, in part from the RNAi-related assets acquired from OPKO Health, Inc.

	Basis of Presentation

	The accompanying condensed financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures included in the Company’s annual financial statements have been condensed or omitted. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of the condensed financial statements have been included. Interim results are not necessarily indicative of results for a full year.

	Uses of Estimates in Preparation of Financial Statements

	The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.

	Cash and Cash Equivalents

	The Company considers all highly liquid debt instruments with an original maturity of three months or less to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market accounts and certificates of deposit.

	Restricted Cash

	Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards.

	Short-term Investments

	The Company’s short-term investments consist of certificates of deposit with original maturities ranging from three months to one year.

	Revenue Recognition

	Principal sources of revenue consist of government research grants. Revenue from government grants is recognized over the respective contract periods as the services are performed, provided there is persuasive evidence of an arrangement, the fee is fixed or determinable and collection of the related receivable is reasonably assured, and no contingencies remain outstanding. Monies received prior to the recognition of revenue are recorded as deferred revenue.

	Research and Development Expenses

	Research and development costs are charged to expense as incurred and relate to salaries, employee benefits, facility-related expenses, supplies, share-based compensation related to employees and non-employees involved in the Company’s research and development, external services, other operating costs and overhead related to our research and development departments, costs to acquire technology licenses and expenses associated with preclinical activities and our clinical trials. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed us with respect to services provided and/or materials that we have received.

	Preclinical and clinical trial expenses relate to third-party services, patient-related fees at the sites where our clinical trials are being conducted, laboratory costs, analysis costs, toxicology studies and investigator fees. Costs associated with these expenses are generally payable on the passage of time or when certain milestones are achieved. Expense is recorded during the period incurred or in the period in which a milestone is achieved. In order to ensure that we have adequately provided for preclinical and clinical expenses during the proper period, we maintain an accrual to cover these expenses. These accruals are assessed on a quarterly basis and are based on such assumptions as expected total cost, the number of patients and clinical trial sites and length of the study. Actual results may differ from these estimates and could have a material impact on our reported results. Our historical accrual estimates have not been materially different from our actual costs.

	Stock-based Compensation

	The Company follows the provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 718, “Compensation — Stock Compensation” (“ASC 718”), which requires the measurement and recognition of compensation expense for all stock-based payment awards made to employees, officers and non-employee directors, including stock options. Stock compensation expense based on the grant date fair value estimated in accordance with the provisions of ASC 718 is recognized as an expense over the requisite service period.

	Net Loss per Share

	The Company accounts for and discloses net loss per common share in accordance with FASB ASC Topic 260, “Earnings per Share.” Basic and diluted net loss per common share is computed by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding. When the effects are not anti-dilutive, diluted earnings per share is computed by dividing the Company’s net earnings by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares.

	The following table sets forth the potential common shares excluded from the calculation of net loss per common share because their inclusion would be anti-dilutive:



		September 30,
		2014		2013
	Options to purchase common stock		2,987,264		2,556,269
	Common stock underlying Series A and Series A-1 convertible preferred stock		16,743,495		23,986,054
	Warrants to purchase common stock		4,615		4,615

	Total		19,735,374		26,546,938


	Comprehensive Loss

	The Company’s net loss is equal to its comprehensive loss for all periods presented.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	9 Months Ended
Recent Accounting Pronouncements	Sep. 30, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recent Accounting Pronouncements	'

	2. Recent Accounting Pronouncements

	In June 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-10, “Development Stage Entities (Topic 915) — Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation.” ASU 2014-10 eliminates the concept of a development-stage entity in its entirety from current accounting guidance. Under current guidance, development-stage entities are required to present inception-to-date financial information in their annual statements. The new standard eliminates the concept of a development-stage entity from generally accepted accounting principles. Therefore, the current incremental reporting requirements for a development-stage entity, including inception-to-date information, will no longer apply. For public companies, the new standard is effective for reporting periods beginning after December 15, 2014, and interim periods therein. The Company adopted this standard in June 2014. Other than the exclusion of the presentation of inception-to-date financial information, the adoption of this standard did not have a material impact on the Company’s financial statements.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'

	3. Fair Value Measurements

	The Company follows the provisions of FASB ASC Topic 820, “Fair Value Measurements and Disclosures,” for the Company’s financial assets and liabilities that are re-measured and reported at fair value at each reporting period and are re-measured and reported at fair value at least annually using a fair value hierarchy that is broken down into three levels. Level inputs are as defined as follows:

	Level 1 — quoted prices in active markets for identical assets or liabilities.

	Level 2 — other significant observable inputs for the assets or liabilities through corroboration with market data at the measurement date.

	Level 3 — significant unobservable inputs that reflect management’s best estimate of what market participants would use to price the assets or liabilities at the measurement date.



	The Company categorized its restricted cash, cash equivalents and short-term investments as Level 2 hierarchy. The assets classified as Level 2 have initially been valued at the applicable transaction price and subsequently revalued, at the end of each reporting period, using other market observable data. Observable market data points include quoted prices, interest rates, reportable trades and other industry and economic events. Financial assets measured at fair value on a recurring basis are summarized as follows, in thousands:



	Description	September 30, 2014		Quoted		Significant		Unobservable
				Prices in		Other		Inputs
				Active		Observable		(Level 3)
				Markets		Inputs
				(Level 1)		(Level 2)
	Assets:
	Cash equivalents	$	3,000	$	—	$	3,000	$	—
	Restricted cash		50		—		50		—
	Short-term investments		5,000		—		5,000		—

	Total	$	8,050	$	—	$	8,050	$	—


	Description	December 31, 2013		Quoted		Significant		Unobservable
				Prices in		Other		Inputs
				Active		Observable		(Level 3)
				Markets		Inputs
				(Level 1)		(Level 2)
	Assets:
	Cash equivalents	$	9,500	$	—	$	9,500	$	—
	Restricted cash		50		—		50		—
	Short-term investments		3,000		—		3,000		—

	Total	$	12,550	$	—	$	12,550	$	—


	Fair Value of Financial Instruments

	The carrying amounts reported in the balance sheet for cash equivalents, restricted cash, short-term investments and accounts payable approximate their fair values due to their short-term nature.

Preferred_Stock

Preferred Stock	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Preferred Stock	'

	4. Preferred Stock

	The Company currently has authorized a total of 15,000 shares of Series A convertible preferred stock (“Series A Preferred Stock”), $0.0001 par value per share, for issuance.

	The following table summarizes the Series A Preferred Stock activity for the nine months ended September 30, 2014:



	Issued and Outstanding at January 1, 2014	7,920
	Conversions of Series A Preferred Stock into common stock	(166	)
	Exchange of Series A Preferred Stock into Series A-1 convertible preferred stock	(3,000	)
	Dividends issued on Series A Preferred Stock	268

	Issued and Outstanding at September 30, 2014	5,022


	Accounting Treatment

	The Series A Preferred Stock has been classified outside of permanent equity (within the mezzanine section between liabilities and equity on the condensed balance sheets) as the Company may not be able to control the actions necessary to issue the maximum number of common shares needed to provide for a conversion in full of the then outstanding Series A Preferred Stock, at which time a holder of the Series A Preferred Stock may elect to redeem their preferred shares outstanding in the amount equal to the face value per share, plus unpaid accrued dividends. The Company’s Series A-1 convertible preferred stock (the “Series A-1 Preferred Stock”) has the same rights, privileges and preferences as the Series A Preferred Stock, but does not provide for any potential payment in cash in the event that the Company has insufficient shares of common stock authorized to honor conversions. Accordingly, the Series A-1 Preferred Stock is classified within permanent equity. The Series A-1 Preferred Stock is discussed further in Note 5 to the notes of the condensed financial statements.

	Dividends

	Holders of Series A Preferred Stock are entitled to receive cumulative mandatory dividends at the rate per share of seven percent (7%) of the face amount ($1,000 per share) per annum, payable quarterly on each March 31, June 30, September 30 and December 31. Dividends shall be payable in additional shares of Series A Preferred Stock valued for this purpose at the face amount. In the event there are not sufficient authorized Series A Preferred Shares available to pay such a dividend, the dividend shall instead accrete to and increase the face value of the outstanding Series A Preferred Stock. The fair value of the Series A Preferred Stock dividend, which is included in the Company’s net loss applicable to common shareholders, is calculated by multiplying the number of common shares that a preferred holder would receive upon conversion by the closing price of the Company’s common stock on the dividend payment date.



	Included in the Company’s net loss applicable to common shareholders related to the fair value of the Series A Preferred Stock dividends was $421,000 and $1,285,000 for the three months ended September 30, 2014 and 2013, respectively.

	Included in the Company’s net loss applicable to common shareholders related to the fair value of the Series A Preferred Stock dividends was $2,056,000 and $7,231,000 for the nine months ended September 30, 2014 and 2013, respectively.

	Conversion

	Each holder of shares of Series A Preferred Stock may, at any time and from time to time, convert each of its shares into a number of fully paid and non-assessable shares of common stock at the defined conversion rate. Each share of Series A Preferred Stock is convertible into 2,437.57 shares of common stock. In no event shall any holder of shares of Series A Preferred Stock have the right to convert shares of Series A Preferred Stock into shares of common stock to the extent that, after giving effect to such conversion, the holder, together with any of its affiliates, would beneficially own more than 9.999% of the then-issued and outstanding shares of common stock.

	During the three months ended September 30, 2014, there were no shares of Series A Preferred Stock converted into shares of common stock. During the three months ended September 30, 2013, 101 shares of Series A Preferred Stock were converted into 244,975 shares of common stock.

	During the nine months ended September 30, 2014 and 2013, 166 and 396 shares of Series A Preferred Stock were converted into 405,720 and 964,057 shares of common stock, respectively.

	Exchange Transaction

	On January 24, 2014, the Company entered into an exchange agreement (the “Exchange Agreement”) with Tang Capital Partners, L.P. (“TCP”) pursuant to which TCP exchanged a total of 3,000 shares of Series A Preferred Stock for a like number of shares of Series A-1 Preferred Stock.

	Liquidation Preference

	The “Liquidation Preference” with respect to a share of Series A Preferred Stock means an amount equal to the face amount of the shares ($1,000 per share) plus all accrued and unpaid dividends on the Series A Preferred Stock (as adjusted for any stock dividends, combinations, splits, recapitalizations and the like with respect to such shares). In the event of a liquidation, dissolution, or winding up, whether voluntary or involuntary, no distribution shall be made to the holders of any shares of capital stock of the Company (other than Senior Securities (as defined in the Certificate of Designations) pursuant to the rights, preferences and privileges thereof) unless prior thereto the holders of shares of Series A Preferred Stock have received the Liquidation Preference with respect to each share then outstanding.

	Voting

	The holders of Series A Preferred Stock do not have any right to elect directors and have only limited voting rights, which consist primarily of the right to vote under certain protective provisions set forth in the Certificate of Designations, regarding: (i) any proposed amendment to the Series A Preferred Stock or its right and preferences; and (ii) any proposed “Deemed Liquidation Event” as defined in the Certificate of Designations.

Stockholders_Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Stockholder's Equity	'

	5. Stockholder’s Equity

	Series A-1 Preferred Stock

	The Company currently has authorized a total of 10,000 shares of Series A-1 Preferred Stock, $0.0001 par value per share, for issuance. On January 24, 2014, the Company filed a Certificate of Increase with the Secretary of State of the State of Delaware amending the Company’s previously filed Certificate of Designation for the Series A-1 Preferred Stock to increase the total number of shares of Series A-1 Preferred Stock authorized from 5,000 shares to 10,000 shares.

	The following table summarizes the Series A-1 Preferred Stock activity for the nine months ended September 30, 2014:



	Issued and Outstanding at January 1, 2014	2,054
	Conversion of Series A-1 Preferred Stock into common stock	(3,416	)
	Exchange of Series A Preferred Stock into Series A-1 Preferred Stock	3,000
	Dividends issued on Series A-1 Preferred Stock	209

	Issued and Outstanding at September 30, 2014	1,847




	Accounting Treatment

	The Series A-1 Preferred Stock has been classified as permanent equity as the Company is not required to effect a net cash settlement in the instance that the Company does not have enough shares of common stock available to permit the conversion of Series A-1 Preferred Stock into common stock.

	Dividends

	Holders of Series A-1 Preferred Stock are entitled to receive cumulative mandatory dividends at the rate per share of seven percent (7%) of the face amount ($1,000 per share) per annum, payable quarterly on each March 31, June 30, September 30 and December 31. Dividends shall be payable in additional shares of Series A-1 Preferred Stock valued for this purpose at the face amount. In the event there are not sufficient authorized Series A-1 Preferred Shares available to pay such a dividend, the dividend shall instead accrete to and increase the face value of the outstanding Series A-1 Preferred Stock. The fair value of the Series A-1 Preferred Stock dividend, which is included in the Company’s net loss applicable to common shareholders, is calculated by multiplying the number of common shares that a preferred holder would receive upon conversion by the closing price of the Company’s common stock on the dividend payment date.

	Included in the Company’s net loss applicable to common shareholders related to the fair value of the Series A-1 Preferred Stock dividends was $279,000 and $162,000 for the three months ended September 30, 2014 and 2013, respectively.

	Included in the Company’s net loss applicable to common shareholders related to the fair value of the Series A-1 Preferred Stock dividends was $1,612,000 and $162,000 for the nine months ended September 30, 2014 and 2013, respectively.

	Conversion

	Each holder of shares of Series A-1 Preferred Stock may, at any time and from time to time, convert each of its shares into a number of fully paid and non-assessable shares of common stock at the defined conversion rate. Each share of Series A-1 Preferred Stock is convertible into 2,437.57 shares of common stock. In no event shall any holder of shares of Series A-1 Preferred Stock have the right to convert shares of Series A-1 Preferred Stock into shares of common stock to the extent that such issuance or sale or right to effect such conversion would result in the holder or any of its affiliates together beneficially owning more than 9.999% of the then issued and outstanding shares of common stock.

	During the three months ended September 30, 2014, 2,557 shares of Series A-1 Preferred Stock were converted into 6,232,862 shares of common stock. During the three months ended September 30, 2013, there were no shares of Series A-1 Preferred Stock converted into shares of common stock.

	During the nine months ended September 30, 2014, 3,416 shares of Series A-1 Preferred Stock were converted into 8,326,721 shares of common stock. During the nine months ended September 30, 2013, there were no shares of Series A-1 Preferred Stock converted into shares of common stock.

	Exchange Transaction

	On January 24, 2014, the Company entered into the Exchange Agreement with TCP pursuant to which TCP exchanged a total of 3,000 shares of Series A Preferred Stock for a like number of shares of Series A-1 Preferred Stock.

	Liquidation Preference

	The “Liquidation Preference” with respect to a share of Series A-1 Preferred Stock means an amount equal to the face amount of the shares ($1,000 per share) plus all accrued and unpaid dividends on the Series A-1 Preferred Stock (as adjusted for any stock dividends, combinations, splits, recapitalizations and the like with respect to such shares). In the event of a liquidation, dissolution, or winding up, whether voluntary or involuntary, no distribution shall be made to the holders of any shares of capital stock of the Company (other than Senior Securities (as defined in the Certificate of Designations) pursuant to the rights, preferences and privileges thereof) unless prior thereto the holders of shares of Series A-1 Preferred Stock have received the Liquidation Preference with respect to each share then outstanding. The liquidation preference of the Series A Preferred Stock is pari passu with the liquidation preference of the Series A-1 Preferred Stock.

	Voting

	The holders of Series A-1 Preferred Stock do not have any right to elect directors and have only limited voting rights, which consist primarily of the right to vote under certain protective provisions set forth in the Certificate of Designations, regarding: (i) any proposed amendment to the Series A-1 Preferred Stock or its right and preferences; and (ii) any proposed “Deemed Liquidation Event” as defined in the Certificate of Designations.



	Common Stock

	On July 10, 2014, the Company filed a Certificate of Amendment with the Secretary of State of the State of Delaware amending the Company’s previously filed Amended and Restated Certificate of Incorporation to decrease the total number of shares of common stock authorized to 100,000,000. The decrease in the total number of shares of common stock authorized was approved by the Company’s shareholders at the Company’s Annual Meeting of Stockholders held on June 2, 2014.

	On April 22, 2014, the Company entered into a purchase agreement (the “Purchase Agreement”) with Lincoln Park Capital Fund, LLC (“LPC”), pursuant to which the Company has the right to sell to LPC up to $20,000,000 in shares of the Company’s common stock, subject to certain limitations and conditions set forth therein, over the 30-month term of the Purchase Agreement. Pursuant to the Purchase Agreement, on April 22, 2014, LPC purchased 500,000 shares of the Company’s common stock at $4.00 per share and the Company issued 100,000 shares of common stock at $4.00 per share to LPC as a commitment fee, which was recorded as a cost of capital. As a result of this issuance, the Company received initial net proceeds of approximately $1.9 million, after deducting commissions and other offering expenses of approximately $0.1 million. The Company intends to use the proceeds received from the Purchase Agreement for working capital to support the advancement of the Company’s ophthalmology franchise and for other general corporate purposes.

	During the three months ended September 30, 2014 and 2013, the Company issued 6,232,862 and 244,975 shares of common stock, respectively, upon the conversion of Series A and Series A-1 Preferred Stock.

During the nine months ended September 30, 2014 and 2013, the Company issued 8,732,441 and 964,057 shares of common stock, respectively, upon the conversion of Series A and Series A-1 Preferred Stock.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'

	6. Stock-Based Compensation

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

	For stock options granted as consideration for services rendered by non-employees, the Company recognizes compensation expense in accordance with the requirements of FASB ASC Topic 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 requisite service 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 compensation 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 compensation expense will include fair value re-measurements until the stock options are fully vested.

	Stock-Based Compensation

	The Company is currently using the Black-Scholes option-pricing model to determine the fair value of all its option grants. For options granted during the three and nine months ended September 30, 2014 and 2013, the following assumptions were used:



		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Risk-free interest rate		2.52	%		1.75	%		1.60-2.73	%		0.71-2.19	%
	Expected volatility		103.47	%		107.3	%		97.91-107.01	%		74.53-107.30	%
	Weighted average expected volatility		103.47	%		107.3	%		101.5	%		76.27	%
	Expected lives (years)		10			6.25			5.20-10.00			5.20-10.00
	Expected dividend yield		0	%		0	%		0	%		0	%

	The weighted average fair value of options granted during the three month periods ended September 30, 2014 and 2013 was $2.71 and $4.24, respectively. The weighted average fair value of options granted during the nine month periods ended September 30, 2014 and 2013 was $2.46 and $4.05, respectively.

	The risk-free interest rate used for each grant was based upon the yield on zero-coupon U.S. Treasury securities with a term similar to the expected life of the related option. The Company’s expected stock price volatility assumption is based upon the volatility of a composition of comparable companies. The expected life assumption for employee grants was based upon the simplified method provided for under ASC 718-10 and the expected life assumptions for non-employees was based upon the contractual term of the option. The dividend yield assumption of zero is based upon the fact that the Company has never paid cash dividends and presently has no intention of paying cash dividends.



	The following table summarizes the activity of Company’s stock option plan for the period January 1, 2014 to September 30, 2014:



		Total Number			Weighted-			Weighted-			Aggregate
		of Shares			Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price			Contractual
					Per Share			Term
	Balance at January 1, 2014		2,556,269		$	3.47
	Granted		430,995			2.99
	Exercised		—			—
	Cancelled		—			—

	Balance at September 30, 2014		2,987,264		$	3.4			8.10 years		$	—

	Exercisable at September 30, 2014		1,582,211		$	3.41			7.81 years		$	—


	Stock-based compensation expense for the three months ended September 30, 2014 and 2013 was approximately $454,000 and $449,000, respectively. Of this, the Company recognized approximately $24,000 of expense and $7,600 of income related to non-employee stock options for the same respective periods.

	Stock-based compensation expense for the nine months ended September 30, 2014 and 2013 was approximately $1,402,000 and $1,506,000, respectively. Of this, the Company recognized approximately $71,000 and $36,000 of expense related to non-employee stock options for the same respective periods.

	Employee Stock Purchase Plan

	The Company’s Employee Stock Purchase Plan (“ESPP”) allows employees to contribute a percentage of their cash earnings, subject to certain maximum amounts, to be used to purchase shares of the Company’s common stock on each of two semi-annual purchase dates. The purchase price is equal to 90% of the market value per share on either (a) the date of grant of a purchase right under the ESPP or (b) the date on which such purchase right is deemed exercised, whichever is lower. The maximum number of shares available for issuance pursuant to the ESPP is equal to 113,333 shares.

	The Company is currently using the Black-Scholes option-pricing model to determine the fair value of the ESPP stock rights. For stock rights issued in the three and nine months ended September 30, 2014 and 2013, the following assumptions were used:



		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Risk-free interest rate		0.06	%		0.09	%		0.06-0.09	%		0.09	%
Expected volatility		103.36	%		88.68	%		94.99-103.36	%		88.68	%
Weighted average expected volatility		103.36	%		88.68	%		99.37	%		88.68	%
Expected lives (years)		0.5			0.5			0.5			0.5
Expected dividend yield		0	%		0	%		0	%		0	%

The weighted average fair value of stock rights issued during the three month periods ended September 30, 2014 and 2013 was $1.24 and $2.04, respectively. The weighted average fair value of stock rights issued during the nine month periods ended September 30, 2014 and 2013 was $1.62 and $2.04, respectively.

The risk-free interest rate used was based upon the yield on zero-coupon U.S. Treasury securities with a term similar to the expected life of the related option. The Company’s expected volatility is based upon the volatility of a composition of comparable companies for the expected term. The expected life assumption was based upon the purchase period and the dividend yield assumption of zero is based upon the fact that the Company has never paid cash dividends and presently has no intention of paying cash dividends.

The Company recorded $7,800 and $5,100 of stock-based compensation expense for the three months ended September 30, 2014 and 2013, respectively, related to the ESPP. The Company recorded $21,000 and $5,100 of stock-based compensation expense for the nine months ended September 30, 2014 and 2013, respectively, related to the ESPP.

Nature_of_Business_and_Basis_o1

Nature of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'

	Basis of Presentation

	The accompanying condensed financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures included in the Company’s annual financial statements have been condensed or omitted. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of the condensed financial statements have been included. Interim results are not necessarily indicative of results for a full year.
Uses of estimates in preparation of financial statements	'

	Uses of Estimates in Preparation of Financial Statements

	The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
Cash and Cash Equivalents	'

	Cash and Cash Equivalents

	The Company considers all highly liquid debt instruments with an original maturity of three months or less to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market accounts and certificates of deposit.
Restricted Cash	'

	Restricted Cash

	Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards.
Short-term Investments	'

	Short-term Investments

	The Company’s short-term investments consist of certificates of deposit with original maturities ranging from three months to one year.
Revenue Recognition	'

	Revenue Recognition

	Principal sources of revenue consist of government research grants. Revenue from government grants is recognized over the respective contract periods as the services are performed, provided there is persuasive evidence of an arrangement, the fee is fixed or determinable and collection of the related receivable is reasonably assured, and no contingencies remain outstanding. Monies received prior to the recognition of revenue are recorded as deferred revenue.
Research and Development Expenses	'

	Research and Development Expenses

	Research and development costs are charged to expense as incurred and relate to salaries, employee benefits, facility-related expenses, supplies, share-based compensation related to employees and non-employees involved in the Company’s research and development, external services, other operating costs and overhead related to our research and development departments, costs to acquire technology licenses and expenses associated with preclinical activities and our clinical trials. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed us with respect to services provided and/or materials that we have received.

	Preclinical and clinical trial expenses relate to third-party services, patient-related fees at the sites where our clinical trials are being conducted, laboratory costs, analysis costs, toxicology studies and investigator fees. Costs associated with these expenses are generally payable on the passage of time or when certain milestones are achieved. Expense is recorded during the period incurred or in the period in which a milestone is achieved. In order to ensure that we have adequately provided for preclinical and clinical expenses during the proper period, we maintain an accrual to cover these expenses. These accruals are assessed on a quarterly basis and are based on such assumptions as expected total cost, the number of patients and clinical trial sites and length of the study. Actual results may differ from these estimates and could have a material impact on our reported results. Our historical accrual estimates have not been materially different from our actual costs.
Stock-based Compensation	'

	Stock-based Compensation

	The Company follows the provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 718, “Compensation — Stock Compensation” (“ASC 718”), which requires the measurement and recognition of compensation expense for all stock-based payment awards made to employees, officers and non-employee directors, including stock options. Stock compensation expense based on the grant date fair value estimated in accordance with the provisions of ASC 718 is recognized as an expense over the requisite service period.
Net loss per share	'

	Net Loss per Share

	The Company accounts for and discloses net loss per common share in accordance with FASB ASC Topic 260, “Earnings per Share.” Basic and diluted net loss per common share is computed by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding. When the effects are not anti-dilutive, diluted earnings per share is computed by dividing the Company’s net earnings by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares.

	The following table sets forth the potential common shares excluded from the calculation of net loss per common share because their inclusion would be anti-dilutive:



		September 30,
		2014		2013
	Options to purchase common stock		2,987,264		2,556,269
	Common stock underlying Series A and Series A-1 convertible preferred stock		16,743,495		23,986,054
	Warrants to purchase common stock		4,615		4,615

	Total		19,735,374		26,546,938

Comprehensive Loss	'

	Comprehensive Loss

	The Company’s net loss is equal to its comprehensive loss for all periods presented.

Nature_of_Business_and_Basis_o2

Nature of Business and Basis of Presentation (Tables)	9 Months Ended
Nature of Business and Basis of Presentation (Tables)	Sep. 30, 2014
Accounting Policies [Abstract]	'
Common Shares Excluded from Calculation of Net Loss Per Common Share	'

	The following table sets forth the potential common shares excluded from the calculation of net loss per common share because their inclusion would be anti-dilutive:



		September 30,
		2014		2013
	Options to purchase common stock		2,987,264		2,556,269
	Common stock underlying Series A and Series A-1 convertible preferred stock		16,743,495		23,986,054
	Warrants to purchase common stock		4,615		4,615

	Total		19,735,374		26,546,938

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'

	The assets classified as Level 2 have initially been valued at the applicable transaction price and subsequently revalued, at the end of each reporting period, using other market observable data. Observable market data points include quoted prices, interest rates, reportable trades and other industry and economic events. Financial assets measured at fair value on a recurring basis are summarized as follows, in thousands:



	Description	September 30, 2014		Quoted		Significant		Unobservable
				Prices in		Other		Inputs
				Active		Observable		(Level 3)
				Markets		Inputs
				(Level 1)		(Level 2)
	Assets:
	Cash equivalents	$	3,000	$	—	$	3,000	$	—
	Restricted cash		50		—		50		—
	Short-term investments		5,000		—		5,000		—

	Total	$	8,050	$	—	$	8,050	$	—


	Description	December 31, 2013		Quoted		Significant		Unobservable
				Prices in		Other		Inputs
				Active		Observable		(Level 3)
				Markets		Inputs
				(Level 1)		(Level 2)
	Assets:
	Cash equivalents	$	9,500	$	—	$	9,500	$	—
	Restricted cash		50		—		50		—
	Short-term investments		3,000		—		3,000		—

	Total	$	12,550	$	—	$	12,550	$	—

Preferred_Stock_Tables

Preferred Stock (Tables)	9 Months Ended
Preferred Stock (Tables)	Sep. 30, 2014
Equity [Abstract]	'
Summary of Series A Preferred Stock	'

	The following table summarizes the Series A Preferred Stock activity for the nine months ended September 30, 2014:



	Issued and Outstanding at January 1, 2014	7,920
	Conversions of Series A Preferred Stock into common stock	(166	)
	Exchange of Series A Preferred Stock into Series A-1 convertible preferred stock	(3,000	)
	Dividends issued on Series A Preferred Stock	268

	Issued and Outstanding at September 30, 2014	5,022

Stockholders_Equity_Tables

Stockholder's Equity (Tables)	9 Months Ended
Stockholder's Equity (Tables)	Sep. 30, 2014
Equity [Abstract]	'
Summary of Series A-1 Preferred Stock	'

	The following table summarizes the Series A-1 Preferred Stock activity for the nine months ended September 30, 2014:



	Issued and Outstanding at January 1, 2014	2,054
	Conversion of Series A-1 Preferred Stock into common stock	(3,416	)
	Exchange of Series A Preferred Stock into Series A-1 Preferred Stock	3,000
	Dividends issued on Series A-1 Preferred Stock	209

	Issued and Outstanding at September 30, 2014	1,847

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Assumptions Used to Determine Fair Value of Employee Stock Purchase Plan Stock Rights	'

	The Company is currently using the Black-Scholes option-pricing model to determine the fair value of all its option grants. For options granted during the three and nine months ended September 30, 2014 and 2013, the following assumptions were used:



		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Risk-free interest rate		2.52	%		1.75	%		1.60-2.73	%		0.71-2.19	%
	Expected volatility		103.47	%		107.3	%		97.91-107.01	%		74.53-107.30	%
	Weighted average expected volatility		103.47	%		107.3	%		101.5	%		76.27	%
	Expected lives (years)		10			6.25			5.20-10.00			5.20-10.00
	Expected dividend yield		0	%		0	%		0	%		0	%
Summary of Stock Option Activity	'
	The following table summarizes the activity of Company’s stock option plan for the period January 1, 2014 to September 30, 2014:


		Total Number			Weighted-			Weighted-			Aggregate
		of Shares			Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price			Contractual
					Per Share			Term
	Balance at January 1, 2014		2,556,269		$	3.47
	Granted		430,995			2.99
	Exercised		—			—
	Cancelled		—			—

	Balance at September 30, 2014		2,987,264		$	3.4			8.10 years		$	—

	Exercisable at September 30, 2014		1,582,211		$	3.41			7.81 years		$	—

Schedule of Assumptions Used to Determine Fair Value of Option Grants	'

	The Company is currently using the Black-Scholes option-pricing model to determine the fair value of the ESPP stock rights. For stock rights issued in the three and nine months ended September 30, 2014 and 2013, the following assumptions were used:



		For the Three Months Ended						For the Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Risk-free interest rate		0.06	%		0.09	%		0.06-0.09	%		0.09	%
	Expected volatility		103.36	%		88.68	%		94.99-103.36	%		88.68	%
	Weighted average expected volatility		103.36	%		88.68	%		99.37	%		88.68	%
	Expected lives (years)		0.5			0.5			0.5			0.5
	Expected dividend yield		0	%		0	%		0	%		0	%

Nature_of_Business_and_Basis_o3

Nature of Business and Basis of Presentation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2014
Cash and Cash Equivalents [Member]	'
Description Of Business And Basis Of Presentation [Line Items]	'
Debt instrument maturity period	'Three months or less
Minimum [Member] \| Certificates of Deposit [Member] \| Short-term Investments [Member]	'
Description Of Business And Basis Of Presentation [Line Items]	'
Certificates of deposit, maturity period	'3 months
Maximum [Member] \| Certificates of Deposit [Member] \| Short-term Investments [Member]	'
Description Of Business And Basis Of Presentation [Line Items]	'
Certificates of deposit, maturity period	'1 year

Nature_of_Business_and_Basis_o4

Nature of Business and Basis of Presentation - Common Shares Excluded from Calculation of Net Loss Per Common Share (Detail)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total amount of anti-dilutive securities excluded from computation of earnings per share	19,735,374	26,546,938
Options to Purchase Common Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total amount of anti-dilutive securities excluded from computation of earnings per share	2,987,264	2,556,269
Common Stock Underlying Series A and Series A-1 Convertible Preferred Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total amount of anti-dilutive securities excluded from computation of earnings per share	16,743,495	23,986,054
Warrants to Purchase Common Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total amount of anti-dilutive securities excluded from computation of earnings per share	4,615	4,615

Fair_Value_Measurements_Fair_V

Fair Value Measurements - Fair Value Measurements (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets:	'	'
Restricted cash	$50	$50
Short-term investments	5,000	3,000
Fair Value, Measurements, Recurring [Member]	'	'
Assets:	'	'
Cash equivalents	3,000	9,500
Restricted cash	50	50
Short-term investments	5,000	3,000
Total	8,050	12,550
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]	'	'
Assets:	'	'
Cash equivalents	3,000	9,500
Restricted cash	50	50
Short-term investments	5,000	3,000
Total	$8,050	$12,550

Preferred_Stock_Additional_Inf

Preferred Stock - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jan. 24, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
	Series A Convertible Preferred Stock [Member]	Series A Convertible Preferred Stock [Member]	Series A Convertible Preferred Stock [Member]	Series A Convertible Preferred Stock [Member]	Series A Convertible Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]
Temporary Equity [Line Items]	'	'	'	'	'	'	'	'	'	'
Preferred stock, shares authorized	15,000	'	15,000	'	15,000	'	'	'	'	'
Preferred stock, par value	$0.00	'	$0.00	'	$0.00	'	'	'	'	'
Preferred stock, dividend rate per share	'	'	7.00%	'	'	'	'	'	7.00%	'
Preferred stock, face amount	$1,000	'	$1,000	'	'	'	$1,000	'	$1,000	'
Fair value of Series A Preferred Stock dividends	$421,000	$1,285,000	$2,056,000	$7,231,000	'	'	'	'	'	'
Preferred stock, convertible to common stock	2,437.57	'	2,437.57	'	'	'	2,437.57	'	2,437.57	'
Percentage of affiliates owning shares	'	'	10.00%	'	'	'	'	'	10.00%	'
Conversion of Series A Preferred Stock into Common Shares	0	101	166	396	'	'	2,557	0	3,416	0
Number of common stock issuable on conversion of preferred stock per preferred stock	'	244,975	405,720	964,057	'	'	6,232,862	'	8,326,721	'
Shares of Series A Preferred Stock exchanged for Series A-1 Preferred Stock	'	'	3,000	'	'	3,000	'	'	3,000	'
Capital distribution	$0	'	$0	'	'	'	$0	'	$0	'

Preferred_Stock_Summary_of_Ser

Preferred Stock - Summary of Series A Preferred Stock (Detail) (Series A Convertible Preferred Stock [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Series A Convertible Preferred Stock [Member]	'	'	'	'
Increase (Decrease) in Temporary Equity [Roll Forward]	'	'	'	'
Issued, Beginning Balance	'	'	7,920	'
Outstanding, Beginning Balance	'	'	7,920	'
Conversions of Series A Preferred Stock into common stock	0	-101	-166	-396
Exchange of Series A Preferred Stock into Series A-1 convertible preferred stock	'	'	-3,000	'
Dividends issued on Series A Preferred Stock	'	'	268	'
Issued, Ending Balance	5,022	'	5,022	'
Outstanding, Ending Balance	5,022	'	5,022	'

Stockholders_Equity_Additional

Stockholder's Equity - Additional Information (Detail) (USD $)

Sep. 30, 2014

Jul. 10, 2014

Dec. 31, 2013

Apr. 22, 2014

Jan. 24, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Jan. 24, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Lincoln Park Capital Fund, LLC [Member]

Series A-1 Convertible Preferred Stock [Member]

Series A and Series A-1 Preferred Stock [Member]

Minimum [Member]

Maximum [Member]

Class of Stock [Line Items]

Preferred stock, par value, per share

$0.00

Preferred stock, shares authorized

10,000,000

10,000

5,000

10,000

Preferred stock, dividend rate per share

7.00%

Preferred stock, face amount

$1,000

Fair value of Series A-1 Preferred Stock dividends

$279,000

$162,000

$1,612,000

$162,000

Percentage of affiliates owning shares

10.00%

Preferred Stock convertible to common stock

2,437.57

Conversion of preferred stock into common shares

2,557

3,416

Number of common stock issuable on conversion of preferred stock per preferred stock

6,232,862

8,326,721

6,232,862

244,975

8,732,441

964,057

Shares of Series A Preferred Stock exchanged for Series A-1 Preferred Stock

3,000

Capital distribution

Common stock, shares authorized

100,000,000

Stock reserved during period, value

20,000,000

Stock issued during period, shares

500,000

Stock issued during period, per share price

Stock issued as a commitment fee, shares

100,000

Stock issued as a commitment fee, per shares

Stock issued during period, net Proceeds

1,900,000

Commissions and other offering expenses related to stock issuance

$100,000

Stockholders_Equity_Summary_of

Stockholder's Equity - Summary of Series A -1 Preferred Stock (Detail) (Series A-1 Convertible Preferred Stock [Member])	0 Months Ended	3 Months Ended		9 Months Ended
	Jan. 24, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Series A-1 Convertible Preferred Stock [Member]	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'
Issued, Beginning Balance	'	'	'	2,054	'
Outstanding, Beginning Balance	'	'	'	2,054	'
Conversion of Series A-1 Preferred Stock into common stock	'	-2,557	0	-3,416	0
Exchange of Series A Preferred Stock into Series A-1 Preferred Stock	3,000	'	'	3,000	'
Dividends issued on Series A-1 Preferred Stock	'	'	'	209	'
Issued, Ending Balance	'	1,847	'	1,847	'
Outstanding, Ending Balance	'	1,847	'	1,847	'

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Option Grants (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	2.52%	1.75%	'	'
Expected volatility	103.47%	107.30%	'	'
Weighted average expected volatility	103.47%	107.30%	101.50%	76.27%
Expected lives (years)	'10 years	'6 years 3 months	'	'
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	1.60%	0.71%
Expected volatility	'	'	97.91%	74.53%
Expected lives (years)	'	'	'5 years 2 months 12 days	'5 years 2 months 12 days
Maximum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	2.73%	2.19%
Expected volatility	'	'	107.01%	107.30%
Expected lives (years)	'	'	'10 years	'10 years

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Weighted average grant date fair value per share of options granted	$2.71	$4.24	$2.46	$4.05
Dividend yield	0.00%	0.00%	0.00%	0.00%
Stock-based compensation expense	$454,000	$449,000	$1,402,000	$1,506,000
Stock-based compensation expense, non-employee stock options	24,000	'	71,000	36,000
Stock-based compensation gain, non-employee stock options	'	7,600	'	'
Employee Stock Purchase Plan [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Weighted average grant date fair value per share of options granted	$1.24	$2.04	$1.62	$2.04
Dividend yield	0.00%	0.00%	0.00%	0.00%
Percentage of common share offer price as to market price	'	'	90.00%	'
Maximum number of shares available for issuance	113,333	'	113,333	'
Stock-based compensation expense related to the ESPP	$7,800	$5,100	$21,000	$5,100

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Stock Option Activity (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Total Number of Shares, Beginning Balance	2,556,269
Total Number of Shares, Granted	430,995
Total Number of Shares, Exercised	'
Total Number of Shares, Cancelled	'
Total Number of Shares, Ending Balance	2,987,264
Total Number of Shares, Exercisable	1,582,211
Weighted-Average Exercise Price Per Share, Beginning Balance	$3.47
Weighted-Average Exercise Price Per Share, Granted	$2.99
Weighted-Average Exercise Price Per Share, Exercised	'
Weighted-Average Exercise Price Per Share, Cancelled	'
Weighted-Average Exercise Price Per Share, Ending Balance	$3.40
Weighted-Average Exercise Price Per Share, Exercisable	$3.41
Weighted-Average Remaining Contractual Term, Ending Balance	'8 years 1 month 6 days
Weighted-Average Remaining Contractual Term, Exercisable	'7 years 9 months 22 days
Aggregate Intrinsic Value, Ending Balance	'
Aggregate Intrinsic Value, Exercisable	'

StockBased_Compensation_Schedu1

Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Employee Stock Purchase Plan Stock Rights (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	2.52%	1.75%	'	'
Expected volatility	103.47%	107.30%	'	'
Weighted average expected volatility	103.47%	107.30%	101.50%	76.27%
Expected lives (years)	'10 years	'6 years 3 months	'	'
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	1.60%	0.71%
Expected volatility	'	'	97.91%	74.53%
Expected lives (years)	'	'	'5 years 2 months 12 days	'5 years 2 months 12 days
Maximum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	2.73%	2.19%
Expected volatility	'	'	107.01%	107.30%
Expected lives (years)	'	'	'10 years	'10 years
Employee Stock Purchase Plan [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	0.06%	0.09%	'	0.09%
Expected volatility	103.36%	88.68%	'	88.68%
Weighted average expected volatility	103.36%	88.68%	99.37%	88.68%
Expected lives (years)	'6 months	'6 months	'6 months	'6 months
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Employee Stock Purchase Plan [Member] \| Minimum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	0.06%	'
Expected volatility	'	'	94.99%	'
Employee Stock Purchase Plan [Member] \| Maximum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	0.09%	'
Expected volatility	'	'	103.36%	'