REVA Medical (RVALL) 10-K 30 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 15, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	REVA Medical, Inc.
Entity Central Index Key	1496268
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float			$35,163,000
Entity Common Stock, Shares Outstanding		33,579,778
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$25,814,000	$19,229,000
Short-term investments	995,000	1,492,000
Prepaid expenses and other current assets	406,000	415,000
Total current assets	27,215,000	21,136,000
Non-Current Assets:
Property and equipment, net	2,920,000	3,589,000
Other non-current assets	60,000	60,000
Total non-current assets	2,980,000	3,649,000
Total Assets	30,195,000	24,785,000
Current Liabilities:
Accounts payable	651,000	1,400,000
Accrued expenses and other current liabilities	2,213,000	2,080,000
Total current liabilities	2,864,000	3,480,000
Long-Term Liabilities:
Convertible Notes Payable	37,780,000
Common stock warrant liability	15,389,000
Other long-term liabilities	611,000	480,000
Total Long-term liabilities	53,780,000	480,000
Total Liabilities	56,644,000	3,960,000
Commitments and contingencies (Note 9)
Stockholders' Equity (Deficit):
Undesignated preferred stock - $0.0001 par value; 5,000,000 shares authorized; no shares issued or outstanding
Additional paid-in capital	226,094,000	222,331,000
Accumulated deficit	-252,546,000	-201,509,000
Total Stockholders' Equity (Deficit)	-26,449,000	20,825,000
Total Liabilities and Stockholders' Equity (Deficit)	30,195,000	24,785,000
Common Stock
Stockholders' Equity (Deficit):
Common stock	3,000	3,000
Class B common stock
Stockholders' Equity (Deficit):
Common stock

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Common stock, par value (in dollars per share)		$0.61
Undesignated preferred stock, par value (in dollars per share)	$0.00	$0.00
Undesignated preferred stock, shares authorized	5,000,000	5,000,000
Undesignated preferred stock, shares issued	0	0
Undesignated preferred stock, shares outstanding	0	0
Common Stock
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	33,529,778	33,270,053
Common stock, shares outstanding	33,529,778	33,270,053
Class B common stock
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Loss (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Expense:
Research and development	$14,318	$19,212	$15,822
General and administrative	7,645	8,731	8,043
Loss from operations	-21,963	-27,943	-23,865
Other Income (Expense):
Interest income	8	30	92
Interest expense	-986
Loss on issuance of convertible notes payable	-15,627
Loss on change in fair value of convertible notes payable and warrant liability	-12,542
Other income (expense)	73	-9	-3
Other income (expense)	-29,074	21	89
Net Loss and Comprehensive Loss	($51,037)	($27,922)	($23,776)
Net Loss Per Common Share:
Net loss per share, basic and diluted (in dollars per share)	($1.53)	($0.84)	($0.72)
Shares used to compute net loss per share, basic and diluted (in shares)	33,382,381	33,124,655	33,072,058

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities:
Net loss	($51,037)	($27,922)	($23,776)
Non-cash adjustments to reconcile net loss to net cash used for operating activities:
Depreciation and amortization	1,027	892	677
Loss on property and equipment disposal		1	1
Stock-based compensation	3,516	4,090	3,497
Interest on convertible notes payable	986
Loss on issuance of convertible notes payable	15,627
Loss on change in fair value of convertible notes payable and warrant liability	12,542
Other non-cash expenses	19	18	80
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	9	2	496
Accounts payable	-566	549	-218
Accrued expenses and other current liabilities	64	525	522
Other non-current liabilities	-117	-98	60
Net cash used for operating activities	-17,930	-21,943	-18,661
Cash Flows from Investing Activities:
Purchases of property and equipment	-541	-1,466	-1,949
Purchases of investments	-995	-1,492	-1,989
Maturities of investments	1,492	5,223	1,992
Net cash provided by (used for) investing activities	-44	2,265	-1,946
Cash Flows from Financing Activities:
Proceeds from issuances of common stock	247	31	322
Proceeds from notes payable and warrants, net	24,312
Net cash provided by financing activities	24,559	31	322
Net increase (decrease) in cash and cash equivalents	6,585	-19,647	-20,285
Cash and cash equivalents at beginning of period	19,229	38,876	59,161
Cash and Cash Equivalents at End of Period	25,814	19,229	38,876
Supplemental Non-Cash information:
Property and equipment in accounts payable	$12	$195	$99

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (Deficit) (USD $)	Additional Paid In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Common Stock [Member]	Total
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011	$214,391	($149,811)	$3	$64,583
Balance (in shares) at Dec. 31, 2011			32,810,503
Increase (Decrease) in Stockholders' Equity
Net loss and comprehensive loss		-23,776		-23,776
Common stock issued January through August upon exercise of stock options for cash at $0.61 to $1.40 per share	322			322
Common stock issued upon exercise of stock options for cash (in shares)			288,700
Restricted common stock issued under equity incentive plan (in shares)			33,000
Stock-based compensation expense	3,497			3,497
Balance at Dec. 31, 2012	218,210	-173,587	3	44,626
Balance (in shares) at Dec. 31, 2012			33,132,203
Increase (Decrease) in Stockholders' Equity
Net loss and comprehensive loss		-27,922		-27,922
Common stock issued January through August upon exercise of stock options for cash at $0.61 to $1.40 per share	31			31
Common stock issued upon exercise of stock options for cash (in shares)			50,350
Restricted common stock issued under equity incentive plan (in shares)			87,500
Stock-based compensation expense	4,090			4,090
Balance at Dec. 31, 2013	222,331	-201,509	3	20,825
Balance (in shares) at Dec. 31, 2013			33,270,053
Increase (Decrease) in Stockholders' Equity
Net loss and comprehensive loss		-51,037		-51,037
Common stock issued January through August upon exercise of stock options for cash at $0.61 to $1.40 per share	247			247
Common stock issued upon exercise of stock options for cash (in shares)			259,725
Stock-based compensation expense	3,516			3,516
Balance at Dec. 31, 2014	$226,094	($252,546)	$3	($26,449)
Balance (in shares) at Dec. 31, 2014			33,529,778

Consolidated_Statement_of_Stoc1

Consolidated Statement of Stockholders' Equity (Deficit) (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2012
Minimum [Member]
Common stock, par value (in dollars per share)	$0.61	$0.61
Maximum [Member]
Common stock, par value (in dollars per share)	$1.40	$1.40

Description_of_Business

Description of Business	12 Months Ended
	Dec. 31, 2014
Description of Business
Description of Business	1.  Description of Business
	REVA Medical, Inc. (“REVA” or the “Company”) was incorporated in California in 1998 under the name MD3, Inc. In March 2002 we changed our name to REVA Medical, Inc. In October 2010 we reincorporated in Delaware. We established a non-operating wholly owned subsidiary, REVA Germany GmbH, in 2007. In these notes the terms “us,” “we,” or “our” refer to REVA and our consolidated subsidiary unless context dictates otherwise.
	We do not yet have a product available for sale; our product(s) will become available following completion of required clinical studies with acceptable data and when, and if, we receive regulatory approval. We are currently developing and testing a bioresorbable stent to treat vascular disease in humans. This stent, which we have named Fantom, was introduced in humans during December 2014. We intend to enroll up t o 110 patients in a clinical trial with Fantom, obtain follow-up data at a six-month time point, and if this data has acceptable safety and efficacy results, apply for a European CE Marking, the regulatory approval that would allow us to commercialize Fantom in Europe.
	In December 2010 we completed an initial public offering (the “IPO”) of our common stock in Australia and registered with the U.S. Securities and Exchange Commission (“SEC”) and, consequently, became an SEC filer. Our stock is traded in the form of CHESS Depository Interests (“CDIs”) on the Australian Securities Exchange (“ASX”); each share of our common stock is equivalent to ten CDIs. Our trading symbol is “RVA.AX.”

Capital_Resources_and_Basis_of

Capital Resources and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Stage of Company, Capital Resources, and Basis of Presentation
Capital Resources and Basis of Presentation	2.  Capital Resources and Basis of Presentation
	Capital Resources:  We had cash and investments totaling $26,809,000 as of December 31, 2014, which reflect the receipt of $25,000,000 cash proceeds from the issuance of convertible notes payable and warrants to purchase common stock on November 14, 2014. We believe these resources are sufficient to meet our operating and capital needs through at least 2015. We have experienced recurring losses and negative cash flows from operating activities since our inception and, as of December 31, 2014, we had an accumulated deficit of $252,546,000. Until we generate revenue, and at a level to support our cost structure, we expect to continue to incur substantial operating losses and net cash outflows. Even if we do attain revenue, we may never become profitable and even if we do attain profitable operations, we may not be able to sustain that profitability or positive cash flows on a recurring basis.
	Basis of Presentation:  We have prepared the accompanying consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) and the rules and regulations of the SEC. The consolidated financial statements include the accounts of REVA and our wholly owned subsidiary, REVA Germany GmbH. All intercompany transactions and balances, if any, have been eliminated in consolidation.
	Use of Estimates:  In order to prepare our financial statements in conformity with accounting principles generally accepted in the United States, we are required to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Our most significant estimates relate to the fair value of our convertible notes payable, the fair value of our warrant liability, our expense accruals, including clinical study expenses, and our stock-based compensation expense. Actual results could differ from our estimates.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Significant Accounting Policies	3.  Significant Accounting Policies
	Cash and Cash Equivalents:  All highly liquid investments with original maturities of three months or less are classified as cash equivalents.
	Investments:  Excess cash is invested in high-quality marketable securities. Our investments are classified as either short- or long-term based on their maturity dates. Investments with a maturity of less than one year are classified as short-term; all others are classified as long-term. We have categorized the investments as “held-to-maturity” based on our intent and ability to hold to maturity. Our investments are stated at cost; their fair value is determined each reporting period through quoted market prices of similar instruments in active markets. During the reporting period there were no declines in fair value that were deemed to be other than temporary.
	Property and Equipment:  Property and equipment is stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the related assets, generally three to five years. Amortization of leasehold improvements is determined using the straight-line method over the lesser of the useful life of the asset or the term of the underlying lease. Upon disposition or retirement of an asset, its cost and related accumulated depreciation or amortization are removed from the accounts and any gain or loss is recognized in the consolidated statement of operations.
	Patents:  Costs related to patent development, filing, and maintenance are expensed as incurred since the underlying technology associated with these assets is purchased or incurred in connection with our research and development efforts and the future realizable value cannot be determined.
	Impairment of Long-Lived Assets:  We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable and exceeds its undiscounted future cash flows. The amount of impairment, if any, is determined by comparing an asset’s estimated fair value to the asset’s respective carrying amount. During the years ended December 31, 2012, 2013, and 2014 we determined there were no indications of asset impairment.
	Concentrations of Credit Risk:  Our financial instruments, which potentially subject us to concentration of credit risk, comprise cash, cash equivalents, and investments. We maintain our cash and cash equivalents in bank accounts, the balances of which generally exceed limits that are insured by the Federal Deposit Insurance Corporation. Our investments are held in custody by a large financial asset manager in the United States. Management believes the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which the assets are held. Additionally, we maintain our cash and investments in accordance with our investment policy, which is designed to maintain safety and liquidity. We have not realized any losses in our investments and believe we are not exposed to significant credit risk related to our cash and cash equivalents.
	Convertible Notes Payable:  Convertible notes payable are analyzed at issue date to determine balance sheet classification, issue discounts or premiums, and embedded or derivative features. Embedded or derivative features are evaluated in accordance with accounting guidance for derivative securities and, if the features give rise to separate accounting, we make an election to account for the notes at cost or at fair value. If fair value accounting is elected, on the issue date we record the difference between the issue price of the notes and their fair value as a gain or loss in the consolidated statement of operations. We remeasure the fair value at each reporting date and record a gain (upon a decrease in fair value) or loss (upon an increase in fair value) for the change in fair value. Fair value is determined using a binomial valuation model with; inputs to the model include the market value of the underlying stock, a life equal to the contractual life of the notes, incremental borrowing rates that correspond to debt with similar credit worthiness, estimated volatility based on the historical prices of our trading securities, and we make assumptions as to our abilities to test and commercialize our product(s), to obtain future financings when and if needed, and to comply with the terms and conditions of the notes. Following an analysis of their embedded and derivative features and a projection of the volatility of their effective interest rates under the cost method, we elected to utilize fair value accounting for the convertible notes payable we issued on November 14, 2014. Management believes the fair value method of accounting provides a more appropriate presentation of these liabilities than would be provided under the cost method.
	Common Stock Warrants:  In accordance with ASC 480 “Distinguishing Liabilities from Equity,” we record the fair value of warrants issued for the purchase of common stock as a liability since the warrants call for issuance of registered shares upon exercise, a condition that we may not be able to accommodate and which would then result in a net settlement of the warrants. Until the time the warrants are exercised or expire, the fair value is assessed at each reporting date utilizing a binomial valuation model and any change in value is recorded as a gain or loss component of other income (expense) in our consolidated statement of operations. Inputs to the valuation model are of the same nature as those used for our convertible notes payable.
	Research and Development:  Research and development costs are expensed as incurred. These costs include salaries, employee benefits, laboratory supplies, consulting services, manufacturing products and services, preclinical and clinical costs, technology license fees, laboratory equipment depreciation, facility costs, and certain indirect costs.
	Segment Information:  We operate in one business segment, which is the development and commercialization of medical devices.
	Foreign Currency:  The functional currency of our subsidiary REVA Germany GmbH is the euro. Balance sheet accounts of our subsidiary are translated into United States dollars using the exchange rate in effect at the balance sheet date while expenses are translated using the average exchange rate in effect during the period. Gains and losses arising from translation of our subsidiary’s financial statements are recorded to other comprehensive income (loss). These gains and losses, in the aggregate, were insignificant through December 31, 2014.
	Income Taxes:  We account for income taxes using the asset and liability method, under which the current income tax expense or benefit is the amount of income tax expected to be payable or refundable in the current year. Deferred tax assets and liabilities are recorded for the estimated future tax consequences of temporary differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases, and for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled.
	We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is more likely than not that all or a portion of our deferred tax assets will not be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies, and results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.
	We account for the uncertainty in income tax components based on tax positions taken or expected to be taken in a tax return. To recognize a benefit, a tax position must be more likely than not to be sustained upon examination by taxing authorities. We do not recognize tax benefits that have a less than 50 percent likelihood of being sustained. Our policy is to recognize interest and tax penalties related to unrecognized tax benefits in income tax expense; no interest or tax penalties on uncertain tax benefits have been recorded through December 31, 2014.
	We are subject to taxation in U.S. and California jurisdictions. As of December 31, 2014, our tax years beginning December 1, 1999 remain subject to examination by taxing authorities. We are not currently under Internal Revenue Service (“IRS”), state, or local tax examination.
	Stock-Based Compensation:  We account for stock-based compensation by measuring and recognizing expense for all stock-based payments made to employees and directors based on estimated grant date fair values. We use the straight-line method to allocate compensation expense to reporting periods over each optionee’s requisite service period, which is generally the vesting period, and estimate the fair value of stock-based awards to employees and directors using the Black-Scholes option valuation model. The Black-Scholes model requires the input of assumptions, including volatility, the expected term, and the fair value of the underlying common stock on the date of grant, among other inputs. We record the option value to compensation expense based on the financial statement category for which an optionee’s services are rendered and cash compensation is recorded. We adjust stock-based compensation expense for estimated option forfeitures based on our five-year historical average of actual forfeitures.
	We account for stock options issued to consultants as expense at their fair value over the related service period, as determined in accordance with authoritative guidance. We revalue the consultants’ stock options as they vest.
	Net Loss Per Common Share:  Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common share equivalents outstanding for the period determined using the treasury-stock method and the if-converted method, as applicable. For purpose of this calculation, unvested restricted stock and stock options are considered to be common stock equivalents and are included in the calculation of diluted net loss per share only when their effect is dilutive.
	During the years ended December 31, 2012, 2013, and 2014 we excluded options to purchase common stock of 3,300,039, 3,901,316, and 4,355,536 weighted average shares, respectively, and excluded 17,648, 96,347, and 91,750 weighted average shares, respectively, of restricted common stock from the computation of diluted net loss per share because including them would have been antidilutive. During the year ended December 31, 2014, we additionally excluded weighted average common share equivalents attributable to the convertible notes payable and warrants issued on November 14, 2014, of 1,513,138 and 1,150,685 shares, respectively, from the computation of diluted net loss per share as they would have been antidilutive.
	Fair Value Measurements:   We measure the fair value of our financial and non-financial assets and liabilities at each reporting date. Fair value is defined as the exchange price at which an asset or liability would be transferred in the principal or most advantageous market in an orderly transaction between market participants as of a measurement date. Accounting guidance provides an established hierarchy to be used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs; observable inputs are required to be used when available. Observable inputs are those used by market participants to value an asset or liability and are developed based on market data obtained from sources independent of us. Unobservable inputs are those that reflect our assumptions about factors that market participants would use to value an asset or liability. Fair value measurements are classified and disclosed in one of the following three categories:
	Level 1 — Quoted market prices for identical assets or liabilities in active markets at the measurement date;
	Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities in active or non-active markets, or other inputs that can be corroborated by observable market data for substantially the full term of an asset or liability; and,
	Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of an asset or liability, including management’s best estimate of the factors that market participants would use in pricing an asset or liability at the measurement date.
	We carry our convertible notes payable and common stock warrant liability at fair value. We carry our other financial instruments at amortized cost; these items include cash, investments, accounts payable, and accrued expenses. The carrying amounts of our cash and cash equivalents, accounts payable, and accrued expenses are considered to be reasonable estimates of their respective fair values due to their short-term nature and, therefore, fair value information is not provided in the following table.
	Fair Value Measurements (continued):  Utilizing the lowest level inputs available under the measurement hierarchy, the fair values of our measured financial instruments comprise the following (we had no Level 1 financial instruments):
		Level 2			Level 3
		(in thousands)
	Fair Value at December 31, 2013:
	Certificates of deposit due in one year or less	$	1,488		$	—
	Fair Value at December 31, 2014:
	Assets:
	Certificates of deposit due in one year or less	$	991		$	—
	Liabilities:
	Convertible notes payable	$	—		$	37,780
	Common stock warrant liability	—			15,389
		$	—		$	53,169
	Our Level 2 financial assets consist of certificates of deposit (“CDs”) that are held to maturity and carried at cost; their fair value is determined each reporting period through quoted market prices of similar instruments in active markets. Unrealized losses on these CDs as of December 31, 2013 and 2014 were $4,000 each year.
	Our Level 3 financial liabilities consist of convertible notes payable (the “Notes”) and warrants for the purchase of common stock, all of which were issued on November 14, 2014. The fair values of these liabilities as of their issuance date and the subsequent measurement date of December 31, 2014 were determined utilizing a binomial valuation model, which requires use of unobservable inputs. The inputs are determined by management, with the assistance of independent experts; they represent our best estimates, but involve certain inherent uncertainties. We used the market value of the underlying stock, a life equal to the contractual life of the financial instrument, incremental borrowing rates and bond yields that correspond to instruments of similar credit worthiness and the instrument’s remaining life, an estimate of volatility based on the historical prices of our trading securities, and we made assumptions as to our abilities to test and commercialize our product(s), to obtain future financings when and if needed, and to comply with the terms and conditions of our Notes. A summary of the assumptions used to value the Notes and warrants at each valuation date in 2014 is as follows:
		November 14,			December 31,
		2014			2014
	Market price per share of common stock	$	2.71		$	3.35
	Risk-free interest rate	2.89		%	2.30		%
	Expected volatility of common stock	88.1		%	87.2		%
	Expected life — years	5.00			4.87
	Bond yield of equivalent securities	29.9		%	28.4		%
	A significant change in the market price per share, expected volatility, or bond yield of equivalent securities, in isolation, would result in significantly higher or lower fair value measurements. In combination, changes in these inputs could result in a significantly higher or lower fair value measurement if the input changes were to be aligned, or could result in a minimally higher or lower fair value measurement if the input changes were of a compensating nature.
	Fair Value Measurements (continued):  The fair value activity of our Level 3 financial liabilities, which were issued and arose on November 14, 2014, is as follows:
		Level 3
		(in thousands)
	Balance at December 31, 2013	$	—
	Fair Value on Issuance Date:
	Convertible notes payable	29,689
	Warrants to purchase common stock	10,938
	Balance at November 14, 2014	40,627
	Change in Fair Value:
	Convertible notes payable	8,091
	Warrants to purchase common stock	4,451
	Balance at December 31, 2014	$	53,169
	Recent Accounting Pronouncements:  Effective January 1, 2014, we adopted Accounting Standards Update No. 2013-11 (“ASU 2013-11”), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. ASU 2013-11 provides explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The adoption of ASU 2013-11 did not have an effect on our financial position, results of operations, or related financial statement disclosures.
	In April 2014, ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, was issued. ASU 2014-08 raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures for certain other disposals that do not meet the definition of a discontinued operation. This ASU is effective for REVA beginning January 1, 2015; we do not expect the implementation to have an effect on our financial position or results of operations.
	In June 2014, ASU 2014-10, Development Stage Entities:  Elimination of Certain Financial Reporting Requirements, was issued. ASU 2014-10 removes financial reporting distinction between development stage entities and other reporting entities. Although ASU 2014-10 is effective beginning January 1, 2015, we elected early adoption for the year ended December 31, 2014. The adoption of ASU 2014-10 did not have an effect on our financial position or results of operations. Upon adoption, we conformed our financial statement presentation and disclosures and, accordingly, eliminated all references to “development stage” and discontinued presentation of “inception to date” information.
	In August 2014, ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, was issued. ASU 2014-15 requires management to assess an entity’s ability to continue as a going concern and to provide related footnote disclosure in certain circumstances. This ASU is effective for annual and interim periods ending after December 15, 2016. We are currently evaluating the provisions of ASU 2014-15 and assessing the impact, if any, it may have on our financial disclosures.

Convertible_Notes_Payable_and_

Convertible Notes Payable and Warrants to Purchase Common Stock	12 Months Ended
	Dec. 31, 2014
Convertible Notes Payable and Warrants to Purchase Common Stock
Convertible Notes Payable and Warrants to Purchase Common Stock	4.  Convertible Notes Payable and Warrants to Purchase Common Stock
	On November 14, 2014, we issued 250 convertible notes payable (the “Notes”), each with a face value of $100,000, for total cash proceeds of $25,000,000. The Notes are convertible into 11,506,155 shares of common stock, which is a conversion rate of $2.17275 per share. The Notes are convertible at any time at the holders’ election, except the Notes will automatically convert in the case where the Company has received a CE Mark approval for its Fantom product and has sustained a market trading price of A$0.60 per CDI for 20 consecutive trading days. The Notes mature on November 14, 2019, if not converted or redeemed earlier. Interest accrues on the Notes at the rate of 7.54 percent per annum, compounded annually, and is payable upon redemption or maturity; accrued interest is not payable or convertible upon conversion of the Notes. Interest expense of $248,000 for the year ended December 31, 2014 was recorded in the consolidated statement of operations. The Notes provide the holders a one-time option for cash redemption in January 2017, if not previously converted or redeemed, for the face value plus accrued interest.
	On the issue date, we evaluated the embedded conversion feature of the Notes and certain other rights provided to the noteholders and determined that they qualified as embedded derivatives that required bifurcation from the Notes and separate accounting. Following this evaluation, we made an irrevocable election to account for the Notes at fair value. The fair value of the Notes on the date of issue was calculated to be $29,689,000. This fair value exceeded the stated value of the Notes by $4,689,000; we recorded the excess as a loss on issuance. The fair value of the Notes as of December 31, 2014 was calculated to be $37,780,000, which was $12,780,000 more than the unpaid principal balance of the Notes. The change in fair value of the Notes between November 14, 2014 and December 31, 2014 of $8,091,000 was recorded as a loss in the consolidated statement of operations. As of December 31, 2014, the fair value of the 11,506,155 shares into which the Notes are convertible was calculated to be $38,200,000.
	In connection with issuing the Notes, we issued warrants to the noteholders to purchase up to 8,750,000 shares of common stock at $2.17275 per share. The warrants are exercisable immediately and expire in November 2019. The exercise price of the warrants will increase to $2.6073 per share if, and when, we achieve full enrollment in our clinical trial of Fantom with the required number of patients that would provide data for a CE Mark application. The fair value of the warrants on the date of issue of $10,938,000 was recorded as a loss on issuance since we elected fair value accounting for the Notes. The fair value of the warrants as of December 31, 2014 was calculated to be $15,389,000; the change in fair value of the warrant liability between November 14, 2014 and December 31, 2014 of $4,451,000 was recorded as a loss in the consolidated statement of operations.

Balance_Sheet_Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2014
Balance Sheet Details
Balance Sheet Details	5.  Balance Sheet Details
		December 31,
		2013			2014
		(in thousands)
	Property and equipment:
	Furniture, office equipment, and software	$	656		$	648
	Laboratory equipment	4,896			5,187
	Leasehold improvements	2,305			2,361
		7,857			8,196
	Accumulated depreciation and amortization	(4,268		)	(5,276		)
		$	3,589		$	2,920
	Accrued expenses and other current liabilities:
	Accrued salaries and other employee costs	$	1,371		$	1,315
	Accrued operating expenses	560			769
	Accrued use taxes and other	149			129
		$	2,080		$	2,213

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes	6.  Income Taxes
	We have reported net losses for all periods through December 31, 2014; therefore, no provision for income taxes has been recorded. The following table provides the reconciliation between income taxes computed at the federal statutory rate and our provision for income taxes:
		Year Ended December 31,
		2012			2013			2014
		(in thousands)
	Federal income taxes at 34%	$	(8,084	)	$	(9,493	)	$	(17,352	)
	State income taxes, net of federal benefit	(1,363		)	(1,553		)	(1,243		)
	Research and development credits	(240		)	(1,425		)	(660		)
	Fair value adjustments on convertible notes payable and common stock warrant liability	—			—			9,577
	Interest on convertible notes payable	—			—			152
	Stock-based compensation expense	131			191			358
	Increase in valuation allowance	59,186			11,622			8,716
	Reinstatement of deferred tax assets for net operating loss and tax credit carryover deferred tax assets	(50,311		)	—			—
	Expiration of state net operating losses	673			677			450
	Other	8			(19		)	2
	Provision for income taxes	$	—		$	—		$	—
	Our deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets and liabilities are as follows:
		December 31,
		2013			2014
		(in thousands)
	Deferred Tax Assets:
	Net operating loss carryforwards	$	61,629		$	62,738
	Research and development credits	6,277			6,891
	Amortization	2			5,737
	Stock-based compensation expense	4,182			5,085
	Depreciation	230			366
	Accrued operating expenses	12			64
	Other	291			459
		72,623			81,340
	Valuation Allowance	(72,623		)	(81,340		)
	Net Deferred Income Taxes	$	—		$	—
	As of December 31, 2014 we had aggregate federal and California state net operating loss carryforwards of approximately $162,797,000 and $128,411,000, respectively, which may be available to offset future taxable income for income tax purposes. The federal net operating loss carryforwards begin to expire in 2019 and the California carryforwards begin to expire in 2015, with $11,869,000 expiring in 2015.
	As of December 31, 2014, we also had federal and California state research tax credit carryforwards of approximately $5,797,000 and $5,137,000, respectively. The federal carryforwards begin to expire in 2020 and the California carryforwards have no expiration.
	A total of $267,000 of the federal and California net operating loss relates to excess tax benefits generated from stock compensation that will be recorded as an increase to additional paid-in capital if, and when, realized.
	Under Internal Revenue Code (“IRC”) Sections 382 and 383, annual use of our net operating loss and research tax credit carryforwards to offset taxable income may be limited based on cumulative changes in ownership. An analysis of the impact of this provision from December 1, 1999 through December 31, 2014 has been performed and it was determined that, although ownership changes had occurred, the carryovers should be available for utilization by the Company before they expire, provided we generate sufficient future taxable income. Based on the results of this analysis in 2012, we reinstated the deferred tax assets arising from the net operating loss and tax credit carryforwards, with a corresponding increase to the valuation allowance for the year ended December 31, 2012. Future ownership changes could result in further limitations and may impact the realizability of these loss and credit carryforwards in future periods.
	As of December 31, 2014, we had deferred tax assets of $81,340,000 primarily comprising net operating loss and research tax credit carryforwards. We have established a valuation allowance against our deferred tax assets due to the uncertainty surrounding the Company’s ability to generate future taxable income to realize those assets. The change in the valuation allowance for the years ended December 31, 2013 and 2014 was $11,622,000 and $8,717,000, respectively.
	We recognize a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more-likely-than-not recognition at the effective date to be recognized. As of December 31, 2014, the unrecognized tax benefits recorded were approximately $2,734,000. We do not anticipate a significant change in the unrecognized tax benefits within the next 12 months.
	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits for 2013 and 2014, excluding interest and penalties, is as follows:
		December 31,
		2013			2014
		(in thousands)
	Balance at Beginning of Year	$	1,954		$	2,490
	Additions (reductions) for prior year tax positions	167			(15		)
	Additions for current year tax positions	369			259
	Balance at End of Year	$	2,490		$	2,734
	Due to our valuation allowance position, none of the unrecognized tax benefits, if recognized, will impact the Company’s effective tax rate.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Stock-Based Compensation
Stock-Based Compensation	7.  Stock-Based Compensation
	Our 2010 Equity Incentive Award Plan was a follow-on to our 2001 Stock Option/Stock Issuance Plan and the two plans are collectively referred to as the “Plan.” The Plan provides for restricted stock awards as well as for grants of incentive and non-qualified stock options to purchase our common stock at a price per share equal to the closing market price of our stock on the date of option grant. All stock issuances under the plan are made with new shares. The number of shares reserved under the Plan may be increased annually by up to three percent of the outstanding stock of the Company. On January 1, 2014, an additional 998,101 shares were added, resulting in a total of 7,256,260 shares reserved under the Plan as of December 31, 2014. The term of the options granted under the Plan may not exceed ten years. Vesting periods of stock awards and option grants are determined by the Company’s board of directors and are generally four- or five-year periods. All options are immediately exercisable upon grant and are subject to repurchase by us at the exercise price in the event an optionee terminates service prior to being fully vested.
	Option activity under the Plan is as follows:
							Weighted
				Weighted			Average
				Average			Remaining		Aggregate
		Options		Exercise			Contractual		Intrinsic
		Outstanding		Price			Term (years)		Value
	Balance at December 31, 2011	3,304,000		$	6.99
	Granted	544,000		$	5.95
	Cancelled	(9,300	)	$	12.64
	Exercised	(288,700	)	$	1.11
	Balance at December 31, 2012	3,550,000		$	7.3
	Granted	589,500		$	5.36
	Cancelled	(42,500	)	$	2
	Exercised	(50,350	)	$	0.61
	Balance at December 31, 2013	4,046,650		$	7.15
	Granted	637,000		$	3.53
	Cancelled	(180,500	)	$	6.61
	Exercised	(259,725	)	$	0.95
	Balance at December 31, 2014	4,243,425		$	7.01		6.43		$	1,659,000
	Vested at December 31, 2014	3,164,746		$	7.78		5.48		$	1,604,000
	Vested and Expected to Vest at December 31, 2014	4,218,131		$	7.02		6.19		$	1,657,000
	The unvested portion of outstanding options as of December 31, 2014 has vesting dates scheduled through 2018. Following is the vesting activity under the Plan for the year ended December 31, 2014:
				Weighted
				Average
		Options		Grant Date
		Outstanding		Fair Value
	Unvested Options at December 31, 2013	1,308,149		$	4.2
	Granted	637,000		$	1.89
	Vested	(795,709	)	$	4.46
	Forfeited	(70,761	)	$	2.82
	Unvested Options at December 31, 2014	1,078,679		$	2.64
	We awarded 33,000 and 87,500 shares of restricted stock during the years ended December 31, 2012 and 2013, respectively, all of which vest at the rate of 25 percent annually on each award anniversary date. No restricted stock was awarded during the year ended December 31, 2014.
	No tax benefits arising from stock-based compensation have been recognized in the consolidated statements of operations through December 31, 2014.
	Stock Options and Restricted Stock to Employees:  We account for option grants and restricted stock awards to employees based on the estimated fair values on the date of grant or award, with the resulting stock-based compensation recorded over the vesting period on a straight-line basis. We include non-employee directors as employees for this purpose.
	Expense recorded for employee options and awards under the Plan is as follows:
		Year Ended December 31,
		2012			2013			2014
		(in thousands)
	Research and development	$	832		$	1,069		$	1,142
	General and administrative	2,647			2,965			2,284
	Total stock-based compensation	$	3,479		$	4,034		$	3,426
	As of December 31, 2014, we had approximately $2,234,000 of total unrecognized compensation costs related to unvested employee options that are expected to be recognized over a weighted average period of 1.63 years.
	The fair value of options granted was estimated using the following weighted-average assumptions:
		Year Ended December 31,
		2012		2013		2014
	Risk-free interest rate	1.03	%	1.38	%	2.18	%
	Expected volatility of common stock	62.1	%	60.1	%	59.3	%
	Expected life in years	6.25		6.25		6.14
	Dividend yield	0	%	0	%	0	%
	The assumed risk-free interest rate was based on the implied yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected life of the option. The assumed volatility was calculated from the historical market prices of a selected group of publicly traded companies considered to be our peers. We used peer group data due to the fact that we have limited historical trading data. The expected option life was calculated using the simplified method under the accounting standard for stock compensation and a ten-year option expiration. The simplified method is used since we believe our future option activity as a public company will differ from that of our own historical experience. The expected dividend yield of zero reflects that we have not paid cash dividends since inception and do not intend to pay cash dividends in the foreseeable future.
	A summary of grant date fair value and intrinsic value for options granted to employees is as follows:
		Year Ended December 31,
		2012			2013			2014
		(in thousands, except per share data)
	Weighted average grant date fair value per share	$	3.43		$	2.95		$	1.98
	Intrinsic value of options exercised	$	1,392		$	231		$	553
	Total fair value of options vested during period	$	3,802		$	3,809		$	3,546
	Stock Options to Consultants:  We account for stock options granted to consultants at their fair value. Under this method, the fair value is estimated at each reporting date during the vesting period using the Black-Scholes option-pricing model. The resulting stock-based compensation is recorded over the consultant’s service period. No options were issued to consultants during 2012; options to purchase 100,000 and 110,000 shares of common stock were granted to consultants during the years ended December 31, 2013 and 2014, respectively. The fair value of these awards was determined with the following assumptions:  Assumed risk-free interest rate of 1.7 to 2.8 percent; assumed volatility of 57 to 59 percent; expected option life of 5.0 to 10.0 years; and, expected dividend yield of zero percent. The total fair value of consultant options vested during 2012, 2013 and 2014 was $42,000, $40,000, and $116,000, respectively. The weighted average fair value of unvested consultant options at December 31, 2012, 2013, and 2014 was estimated to be $4.37, $2.84, and $1.92 per share, respectively, based on the following assumptions:
		Year Ended December 31,
		2012		2013		2014
	Risk-free interest rate	1.18	%	2.96	%	2.17	%
	Expected volatility of common stock	62.1	%	59.4	%	57.2	%
Expected life — years	6.71		9.45		8.94
Dividend yield	0.0	%	0.0	%	0.0	%
Consultant stock-based compensation expense, or income if the fair value declined in a reporting period, is recorded to the financial statement line item for which the optionee’s services are rendered. Expense recorded for consultant stock options under the Plan is as follows:
	Year Ended December 31,
	2012			2013			2014
	(in thousands)
Research and development	$	18		$	9		$	69
General and administrative	—			47			21
Total stock-based compensation	$	18		$	56		$	90

Retirement_Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2014
Retirement Plan
Retirement Plan	8.  Retirement Plan
	In 2003 we adopted a qualified 401(k) profit sharing plan (the “401(k) Plan”) for the benefit of our employees. Employees are eligible to participate in the 401(k) Plan the month following hire and may defer up to the maximum allowed under IRS regulations, on an annual basis. We match 25 percent of an employee’s deferral amount, up to a maximum of four percent of qualified compensation. We may, at our discretion, make additional contributions. Employees are immediately vested in the employer matching contributions. Our contributions to the 401(k) Plan were $46,000, $52,000, and $46,000 for the years ended December 31, 2012, 2013, and 2014, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies.
Commitments and Contingencies	9.  Commitments and Contingencies
	We have licensed certain patents and other intellectual property rights related to the composition and coating of our bioresorbable stent and our other biomaterial products. Terms of these licenses include provisions for royalty payments on any future sales of products, if any, utilizing this technology, with provisions for minimum royalties once product sales begin. The amount of royalties varies depending upon type of product, use of product, stage of product, location of sale, and ultimate sales volume, and ranges from a minimum of approximately $25 per unit to a maximum of approximately $100 per unit sold, with license provisions for escalating minimum royalties that could be as high as $2,200,000 per year. Additionally, in the event we sublicense the technology and receive certain milestone payments, the licenses require that up to 40 percent of the milestone amount be paid to the licensors. Additional terms of the technology licenses include annual licensing payments of $175,000 until the underlying technology has been commercialized. Terms of the licenses also include other payments to occur during commercialization that could total $950,000, payment of $350,000 upon a change in control of ownership, payments of up to $300,000 annually to extend filing periods related to certain technology, and payment of patent filing, maintenance, and defense fees. The license terms remain in effect until the last patent expires.
	In connection with our development activities, we periodically enter into contracts with consultants and vendors. These contracts are generally cancelable with 30 days’ written notice. As of December 31, 2014, the minimum future payments on these contracts totaled approximately $108,000.
	We currently lease our office and lab facilities under a non-cancelable operating lease that expires in January 2018. The lease contains fixed annual escalations, an option for a five-year extension, leasehold improvement allowances and credits of $523,000, and rent abatements of $136,000. We record rent expense on a straight-line basis over the life of the lease; the difference between average rent expense and cash payments for rent is recorded as a deferred liability. As of December 31, 2014, our deferred rent totaled $480,000, of which $117,000 was classified as a current liability. We recorded rent expense of $636,000, $666,000, and $683,000 for the years ended December 31, 2012, 2013, and 2014, respectively.
	Future minimum payments under the lease as of December 31, 2014 are as follows:
		Minimum
		Payment
		(in thousands)
	2015	$	644
	2016	690
	2017	711
	2018	60
	Total minimum lease payments	$	2,105

Related_Parties

Related Parties	12 Months Ended
	Dec. 31, 2014
Related Parties
Related Parties	10.  Related Parties
	Our related parties include the members of our board of directors and investors with five percent or more of our outstanding securities. We had no related party transactions during the years ended December 31, 2012, 2013, or 2014.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information (unaudited)
Selected Quarterly Financial Information (unaudited)
	11.  Selected Quarterly Financial Information (unaudited)
	The following table presents selected quarterly financial information that has been derived from our unaudited quarterly consolidated financial statements, which, in the opinion of management, include all adjustments (consisting only of normal recurring items) necessary for a fair presentation. The quarterly per share data presented below was calculated separately and may not sum to the annual figures presented in the consolidated financial statements. These operating results are also not necessarily indicative of results for any future period.
		Quarter Ended												Year Ended
		March 31,			June 30,			September 30,			December 31,			December 31,
		(in thousands, except per share amounts)
	2013:00:00
	Loss from operations	$	(6,343	)	$	(6,666	)	$	(7,182	)	$	(7,752	)	$	(27,943	)
	Net loss	(6,331		)	(6,647		)	(7,191		)	(7,753		)	(27,922		)
	Net loss per common share, basic and diluted	$	(0.19	)	$	(0.20	)	$	(0.22	)	$	(0.23	)	$	(0.84	)
	2014:00:00
	Loss from operations	$	(7,272	)	$	(4,832	)	$	(4,446	)	$	(5,413	)	$	(21,963	)
	Net loss	(7,276		)	(4,833		)	(4,397		)	(34,531		)	(51,037		)
	Net loss per common share, basic and diluted	$	(0.22	)	$	(0.14	)	$	(0.13	)	$	(1.03	)	$	(1.53	)

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Cash and Cash Equivalents
	Cash and Cash Equivalents:  All highly liquid investments with original maturities of three months or less are classified as cash equivalents.
Investments	Investments:  Excess cash is invested in high-quality marketable securities. Our investments are classified as either short- or long-term based on their maturity dates. Investments with a maturity of less than one year are classified as short-term; all others are classified as long-term. We have categorized the investments as “held-to-maturity” based on our intent and ability to hold to maturity. Our investments are stated at cost; their fair value is determined each reporting period through quoted market prices of similar instruments in active markets. During the reporting period there were no declines in fair value that were deemed to be other than temporary.
Property and Equipment
	Property and Equipment:  Property and equipment is stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the related assets, generally three to five years. Amortization of leasehold improvements is determined using the straight-line method over the lesser of the useful life of the asset or the term of the underlying lease. Upon disposition or retirement of an asset, its cost and related accumulated depreciation or amortization are removed from the accounts and any gain or loss is recognized in the consolidated statement of operations.
Patents
	Patents:  Costs related to patent development, filing, and maintenance are expensed as incurred since the underlying technology associated with these assets is purchased or incurred in connection with our research and development efforts and the future realizable value cannot be determined.
Impairment of Long-Lived Assets
	Impairment of Long-Lived Assets:  We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable and exceeds its undiscounted future cash flows. The amount of impairment, if any, is determined by comparing an asset’s estimated fair value to the asset’s respective carrying amount. During the years ended December 31, 2012, 2013, and 2014 we determined there were no indications of asset impairment.
Concentrations of Credit Risk
	Concentrations of Credit Risk:  Our financial instruments, which potentially subject us to concentration of credit risk, comprise cash, cash equivalents, and investments. We maintain our cash and cash equivalents in bank accounts, the balances of which generally exceed limits that are insured by the Federal Deposit Insurance Corporation. Our investments are held in custody by a large financial asset manager in the United States. Management believes the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which the assets are held. Additionally, we maintain our cash and investments in accordance with our investment policy, which is designed to maintain safety and liquidity. We have not realized any losses in our investments and believe we are not exposed to significant credit risk related to our cash and cash equivalents.
Convertible Notes Payable
	Convertible Notes Payable:  Convertible notes payable are analyzed at issue date to determine balance sheet classification, issue discounts or premiums, and embedded or derivative features. Embedded or derivative features are evaluated in accordance with accounting guidance for derivative securities and, if the features give rise to separate accounting, we make an election to account for the notes at cost or at fair value. If fair value accounting is elected, on the issue date we record the difference between the issue price of the notes and their fair value as a gain or loss in the consolidated statement of operations. We remeasure the fair value at each reporting date and record a gain (upon a decrease in fair value) or loss (upon an increase in fair value) for the change in fair value. Fair value is determined using a binomial valuation model with; inputs to the model include the market value of the underlying stock, a life equal to the contractual life of the notes, incremental borrowing rates that correspond to debt with similar credit worthiness, estimated volatility based on the historical prices of our trading securities, and we make assumptions as to our abilities to test and commercialize our product(s), to obtain future financings when and if needed, and to comply with the terms and conditions of the notes. Following an analysis of their embedded and derivative features and a projection of the volatility of their effective interest rates under the cost method, we elected to utilize fair value accounting for the convertible notes payable we issued on November 14, 2014. Management believes the fair value method of accounting provides a more appropriate presentation of these liabilities than would be provided under the cost method.
Common Stock Warrants
	Common Stock Warrants:  In accordance with ASC 480 “Distinguishing Liabilities from Equity,” we record the fair value of warrants issued for the purchase of common stock as a liability since the warrants call for issuance of registered shares upon exercise, a condition that we may not be able to accommodate and which would then result in a net settlement of the warroants. Until the time the warrants are exercised or expire, the fair value is assessed at each reporting date utilizing a binomial valuation model and any change in value is recorded as a gain or loss component of other income (expense) in our consolidated statement of operations. Inputs to the valuation model are of the same nature as those used for our convertible notes payable.
Research and Development
	Research and Development:  Research and development costs are expensed as incurred. These costs include salaries, employee benefits, laboratory supplies, consulting services, manufacturing products and services, preclinical and clinical costs, technology license fees, laboratory equipment depreciation, facility costs, and certain indirect costs.
Segment Information
	Segment Information:  We operate in one business segment, which is the development and commercialization of medical devices.
Foreign Currency
	Foreign Currency:  The functional currency of our subsidiary REVA Germany GmbH is the euro. Balance sheet accounts of our subsidiary are translated into United States dollars using the exchange rate in effect at the balance sheet date while expenses are translated using the average exchange rate in effect during the period. Gains and losses arising from translation of our subsidiary’s financial statements are recorded to other comprehensive income (loss). These gains and losses, in the aggregate, were insignificant through December 31, 2014.
Income Taxes
	Income Taxes:  We account for income taxes using the asset and liability method, under which the current income tax expense or benefit is the amount of income tax expected to be payable or refundable in the current year. Deferred tax assets and liabilities are recorded for the estimated future tax consequences of temporary differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases, and for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled.
	We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is more likely than not that all or a portion of our deferred tax assets will not be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies, and results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.
	We account for the uncertainty in income tax components based on tax positions taken or expected to be taken in a tax return. To recognize a benefit, a tax position must be more likely than not to be sustained upon examination by taxing authorities. We do not recognize tax benefits that have a less than 50 percent likelihood of being sustained. Our policy is to recognize interest and tax penalties related to unrecognized tax benefits in income tax expense; no interest or tax penalties on uncertain tax benefits have been recorded through December 31, 2014.
	We are subject to taxation in U.S. and California jurisdictions. As of December 31, 2014, our tax years beginning December 1, 1999 remain subject to examination by taxing authorities. We are not currently under Internal Revenue Service (“IRS”), state, or local tax examination.
Stock-Based Compensation
	Stock-Based Compensation:  We account for stock-based compensation by measuring and recognizing expense for all stock-based payments made to employees and directors based on estimated grant date fair values. We use the straight-line method to allocate compensation expense to reporting periods over each optionee’s requisite service period, which is generally the vesting period, and estimate the fair value of stock-based awards to employees and directors using the Black-Scholes option valuation model. The Black-Scholes model requires the input of assumptions, including volatility, the expected term, and the fair value of the underlying common stock on the date of grant, among other inputs. We record the option value to compensation expense based on the financial statement category for which an optionee’s services are rendered and cash compensation is recorded. We adjust stock-based compensation expense for estimated option forfeitures based on our five-year historical average of actual forfeitures.
	We account for stock options issued to consultants as expense at their fair value over the related service period, as determined in accordance with authoritative guidance. We revalue the consultants’ stock options as they vest.
Net Loss Per Common Share
	Net Loss Per Common Share:  Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common share equivalents outstanding for the period determined using the treasury-stock method and the if-converted method, as applicable. For purpose of this calculation, unvested restricted stock and stock options are considered to be common stock equivalents and are included in the calculation of diluted net loss per share only when their effect is dilutive.
	During the years ended December 31, 2012, 2013, and 2014 we excluded options to purchase common stock of 3,300,039, 3,901,316, and 4,355,536 weighted average shares, respectively, and excluded 17,648, 96,347, and 91,750 weighted average shares, respectively, of restricted common stock from the computation of diluted net loss per share because including them would have been antidilutive. During the year ended December 31, 2014, we additionally excluded weighted average common share equivalents attributable to the convertible notes payable and warrants issued on November 14, 2014, of 1,513,138 and 1,150,685 shares, respectively, from the computation of diluted net loss per share as they would have been antidilutive.
Fair Value Measurements
	Fair Value Measurements:   We measure the fair value of our financial and non-financial assets and liabilities at each reporting date. Fair value is defined as the exchange price at which an asset or liability would be transferred in the principal or most advantageous market in an orderly transaction between market participants as of a measurement date. Accounting guidance provides an established hierarchy to be used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs; observable inputs are required to be used when available. Observable inputs are those used by market participants to value an asset or liability and are developed based on market data obtained from sources independent of us. Unobservable inputs are those that reflect our assumptions about factors that market participants would use to value an asset or liability. Fair value measurements are classified and disclosed in one of the following three categories:
	Level 1 — Quoted market prices for identical assets or liabilities in active markets at the measurement date;
	Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities in active or non-active markets, or other inputs that can be corroborated by observable market data for substantially the full term of an asset or liability; and,
	Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of an asset or liability, including management’s best estimate of the factors that market participants would use in pricing an asset or liability at the measurement date.
	We carry our convertible notes payable and common stock warrant liability at fair value. We carry our other financial instruments at amortized cost; these items include cash, investments, accounts payable, and accrued expenses. The carrying amounts of our cash and cash equivalents, accounts payable, and accrued expenses are considered to be reasonable estimates of their respective fair values due to their short-term nature and, therefore, fair value information is not provided in the following table.
	Fair Value Measurements (continued):  Utilizing the lowest level inputs available under the measurement hierarchy, the fair values of our measured financial instruments comprise the following (we had no Level 1 financial instruments):
		Level 2			Level 3
		(in thousands)
	Fair Value at December 31, 2013:
	Certificates of deposit due in one year or less	$	1,488		$	—
	Fair Value at December 31, 2014:
	Assets:
	Certificates of deposit due in one year or less	$	991		$	—
	Liabilities:
	Convertible notes payable	$	—		$	37,780
	Common stock warrant liability	—			15,389
		$	—		$	53,169
	Our Level 2 financial assets consist of certificates of deposit (“CDs”) that are held to maturity and carried at cost; their fair value is determined each reporting period through quoted market prices of similar instruments in active markets. Unrealized losses on these CDs as of December 31, 2013 and 2014 were $4,000 each year.
	Our Level 3 financial liabilities consist of convertible notes payable (the “Notes”) and warrants for the purchase of common stock, all of which were issued on November 14, 2014. The fair values of these liabilities as of their issuance date and the subsequent measurement date of December 31, 2014 were determined utilizing a binomial valuation model, which requires use of unobservable inputs. The inputs are determined by management, with the assistance of independent experts; they represent our best estimates, but involve certain inherent uncertainties. We used the market value of the underlying stock, a life equal to the contractual life of the financial instrument, incremental borrowing rates and bond yields that correspond to instruments of similar credit worthiness and the instrument’s remaining life, an estimate of volatility based on the historical prices of our trading securities, and we made assumptions as to our abilities to test and commercialize our product(s), to obtain future financings when and if needed, and to comply with the terms and conditions of our Notes. A summary of the assumptions used to value the Notes and warrants at each valuation date in 2014 is as follows:
		November 14,			December 31,
		2014			2014
	Market price per share of common stock	$	2.71		$	3.35
	Risk-free interest rate	2.89		%	2.30		%
	Expected volatility of common stock	88.1		%	87.2		%
	Expected life — years	5.00			4.87
	Bond yield of equivalent securities	29.9		%	28.4		%
	A significant change in the market price per share, expected volatility, or bond yield of equivalent securities, in isolation, would result in significantly higher or lower fair value measurements. In combination, changes in these inputs could result in a significantly higher or lower fair value measurement if the input changes were to be aligned, or could result in a minimally higher or lower fair value measurement if the input changes were of a compensating nature.
	Fair Value Measurements (continued):  The fair value activity of our Level 3 financial liabilities, which were issued and arose on November 14, 2014, is as follows:
		Level 3
		(in thousands)
	Balance at December 31, 2013	$	—
	Fair Value on Issuance Date:
	Convertible notes payable	29,689
	Warrants to purchase common stock	10,938
	Balance at November 14, 2014	40,627
	Change in Fair Value:
	Convertible notes payable	8,091
	Warrants to purchase common stock	4,451
	Balance at December 31, 2014	$	53,169
Recent Accounting Pronouncements
	Recent Accounting Pronouncements:  Effective January 1, 2014, we adopted Accounting Standards Update No. 2013-11 (“ASU 2013-11”), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. ASU 2013-11 provides explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The adoption of ASU 2013-11 did not have an effect on our financial position, results of operations, or related financial statement disclosures.
	In April 2014, ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, was issued. ASU 2014-08 raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures for certain other disposals that do not meet the definition of a discontinued operation. This ASU is effective for REVA beginning January 1, 2015; we do not expect the implementation to have an effect on our financial position or results of operations.
	In June 2014, ASU 2014-10, Development Stage Entities:  Elimination of Certain Financial Reporting Requirements, was issued. ASU 2014-10 removes financial reporting distinction between development stage entities and other reporting entities. Although ASU 2014-10 is effective beginning January 1, 2015, we elected early adoption for the year ended December 31, 2014. The adoption of ASU 2014-10 did not have an effect on our financial position or results of operations. Upon adoption, we conformed our financial statement presentation and disclosures and, accordingly, eliminated all references to “development stage” and discontinued presentation of “inception to date” information.
	In August 2014, ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, was issued. ASU 2014-15 requires management to assess an entity’s ability to continue as a going concern and to provide related footnote disclosure in certain circumstances. This ASU is effective for annual and interim periods ending after December 15, 2016. We are currently evaluating the provisions of ASU 2014-15 and assessing the impact, if any, it may have on our financial disclosures.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Schedule of fair values of investments and liabilities, determined from level 2 and 3 inputs		Level 2			Level 3
		(in thousands)
	Fair Value at December 31, 2013:
	Certificates of deposit due in one year or less	$	1,488		$	—
	Fair Value at December 31, 2014:
	Assets:
	Certificates of deposit due in one year or less	$	991		$	—
	Liabilities:
	Convertible notes payable	$	—		$	37,780
	Common stock warrant liability	—			15,389
		$	—		$	53,169
Summary of assumptions used to value the Notes and warrants		November 14,			December 31,
		2014			2014
	Market price per share of common stock	$	2.71		$	3.35
	Risk-free interest rate	2.89		%	2.30		%
	Expected volatility of common stock	88.1		%	87.2		%
	Expected life — years	5.00			4.87
	Bond yield of equivalent securities	29.9		%	28.4		%
Summary of fair value of financial liabilities determined from "Level 3" inputs		Level 3
		(in thousands)
	Balance at December 31, 2013	$	—
	Fair Value on Issuance Date:
	Convertible notes payable	29,689
	Warrants to purchase common stock	10,938
	Balance at November 14, 2014	40,627
	Change in Fair Value:
	Convertible notes payable	8,091
	Warrants to purchase common stock	4,451
	Balance at December 31, 2014	$	53,169

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2014
Balance Sheet Details
Schedule of components of property and equipment		December 31,
		2013			2014
		(in thousands)
	Property and equipment:
	Furniture, office equipment, and software	$	656		$	648
	Laboratory equipment	4,896			5,187
	Leasehold improvements	2,305			2,361
		7,857			8,196
	Accumulated depreciation and amortization	(4,268		)	(5,276		)
		$	3,589		$	2,920
Schedule of components of accrued expenses and other current liabilities	Accrued expenses and other current liabilities:
	Accrued salaries and other employee costs	$	1,371		$	1,315
	Accrued operating expenses	560			769
	Accrued use taxes and other	149			129
		$	2,080		$	2,213

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Schedule of the reconciliation between income taxes computed at the federal statutory rate and provision for income taxes		Year Ended December 31,
		2012			2013			2014
		(in thousands)
	Federal income taxes at 34%	$	(8,084	)	$	(9,493	)	$	(17,352	)
	State income taxes, net of federal benefit	(1,363		)	(1,553		)	(1,243		)
	Research and development credits	(240		)	(1,425		)	(660		)
	Fair value adjustments on convertible notes payable and common stock warrant liability	—			—			9,577
	Interest on convertible notes payable	—			—			152
	Stock-based compensation expense	131			191			358
	Increase in valuation allowance	59,186			11,622			8,716
	Reinstatement of deferred tax assets for net operating loss and tax credit carryover deferred tax assets	(50,311		)	—			—
	Expiration of state net operating losses	673			677			450
	Other	8			(19		)	2
	Provision for income taxes	$	—		$	—		$	—
Schedule of the significant components of deferred tax assets and liabilities		December 31,
		2013			2014
		(in thousands)
	Deferred Tax Assets:
	Net operating loss carryforwards	$	61,629		$	62,738
	Research and development credits	6,277			6,891
	Amortization	2			5,737
	Stock-based compensation expense	4,182			5,085
	Depreciation	230			366
	Accrued operating expenses	12			64
	Other	291			459
		72,623			81,340
	Valuation Allowance	(72,623		)	(81,340		)
	Net Deferred Income Taxes	$	—		$	—
Schedule of the reconciliation of the beginning and ending amount of gross unrecognized tax benefits for period excluding interest and penalties		December 31,
		2013			2014
		(in thousands)
	Balance at Beginning of Year	$	1,954		$	2,490
	Additions (reductions) for prior year tax positions	167			(15		)
	Additions for current year tax positions	369			259
	Balance at End of Year	$	2,490		$	2,734

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Stock-Based Compensation
Schedule of the option activity under the plan							Weighted
				Weighted			Average
				Average			Remaining		Aggregate
		Options		Exercise			Contractual		Intrinsic
		Outstanding		Price			Term (years)		Value
	Balance at December 31, 2011	3,304,000		$	6.99
	Granted	544,000		$	5.95
	Cancelled	(9,300	)	$	12.64
	Exercised	(288,700	)	$	1.11
	Balance at December 31, 2012	3,550,000		$	7.3
	Granted	589,500		$	5.36
	Cancelled	(42,500	)	$	2
	Exercised	(50,350	)	$	0.61
	Balance at December 31, 2013	4,046,650		$	7.15
	Granted	637,000		$	3.53
	Cancelled	(180,500	)	$	6.61
	Exercised	(259,725	)	$	0.95
	Balance at December 31, 2014	4,243,425		$	7.01		6.43		$	1,659,000
	Vested at December 31, 2014	3,164,746		$	7.78		5.48		$	1,604,000
	Vested and Expected to Vest at December 31, 2014	4,218,131		$	7.02		6.19		$	1,657,000
Schedule of the vesting activity under the plan				Weighted
				Average
		Options		Grant Date
		Outstanding		Fair Value
	Unvested Options at December 31, 2013	1,308,149		$	4.2
	Granted	637,000		$	1.89
	Vested	(795,709	)	$	4.46
	Forfeited	(70,761	)	$	2.82
	Unvested Options at December 31, 2014	1,078,679		$	2.64
Options Granted [Member]
Stock-Based Compensation
Schedule of the expense (income) recorded under the plan		Year Ended December 31,
		2012			2013			2014
		(in thousands)
	Research and development	$	832		$	1,069		$	1,142
	General and administrative	2,647			2,965			2,284
	Total stock-based compensation	$	3,479		$	4,034		$	3,426
Schedule of the weighted-average assumptions used to estimate fair value of options granted		Year Ended December 31,
		2012		2013		2014
	Risk-free interest rate	1.03	%	1.38	%	2.18	%
	Expected volatility of common stock	62.1	%	60.1	%	59.3	%
	Expected life in years	6.25		6.25		6.14
	Dividend yield	0	%	0	%	0	%
Schedule of the grant date fair value and intrinsic value information of options granted to employees		Year Ended December 31,
		2012			2013			2014
		(in thousands, except per share data)
	Weighted average grant date fair value per share	$	3.43		$	2.95		$	1.98
	Intrinsic value of options exercised	$	1,392		$	231		$	553
	Total fair value of options vested during period	$	3,802		$	3,809		$	3,546
Stock Options To Consultants [Member]
Stock-Based Compensation
Schedule of the weighted-average assumptions used to estimate fair value of options granted		Year Ended December 31,
		2012		2013		2014
	Risk-free interest rate	1.18	%	2.96	%	2.17	%
	Expected volatility of common stock	62.1	%	59.4	%	57.2	%
	Expected life — years	6.71		9.45		8.94
	Dividend yield	0.0	%	0.0	%	0.0	%
Stock Options To Consultants And Stock Awards [Member]
Stock-Based Compensation
Schedule of the expense (income) recorded under the plan		Year Ended December 31,
		2012			2013			2014
		(in thousands)
	Research and development	$	18		$	9		$	69
	General and administrative	—			47			21
	Total stock-based compensation	$	18		$	56		$	90

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies.
Schedule of the future minimum payments under the lease		Minimum
		Payment
		(in thousands)
	2015	$	644
	2016	690
	2017	711
	2018	60
	Total minimum lease payments	$	2,105

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information (unaudited)
Schedule of the selected quarterly financial information		Quarter Ended												Year Ended
		March 31,			June 30,			September 30,			December 31,			December 31,
		(in thousands, except per share amounts)
	2013:00:00
	Loss from operations	$	(6,343	)	$	(6,666	)	$	(7,182	)	$	(7,752	)	$	(27,943	)
	Net loss	(6,331		)	(6,647		)	(7,191		)	(7,753		)	(27,922		)
	Net loss per common share, basic and diluted	$	(0.19	)	$	(0.20	)	$	(0.22	)	$	(0.23	)	$	(0.84	)
	2014:00:00
	Loss from operations	$	(7,272	)	$	(4,832	)	$	(4,446	)	$	(5,413	)	$	(21,963	)
	Net loss	(7,276		)	(4,833		)	(4,397		)	(34,531		)	(51,037		)
	Net loss per common share, basic and diluted	$	(0.22	)	$	(0.14	)	$	(0.13	)	$	(1.03	)	$	(1.53	)

Description_of_Business_Detail

Description of Business (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2010
	item	item
Description of Business
Common stock to CDIs conversion ratio		10
Number of patients enrolled in a clinical trial of current stent product	110

Capital_Resources_and_Basis_of1

Capital Resources and Basis of Presentation (Details) (USD $)	0 Months Ended
	Nov. 14, 2014	Dec. 31, 2014	Dec. 31, 2013
Stage of Company, Capital Resources, and Basis of Presentation
Cash and investments		$26,809,000
Cash proceeds from the issuance of convertible notes payable and warrants to purchase common stock	25,000,000
Accumulated deficit		($252,546,000)	($201,509,000)

Significant_Accounting_Policie3

Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
	segment
Property and Equipment:
Number of business segment	1
Interest or tax penalties on uncertain tax benefits	$0
Historical average period of actual forfeitures	5 years
Minimum [Member]
Property and Equipment:
Property and equipment, useful life	3 years
Maximum [Member]
Property and Equipment:
Property and equipment, useful life	5 years

Significant_Accounting_Policie4

Significant Accounting Policies (Details 2)	2 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Convertible Notes Payable
Net Income Loss Per Common Share
Securities excluded from the computation of diluted net loss per share (in shares)	1,513,138
Employee Stock Option
Net Income Loss Per Common Share
Securities excluded from the computation of diluted net loss per share (in shares)		4,355,536	3,901,316	3,300,039
Restricted Stock
Net Income Loss Per Common Share
Securities excluded from the computation of diluted net loss per share (in shares)		91,750	96,347	17,648
Warrant
Net Income Loss Per Common Share
Securities excluded from the computation of diluted net loss per share (in shares)	1,150,685

Significant_Accounting_Policie5

Significant Accounting Policies (Details 3) (USD $)	0 Months Ended	2 Months Ended	12 Months Ended
	Nov. 14, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Convertible Notes Payable	$29,689,000	$37,780,000	$37,780,000
Common stock warrant liability	10,938,000	15,389,000	15,389,000
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Market price per share of common stock	$2.71	$3.35	$3.35
Risk-free interest rate	2.89%		2.30%
Expected volatility of common stock	88.10%		87.20%
Expected life - years	5 years		4 years 10 months 13 days
Bond yield of equivalent securities	29.90%		28.40%
Fair Value on Issuance Date
Convertible Notes Payable	29,689,000	37,780,000	37,780,000
Common stock warrant liability	10,938,000	15,389,000	15,389,000
Change in Fair Value
Convertible note payable		8,091,000
Warrants to purchase common stock		4,451,000
Level 3
Convertible Notes Payable	29,689,000	37,780,000	37,780,000
Common stock warrant liability	10,938,000	15,389,000	15,389,000
Liabilities		53,169,000	53,169,000
Financial Liabilities Fair Value Disclosure
Beginning balance	40,627,000	40,627,000
Fair Value on Issuance Date
Convertible Notes Payable	29,689,000	37,780,000	37,780,000
Common stock warrant liability	10,938,000	15,389,000	15,389,000
Change in Fair Value
Convertible note payable		8,091,000
Warrants to purchase common stock		4,451,000
Ending balance		53,169,000	53,169,000
Certificates of Deposit [Member]
Gross Unrealized loss			4,000	4,000
Certificates of Deposit [Member] | Level 2
Cost, one year or less		$991,000	$991,000	$1,488,000

Convertible_Notes_Payable_and_1

Convertible Notes Payable and Warrants to Purchase Common Stock (Details) (USD $)	0 Months Ended	2 Months Ended	12 Months Ended
	Nov. 14, 2014	Dec. 31, 2014	Dec. 31, 2014	Nov. 14, 2014
Convertible Notes Payable
Proceeds from Notes Payable and Warrants	$25,000,000
Interest Expense			986,000
Increased exercise price of warrants			$2.61
Loss on issuance			-15,627,000
Convertible Notes Payable	29,689,000	37,780,000	37,780,000	29,689,000
Common stock warrant liability	10,938,000	15,389,000	15,389,000	10,938,000
Change in fair value of Notes		8,091,000
Change in fair value of Warrants		4,451,000
Convertible Notes Payable
Convertible Notes Payable
Number of convertible notes payable	250
Face Amount	100,000			100,000
Number of converted shares of common stock	11,506,155
Convertible rate into common stock	$2.17			$2.17
Market trading price			$0.60
Consecutive trading days			20
Interest rate (as a percent) accrued on notes		7.54%	7.54%
Interest Expense			248,000
Loss on issuance	4,689,000
Convertible notes excluding unpaid principal balance			12,780,000
Amount of shares converted			38,200,000
Warrant
Convertible Notes Payable
Convertible rate into common stock	$2.17			$2.17
Warrants issued to purchase common stock (in shares)	8,750,000
Loss on issuance	$10,938,000

Balance_Sheet_Details_Details_

Balance Sheet Details (Details 1) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property and equipment:
Property and equipment, gross	$8,196	$7,857
Accumulated depreciation and amortization	-5,276	-4,268
Property and equipment, net	2,920	3,589
Office Equipment [Member]
Property and equipment:
Property and equipment, gross	648	656
Equipment [Member]
Property and equipment:
Property and equipment, gross	5,187	4,896
Leasehold Improvements [Member]
Property and equipment:
Property and equipment, gross	$2,361	$2,305

Balance_Sheet_Details_Details_1

Balance Sheet Details (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued expenses and other current liabilities:
Accrued salaries and other employee costs	$1,315	$1,371
Accrued operating expenses	769	560
Accrued use taxes and other	129	149
Accrued expenses and other current liabilities, total	$2,213	$2,080

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation between income taxes computed at the federal statutory rate and provision for income taxes
Federal income taxes at 34%	($17,352)	($9,493)	($8,084)
State income taxes, net of federal benefit	-1,243	-1,553	-1,363
Research and development credits	-660	-1,425	-240
Fair value adjustments on convertible notes payable and common stock warrant liability	9,577
Interest on convertible notes payable	152
Stock-based compensation expense	358	191	131
Increase in valuation allowance	8,716	11,622	59,186
Reinstatement of deferred tax assets for net operating loss and tax credit carryover deferred tax assets			-50,311
Expiration of state net operating losses	450	677	673
Other	$2	($19)	$8
Federal income tax rate	34.00%	34.00%	34.00%

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Tax Assets:
Net operating loss carryforwards	$62,738	$61,629
Research and development credits	6,891	6,277
Amortization	5,737	2
Stock-based compensation expense	5,085	4,182
Depreciation	366	230
Accrued operating expenses	64	12
Other	459	291
Deferred Tax Assets	81,340	72,623
Valuation Allowance	($81,340)	($72,623)

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Taxes
Net operating loss related to excess tax benefits from stock compensation	$267,000
Deferred tax assets	81,340,000
Change in valuation allowance	8,717,000	11,622,000
Domestic Country [Member]
Income Taxes
Net operating loss carryforwards	162,797,000
Research tax credit carryforward, amount	5,797,000
C [A]
Income Taxes
Net operating loss carryforwards	128,411,000
Net operating loss carryforwards with expiration in 2015	11,869,000
Research tax credit carryforward, amount	$5,137,000

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency
Balance at Beginning of Year	$2,490	$1,954
Additions for tax positions (prior years)	-15	167
Additions for current year tax positions	259	369
Balance at End of Year	$2,734	$2,490

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options Outstanding
Granted (in shares)	637,000
Employee Stock Option
Stock-Based Compensation
Term of options granted under the plan	10 years
Equity Incentive Plan2010 And Stock Option And Stock Issuance Plan2001 Plan [Member]
Stock-Based Compensation
Number of plans covered under stock-based compensation arrangement	2
Number of shares added in reserve	998,101
Total number of shares in reserve with additional shares under the Plan	7,256,260
Aggregate Intrinsic Value
Tax benefits from stock based compensation	$0
Equity Incentive Plan2010 And Stock Option And Stock Issuance Plan2001 Plan [Member] | Maximum [Member]
Stock-Based Compensation
Increment in the number of shares reserved under the Plan annually (as a percent)	3.00%
Term of options granted under the plan	10 years
Vesting periods	5 years
Equity Incentive Plan2010 And Stock Option And Stock Issuance Plan2001 Plan [Member] | Minimum [Member]
Stock-Based Compensation
Vesting periods	4 years
Equity Incentive Plan2010 And Stock Option And Stock Issuance Plan2001 Plan [Member] | Employee Stock Option
Options Outstanding
Balance at the beginning of period (in shares)	4,046,650	3,550,000	3,304,000
Granted (in shares)	637,000	589,500	544,000
Cancelled (in shares)	-180,500	-42,500	-9,300
Exercised (in shares)	-259,725	-50,350	-288,700
Balance at the end of period (in shares)	4,243,425	4,046,650	3,550,000
Vested at end of year (in shares)	3,164,746
Vested and Expected to vest at the end of period (in shares)	4,218,131
Weighted Average Exercise Price
Balance at the beginning of period (in dollars per share)	$7.15	$7.30	$6.99
Granted (in dollars per share)	$3.53	$5.36	$5.95
Cancelled (in dollars per share)	$6.61	$2	$12.64
Exercised (in dollars per share)	$0.95	$0.61	$1.11
Balance at the end of period (in dollars per share)	$7.01	$7.15	$7.30
Vested at end of year (in dollars per share)	$7.78
Vested and Expected to vest at the end of period (in dollars per share)	$7.02
Weighted Average Remaining Contractual Term
Balance at end of year	6 years 5 months 5 days
Vested at end of year	5 years 5 months 23 days
Vested and Expected to vest at the end of period	6 years 2 months 9 days
Aggregate Intrinsic Value
Balance at end of year (in dollars)	1,659,000
Vested at end of year (in dollars)	1,604,000
Vested and Expected to vest at the end of period (in dollars)	$1,657,000
Equity Incentive Plan2010 And Stock Option And Stock Issuance Plan2001 Plan [Member] | Restricted Stock
Aggregate Intrinsic Value
Number of shares awarded	0	87,500	33,000
Annual vesting percent		25.00%

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014
Options Outstanding
Balance at the beginning of the period (in shares)	1,308,149
Granted (in shares)	637,000
Vested (in shares)	-795,709
Forfeited (in shares)	-70,761
Balance at the end of the period (in shares)	1,078,679
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$4.20
Weighted average grant date fair value (in dollars per share)	$1.89
Vested (in dollars per share)	$4.46
Forfeited (in dollars per share)	$2.82
Balance at the end of the period (in dollars per share)	$2.64

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 3) (Stock Awards And Option Grants [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options and Restricted Stock to Employees
Total stock-based compensation	$3,426,000	$4,034,000	$3,479,000
Unrecognized compensation cost	2,234,000
Unrecognized compensation cost related to unvested employee options, period for recognition	1 year 7 months 17 days
Research And Development Expense [Member]
Stock Options and Restricted Stock to Employees
Total stock-based compensation	1,142,000	1,069,000	832,000
General And Administrative Expense [Member]
Stock Options and Restricted Stock to Employees
Total stock-based compensation	$2,284,000	$2,965,000	$2,647,000

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Additional information related to fair values of options granted
Weighted average grant date fair value (in dollars per share)	$1.89
Granted (in shares)	637,000
Employee Stock Option
Additional information related to fair values of options granted
Risk-free interest rate (as a percent)	2.18%	1.38%	1.03%
Expected volatility of common stock (as a percent)	59.30%	60.10%	62.10%
Expected life	6 years 1 month 21 days	6 years 3 months	6 years 3 months
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Expiration term	10 years
Weighted average grant date fair value (in dollars per share)	$1.98	$2.95	$3.43
Intrinsic value of options exercised	$553,000	$231,000	$1,392,000
Total fair value of options vested during period	3,546,000	3,809,000	3,802,000
Stock Options To Consultants [Member]
Additional information related to fair values of options granted
Risk-free interest rate (as a percent)	2.17%	2.96%	1.18%
Expected volatility of common stock (as a percent)	57.20%	59.40%	62.10%
Expected life	8 years 11 months 9 days	9 years 5 months 12 days	6 years 8 months 16 days
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Minimum risk-free interest rate (as a percent)	1.70%
Maximum risk-free interest rate (as a percent)	2.80%
Minimum assumed expected volatility (as a percent)	57.00%
Maximum assumed expected volatility (as a percent)	59.00%
Weighted average grant date fair value (in dollars per share)	$1.92	$2.84	$4.37
Total fair value of options vested during period	116,000	40,000	42,000
Shares issued			0
Granted (in shares)	110,000	100,000
Stock Options To Consultants [Member] | Minimum [Member]
Additional information related to fair values of options granted
Expected life	5 years
Stock Options To Consultants [Member] | Maximum [Member]
Additional information related to fair values of options granted
Expected life	10 years
Stock Options To Consultants And Stock Awards [Member]
Additional information related to fair values of options granted
Total stock-based compensation	90,000	56,000	18,000
Stock Options To Consultants And Stock Awards [Member] | Research And Development Expense [Member]
Additional information related to fair values of options granted
Total stock-based compensation	69,000	9,000	18,000
Stock Options To Consultants And Stock Awards [Member] | General And Administrative Expense [Member]
Additional information related to fair values of options granted
Total stock-based compensation	$21,000	$47,000

Retirement_Plan_Details

Retirement Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Retirement Plan
Matching contributions equal to the percentage of the employee's contribution	25.00%
Employer matching contribution, (as a percent)	4.00%
Contributions by employer	$46,000	$52,000	$46,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitment and Contingencies
License provisions for escalating minimum royalties	$2,200,000
Annual licensing payment	175,000
Other payments of royalty agreement occur during commercialization	950,000
Contingent license fee payable only upon a change in ownership of licensee	350,000
Contract cancelable period with written notice	30 days
Minimum future payments on contracts	108,000
Operating Lease Extended Term	5 years
Leasehold improvements allowance and credit	523,000
Rent abatement	136,000
Deferred rent recorded in long-term liability	480,000
Deferred rent recorded in Current liability	117,000
Rent expense	683,000	666,000	636,000
Minimum [Member]
Commitment and Contingencies
Royalty payment per unit (in dollar per unit)	25
Maximum [Member]
Commitment and Contingencies
Royalty payment per unit (in dollar per unit)	100
Milestone amounts paid to the licensors (as a percent)	40.00%
Annual payments to extend filing periods related to certain technology	$300,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Future minimum payments
2015	$644
2016	690
2017	711
2018	60
Total minimum lease payments	$2,105

Related_Parties_Details

Related Parties (Details) (Minimum [Member])	Dec. 31, 2014
Minimum [Member]
Related Party Transaction
Ownership percentage of outstanding securities required to be considered as related party	5.00%

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Information (unaudited)
Loss from operations	($5,413)	($4,446)	($4,832)	($7,272)	($7,752)	($7,182)	($6,666)	($6,343)	($21,963)	($27,943)	($23,865)
Net loss and comprehensive loss	($34,531)	($4,397)	($4,833)	($7,276)	($7,753)	($7,191)	($6,647)	($6,331)	($51,037)	($27,922)	($23,776)
Net loss per common share, basic and diluted (in dollars per share)	($1.03)	($0.13)	($0.14)	($0.22)	($0.23)	($0.22)	($0.20)	($0.19)	($1.53)	($0.84)	($0.72)