Document and Entity Information	6 Months Ended
Document and Entity Information	Jun. 30, 2013	Jul. 31, 2013
Document and Entity Information
Entity Registrant Name	AASTROM BIOSCIENCES INC
Entity Central Index Key	0000887359
Document Type	10-Q
Document Period End Date	Jun. 30, 2013
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		45,664,079
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 4,494	$ 13,638
Other current assets	236	352
Total current assets	4,730	13,990
Property and equipment, net	953	1,188
Total assets	5,683	15,178
Current liabilities:
Accounts payable and accrued expenses	3,334	3,247
Accrued employee benefits	458	383
Current portion of long-term debt	19	34
Warrant liabilities	31	1,995
Total current liabilities	3,842	5,659
Long-term debt		6
Total liabilities	3,842	5,665
Total convertible preferred stock	42,876	41,613
Shareholders' deficit:
Common stock, no par value; shares authorized - 150,000; shares issued and outstanding - 43,784 and 45,664, respectively	245,976	243,215
Deficit accumulated during the development stage	(287,011)	(275,315)
Total shareholders' deficit	(41,035)	(32,100)
Total liabilities, convertible preferred stock and shareholders' deficit	5,683	15,178
Series B-1 non-voting convertible preferred stock
Current liabilities:
Total convertible preferred stock	5,186	3,923
Series B-2 voting convertible preferred stock
Current liabilities:
Total convertible preferred stock	$ 37,690	$ 37,690

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Par value of common stock (in dollars per share)	$ 0	$ 0
Common Stock, shares authorized	150,000	150,000
Common Stock, shares issued	45,664	43,784
Common Stock, shares outstanding	45,664	43,784
Series B-1 non-voting convertible preferred stock
Par value of convertible preferred stock (in dollars per share)	$ 0	$ 0
Convertible preferred stock, shares authorized	39	39
Convertible preferred stock, shares reserved	39	39
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Series B-2 voting convertible preferred stock
Par value of convertible preferred stock (in dollars per share)	$ 0	$ 0
Convertible preferred stock, shares authorized	39	39
Convertible preferred stock, shares reserved	39	39
Convertible preferred stock, shares issued	12	12
Convertible preferred stock, shares outstanding	12	12

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References+ Details

- Definition

Issuance value per share of no-par value, nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer); generally not indicative of the fair market value per share.

+ References+ Details

- Definition

The maximum number of securities classified as temporary equity that are permitted to be issued by an entity's charter and bylaws. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References+ Details

- Definition

The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References+ Details

- Definition

The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References+ Details

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		291 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013
Revenues:
Product sales and rentals	$ 3		$ 11	$ 2	$ 1,909
Research and development agreements					2,105
Grants					9,901
Total revenues	3		11	2	13,915
Costs and expenses:
Cost of product sales and rentals	1		3	2	3,050
Research and development	3,676	7,069	9,214	13,865	225,944
Selling, general and administrative	1,560	2,231	3,193	3,993	95,791
Total costs and expenses	5,237	9,300	12,410	17,860	324,785
Loss from operations	(5,234)	(9,300)	(12,399)	(17,858)	(310,870)
Other income (expense):
Decrease in fair value of warrants	345	1,948	1,964	1,048	18,501
Other income					1,249
Interest income	3	20	8	26	10,830
Interest expense	(3)	(3)	(6)	(6)	(497)
Total other income	345	1,965	1,966	1,068	30,083
Net loss	(4,889)	(7,335)	(10,433)	(16,790)	(280,787)
Accretion of convertible preferred stock		1,231	1,263	1,520	6,224
Net loss attributable to common shareholders	$ (4,889)	$ (8,566)	$ (11,696)	$ (18,310)	$ (287,011)
Net loss per share attributable to common shareholders (Basic and Diluted) (in dollars per share)	$ (0.11)	$ (0.22)	$ (0.26)	$ (0.47)
Weighted average number of common shares outstanding (Basic and Diluted)	45,664	38,882	45,266	38,812

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended		291 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013
Operating activities:
Net loss	$ (10,433)	$ (16,790)	$ (280,787)
Adjustments to reconcile net loss to net cash used for operating activities:
Depreciation and amortization	275	341	8,422
Loss on property held for resale			110
Amortization of discounts and premiums on investments			(1,704)
Stock compensation expense	383	2,039	17,878
Decrease due to change in fair value of warrants	(1,964)	(1,048)	(18,501)
Inventory write downs and reserves			2,240
Stock issued pursuant to license agreement			3,300
Provision for losses on accounts receivable			204
Changes in operating assets and liabilities:
Inventories			(2,335)
Other current assets	116	181	(465)
Accounts payable and accrued expenses	87	821	3,102
Accrued employee benefits	75	(97)	458
Net cash used for operating activities	(11,461)	(14,553)	(268,078)
Investing activities:
Organizational costs			(73)
Purchase of short-term investments			(217,041)
Maturities of short-term investments			218,745
Property and equipment purchases	(40)	(86)	(7,530)
Proceeds from sale of property held for resale			400
Net cash used for investing activities	(40)	(86)	(5,499)
Financing activities:
Net proceeds from issuance of preferred stock		37,620	89,267
Net proceeds from issuance of common stock and warrants	2,378	176	187,432
Payments received for stock purchase rights and other, net			3,500
Proceeds from long-term debt			751
Principal payments under long-term debt obligations	(21)	(21)	(2,861)
Other, net			(18)
Net cash provided by financing activities	2,357	37,775	278,071
Net increase (decrease) in cash and cash equivalents	(9,144)	23,136	4,494
Cash and cash equivalents at beginning of period	13,638	5,530
Cash and cash equivalents at end of period	4,494	28,666	4,494
Supplemental cash flow information (non-cash):
Accretion of convertible preferred stock	1,263	1,520	6,224
Warrants exchanged for common stock		$ 8,356	$ 10,382

Organization and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2013
Organization and Summary of Significant Accounting Policies
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies Aastrom Biosciences, Inc. was incorporated in March 1989 (Inception), began employee-based operations in 1991, and is in the development stage. The Company operates its business in one reportable segment — research and product development involving the development of patient-specific, expanded multicellular therapies for use in the treatment of severe, chronic ischemic cardiovascular diseases. Successful future operations are subject to several technical hurdles and risk factors, including satisfactory product development, timely initiation and completion of clinical trials, regulatory approval and market acceptance of the Company’s products and the Company’s continued ability to obtain future funding. The Company is subject to certain risks related to the operation of its business and development of its products and product candidates. As of June 30, 2013, the Company had $4,494,000 of cash and cash equivalents. This is not sufficient to sustain operations for one year. In light of our financial position, we are evaluating strategic financial opportunities in the short-term in order to maintain adequate liquidity through December 31, 2013 and beyond. The Company could sell shares through an At the Market Sales Agreement (ATM) in order to raise additional capital, though there are certain factors, such as volume of trading in the stock, the stock price and the ability to terminate the agreement with notice, which could limit the amount the Company could raise in a short period of time. On a longer-term basis, the Company will need to raise additional funds in order to complete product development programs and complete clinical trials needed to market and commercialize its products. The Company cannot be certain that such funding will be available on favorable terms, if at all. Some of the factors that will impact the Company’s ability to raise additional capital and our overall success include: the rate and degree of progress for product development, the rate of regulatory approval to proceed with clinical trial programs, the level of success achieved in clinical trials, the requirements for marketing authorization from regulatory bodies in the United States and other countries, the liquidity and market volatility of the Company’s equity securities, regulatory and manufacturing requirements and uncertainties, technological developments by competitors, and other factors. If the Company cannot raise such funds, the Company will not be able to develop or enhance products, take advantage of future opportunities, or respond to competitive pressures or unanticipated requirements, which would have a material adverse impact on the business, financial condition and results of operations. As a result of the need to raise additional capital and a net capital deficiency, there is uncertainty regarding the Company’s ability to maintain liquidity sufficient to operate the business effectively over at least the next twelve months, which raises substantial doubt as to the ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis of Presentation	6 Months Ended
Basis of Presentation	Jun. 30, 2013
Basis of Presentation
Basis of Presentation	2. Basis of Presentation The condensed consolidated financial statements included herein have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) have been omitted pursuant to such rules and regulations. The financial statements reflect, in the opinion of management, all adjustments (consisting only of normal, recurring adjustments) necessary to state fairly the financial position and results of operations as of and for the periods indicated. The results of operations for the six months ended June 30, 2013, are not necessarily indicative of the results to be expected for the full year or for any other period. The December 31, 2012 condensed consolidated balance sheet data was derived from audited consolidated financial statements, but does not include all disclosures required by U.S. GAAP. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the period ended December 31, 2012, as filed with the SEC. The consolidated financial statements include the accounts of Aastrom and its wholly-owned subsidiaries, Aastrom Biosciences GmbH, located in Berlin, Germany, Aastrom Biosciences, SL, located in Barcelona, Spain and Marrow Donation, LLC, located in San Diego, California (collectively, the Company). All inter-company transactions and accounts have been eliminated in consolidation. The subsidiaries are not a significant component of the consolidated financial statements as each has limited operations historically and Aastrom Biosciences GmbH and Aastrom Biosciences, SL have ceased operations.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2013

Stock-Based Compensation

Stock-Based Compensation

3. Stock-Based Compensation

The Company issues nonqualified and incentive stock options as well as other equity awards pursuant to its 2009 Omnibus Incentive Plan, as amended (Option Plan). Such awards pursuant to the Option Plan may be granted by the Company’s Board of Directors to certain of the Company’s employees, directors and consultants.

During the six months ended June 30, 2013, the Company granted 1,365,000 service-based options to purchase common stock. These options were granted with exercise prices equal to or greater than the fair market value of the Company’s stock at the grant date, generally vest over four years (other than 240,000 non-employee options which vest over one year) and expire after ten years. The weighted average grant-date fair value of service-based options granted under the Company’s Option Plan during the six months ended June 30, 2012 and 2013 was $1.34 and $0.75, respectively.

The net compensation expense recorded for the service-based stock options related to employees and directors was $426,000 and $383,000 for the quarter and six months ended June 30, 2013, respectively, compared to $1,224,000 and $2,039,000 for the corresponding periods ended June 30, 2012. The June 30, 2013 compensation cost includes forfeiture adjustments, primarily due to restructuring activities announced on March 27, 2013, which reduced expense by $1,125,000.

The fair value of each service-based stock option grant for the reported periods is estimated on the date of the grant using the Black-Scholes option-pricing model using the weighted average assumptions noted in the following table.

	Six Months Ended June 30,
Service-Based Stock Options	2012	2013

Expected dividend rate	0%	0%
Expected stock price volatility	73.8 – 74.9%	74.0 – 80.7%
Risk-free interest rate	1.1 - 1.5%	0.1 - 1.4%
Expected life (years)	6.0 - 6.3	5.0 - 6.3

The following table summarizes the activity for service-based stock options for the indicated periods:

Service-Based Stock Options	Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value

Outstanding at December 31, 2012	9,987,468	$	2.38	7.5	$	—
Granted	1,365,000	$	1.14
Exercised	—	$	—		$	—
Expired	2,325,132	$	2.75
Forfeited	1,773,470	$	2.26
Outstanding at June 30, 2013	7,253,866	$	2.05	7.8	$	—
Exercisable at June 30, 2013	3,063,263	$	2.38	6.3	$	—

As of June 30, 2013 there was $3,046,000 of total unrecognized compensation cost related to non-vested service-based stock options granted under the Option Plan. That cost is expected to be recognized over a weighted-average period of 2.8 years.

The total fair value of options vested during the six months ended June 30, 2012 and 2013 was $1,362,000 and $1,434,000, respectively.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References

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-Name Statement of Financial Accounting Standard (FAS)

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+ Details

Stock Purchase Warrants

6 Months Ended

Jun. 30, 2013

Stock Purchase Warrants

Stock Purchase Warrants

4. Stock Purchase Warrants

The Company has historically issued warrants to purchase shares of the Company’s common stock in connection with certain of its common stock offerings. The following warrants were outstanding at June 30, 2013, and include provisions that could require cash settlement of the warrants or have anti-dilution price protection provisions requiring each to be recorded as liabilities of the Company at the estimated fair value at the date of issuance, with changes in estimated fair value recorded as non-cash income or expense in the Company’s statement of operations in each subsequent period:

	January 21, 2010 Class A Warrants		December 15, 2010 Warrants
Exercise price	$	2.44	$	1.25
Expiration date	July 21, 2015		December 15, 2015
Warrants outstanding	6,034,637		308,100
Total shares issuable on exercise	4,525,978		308,100

The 740,131 warrants issued on October 17, 2007 in connection with the Company’s registered direct offering, at an exercise price of $12.72 per share expired unexercised as of April 17, 2013. The exercise price per share for the January 15, 2010 and December 15, 2010 warrants were adjusted for the anti-dilution provisions triggered by usage of the Company’s ATM during the six months ended June 30, 2013, which raised gross proceeds of $2,451,000.

The fair value of the Class A warrants and the December 2010 warrants are measured using the Monte Carlo valuation model. The methodology is based, in part, upon inputs for which there is little or no observable market data, requiring the Company to develop its own assumptions. The assumptions used in calculating the estimated fair value of the warrants represent the Company’s best estimates, however; these estimates involve inherent uncertainties and the application of management judgment. As a result, if factors change and different assumptions are used, the warrant liabilities and the change in estimated fair value of the warrants could be materially different.

Inherent in the Monte Carlo valuation model are assumptions related to expected stock-price volatility, expected life, risk-free interest rate and dividend yield. The Company estimates the volatility of its common stock based on historical volatility that matches the expected remaining life of the warrants. The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve on the grant date for a maturity similar to the expected remaining life of the warrants. The expected life of the warrants is assumed to be equivalent to their remaining contractual term. The dividend rate is based on the historical rate, which the Company anticipates to remain at zero.

The Monte Carlo model is used for the Class A warrants and the December 2010 warrants to value the potential future exercise price adjustments triggered by the anti-dilution provisions as well as the value of the put feature of the December 2010 warrants. These both require Level 3 inputs which are based on the Company’s estimates of the probability and timing of potential future financings and fundamental transactions. The other assumptions used by the Company are summarized in the following tables:

January 2010 Class A Warrants	December 31, 2012			June 30, 2013
Closing stock price	$	1.26		$	0.40
Expected dividend rate	0		%	0		%
Expected stock price volatility	74.0		%	59.9		%
Risk-free interest rate	0.4		%	0.4		%
Expected life (years)	2.50			2.00

December 2010 Warrants	December 31, 2012			June 30, 2013
Closing stock price	$	1.26		$	0.40
Expected dividend rate	0		%	0		%
Expected stock price volatility	70.1		%	58.4		%
Risk-free interest rate	0.4		%	0.5		%
Expected life (years)	2.96			2.46

The following table summarizes the change in the estimated fair value of the Company’s warrant liabilities (in thousands):

Warrant Liabilities
Balance at December 31, 2012	$	1,995
Decrease in fair value	(1,964		)
Balance at June 30, 2013	$	31

Series B Convertible Preferred Stock	6 Months Ended
Series B Convertible Preferred Stock	Jun. 30, 2013
Series B Convertible Preferred Stock
Series B Convertible Preferred Stock	5. Series B Convertible Preferred Stock On March 9, 2012, the Company completed the sale of 12,308 shares of Series B-1 Non-Voting Convertible Preferred Stock (Series B-1 preferred stock) at an offering price of $3,250 per share. In addition to the Series B-1 preferred stock, which was issued at the closing, the Company also authorized Series B-2 Voting Convertible preferred Stock (Series B-2 preferred stock). The Series B-1 preferred stock and Series B-2 preferred stock collectively are referred to as the Series B preferred stock. The Series B preferred stock is convertible, at the option of the holder thereof at any time after the five year anniversary of the closing of the offering, into shares of common stock at a conversion price of $3.25 per share of common stock. At any time after the five year anniversary of issuance, the Company may elect to convert any or all outstanding shares of Series B preferred stock into shares of common stock, subject to certain limitations. Dividends on the Series B preferred stock will be cumulative and compound daily, at a rate of 11.5% per annum, payable upon conversion, liquidation, redemption or other similar events, and payable in cash or Series B-1 preferred stock until the five year anniversary of issuance. Unless prohibited by Michigan law governing distributions to shareholders, the Series B-1 preferred stock shall be redeemable at the option of holder of the Series B-1 preferred stock commencing at any time after the five year anniversary of issuance, liquidation, winding up, dissolution or other similar events, subject to certain terms and limitations. The Series B preferred stock does not, in its entirety, require liability classification and has been evaluated for embedded features to determine if those features require bifurcation and separate classification as derivative liabilities. The Series B preferred stock host contract was evaluated for equity or mezzanine classification based upon the nature of the redemption and conversion features. Generally, any feature that could require cash redemption for matters not within the Company’s control, irrespective of probability of the event occurring, requires classification outside of shareholders’ equity. The Series B preferred stock has been recorded as mezzanine in the Condensed Consolidated Balance Sheets and will be accreted to its redemption value through charges to Deficit accumulated during the development stage using the effective interest method. The carrying value of the Series B-1 preferred stock presented as mezzanine in the condensed consolidated financial statements is $5,186,000, as of June 30, 2013. As of June 30, 2013, there are no outstanding shares of Series B-1 preferred stock. The decrease in our stock price has made it unlikely that a material governmental filing by Eastern will be required on the scheduled conversion date. Therefore, the probability of redemption has decreased to a level where that we are no longer required to accrete the Series B-1 preferred stock up to the redemption value of $31,102,000. The potential redemption value is determined by the greater of the conversion price of the Series B-1 Preferred Stock or the common stock price, multiplied by the total accumulated dividends at the five year anniversary of issuance.

Net Loss Per Common Share	6 Months Ended
Net Loss Per Common Share	Jun. 30, 2013
Net Loss Per Common Share
Net Loss Per Common Share	6. Net Loss Per Common Share Basic earnings (loss) per share is calculated using the two-class method, which is an earnings allocation formula that determines earnings (loss) per share for the holders of the Company’s common shares and holders of the Series B preferred stock. The Series B preferred stock shares contain participation rights in undistributed earnings, but do not share in the losses of the Company. Therefore, in the event of a loss from continuing operations, the Series B preferred stock is not considered in the calculation of basic loss per share. Net loss per common share is computed using the weighted-average number of common shares outstanding during the period. Common equivalent shares are not included in the diluted per share calculation where the effect of their inclusion would be anti-dilutive. The aggregate number of common equivalent shares (related to options, warrants and preferred stock) that have been excluded from the computations of diluted net loss per common share at June 30, 2012 and 2013 were 31,355,000 and 26,396,000, respectively.

- Definition

The entire disclosure for earnings per share.

+ References+ Details

Restructuring	6 Months Ended
Restructuring	Jun. 30, 2013
Restructuring
Restructuring	7. Restructuring On March 27, 2013, the Company announced a strategic change in its research and development programs to focus on the clinical development of ixmyelocel-T for the treatment advanced heart failure due to ischemic dilated cardiomyopathy (DCM). The Company, which recently initiated the Phase 2b ixCELL-DCM clinical trial, previously received a U.S. orphan drug designation for the use of ixmyelocel-T in the treatment of DCM. As a result of the strategic change, the Company stopped enrollment of the Phase 3 REVIVE clinical trial in patients with critical limb ischemia (CLI). In addition, the Company executed a corporate restructuring that reduced staff and operating expenses. Employees directly affected by the restructuring plan were provided with severance payments and outplacement assistance. As a result of the termination of the Phase 3 REVIVE clinical trial, the Company recorded a one-time restructuring charge of $408,000 in the first quarter of 2013. The restructuring accrual decreased to $204,000 as of June 30, 2013 as a result of cash payments made for severance and other personnel-related expense during the quarter.

- Definition

The entire disclosure for restructuring and related activities. Description of restructuring activities such as exit and disposal activities, include facts and circumstances leading to the plan, the expected plan completion date, the major types of costs associated with the plan activities, total expected costs, the accrual balance at the end of the period, and the periods over which the remaining accrual will be settled.

+ References+ Details

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

Stock-Based Compensation

Schedule of weighted average assumptions used to estimate fair value of each service-based stock option grant

	Six Months Ended June 30,
Service-Based Stock Options	2012	2013

Expected dividend rate	0%	0%
Expected stock price volatility	73.8 – 74.9%	74.0 – 80.7%
Risk-free interest rate	1.1 - 1.5%	0.1 - 1.4%
Expected life (years)	6.0 - 6.3	5.0 - 6.3

Summary of activity for service-based stock options

Service-Based Stock Options	Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value

Outstanding at December 31, 2012	9,987,468	$	2.38	7.5	$	—
Granted	1,365,000	$	1.14
Exercised	—	$	—		$	—
Expired	2,325,132	$	2.75
Forfeited	1,773,470	$	2.26
Outstanding at June 30, 2013	7,253,866	$	2.05	7.8	$	—
Exercisable at June 30, 2013	3,063,263	$	2.38	6.3	$	—

Stock Purchase Warrants (Tables)

6 Months Ended

Jun. 30, 2013

Stock Purchase Warrants

Schedule of assumptions used in calculating estimated fair value of warrants

	January 21, 2010 Class A Warrants		December 15, 2010 Warrants
Exercise price	$	2.44	$	1.25
Expiration date	July 21, 2015		December 15, 2015
Warrants outstanding	6,034,637		308,100
Total shares issuable on exercise	4,525,978		308,100

January 2010 Class A Warrants	December 31, 2012			June 30, 2013
Closing stock price	$	1.26		$	0.40
Expected dividend rate	0		%	0		%
Expected stock price volatility	74.0		%	59.9		%
Risk-free interest rate	0.4		%	0.4		%
Expected life (years)	2.50			2.00

December 2010 Warrants	December 31, 2012			June 30, 2013
Closing stock price	$	1.26		$	0.40
Expected dividend rate	0		%	0		%
Expected stock price volatility	70.1		%	58.4		%
Risk-free interest rate	0.4		%	0.5		%
Expected life (years)	2.96			2.46

Summary of change in estimated fair value of warrant liabilities

The following table summarizes the change in the estimated fair value of the Company’s warrant liabilities (in thousands):

Warrant Liabilities
Balance at December 31, 2012	$	1,995
Decrease in fair value	(1,964		)
Balance at June 30, 2013	$	31

Organization and Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 item	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Organization and Summary of Significant Accounting Policies
Number of reportable segments	1
Cash and cash equivalents	$ 4,494	$ 13,638	$ 28,666	$ 5,530
Maximum period before cash and cash equivalents are not sufficient to sustain operations	1 year
Minimum period of uncertainty regarding the entity's ability to maintain liquidity sufficient to operate business effectively	12 months

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-Paragraph 1

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Stock-Based Compensation (Details) (Service-based stock options, USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Stock-Based Compensation
Vesting period			4 years
Expiration period			10 years
Weighted average grant-date fair value (in dollars per share)			$ 0.75	$ 1.34
Net compensation expense related to employees and directors (in dollars)	$ 426,000	$ 1,224,000	$ 383,000	$ 2,039,000
Forfeiture adjustments included in compensation costs due to restructuring activities (in dollars)			1,125,000
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected dividend rate (as a percent)			0.00%	0.00%
Options
Outstanding at the beginning of the period (in shares)			9,987,468
Granted (in shares)			1,365,000
Expired (in shares)			2,325,132
Forfeited (in shares)			1,773,470
Outstanding at the end of the period (in shares)	7,253,866		7,253,866		9,987,468
Exercisable at the end of the period (in shares)	3,063,263		3,063,263
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 2.38
Granted (in dollars per share)			$ 1.14
Expired (in dollars per share)			$ 2.75
Forfeited (in dollars per share)			$ 2.26
Outstanding at the end of the period (in dollars per share)	$ 2.05		$ 2.05		$ 2.38
Exercisable at the end of the period (in dollars per share)	$ 2.38		$ 2.38
Weighted Average Remaining Contractual Term
Outstanding at the beginning of the period			7 years 9 months 18 days		7 years 6 months
Outstanding at the end of the period			7 years 9 months 18 days		7 years 6 months
Exercisable at the end of the period			6 years 3 months 18 days
Additional disclosures
Total unrecognized compensation cost (in dollars)	3,046,000		3,046,000
Weighted average period over which unrecognized compensation is expected to be recognized			2 years 9 months 18 days
Total fair value of options vested (in dollars)			$ 1,434,000	$ 1,362,000
Minimum
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected stock price volatility (as a percent)			74.00%	73.80%
Risk-free interest rate (as a percent)			0.10%	1.10%
Expected life			5 years	6 years
Maximum
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected stock price volatility (as a percent)			80.70%	74.90%
Risk-free interest rate (as a percent)			1.40%	1.50%
Expected life			6 years 3 months 18 days	6 years 3 months 18 days
Non-employee
Stock-Based Compensation
Vesting period			1 year
Options
Granted (in shares)			240,000

Stock Purchase Warrants (Details) (USD $)	3 Months Ended		6 Months Ended		291 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
Stock Purchase Warrants (Details) (USD $)	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2013 January 2010 Class A Warrants	Dec. 31, 2012 January 2010 Class A Warrants	Jun. 30, 2013 December 2010 Warrants	Dec. 31, 2012 December 2010 Warrants	Apr. 17, 2013 October 2007 Warrants	Oct. 17, 2007 October 2007 Warrants
Stock Purchase Warrants
Number of warrants issued											740,131
Exercise price per share (in dollars per share)						$ 2.44		$ 1.25		$ 12.72
Warrants outstanding						6,034,637		308,100
Total shares issuable on exercise						4,525,978		308,100
Assumptions used in calculating the estimated fair value of the warrants
Closing stock price (in dollars per share)						$ 0.40	$ 1.26	$ 0.40	$ 1.26
Expected dividend rate (as a percent)						0.00%	0.00%	0.00%	0.00%
Expected stock price volatility (as a percent)						59.90%	74.00%	58.40%	70.10%
Risk-free interest rate (as a percent)						0.40%	0.40%	0.50%	0.40%
Expected life						2 years	2 years 6 months	2 years 5 months 16 days	2 years 11 months 16 days
Change in the estimated fair value of warrant liabilities
Balance at the beginning of the period			$ 1,995,000
Decrease in fair value of warrants	(345,000)	(1,948,000)	(1,964,000)	(1,048,000)	(18,501,000)
Balance at the end of the period	31,000		31,000		31,000
Gross proceeds raised from sale of shares under ATM			$ 2,451,000

Series B Convertible Preferred Stock (Details) (USD $)	1 Months Ended	6 Months Ended
Series B Convertible Preferred Stock (Details) (USD $)	Mar. 31, 2012	Jun. 30, 2013	Dec. 31, 2012
Series B Convertible Preferred Stock
Carrying value of convertible preferred stock		$ 42,876,000	$ 41,613,000
Series B preferred stock
Series B Convertible Preferred Stock
Period of closing of offering after which shares are convertible		5 years
Conversion price per share (in dollars per share)		$ 3.25
Percentage of cumulative dividend rate		11.50%
Period for accrual of dividend		5 years
Series B-1 preferred stock
Series B Convertible Preferred Stock
Number of shares sold	12,308
Offering price per share (in dollars per share)	$ 3,250
Carrying value of convertible preferred stock		5,186,000	3,923,000
Preferred stock, shares outstanding		0	0
Redemption value		$ 31,102,000
Period to determine redemption value		5 years

Net Loss Per Common Share (Details)	6 Months Ended
Net Loss Per Common Share (Details)	Jun. 30, 2013	Jun. 30, 2012
Net Loss Per Common Share
Aggregate number of common equivalent shares (related to options, warrants and preferred stock) that have been excluded from computations of diluted net loss per common share	26,396,000	31,355,000

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Antidilution

-URI http://asc.fasb.org/extlink&oid=6505113

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-URI http://asc.fasb.org/extlink&oid=6510752

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Restructuring (Details) (USD $)	3 Months Ended
Restructuring (Details) (USD $)	Mar. 31, 2013	Jun. 30, 2013
Restructuring
Restructuring charge	$ 408,000
Restructuring reserve related to severance payments		$ 204,000

- Definition

Amount charged against earnings in the period for incurred and estimated costs associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding asset retirement obligations.

+ References+ Details