Restructuring	3 Months Ended
Mar. 31, 2013
Restructuring	3. Restructuring On April 3, 2013, the Company completed a workforce reduction plan to reduce costs as part of the Company’s decision to terminate development of palifosfamide in first-line metastatic soft tissue sarcoma and place exclusive strategic focus on its synthetic biology programs, which are being developed in partnership with Intrexon Corporation (Notes 6, 7 and 9). Pursuant to the workforce reduction plan, the Company eliminated a total of 65 positions, comprised of 40 filled positions and 25 unfilled positions across various functions and locations. Employees whose positions were eliminated as part of the plan were notified beginning on April 2, 2013. Affected employees were offered separation benefits, including severance payments, and temporary healthcare coverage assistance. In connection with the elimination of filled positions as part of the workforce reduction plan, the Company estimated that it will incur total charges of $1.6 million to $1.8 million, primarily for one-time contractual severance benefits. The Company will record these charges in the second quarter of 2013. Additionally, the Company is evaluating its facilities and the associated contractual obligations to determine the appropriate course of action and any associated charges for exit and disposal activities. The Company currently cannot estimate these amounts, but expects to file an amended Current Report on Form 8-K within four business days of making such determination. On July 16, 2012, the Company announced that it restructured its management team and closed its Germantown, MD office. As a result of this action, the Company recorded a restructuring charge, consisting primarily of severance, stock based compensation associated with stock option modifications (see Note 9) and health benefit continuation costs of approximately $1.3 million. These costs are included in general and administrative expense for the period from inception (September 9, 2003) through March 31, 2013.

Restructuring

3 Months Ended

Mar. 31, 2013

3. Restructuring

On April 3, 2013, the Company completed a workforce reduction plan to reduce costs as part of the Company’s decision to terminate development of palifosfamide in first-line metastatic soft tissue sarcoma and place exclusive strategic focus on its synthetic biology programs, which are being developed in partnership with Intrexon Corporation (Notes 6, 7 and 9). Pursuant to the workforce reduction plan, the Company eliminated a total of 65 positions, comprised of 40 filled positions and 25 unfilled positions across various functions and locations. Employees whose positions were eliminated as part of the plan were notified beginning on April 2, 2013. Affected employees were offered separation benefits, including severance payments, and temporary healthcare coverage assistance. In connection with the elimination of filled positions as part of the workforce reduction plan, the Company estimated that it will incur total charges of $1.6 million to $1.8 million, primarily for one-time contractual severance benefits. The Company will record these charges in the second quarter of 2013. Additionally, the Company is evaluating its facilities and the associated contractual obligations to determine the appropriate course of action and any associated charges for exit and disposal activities. The Company currently cannot estimate these amounts, but expects to file an amended Current Report on Form 8-K within four business days of making such determination.

On July 16, 2012, the Company announced that it restructured its management team and closed its Germantown, MD office. As a result of this action, the Company recorded a restructuring charge, consisting primarily of severance, stock based compensation associated with stock option modifications (see Note 9) and health benefit continuation costs of approximately $1.3 million. These costs are included in general and administrative expense for the period from inception (September 9, 2003) through March 31, 2013.