Restricted Cash	3 Months Ended
Mar. 31, 2013
Restricted Cash
Restricted Cash	4. Restricted Cash The Company designated $17.5 million as collateral for a security bond posted in the litigation against Amphastar Pharmaceuticals Inc., or Amphastar, Actavis, Inc., or Actavis (formerly Watson Pharmaceuticals Inc.), and International Medical Systems, Ltd. (a wholly owned subsidiary of Amphastar), as discussed within Note 9, Legal Contingencies. The $17.5 million is held in an escrow account by Hanover Insurance. The Company classified this restricted cash as long-term as the timing of a final decision in the Enoxaparin Sodium Injection patent litigation is not known. The Company designated $2.5 million as collateral for a letter of credit related to the lease of office and laboratory space at its headquarters located at 675 West Kendall Street, Cambridge, Massachusetts. This balance will remain restricted through the remaining term of the lease which ends in April 2015. The Company will earn interest on the balance.

4. Restricted Cash

The Company designated $17.5 million as collateral for a security bond posted in the litigation against Amphastar Pharmaceuticals Inc., or Amphastar, Actavis, Inc., or Actavis (formerly Watson Pharmaceuticals Inc.), and International Medical Systems, Ltd. (a wholly owned subsidiary of Amphastar), as discussed within Note 9, Legal Contingencies. The $17.5 million is held in an escrow account by Hanover Insurance. The Company classified this restricted cash as long-term as the timing of a final decision in the Enoxaparin Sodium Injection patent litigation is not known.

The Company designated $2.5 million as collateral for a letter of credit related to the lease of office and laboratory space at its headquarters located at 675 West Kendall Street, Cambridge, Massachusetts. This balance will remain restricted through the remaining term of the lease which ends in April 2015. The Company will earn interest on the balance.