Significant agreements	3 Months Ended
Mar. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Significant agreements	6. Significant agreements Celgene Corporation On March 19, 2013, the Company entered into a Master Collaboration Agreement (the “Collaboration Agreement”) with Celgene to discover, develop and commercialize potentially disease-altering gene therapies in oncology. The collaboration is focused on applying gene therapy technology to genetically modify a patient’s own T cells, known as chimeric antigen receptor, or CAR, T cells, to target and destroy cancer cells. Additionally, on March 19, 2013, the Company entered into a Platform Technology Sublicense Agreement (the “Sublicense Agreement”) with Celgene pursuant to which the Company obtained a sublicense to certain intellectual property from Celgene, originating under Celgene’s license from Baylor College of Medicine, for use in the collaboration. Under the terms of the Collaboration Agreement, the Company received a $75.0 million up-front, non-refundable cash payment. The Company is responsible for conducting discovery, research and development activities through completion of Phase I clinical studies, if any, during the initial term of the agreement, or three years. The collaboration is governed by a joint steering committee (“JSC”) formed by an equal number of representatives from the Company and Celgene. The JSC will, among other activities, review the collaboration program, review and evaluate product candidates and approve regulatory plans. In addition to the JSC, the Collaboration Agreement provides that the Company and Celgene each appoint representatives to a patent committee, which is responsible for managing the intellectual property developed and used during the collaboration. During each of the three months ended March 31, 2015 and 2014 the Company recognized $6.3 million of revenue associated with its collaboration with Celgene related to the recognition of discovery, research and development services. As of March 31, 2015 and December 31, 2014, there was $24.3 million and $30.7 million of deferred revenue related to the Company’s collaboration with Celgene, which is classified as current or non-current in the condensed consolidated balance sheets based on the contractual term of the arrangement. For additional discussion on significant agreements, please refer to Note 11, "Significant agreements," in the 2014 Annual Report on Form 10-K.

6. Significant agreements

Celgene Corporation

On March 19, 2013, the Company entered into a Master Collaboration Agreement (the “Collaboration Agreement”) with Celgene to discover, develop and commercialize potentially disease-altering gene therapies in oncology. The collaboration is focused on applying gene therapy technology to genetically modify a patient’s own T cells, known as chimeric antigen receptor, or CAR, T cells, to target and destroy cancer cells. Additionally, on March 19, 2013, the Company entered into a Platform Technology Sublicense Agreement (the “Sublicense Agreement”) with Celgene pursuant to which the Company obtained a sublicense to certain intellectual property from Celgene, originating under Celgene’s license from Baylor College of Medicine, for use in the collaboration.

Under the terms of the Collaboration Agreement, the Company received a $75.0 million up-front, non-refundable cash payment. The Company is responsible for conducting discovery, research and development activities through completion of Phase I clinical studies, if any, during the initial term of the agreement, or three years. The collaboration is governed by a joint steering committee (“JSC”) formed by an equal number of representatives from the Company and Celgene. The JSC will, among other activities, review the collaboration program, review and evaluate product candidates and approve regulatory plans. In addition to the JSC, the Collaboration Agreement provides that the Company and Celgene each appoint representatives to a patent committee, which is responsible for managing the intellectual property developed and used during the collaboration.

During each of the three months ended March 31, 2015 and 2014 the Company recognized $6.3 million of revenue associated with its collaboration with Celgene related to the recognition of discovery, research and development services. As of March 31, 2015 and December 31, 2014, there was $24.3 million and $30.7 million of deferred revenue related to the Company’s collaboration with Celgene, which is classified as current or non-current in the condensed consolidated balance sheets based on the contractual term of the arrangement.

For additional discussion on significant agreements, please refer to Note 11, "Significant agreements," in the 2014 Annual Report on Form 10-K.