FDA: Adcetris approval possible despite 'limitations'
FDA identified "limitations" in each of two single-arm Phase II trials of Adcetris brentuximab from Seattle Genetics Inc. (NASDAQ:SGEN), but noted that accelerated approval would be consistent with prior regulatory actions for similar applications based on single-arm trials. The comments came in briefing documents released ahead of Thursday's Oncologic Drugs Advisory Committee meeting to discuss two BLAs for Adcetris to treat relapsed or refractory Hodgkin's lymphoma and to treat relapsed or refractory systemic anaplastic large cell lymphoma (ALCL).
FDA said single-arm trials limit the benefit-risk analysis of the product and results are limited to response rates and duration of responses because endpoints like progression-free survival (PFS) or overall survival (OS) cannot be adequately interpreted. However, the agency did say it advised the company in 2008 that a response rate with prolonged duration and an acceptable risk-benefit may support accelerated approval. Adcetris led to an overall response rate of 75% in 102 Hodgkin's lymphoma patients, with a median duration of 6.7 months, and an ORR of 86% in 58 ALCL patients, with a median duration of 12.6 months. ...