Sponsor had hoped to use retrospective case review study as an external control arm to support regular approval of tazemetostat; US FDA not only rejected this idea, it found the study design so flawed that it did not consider the results in its efficacy assessment for accelerated approval.

Sponsor had hoped to use retrospective case review study as an external control arm to support regular approval of tazemetostat; US FDA not only rejected this idea, it found the study design so flawed that it did not consider the results in its efficacy assessment for accelerated approval.

Given the rarity of epithelioid sarcoma, ‘the possibility exists that this trial will not be completed,’ Division of Oncology 3 acting director Steven Lemery said in recommending approval; confirmatory trial is not expected to complete until 2029, and FDA reviewers suggest it may be underpowered to show an effect on progression-free survival. (Part 2 of our Drug Review Profile on the product.)