FDA to Reconsider Ebvallo Treatment for Rare Cancer After Surprise Rejection

The FDA reached an agreement with Pierre Fabre Pharmaceuticals and Atara Biotherapeutics in late April 2026 to reconsider Ebvallo, a rare blood cancer therapy rejected in January 2026. The agency reversed its main objection, now agreeing that the companies' already completed single-arm clinical trial provides sufficient data to support review and potential approval, despite previously calling the trial flawed and its data insufficient.

FDA reversal on Ebvallo approval

• ▪Ebvallo is a therapy for a rare blood cancer developed by Pierre Fabre Pharmaceuticals and Atara Biotherapeutics.
• ▪Pierre Fabre Pharmaceuticals and Atara Biotherapeutics reached an agreement with the Food and Drug Administration in late April 2026 that walked back the agency's main reason for rejecting Ebvallo in January 2026.
• ▪The Food and Drug Administration agreed that Pierre Fabre Pharmaceuticals and Atara Biotherapeutics' already completed, single-arm clinical trial was sufficient to support a review and potential approval of Ebvallo.
• ▪The Food and Drug Administration rejected Ebvallo in January 2026.

Clinical trial sufficiency dispute

• ▪When the Food and Drug Administration rejected Ebvallo, the agency said the single-arm clinical trial was flawed and the data produced from it was insufficient to support the drug's approval.
• ▪Pierre Fabre Pharmaceuticals and Atara Biotherapeutics announced on May 7, 2026 that a meeting held in late April 2026 with Food and Drug Administration officials ended with the agency agreeing their clinical trial was sufficient.

FDA leadership transition

• ▪Vinay Prasad led the Food and Drug Administration's Center for Biologics Evaluation and Research at the time Ebvallo's review was conducted.
• ▪Vinay Prasad departed the Food and Drug Administration at the end of April 2026.

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