Atara Biotherapeutics announced that the US Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) for the Biologics License Application (BLA) for Ebvallo (tabelecleucel).[2][3] The application sought approval of Ebvall as monotherapy for adult and pediatric patients 2 years of age and older with Epstein-Barr virus-positive post-transplant lymphoproliferative disease (EBV+ PTLD) who have received at least one prior therapy, including anti-CD20 therapy.[2][3] The CRL states that the FDA cannot approve the application in its current form because the single-arm ALLELE study is no longer considered sufficient to demonstrate efficacy for accelerated approval.[3][5] The FDA confirmed that the GMP (good manufacturing practice) compliance issues had been resolved and raised no safety concerns.[2][3] This is the second CRL; the first was released on January 15, 2025 solely due to GMP deficiencies.[3][6] The application was resubmitted in 2025 after agreement with the FDA on the criteria.[3] Pierre Fabre Pharmaceuticals, which received the BLA in November 2025, plans to request a Type A meeting within 45 days to discuss accelerated approval.[2]