The FDA agreed to reconsider its approach to Pierre Fabre and Atara Biotherapeutics’ EBV-specific cytotoxic T-cell therapy Ebvallo (tabelecleucel) after a prior shock rejection. The companies said the regulator indicated that a single-arm study using an appropriate historical control could serve as an adequate and well-controlled design for resubmission. Ebvallo is being pursued for patients with relapsed or refractory Epstein-Barr virus-positive post-transplant lymphoproliferative disease (EBV+PTLD) after failure of an anti-CD20 regimen. Regulators in Europe had already approved the immunotherapy for the indication in 2022, leaving the U.S. as a key remaining market. Pierre Fabre and Atara plan to resubmit without running a separate trial, instead adding more patients and extending follow-up of the Allele study. The resubmission plan is expected to be finalized with the FDA in the coming weeks. Strategically, the development signals a potential shift in how the FDA evaluates ultra-rare cell therapy programs when randomization is difficult and interpretability can be supported through historical controls.