Atara and Pierre Fabre’s Ebvallo resubmission plan follows the FDA’s decision to reconsider the regulatory evidence strategy after a second discussion with agency officials. The companies said the FDA indicated that a single-arm study with an appropriate historical control could meet “adequate and well-controlled” expectations, despite the initial January rejection. The update matters because it changes the decision framework from requiring a new prospective randomized trial to allowing the companies to pursue approval with additional patient enrollment and longer follow-up within the existing Allele single-arm data set. The FDA’s action also signals heightened scrutiny of cell therapy study design, particularly in ultra-rare settings like EBV+PTLD, while offering a path to submission completion for the two sponsors without restarting clinical development from scratch.