The FDA turned away Ebvallo in January, taking issue with the design of the registrational trial. In a recent meeting, however, the agency agreed that the study could in fact support the cell therapy’s approval. The news comes a week after the departure of controversial biologics Director Vinay Prasad.
Is third time the charm for Atara Biotherapeutics and Pierre Fabre Pharmaceuticals’ embattled cell therapy Ebvallo? Quite possibly. One week after Center for Biologics Evaluation and Research (CBER) Director Vinay Prasad exited the FDA, the partners announced they will resubmit the candidate after a positive Type A meeting with the agency.
The FDA has agreed that a single-arm study “using an appropriate historical control applicable to the trial population” may serve as an “adequate and well controlled study” to support approval of Ebvallo for children two years and older diagnosed with post-transplant lymphoproliferative disease (PTLD) who were positive for the Epstein-Barr virus, according to Atara’s Thursday press release. The partners plan to submit an updated dataset with additional patients and longer follow-up time from the pivotal Phase 3 ALLELE study.
The FDA shot down Ebvallo for a second time in January, telling Atara and Pierre Fabre that the ALLELE trial was insufficient to support the biologics license application (BLA)—despite previously saying that it was, according to Atara. The FDA added at the time that the trial’s “interpretability is confounded due to trial study design, conduct, and analysis,” Atara said in January.
Ebvallo was first rejected in this indication in January 2025, with the FDA citing a “a single deficiency” regarding GMP compliance, according to Atara’s January 2026 release.
Atara was up more than 37% to $7.12 at the opening bell on Thursday following the news of a planned resubmission.
“We are grateful to the agency for engaging in a collaborative conversation with our partners, Pierre Fabre, and us,” Atara CEO Cokey Nguyen said in a prepared statement on Thursday. “We appreciate the FDA’s continued engagement with PFP and Atara, and we believe the Type A Meeting provided helpful alignment on the regulatory framework to resubmit.”
While Atara did not give a time estimate for the resubmission, the company did say it anticipates providing a further regulatory update in the third quarter.
Reversals of fortune
The apparent reversal comes after STAT News in February reported that inconsistencies at the FDA may have had something to do with Ebvallo’s most recent rejection, which represented a “complete reversal that I can’t help but think was due to the FDA’s new leadership,” a former FDA staffer told the publication. The CRL was issued by CBER, which was led at the time by Vinay Prasad.
Prasad stepped down from his position last week after a controversial reign. The FDA has tapped his deputy, Katherine Szarama, to serve as interim director.
“The shake-up at the top levels of the FDA over the last couple of months have likely had an impact on today’s news, we think, and continue to read positive to us,” Mizuho analysts wrote in a note to investors Thursday morning.
It also would not be the first time the FDA has seemingly reversed course this year. In February, the FDA refused to review Moderna’s investigational flu vaccine, mRNA-1010. In a refusal-to-file letter signed by Prasad—an unusual move for the CBER director—the agency claimed that Moderna failed to support mRNA-1010’s application with an “adequate and well-controlled” trial. The agency changed its mind a week later, promising an August action date for the vaccine.
Another FDA reversal last summer also featured Prasad. After initially requesting that Sarepta Therapeutics pull its Duchenne muscular dystrophy (DMD) gene therapy Elevidys from the market after the deaths of two non-ambulatory teenage patients, the FDA quickly did a 180, removing the voluntary hold for ambulatory patients, ultimately returning Elevidys to patients with DMD who can walk. The therapy remains unavailable for nonambulatory patients.
