FDA Reopens the Door for Rare Cancer Therapy After Earlier Rejection

STATNews, Business Wire, PRNewswire contributed to this report.

Just a few months after the FDA unexpectedly rejected a treatment for a rare and often deadly blood cancer, the agency is now signaling it may be willing to reconsider.

Atara Biotherapeutics and Pierre Fabre Pharmaceuticals said Thursday they reached an agreement with FDA officials on a possible path forward for Ebvallo, also known as tabelecleucel, a cell therapy designed to treat Epstein-Barr virus-positive post-transplant lymphoproliferative disease, or EBV+ PTLD. The disease can strike transplant patients whose immune systems are severely weakened, and treatment options are extremely limited once standard therapies fail.

The update marks a notable shift from January, when the FDA issued a Complete Response Letter rejecting the companies’ biologics application. At the time, one of the agency’s biggest concerns centered on the type of clinical evidence supporting the drug. Regulators questioned whether a single-arm trial – a study without a randomized comparison group – was enough to justify approval.

Now, after a late-April meeting with the companies, the FDA appears to have softened that stance.

According to Atara and Pierre Fabre, the agency agreed that a single-arm study paired with an appropriate historical control could potentially support a future approval, provided the analysis is conducted in a pre-specified way. That effectively removes the central hurdle that derailed the application earlier this year.

The companies plan to resubmit the application with updated data from the Phase 3 ALLELE study, including additional patients and longer follow-up periods. The trial involves adults and children age two and older with relapsed or refractory EBV+ PTLD following either solid organ or stem cell transplants.

For patients facing the disease, the stakes are high. Pierre Fabre CEO Adriana Herrera said survival after standard treatment failure is often measured “in weeks to months,” and no FDA-approved therapy currently exists for the condition.

“We thank the FDA review team for a productive discussion,” Herrera said, adding that the company hopes to finalize its resubmission plan in the coming weeks.

Ebvallo already holds a distinction in Europe, where it became the world’s first approved allogeneic T-cell immunotherapy. Unlike personalized cell therapies that must be manufactured individually for each patient, the treatment is designed as an “off-the-shelf” product using donor-derived T-cells that target Epstein-Barr virus-infected cells.

Atara CEO Cokey Nguyen described the meeting with regulators as constructive and said the companies now have clearer alignment with the FDA on what a resubmitted application should look like.

The reversal also highlights a broader tension inside the FDA over how to evaluate therapies for ultra-rare diseases, where running large randomized trials is often unrealistic. Drugmakers and patient advocates have increasingly pushed regulators to show more flexibility in cases involving small patient populations and urgent unmet medical needs.

The FDA has not publicly commented on the discussions. But for Atara and Pierre Fabre, the latest meeting appears to have revived a program that looked close to dead at the start of the year.