FDA Center for Drug Evaluation and Research

New Capabilities

Reversed position on ALLELE trial adequacy, requesting new study despite no safety concerns

The FDA rejected tabelecleucel for the second time on January 9, 2026—one day before its scheduled approval decision. The agency reversed its position after five years of dialogue, now claiming the previously accepted ALLELE trial no longer provides sufficient evidence of efficacy due to problems with study design, conduct, and analysis. The companies resolved all manufacturing issues and the FDA raised no safety concerns, but regulators demanded a new study for the first therapy targeting EBV+ post-transplant lymphoproliferative disease.

Updated May 20

New Capabilities

Reviewing BTK inhibitor safety across multiple programs

The FDA rejected Sanofi's tolebrutinib for progressive MS on December 28, 2025—a crushing blow for a drug that had won Breakthrough Therapy status and became the first BTK inhibitor approved anywhere in the world. Meanwhile, Roche's rival drug fenebrutinib is racing toward approval after strong Phase 3 results, and Merck's evobrutinib crashed out entirely. Three pharma giants bet billions that brain-penetrating BTK inhibitors could finally slow the relentless neurodegeneration that leaves MS patients in wheelchairs, and only one looks likely to reach the finish line first.

Updated May 16