Acting FDA chief meets rare disease groups to rebuild trust

Acting FDA Commissioner Kyle Diamantas sat down with rare disease groups as patient advocates and drug developers pressed the agency for faster, clearer decisions on therapies for small populations with little time to wait.

The June 3 meeting brought together groups including Friends of Cancer Research and the Foundation for Angelman Syndrome Therapeutics, with Bloomberg Law reporting that the closed-door roundtable included more than a dozen rare-disease advocacy organizations. Their central demand was not another conversation but a more predictable FDA: clearer standards, more certainty and stronger support for treatments aimed at tiny patient groups whose conditions often progress too quickly for long trials.

The outreach came after a run of decisions that rattled confidence. Rare disease advocates have pointed to the FDA’s refusal to approve Biohaven’s experimental brain-disorder treatment, a strong safety warning tied to Sarepta Therapeutics’ gene therapy and a dismissive comment from a senior official about uniQure’s Huntington’s disease treatment. In Biohaven’s case, FDA’s complete-response letter said substantial evidence of effectiveness had not been established for troriluzole in spinocerebellar ataxia. The agency also rejected reliance on Study 206-RWE, saying the real-world-evidence study could not count as an adequate and well-controlled investigation because of design flaws and fundamental methodological limitations that introduced bias.

The meeting also landed in a period of instability inside the agency. Marty Makary left as FDA commissioner in May 2026 after clashes with the White House, including over vaping policy. Diamantas, the agency’s food chief rather than a veteran drug regulator, has been seen by some inside and outside government as a steadier presence while Washington searches for longer-term leadership.

The policy backdrop matters. On February 23, 2026, FDA issued draft guidance for individualized therapies for ultra-rare diseases, saying sponsors could seek full approval through substantial evidence of safety and effectiveness even when randomized controlled trials are not feasible because patient populations are so small. The agency framed the approach around a “plausible mechanism” standard, a signal that it wants to make room for therapies designed for highly specific genetic diseases.

That shift has yet to erase skepticism. Reporting also indicates FDA recommended that uniQure run a double-blind Phase 3 study with sham surgery for AMT-130, a demand advocates view as a major hurdle for a disease with no easy backup options. As of March 2026, FDA had received 1,622 breakthrough-therapy requests, granted 634 and approved 374 breakthrough-designated products, a reminder of how much rare-disease drug development now depends on expedited pathways. For families facing fast-moving illnesses, the question is whether the agency can move quickly enough, and communicate clearly enough, before another treatment window closes.