In January 2026, the FDA released updated guidance on the use of Bayesian methods in clinical trials. The document does not read like a manifesto. It reads like an attempt to reconcile competing statistical cultures under real regulatory constraints. On its surface, it is pragmatic and flexible, welcoming Bayesian designs
Most statistical frameworks treat errors symmetrically. A false positive is bad. A false negative is bad. Control one, tolerate the other, and let the math do the rest. Clinical reality is not that tidy. Approving an ineffective therapy and withholding a potentially effective one are both errors, but they do
In September 2016, the FDA approved eteplirsen for Duchenne muscular dystrophy. The advisory committee had voted 7 to 6 against accelerated approval. The FDA's own review team recommended against it. The clinical program consisted of 12 boys, and western blot analysis showed a dystrophin increase of 0.93%
