Fulyzaq from Napo/Salix: The First Approved Product Based on an Adaptive Two-stage, "Seamless" Pivotal Study

Napo Pharmaceuticals is developing an HIV/AIDS-related gastrointestinal distress treatment. Facing a narrow orphan protection window, they propose combining Phases 2 and 3 in a two-stage adaptive design, but are rejected by the FDA.

Response - Cytel adaptive two-stage trial design combines objectives, avoids usual Phase 2 – Phase 3 time gap

Using trial simulations, Cytel redesigns the adaptive two-stage trial ensuring strong control of the familywise type-1 error rate to the FDA’s satisfaction.

The new approach starts with three dosing arms, plus one placebo. Simulations also guide selection of the best interim analysis point to determine the optimal doses for the two-arm confirmatory stage.

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