RGNX Phase 3 readout: a negative outcome, -37.8%

On May 14, 2026, REGENXBIO Inc. reached its Phase 3 readout. The result was a negative outcome, and the stock moved -37.8% in the window around the event. It had already run +8.4% in the 30 days into the catalyst — the kind of pre-event run-up that often precedes binary readouts.