Daily close, T-120 (6/5/25) through T+5. Run-up high $179.1 on 11/18/25, low $137.44 on 7/22/25 (T-120 to T-1). FDA decision 11/20/25. Historical price action, not a forecast.
Positioning before the decision
On Nov 6, 2025, 14 days before the decision date, at-the-money options priced a move of ±3.9% through Nov 21, 2025 (the first listed expiry after the decision; ATM implied volatility 23%). The stock closed -0.3% at the first close across the decision and +4.9% five trading days on. A straddle priced weeks out covers ordinary movement plus the event, so this is the move the options market priced through that expiry, not the event-implied move alone. How this compares across 1,000+ decisions.
Decision facts
FDA decision date2025-11-20
DrugKoselugo (selumetinib)
IndicationNeurofibromatosis Type 1-Plexiform Neurofibromas (NF1-PN) in Adults
Yes. The FDA approved the application for Koselugo (selumetinib) on November 20, 2025. The primary source is linked on this page.
What was Koselugo (selumetinib) under FDA review for?
The application covered Neurofibromatosis Type 1-Plexiform Neurofibromas (NF1-PN) in Adults. The FDA approved the application on November 20, 2025.
How did AZN stock react to the FDA decision?
On the decision day AZN moved -1.1%. That is the recorded reaction to this specific event -- historical measurement, not a prediction, and not investment advice.