Daily close, T-120 (4/4/25) through T+5. Run-up high $89.76 on 4/7/25, low $73.47 on 5/20/25 (T-120 to T-1). FDA decision 9/19/25. Historical price action, not a forecast.
Positioning before the decision
On Sep 5, 2025, 14 days before the decision date, at-the-money options priced a move of ±5.3% through Sep 26, 2025 (the first listed expiry after the decision; ATM implied volatility 28%). The stock closed -0.0% at the first close across the decision and -4.8% 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 date2025-09-19
DrugKEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph)
Was KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) approved by the FDA?
Yes. The FDA approved the application for KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) on September 19, 2025. The primary source is linked on this page.
What was KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) under FDA review for?
The application covered Solid tumors. The FDA approved the application on September 19, 2025.
How did MRK stock react to the FDA decision?
On the decision day MRK moved +-0.0%. That is the recorded reaction to this specific event -- historical measurement, not a prediction, and not investment advice.