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IONI FDA Decision Approved · 2025-08-21

Page updated November 5, 2026·next FDA decision on the calendar ·Data as of Nov 5, 2026 9:00 PM ET

Price into the decision (T-120)

Daily close, T-120 (3/6/25) through T+5. Run-up high $1.7 on 8/20/25, low $0.233 on 3/26/25 (T-120 to T-1). FDA decision 8/21/25. Historical price action, not a forecast.

Decision facts

FDA decision date2025-08-21

DrugDawnzera (donidalorsen)

IndicationHereditary angioedema prophylaxis

Outcome✓ Approvedprimary-sourced

Decision-day move-2.4%

T-120 run-up (low→high)+400.0% ($0.3→$1.7)

ValidationVerified 2026-08-12: Drugs@FDA, application NDA219407, action date 2025-08-21

Market-cap tierNano

Cohort decision-day move (history)8.0% median (n=122)

Cohort move is the historical median absolute decision-day move for this market-cap tier across our run-up study. History, not a prediction.

See the full 2026 PDUFA calendar →

Every FDA approval letter and released Complete Response Letter we hold, by FDA action date: FDA approval letters.

Questions

Was Dawnzera (donidalorsen) approved by the FDA?

Yes. The FDA approved the application for Dawnzera (donidalorsen) on August 21, 2025, per the FDA's own record. The primary source is linked on this page.

What was Dawnzera (donidalorsen) under FDA review for?

The application covered Hereditary angioedema prophylaxis. The FDA approved the application on August 21, 2025.

How did IONI stock react to the FDA decision?

On the decision day IONI moved -2.4%. That is the recorded reaction to this specific event. Historical measurement, not a prediction, and not investment advice.