Ionis Pharmaceuticals, Inc. announced positive topline results for the Phase 3 OASIS-HAE study of donidalorsen in people with hereditary angioedema (HAE). The trial met its primary endpoint of reduction in rate of angioedema attacks in patients treated with donidalorsen (80mg) via subcutaneous injection dosed every 4 weeks (Q4W) (p<0.001) or every 8 weeks (Q8W) (p=0.004), compared to placebo. In addition, the trial showed donidalorsen achieved statistical significance on all secondary endpoints in the Q4W group and key secondary endpoints in the Q8W group.

Donidalorsen demonstrated a favorable safety and tolerability profile in the study, and there were no serious adverse events in the patients treated with donidalorsen. HAE is a rare and life-threatening genetic disease that causes unpredictable and frequent severe swelling of the skin, gastrointestinal (GI) tract, upper respiratory system, face and throat. Donidalorsen is an investigational RNA-targeted prophylactic medicine designed to precisely target and silence the production of prekallikrein (PKK), interrupting the pathway that leads to HAE attacks.

Based on these data, Ionis is preparing to submit a New Drug Application with the U.S. Food and Drug Administration. Otsuka, which has exclusive rights to commercialize donidalorsen in Europe, is preparing to submit a Marketing Authorization Application to the European Medicines Agency. Donidalorsen received Orphan Drug Designation in the U.S., and the Orphan Drug Designation procedure in the EU is ongoing.

Ionis plans to present the Phase 3 OASIS-HAE results at an upcoming medical congress by mid-year. Ionis also plans to share results from the Phase 3 OASIS-Plus study by mid-year, which includes both the open-label extension of the Phase 3 trial and a separate cohort of patients who have transitioned to donidalorsen from another prophylactic HAE medication.