Positive topline results from phase III OASIS-HAE study of investigational donidalorsen in patients with hereditary angioedema

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 Otsuka, which has exclusive rights to commercialize donidalorsen in Europe and 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.

"We are very pleased with the positive topline results from the Phase III OASIS-HAE study of donidalorsen," said Kenneth Newman, M.D., senior vice president, head of clinical development at Ionis. "Based on these results and the durable efficacy and favorable safety data seen in the ongoing Phase II open-label extension study, we believe donidalorsen, if approved, could be an attractive new treatment option for patients with HAE, many of whom continue to experience unpredictable, painful and severe breakthrough attacks despite currently available prophylactic treatments. We are grateful to the patients, caregivers, investigators and study teams who participated in the OASIS-HAE study."

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