Rare Disease Focused Ionis Pharmaceuticals Gears Up for FDA Submission After Donidalorsen Outperforms Placebo In Swollen Vessels Study

Monday, Ionis Pharmaceuticals Inc IONS announced 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 the 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.

Ionis is preparing to submit a New Drug Application to the FDA. Otsuka, which has exclusive rights to commercialize donidalorsen in Europe, is preparing to submit a Marketing Authorization Application to the European Medicines Agency. 

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 (switch cohort).

William Blair emphasizes that the specific details provided will play a crucial role in assessing the overall competitive profile and commercial prospects of donidalorsen. 

Despite the importance of these details, the positive aspects highlighted include the highly statistically significant outcome, successful attainment of secondary measures, and solid results observed in the previous Phase 2 study.

The analyst suggests that the switch data for donidalorsen could help distinguish it commercially from other treatments by providing guidance to clinicians on patient switching. However, it’s important to note that this data is not mandatory for regulatory approval.

Ionis remains William Blair’s top pick for 2024 with multiple upcoming catalysts, a pedigree of strong execution, and reiterates its Outperform rating.

Price Action: IONS shares are up 0.82% at $51.40 on the last check Monday.