Ionis Delivers Positive Late-Stage Results for Two Partnered Drugs

Ionis Pharmaceuticals reported positive phase III data for two partnered programs. Ulefnersen met its primary endpoint in the FUSION study for FUS-ALS, prompting partner Otsuka to begin regulatory discussions. Sefaxersen demonstrated statistically significant proteinuria reductions in the IMAgINATION study for IgAN, with Roche continuing the trial.

The readouts mark a reversal for IONS after recent cardiovascular program setbacks and follow FDA approval of Zanvastro for Alexander disease. The ulefnersen program positions Otsuka for potential near-term filing, while the sefaxersen data validates the mechanism in a kidney indication with few treatment options.

Both drugs leverage Ionis' antisense platform but were developed through partnerships, meaning economics will be shared. The FUSION success is notable given the limited treatment landscape for ALS subtypes, and the IMAgINATION proteinuria data provides a concrete efficacy signal in a phase III trial that remains ongoing.