Savara Inc. announced positive results from the pivotal, Phase 3 IMPALA-2 clinical trial. IMPALA-2 is a 48-week, randomized, double-blind, placebo-controlled trial assessing the efficacy and safety of molgramostim 300 mcg administered once daily by inhalation with matching placebo in adult patients with aPAP (NCT04544293). Molgramostim is an inhaled form of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF).

The trial met its primary endpoint. The treatment difference between molgramostim and placebo for mean change from baseline to Week 24 in hemoglobin-adjusted percent predicted DLCO achieved statistical significance. This statistically significant treatment difference was sustained at Week 48, a secondary endpoint, which demonstrated durability of effect.

The treatment difference between molgramostim and placebo for mean change from baseline to Week 24 in SGRQ Total Score achieved statistical significance. Two additional secondary endpoints reached nominal significance: SGRQ Activity Score at Week 24 and exercise capacity using a treadmill test at Week 48. Molgramostim was well tolerated.

The frequency of adverse events was generally similar between treatment groups. Two patients (2.5%) discontinued molgramostim treatment due to adverse events, both of which were considered unrelated to trial drug. The most commonly reported adverse events in the molgramostim group were COVID-19, cough, and pyrexia, with COVID-19 occurring more frequently with molgramostim than with placebo.

Molgramostim has been granted Orphan Drug, Fast Track, and Breakthrough Therapy designation from the U.S. Food and Drug Administration, Orphan Drug designation from the European Medicines Agency and Innovative Passport and Promising Innovative Medicine designation from the UK's Medicines and Healthcare Products Regulatory Agency for the treatment of aPAP.