Roivant’s mosliciguat clears Phase 2 with huge PH-ILD efficacy, now faces Phase 3

The timing was expected; the magnitude was the surprise. Roivant had already flagged PHocus topline data for the second half of 2026, so the existence of this catalyst was not new. But there was no clean published efficacy consensus to anchor against; the relevant test was whether the study cleared its clinical success bar. It did, across the primary endpoint and both key secondary endpoints.

The Phase 2 result was broad rather than a single-endpoint win. At Week 16, mosliciguat produced a 56.3% placebo-adjusted reduction in pulmonary vascular resistance, with p<0.0001. 〔0〕 It also improved walking distance while reducing a cardiac-stress biomarker, making the result more credible than a purely hemodynamic readout.

The durability signal strengthens the read, although Week 24 is exploratory. Treatment effects continued to improve through the placebo-controlled period, with the walking-distance benefit reaching 52.7 meters and NT-proBNP falling 75.9% versus baseline on a placebo-adjusted basis. That supports the company's chronic-dosing thesis, but the exploratory designation means the Week 16 endpoints carry the core evidentiary weight.

The filing materially de-risks mosliciguat but does not establish approval or commercial success. Phase 3 PHrontier has begun and is designed to enroll approximately 375 patients, moving the program directly into confirmatory testing. 〔1〕 The remaining risk is therefore not whether PHocus produced a signal—it clearly did—but whether the effect reproduces in a larger study and translates into regulatory and commercial value. Net, this is an above-the-bar clinical readout and a meaningful upgrade to the mosliciguat program.