Mosliciguat Phase 2 Data Confirms Roivant's Early Bet on Pulmonary Hypertension Therapy

Key points

• The Phase 2 PHocus trial, presented at the European Respiratory Society International Congress in Barcelona, met its primary endpoint with a 56.3% placebo-adjusted reduction in pulmonary vascular resistance at Week 16.
• Secondary endpoints were also achieved, including a 35.2-meter improvement in six-minute walk distance and a 53.2% reduction in NT-proBNP, a biomarker for cardiac strain.
• Safety data showed a lower incidence of cough (12.1%) for mosliciguat compared to the placebo group (18.2%), addressing a common side effect of existing inhaled prostacyclins.
• Roivant's subsidiary Pulmovant has already initiated Phase 3 trials, aiming to bring the therapy to approximately 200,000 patients in the US and Europe.
• The drug requires only one daily inhalation, unlike current therapies that require multiple daily doses, and is described as a potential first-in-class soluble guanylate cyclase activator.

Background

In 2024, Roivant Sciences agreed to a $294 million deal with Bayer to acquire mosliciguat, paying a $14 million upfront fee. At the time, Phase 1 results showed a 38% reduction in pulmonary vascular resistance, which Roivant described as one of the highest reductions seen in pulmonary hypertension trials. The current Phase 2 results suggest that chronic dosing may yield significantly greater benefits than initial short-term data indicated.

How outlets are covering it

Fierce Biotech emphasizes the financial efficiency of the initial $14 million upfront payment and the drug's potential as a single-agent therapy. STAT highlights the magnitude of the results, noting that Roivant was 'pleasantly surprised' by the data, and frames the success as a potential second blockbuster medicine for the company. Yahoo Finance, while its content was largely obscured by technical errors, indicated that Roivant's stock surged in response to the 'robust' data, reflecting market confidence in the candidate's commercial potential.

Why it matters

PH-ILD is a severe condition with a median survival of 1.5 to 2 years despite current standard care. Mosliciguat's strong efficacy and improved safety profile could provide a significant therapeutic advance for this patient population. For Roivant, the success of this asset could bolster its financial health and validate its strategy of acquiring early-stage assets with high potential.

What to watch

Pulmovant will continue Phase 3 trials to determine if mosliciguat can be approved as a single-agent treatment or in combination with other therapies. The company aims to rapidly bring the therapy to market for the estimated 200,000 patients in the US and Europe affected by PH-ILD.