Pulmovant to present Phase 2 PHocus topline data at ERS 2026
Pulmovant, a Roivant subsidiary focused on pulmonary disease, will present topline results from its Phase 2 PHocus study of mosliciguat at the European Respiratory Society International Congress 2026 on Tuesday, 8 September. The presentation will be delivered by Marc Humbert, Professor of Respiratory Medicine at Université Paris-Saclay and Director of the French National Reference Centre for Pulmonary Hypertension, at 12:15 CEST.
Mosliciguat is an inhaled soluble guanylate cyclase (sGC) activator designed to produce targeted pulmonary vasodilation with limited systemic exposure. The company positions it as a potential first-in-class agent in its mechanistic class, distinguishing it from approved sGC stimulators such as riociguat on the basis that it acts independently of haem and nitric oxide, meaning it may retain activity in patients where the NO signalling pathway is impaired.
The PHocus study
The PHocus trial (NCT06635850) is a randomised, double-blind, placebo-controlled global study that enrolled 135 adult participants with pulmonary hypertension associated with interstitial lung disease (PH-ILD), a Group 3 PH subtype. The study assessed both the safety and efficacy of once-daily inhaled mosliciguat, with the topline readout expected to anchor discussions at ERS around the mechanistic differentiation of sGC activators versus stimulators.
Earlier Phase 1b data from the ATMOS study provided a degree of clinical signal: a single inhaled dose produced a mean peak reduction in pulmonary vascular resistance of up to 38% in PH patients, which the company describes as among the largest reductions recorded in pulmonary hypertension trials. Investors will now be looking at whether a chronic dosing regimen in a broader PH-ILD population translates that signal into statistically meaningful and durable endpoints.
Pulmovant is also running a second Phase 2 programme, PHactor (NCT07333183), an open-label study evaluating the tolerability and safety of mosliciguat in combination with inhaled treprostinil, a prostacyclin analogue already approved in some PH subtypes. Positive combination data would strengthen the case for mosliciguat as a complement to existing standard of care rather than a standalone replacement.
Market context and competitive landscape
PH-ILD represents a significant unmet need. Pulmovant cites an estimated patient population of up to 200,000 across the United States and Europe, with few or no approved treatment options specifically for the Group 3 subtype. This contrasts with Group 1 pulmonary arterial hypertension, where a crowded field of approved therapies exists, including endothelin receptor antagonists, phosphodiesterase-5 inhibitors and prostacyclins.
The regulatory precedent for Group 3 PH remains thin. Neither the FDA nor the EMA has approved a therapy specifically for PH-ILD, though United Therapeutics' inhaled treprostinil (Tyvaso) has been approved in the US for PH associated with interstitial lung disease following the INCREASE trial, providing a reference point for the regulatory path. If PHocus data are positive, Pulmovant would likely pursue a similar approval route, with discussions with both agencies expected before initiating a pivotal programme.
The inhaled delivery approach is clinically notable. Systemic PH therapies carry a risk of off-target vasodilation leading to hypotension, a particular concern in Group 3 patients who already have compromised respiratory function. An inhaled agent that achieves pulmonary selectivity could offer a meaningful tolerability advantage, though this will need to be borne out in the full safety dataset presented at ERS.
The ERS presentation marks the most material public event in mosliciguat's development to date, and the Roivant parent's investors will be closely monitoring the outcome ahead of any decisions on advancing to a Phase 3 design.