Winrevair yielded significant and meaningful clinical benefits for patients with combined post- and precapillary pulmonary hypertension, an indication that, according to BMO Capital Markets, has few treatment options.
Merck’s activin blocker Winrevair improved pulmonary vascular resistance in a mid-stage study of patients with combined post- and pre-capillary pulmonary hypertension, further establishing the drug as a leading treatment in this space.
With this Phase II success, Merck plans to push Winrevair forward into late-stage development for combined post- and precapillary pulmonary hypertension (CpcPH) due to heart failure with preserved ejection fraction (HFpEF).
“Merck’s Winrevair continues its trend of successful pulmonary hypertension trials,” BMO Capital Markets wrote in an investor note on Monday. This target indication is one that has “few options” available by way of treatment, the analysts added, but nevertheless presents a “significant commercial opportunity” for Merck.
The pharma did not provide specific data in its news release on Tuesday, announcing only that Winrevair met its primary endpoint in the Phase II CADENCE study. Patients treated with the drug saw a “statistically significant and clinically meaningful” decrease in pulmonary vascular resistance, a measure of the ease of blood flow, at 24 weeks, as compared with placebo.
Merck was similarly tight-lipped about CADENCE’s secondary outcomes, though the company reported that Winrevair’s safety profile in the study was “generally consistent” with what had been established in prior studies.
BMO flagged this lack of detail, writing that investors will “anxiously await” the opportunity to see the full CADENCE data. Merck has promised to present that data at an upcoming medical meeting.
In particular, BMO is looking forward to functional findings, such as how patients will fare on the 6-minute walk test. “Reducing pulmonary resistance is critical for indicating improvement in the underlying biology of CpcPH,” they said. “But patient quality of life and functional outcomes may be more clearly demonstrated by a significant improvement in six-minute walking distance.”
Still, BMO remains optimistic about Winrevair, contending that the drug could potentially stand out in this space by directly addressing the biology of the disease. “Existing therapies today for CpcPH focus on managing the underlying heart failure,” they explained, “rather than modifying the fundamental structure of the vasculature.”
Data from CADENCE, if validated in Phase III, could help establish Winrevair as a drug that takes this latter approach to CpcPH.
The last few months have been good for Winrevair, which first won the FDA’s approval in March 2024 and was hailed at the time as a “game changer” for pulmonary arterial hypertension. In January, Merck ended the Phase III HYPERION study early due to “strong, positive interim efficacy data” from a parallel Phase III study, dubbed ZENITH, which gave the company reason to push HYPERION forward into its final analysis.
ZENITH’s readout in April showed that treatment with the drug resulted in a 76% decrease in the likelihood of major morbidity or mortality, as compared with placebo. Meanwhile, detailed data from HYPERION released in September demonstrated a similar 76% reduction in clinical worsening events, defined as a composite of death, atrial septostomy, lung transplant, disease deterioration or non-planned hospitalization lasting for at least 24 hours.
