Merck & Co. Inc. (NYSE:MRK) announced results Tuesday from its Phase 3 HYPERION trial evaluating Winrevair (sotatercept-csrk) versus placebo (both in combination with background therapy) in recently diagnosed adults with pulmonary arterial hypertension (PAH, WHO Group 1) functional class (FC) II or III at intermediate or high risk of disease progression.
In the study, Winrevair reduced the risk of clinical worsening events by 76%, as measured by a composite endpoint that included all-cause death, the need for non-planned PAH-related hospitalization, atrial septostomy, lung transplantation, or PAH deterioration.
Results showed that 10.6% of patients treated with Winrevair, compared to 36.9% (n=59/160) in the placebo group, experienced at least one clinical worsening event.
The treatment effect was consistent across all prespecified subgroups treated with Winrevair.
The safety profile of Winrevair in HYPERION was generally consistent with that observed in previous studies.
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The median duration of follow-up was more extended in those receiving Winrevair (14.6 months) than in those receiving placebo (11.5 months).
Adverse events occurred in 89.4% versus 90.0% and serious adverse events in 24.4% versus 28.1% of participants in the Winrevair and placebo groups, respectively.
Results showed that 29.4% of patients treated with Winrevair met all three criteria of multicomponent improvement (improvement in 6MWD, improvement or maintenance/achievement of NT-proBNP, and improvement in WHO FC or maintenance of WHO FC II) versus 14.6% treated with placebo.
An additional secondary endpoint demonstrated that 60.1% of patients treated with Winrevair maintained or achieved a low REVEAL LITE 2 score (≤5) relative to baseline at Week 24, compared to 47.9% of patients treated with placebo. Winrevair did not demonstrate statistical significance in achieving or maintaining a low risk, as indicated by a simplified French risk score (SFRS).
Subsequent secondary endpoints showed numerical improvements in the Winrevair arm (including NT-proBNP, WHO class, and 6MWD), but were not formally tested due to the prespecified hierarchical testing strategy.
Earlier this year, the HYPERION trial was stopped early based on a review of the totality of data from the Winrevair clinical program at that time. All patients were then offered the opportunity to receive Winrevair through the SOTERIA open-label extension study.
Price Action: MRK stock is down 0.18% at $78.44 during the premarket session at the last check on Tuesday.
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