FDA updates PAH therapy label with data from recently diagnosed adults

The U.S. Food and Drug Administration (FDA) has approved an update to the prescribing information for Winrevair (sotatercept-csrk), an approved injection therapy for adults with pulmonary arterial hypertension (PAH) marketed by Merck.

The most notable change in this update is the addition of a contraindication (a condition or situation in which a medicine should not be used because it may be harmful). Whereas Winrevair’s prescribing information previously listed no contraindications, the new information states that the therapy should not be used in patients with serious hypersensitivity — including anaphylaxis or angioedema — to Winrevair or any of its ingredients. If a serious hypersensitivity reaction occurs, Winrevair should be discontinued and appropriate emergency treatment started immediately.

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Phase 3 HYPERION tests Winrevair in recently diagnosed PAH

The update also adds new safety and efficacy data from a Phase 3 clinical trial called HYPERION (NCT04811092), which tested Winrevair against a placebo, both added to background therapy, in adults with recently diagnosed PAH who are at intermediate to high risk of disease progression.

“The HYPERION study included people with PAH who closely reflect those we see in everyday clinical practice, including individuals who were recently diagnosed, older adults and people managing other health conditions,” Vallerie McLaughlin, MD, an investigator on the HYPERION study and paid consultant for Merck, said in a press release from the company.

“The results of HYPERION provide evidence for the use of WINREVAIR in adults diagnosed with PAH within the previous year who were receiving background therapy. The addition of these data to the U.S. product label provide meaningful information when making treatment decisions and reflect the evolving treatment landscape for PAH,” added McLaughlin, who directs the pulmonary hypertension program at the University of Michigan in Ann Arbor.

Winrevair is an under-the-skin injection therapy that is approved by the FDA to improve exercise capacity and World Health Organization (WHO) functional class, and to reduce the risk of clinical worsening events, in adults with PAH. HYPERION’s main goal was to measure the time to death or a first confirmed morbidity event. These events included death from any cause, an unplanned PAH-related hospitalization lasting at least 24 hours, atrial septostomy, lung transplant, or a decline in six-minute walking distance accompanied by another sign of clinical worsening. Study results showed that Winrevair added to background therapy reduced the risk of this composite endpoint by 76% compared with placebo plus background therapy.

Other Phase 3 trials add to Winrevair evidence

Winrevair also showed benefits in two other Phase 3 trials, STELLAR (NCT04576988) and ZENITH (NCT04896008), which evaluated different PAH populations and outcomes.

“HYPERION is the third Phase 3 study of WINREVAIR in PAH and provides robust clinical evidence in adults with PAH when added to background therapy, including within the first year following a diagnosis,” said Joerg Koglin, MD, PhD, senior vice president, head of general and specialty medicine, global clinical development, Merck Research Laboratories.

The company also noted the recent clinical guidelines published by the European Respiratory Society, which, for the first time, include Winrevair. According to Merck, the guidelines were updated based on evidence supporting Winrevair’s use in PAH.

The ERS guidelines give Winrevair a “strong” recommendation for adults with PAH who are on background therapy but have not achieved low-risk status at follow up, including those at intermediate-low, intermediate-high, or high risk, according to Merck. The guidelines rate the certainty of evidence for the recommendation as “high.” Merck also noted that Winrevair is the only add-on PAH therapy to receive a “strong” recommendation in the guidelines.

“The totality of clinical evidence supporting the use of WINREVAIR to date continues to reinforce our confidence in its potential as a standard of care. Together, the clinical evidence reflected in the label as well as the updated treatment guidelines can provide meaningful information to support care decisions about the critical role WINREVAIR can play for a broad range of patients with PAH,” Koglin added.