Biotechnology company United Therapeutics Corporation (Nasdaq:UTHR) announced on Monday that its long-term pivotal phase 3 ADVANCE OUTCOMES study of ralinepag met the primary endpoint, showing a 55% reduction in the risk of clinical worsening compared with placebo in patients with pulmonary arterial hypertension (PAH).

The study included predominantly pre-treated patients, with 80% on dual background therapy and 70% classified as WHO/NYHA Functional Class II at baseline.

Ralinepag also significantly improved secondary endpoints, including six-minute walk distance and NT-proBNP levels, increasing the odds of clinical improvement by 47% at Week 28. Benefits were consistent across all subgroups, regardless of time since diagnosis, disease etiology, baseline walk distance, or background therapies. The treatment was well-tolerated, with a safety profile consistent with known prostacyclin-related adverse events and no new safety signals observed.

As the potential first once-daily oral prostacyclin, ralinepag combines potent receptor affinity with continuous exposure to deliver durable efficacy and disease-mitigating outcomes.

United Therapeutics plans to present full study results at an upcoming international conference and intends to submit a New Drug Application to the US Food and Drug Administration (FDA) in the second half of 2026.