Biotechnology company United Therapeutics Corporation (Nasdaq:UTHR) announced on Wednesday that the US Food and Drug Administration (FDA) has cleared its Investigational New Drug application for Treprostinil-Iloprost SMI, enabling the company to proceed with a clinical trial for the investigational pulmonary arterial hypertension (PAH) treatment.

The Phase 1, open-label, single ascending dose study will assess the therapy's safety, tolerability and pharmacokinetics in healthy volunteers, with a Phase 2 trial in PAH patients anticipated to begin in 2027, subject to successful results.

Treprostinil-Iloprost SMI combines two prostacyclin analogues, treprostinil and iloprost, delivered as an inhalation spray through a soft mist inhaler for use as needed. The investigational treatment is designed to provide episodic symptom relief during acute flare-ups between doses of patients' ongoing prostacyclin therapy.

If successful, the treatment would be the first as-needed combination inhaled therapy developed for PAH. It is not yet approved for any indication in any jurisdiction.