The protocol and design of an ongoing phase 2b clinical trial of rodatristat ethyl in patients with pulmonary arterial hypertension (PAH) were presented at the European Respiratory Society annual congress as an e-poster.

The aim of the dose-ranging, randomized, double-blind, placebo-controlled, multicenter study is to assess the safety and efficacy of 2 doses of rodatristat ethyl (300 mg and 600 mg) in patients with PAH. The primary endpoint is the change from baseline of pulmonary vascular resistance as measured by right heart catheterization.

The trial started in March 2021 and is currently enrolling an estimated 90 adult patients at sites across the United States. It is also expected to enroll patients in Canada and Europe. Its estimated completion date is February 2023.

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“We are excited to be able to offer this experimental medicine to PAH patients in our clinical trial,” Howard Lazarus, MD, the first author of the poster and the chief medical officer of Altavant, the developer of rodatristat ethyl, said in a press release.

Read more about PAH experimental therapies

Rodatristat ethyl is a tryptophan hydroxylase (TPH) inhibitor designed to block peripheral serotonin production. Due to its molecular structure, it cannot cross the blood-brain barrier and can only act on peripheral serotonin. By lowering circulating levels of serotonin, rodatristat ethyl could be a disease-modifying treatment in diseases like PAH and idiopathic pulmonary fibrosis, which are characterized by excessive serotonin production.

“Rodatristat is a novel molecule with a different mechanism of action than currently available PAH medications,” Dr. Lazarus explained.

The prodrug has been shown to reduce pulmonary vascular remodeling, which is characteristic of PAH, more effectively in animal models than the currently available treatments. Moreover, it reduced levels of peripheral serotonin synthesis and lowered mean pulmonary arterial pressure.

A study in healthy volunteers also showed that twice-daily oral rodatristat ethyl reduced peripheral serotonin levels by up to 60%.


Altavant Sciences highlights ongoing phase 2b ELEVATE 2 study of rodatristat ethyl in patients with pulmonary arterial hypertension at European Respiratory Society annual congress. News release. Altavant Sciences; September 13, 2021.

A study of rodatristat ethyl in patients with pulmonary arterial hypertension (ELEVATE 2). January 15, 2021. Updated August 20, 2021. Accessed September 23, 2021.

Lazarus HM, Denning J, Kamau-Kelley W, Wring S, Palacios M, Humbert M. ELEVATE 2: a multicenter study of rodatristat ethyl in patients with WHO group 1 pulmonary arterial hypertension. Poster presented at: European Respiratory Society (ERS) annual congress 2021; September 5-8, 2021; Virtual.