Acceleron Reaches Enrollment Goal in PULSAR Trial Testing Sotatercept for PAH

Acceleron Pharma has reached its patient enrollment goal in the ongoing Phase 2 PULSAR trial, with more than 100 participants. The trial is testing the safety and effectiveness of sotatercept (ACE-011), the company’s investigational therapy for the treatment of people with pulmonary arterial hyptertension (PAH).

The company expects to announce top-line findings of PULSAR at the beginning of 2020.

Sotatercept is an investigational compound designed to bind and trap members of the transforming growth factor-beta (TGF-beta) family — which control numerous aspects and effects of cell functions — especially those directly involved in the bone morphogenic protein (BMP) pathway. This BMP signaling cascade is known to play an important role in the maintenance of healthy lung blood vessels.

The treatment works by restoring the balance of BMP signals in the lungs, which are believed to be critical drivers of PAH development and progression.

Previous studies in animal models of PAH have shown that treatment with sotatercept can lower pulmonary arterial pressure and prevent muscularization of pulmonary blood vessels — the second major effect of PAH. It also can reduce the risk of heart failure.

The therapeutic effects of sotatercept are currently being investigated in people with PAH in two ongoing Phase 2 clinical trials — PULSAR (NCT03496207) and SPECTRA (NCT03738150).

PULSAR is a randomized, double-blind, placebo-controlled trial, in which participants are randomly assigned to receive either sotatercept at a dose of 0.3 mg/kg or 0.7 mg/kg through a subcutaneous (under the skin) injection, or a placebo, every 21 days for six months. Sotatercept is administrated in combination with standard-of-care therapies.

After the first six months, study participants may choose to continue treatment for an additional 18 months as part of an extension study.

The trial’s primary goal is to assess changes in pulmonary vascular resistance, measured by right heart catheterization, from before the treatment to the end of the first six months of therapy. Key secondary endpoints, or goals, include changes in the total distance covered in the six-minute walking test or 6MWT, which assesses patients’ exercise capacity.

Acceleron has already reached its target goal of enrolling at least 100 people with PAH into PULSAR. However, patients who are currently being screened for participation in the study may be added over the next weeks.

In the meantime, the company also is recruiting participants for SPECTRA, an exploratory trial of sotatercept. To know more about locations and contacts for this study, visit here.

“We’re thrilled with PULSAR’s rapid enrollment over the past 12 months, which underscores the urgency for new therapeutic options for patients with PAH,” Janethe de Oliveira Pena, MD, PhD, vice president of pulmonary medical research at Acceleron, said in a press release. “We believe that through its targeting of underlying disease mechanisms, sotatercept, when combined with standard-of-care therapies, has the potential to alter the PAH treatment landscape.”