Acceleron Pharma has released the results from Phase 2 of their PULSAR trial, which studied sotatercept as a treatment for pulmonary arterial hypertension. Researchers are very excited by the positive results and are taking the necessary steps to plan the third phase. Hopefully the following phases will present positive results as well.
About Pulmonary Arterial Hypertension (PAH)
PAH is a form of high blood pressure that causes the pulmonary arteries of the lungs to progressively thicken and harden. The heart then has to work harder to get blood to the lungs, which can result in damage and possibly failure. Symptoms may not appear until there has been considerable progression, but when they do appear they include fainting, shortness of breath, dizziness, fatigue, chest pain, and swelling in the ankles and legs. These are caused by a mutated BMPR2, which plays a role in the growth and death of cells. It is passed down in an autosomal dominant pattern. In cases of secondary hypertension, the cause is another disease or the use of certain street drugs.
About the PULSAR Study
This study was placebo-controlled, double-blind, and included 106 participants. For 24 weeks, they were given either .3 mg/kg of sotatercept, .7 mg/kg of sotatercept, or a placebo. All three of these groups were also given background therapies for PAH. The primary endpoint was a statistically significant reduction in pulmonary vascular resistance (PVR), which was met. Those receiving .3 mg/kg of sotatercept saw a 20.5% reduction, and those treated with .7 mg/kg of sotatercept saw a 33.9% reduction. This is comparable to the placebo group, which saw a 2.1% reduction.
Other results include:
- A reduction in amino-terminal brain natriuretic propeptide of 51%
- A reduction in mean pulmonary arterial pressure of 20%
- 23% of participants saw an improvement in their WHO functional class
In terms of adverse events, 6% of those receiving .3 mg/kg of sotatercept experienced a serious one that required treatment. 24% of the group receiving .7 mg/kg experienced this, and 9% of the placebo group did as well. Other adverse events included a hemoglobin increase, thrombocytopenia, headache, diarrhea, fatigue, dizziness, nausea, peripheral edema, and hypokalemia.
Researchers are excited by these positive results, as sotatercept may be a viable treatment when used in combination with existing PAH treatments.