PhaseBio Ends Pemziviptadil Trial for PAH, Citing COVID-19 Impact
PhaseBio Pharmaceuticals has voluntarily ended the Phase 2b trial testing its investigational pulmonary arterial hypertension (PAH) therapy pemziviptadil (PB1046), due to the impact of the COVID-19 pandemic on medicine manufacturing, associated supply, and enrollment rates.
The company said it would conduct an analysis of the trial’s results and, if positive, may continue the program in a future study with improved product presentation and a simplified dosing regimen.
“With the continued impact of the COVID-19 pandemic on this Phase 2b clinical trial, we believe a full evaluation of the program makes sense at this time and that any positive data generated could help galvanize support for the future development of pemziviptadil,” Jonathan Mow, CEO of PhaseBio, said in a press release. “Upon completion of the final analyses of the pemziviptadil trial, we will evaluate the potential for a future trial of pemziviptadil.”
Pemziviptadil is similar to a naturally occurring peptide hormone called vasoactive intestinal peptide (VIP) that acts to lower blood pressure, reduce inflammation, and slow fibrosis (scarring). Peptides are small chains of amino acids, the building blocks of proteins.
The body rapidly degrades VIP within minutes, limiting its therapeutic potential, according to PhaseBio. Pemziviptadil, given by an under-the-skin (subcutaneous) injection, is a modified version of VIP that lasts longer in the body, enabling weekly dosing.
This Phase 2b study (NCT03556020), also called VIP — here, short for Vasoactive Intestinal Peptide in adult patients with pulmonary arterial hypertension — which dosed its first patient in 2018, was designed to evaluate pemziviptadil in up to 63 adults, ages 18 to 79, with PAH. The company said it had successfully enrolled more than 50% of the trial’s target population so far.
PhaseBio also reported that about 90% of the enrolled patients who completed the 16-week (about four-month) main trial had chosen to continue treatment in an open-label extension study, called VIP EXTEND (NCT03795428).
The therapy had shown promise in a small Phase 1b/2a pilot study (NCT03315507) with three PAH patients. Pemziviptadil had a good safety profile, with no serious adverse events (side effects) reported, and a clinically meaningful impact on physical function.
To date, more than 100 patients with PAH and cardiovascular diseases have been treated with pemziviptadil in five clinical trials across the U.S. However, the ongoing COVID-19 pandemic negatively impacted enrollment in this clinical trial, as well as affecting manufacturing and the associated supply of the medication.
Pemziviptadil was granted orphan drug designation for PAH as well as for cardiomyopathy, or heart muscle disease, associated with the muscular degenerative disorder Duchenne muscular dystrophy. According to PhaseBio’s website, the therapy also may have the potential to treat people with cystic fibrosis,
With this trial’s suspension, the company says it will refocus its efforts on its bentracimab therapy candidate, which is designed to reverse the effects of other medications to prevent blood clotting to allow the control of bleeding. It also will continue to advance PB6440 for resistant hypertension.
“We continue to believe pemziviptadil is a potentially valuable asset for the treatment of pulmonary arterial hypertension and other diseases,” Mow said.