Bellerophon Therapeutics recently announced that INOpulse, a type of nitric oxide that helps blood vessels expand, is effective in treating Pulmonary Arterial Hypertension (PAH) based on middle-stage data from a Phase 2 trial. The US Food and Drug Administration (FDA) has issued a Special Protocol Assessment (SPA), which will help to speed up the Phase 3 INOpulse studies.
PAH refers to high blood pressure of the lungs. It is a condition that worsens over time and can be potentially fatal, since pressure in the lung arteries can strain the heart. Although PAH currently has no cure, several medications are used to control symptoms. Vasodilators for example are used to control and improve symptoms, but they do not halt the progression of the disease.
Phase II trials assess dosing and are designed to determine the best drug dose to use and how much of a dose is safe. Phase II studies can also measure efficacy and safety testing in small numbers of participants. Often a treatment must pass Phase II in order to proceed to Phase III, which is typically the final stage of drug testing. Most reports of medical treatment studies focus on Phase III trials. These are the large trials that are required for a drug or other treatment to receive approval for use.
After 16 weeks unknown treatment (blinded), 65 individuals with PAH took INOpulse. Everyone in the trial was taking one to three other PAH treatments.
Twenty people taking Long-Term Oxygen Therapy (LTOT) improved in the six minute walking test, a measurement of PAH severity. Ten of the 20 people on LTOT patients also improved compared to their scores at the beginning of the study. Fourteen people underwent right heart catheterizations, meaning that they had an improvement in pulmonary vascular resistance (PVR) a main measurement of effectiveness in this study. All of these improvements occurred in people who were taking a 75 mg dose treatment.
The researchers measured some improvements in people taking 25 mg of the treatment and LTOT, and in people who were on a different PAH treatment than LTOT. However, overall the best results occurred in those individuals on the 75 mg dose and LTOT.
Jonathan Peacock, Chairman and Chief Executive Officer of Bellerophon Therapeutics, remarked, “The interim analysis is very encouraging for PAH patients, as the data indicates a clinically significant and sustained benefit for patients on the higher iNO 75 dose, when combined with Long-Term Oxygen Therapy. More specifically, the analysis supports the hypothesis, generated from Part 1 of the Phase 2 study, that the optimal benefit of INOpulse is with the iNO 75 dose in patients on LTOT who stay on therapy for at least 12 hours each day. The SPA recently issued by the FDA for our Phase 3 program, and agreed to by the European Medicines Agency through a Scientific Advice Working Party, is well aligned with these findings.”
Bellerophon is now planning a Phase III program including two clinical trials and 450 study participants.