Respira Therapeutics has announced that the results of Phase 1 and Phase 2a clinical studies of RT234-PAH dry powder vardenafil “support its further development as an as-needed (PRN) treatment that will allow patient-controlled dosing to acutely improve episodic symptoms and exercise capacity in pulmonary arterial hypertension (PAH) patients.” The company is presenting the data at the 2020 CHEST annual meeting.
In October 2019, Respira announced that United Therapeutics was returning all rights to RT234 “based on a strategic prioritization of assets within United Therapeutics’ product development portfolio.” United Therapeutics had acquired the license for RT234 and announced an investment in Respira in April 2017.
The Phase 1 SAD/MAD study found that subjects were able to tolerate a 2.4 mg dose 4 times per day for 7 days without any dose-limiting toxicity. In the Phase 2a escalating dose study, PAH patients received 0.2, 0.6, and 1.2 mg doses of RT234 via dry powder inhaler while undergoing right heart catheterization. The 0.6 and 1.2 mg doses both reduced pulmonary vascular resistance (PVR) within 5 minutes post dose, with PVR remaining at the lower level for at least 60 minutes post dose.
Respira President and CEO Bob Curtis commented, “Despite being on multiple PAH maintenance therapies, patients with PAH live with daily acute episodes of shortness of breath, tiredness, racing heart, and lack of exercise capacity that substantially curtail their ability to perform daily functions. Results of our initial clinical studies demonstrate that RT234-PAH, based on its rapid onset of action, extended duration of action, and minimal safety and tolerability issues when used in addition to PAH maintenance therapies, has the potential to be a first-in-class, as-needed treatment that may allow patients to acutely relieve their episodic symptoms of PAH and improve their quality of life. The very positive results of these two clinical studies support the continued development of RT234-PAH as an as-needed, preemptive treatment for PAH patients.”
Read the Respira Therapeutics press release.
