GMA301 is a novel antagonistic antibody in clinical development. GMA301 targets human endothelin receptor A (ETA), a proven therapeutic target for pulmonary arterial hypertension (PAH). In preclinical studies, GMA301 demonstrated significant efficacy in lowering pulmonary arterial pressure in both hypoxia-induced and monocrotaline (MCT)-induced PAH monkey models and further attenuated pulmonary arterial and right ventricular hypertrophy in MCT-induced PAH monkeys. GMA301 exhibited an excellent safety profile in cynomolgus monkeys.  

GMA301 was also found to be safe and well-tolerated at all intravenous (IV) dosing levels (75 mg, 200 mg, 500 mg, and 1000 mg) in phase 1a clinical studies. No serious adverse events (SAEs) occurred. All of the treatment emergent adverse events (TEAEs) were well tolerated without medical intervention. Its half-life was up to 566 hours, and it is suitable for once-a-month administration. Gmax has initiated US-China multicenter phase 1b clinical studies recently. The monthly dosing regimen, superior safety profile and potentially high efficacy of GMA301 may offer PAH patients a new and effective treatment.

Therapeutic antibody, Pulmonary arterial hypertension, Endothelin receptor A, Clinical trials.