Therapeutic Monoclonal Antibody Antagonizing Endothelin Receptor A for Pulmonary Arterial Hypertension

Endothelin receptor A (ETA) is a G protein–coupled receptor and a major therapeutic target for pulmonary arterial hypertension (PAH). We took a novel approach and developed an antagonistic monoclonal antibody, getagozumab, specifically against ETA. Getagozumab displayed a K_d value of 8.7 nM and an IC₅₀ value of 37.9 nM in the cell-based assays. Getagozumab could significantly lower pulmonary arterial pressure in both hypoxia-induced and monocrotaline (MCT)-induced PAH monkey models and further attenuate the pulmonary arterial and right ventricular hypertrophy in MCT-induced PAH monkeys. The preclinical studies demonstrated that getagozumab is safe, long lasting, and efficacious. Getagozumab may provide a new and effective treatment for PAH patients.