Blackstone agreed to invest $1.5 billion behind Pfizer’s obesity program centered on berobenatide, a monthly injectable GLP-1 therapy being developed for chronic weight management and obesity-related comorbidities. The capital is structured to fund development through 2028, with Blackstone eligible for milestone payments tied to US regulatory approval. Pfizer said it will retain full operational control, with the investment managed through Blackstone Life Sciences and its BXPE perpetual private equity strategy. Berobenatide is being evaluated across ten Phase III studies already ongoing and planned, including combinations with other nutrient-stimulated hormone peptides. The deal underscores how obesity’s late-stage pipeline continues to draw large-scale structured financing, as developers seek runway through expensive Phase III programs while expanding broader cardiometabolic trials in parallel.