Pfizer Secures Up to $1.5 Billion From Blackstone to Fund Monthly Obesity Drug Berobenatide

PFE said on Wednesday that funds managed by Blackstone Life Sciences will pay up to $1.5 billion of development costs through 2028 for berobenatide, an experimental once-monthly GLP-1 receptor agonist being studied for chronic weight management and obesity-related conditions. Pfizer picked up the drug last year in its acquisition of Metsera, a deal worth up to $10 billion.

The structure keeps the asset entirely in Pfizer's hands. Blackstone acquires no rights or ownership in berobenatide and Pfizer retains full operational control and decision-making. In return, Blackstone receives milestone-based payments over several years, triggered only by U.S. approval of monthly injectable berobenatide as monotherapy for chronic weight management and by specified sales milestones; the size of those payments was not disclosed. Pfizer said the arrangement gives it more flexibility to invest across its broader pipeline. It is not the first such deal between the two: in April 2023 Blackstone agreed to provide up to $550 million to co-fund development of certain Pfizer treatments.

The money lands as Pfizer scales a large late-stage obesity program, with 10 ongoing and planned Phase 3 trials for berobenatide and more than 20 obesity and comorbidity trials, including knee osteoarthritis and obstructive sleep apnea, slated for 2026. For BX, the deal extends a milestone-based co-funding model from a life sciences arm that manages about $18 billion. Pfizer shares closed up slightly at $29.45 and rose 0.2% to $29.52 in extended trading.

What to watch: Phase 3 readouts for berobenatide, which determine whether the milestone payments ever come due, and whether Pfizer uses the freed-up capital to add further obesity assets in a market led by Eli Lilly and Novo Nordisk.