Pfizer Secures Up to $1.5B in Blackstone Obesity Drug Co-Funding

Pfizer and Blackstone Life Sciences announced a strategic co-funding agreement on November 11, 2026, under which Blackstone-managed funds will pay up to $1.5 billion of development costs through 2028 for berobenatide, an investigational monthly GLP-1 receptor agonist peptide being studied for chronic weight management and obesity-related conditions.

In exchange for the funding, Blackstone will be eligible for milestone-based payments tied to U.S. regulatory approval of monthly dosing of injectable berobenatide monotherapy for chronic weight management and the achievement of certain commercial sales milestones. Any milestone payments earned will be payable over a multi-year period. The structure ties Blackstone’s compensation to both regulatory and commercial progress.

Ownership Stays With Pfizer

Blackstone does not acquire any rights or ownership in berobenatide under the agreement, and Pfizer retains full operational control and decision-making for the program. Pfizer therefore gains an external source of development funding while continuing to direct the clinical work.

The distinction separates the financing from ownership of the underlying medicine. Blackstone’s claim is to conditional milestone payments, while Pfizer keeps authority over how the development program is conducted.

Funding Supports a Large Late-Stage Program

Pfizer (PFE ) plans to advance more than 20 trials for obesity and related comorbidities in 2026. The plan includes 10 ongoing and planned Phase 3 trials for berobenatide, also identified as PF’3944. Its development program covers chronic weight management and obesity-related comorbidities including knee osteoarthritis and obstructive sleep apnea. The co-funding therefore supports a program extending beyond a single trial or a standalone weight-management indication.

Pfizer is advancing berobenatide as a monotherapy and in combination with various Nutrient-Stimulated Hormone peptides, including amylin analogs. That approach gives the development plan two distinct tracks: studying the drug on its own and evaluating it alongside other peptides. Monthly injectable monotherapy also has direct financial significance under the agreement because its U.S. approval for chronic weight management is the regulatory condition attached to Blackstone’s milestone eligibility.

Pfizer Chief Financial Officer and Executive Vice President Cecile Guegan said: “Our aim is to bring important new medicines to patients while taking a disciplined approach that pairs internal research investments with targeted investment from capital partners. Today’s announcement helps us advance our comprehensive obesity program and maintain the financial capacity and flexibility to invest in our broader pipeline across all therapeutic areas.”

Blackstone Life Sciences global head Dr. Nicholas Galakatos described berobenatide as the anchor of Pfizer’s cardiometabolic pipeline and said the agreement expands Blackstone’s relationship with Pfizer. Funds managed by Blackstone’s perpetual private equity strategy, BXPE, will invest alongside funds managed by Blackstone Life Sciences, extending participation beyond a single Blackstone investment strategy.

The deal gives Pfizer outside capital for a broad clinical effort without surrendering ownership or operational authority. For Blackstone, the potential payments remain contingent on the specified approval and commercial sales performance. The scale and timing of its milestone receipts will therefore depend on whether berobenatide clears those regulatory and commercial hurdles.