Pfizer Secures Up to $1.5 Billion From Blackstone to Fund Obesity Drug
Pfizer signed an agreement with Blackstone Life Sciences for up to $1.5 billion to fund development of its monthly experimental obesity drug through 2028.
Pfizer Inc. announced on November 11 that it has entered into a strategic co-funding agreement with Blackstone Life Sciences to support its obesity program. Under the agreement, funds managed by Blackstone will cover up to $1.5 billion of development expenses through 2028 for berobenatide, also known as PF'3944, an investigational monthly GLP-1 receptor agonist peptide.
In exchange for funding, Blackstone will be eligible to receive milestone-based payments over several years. These payments depend on U.S. regulatory approval of the monthly injectable treatment as a monotherapy for chronic weight management and the achievement of specified commercial sales targets. Blackstone will acquire no ownership or development rights to berobenatide, allowing Pfizer to keep full operational control and decision-making authority.
Capital from Blackstone's perpetual private equity vehicle, BXPE, will invest alongside its Life Sciences funds, which manage about $18 billion. Pfizer chief financial officer Cecile Guegan noted that the partnership pairs internal research investments with targeted capital partner funds, advancing its obesity initiatives while maintaining financial flexibility to support other therapeutic pipelines.
Pfizer added berobenatide through its November 2025 acquisition of Metsera. The drugmaker plans 10 ongoing and planned Phase III studies for berobenatide covering obesity and related comorbidities such as knee osteoarthritis and obstructive sleep apnea, with three Phase III studies already underway. Pfizer is aiming for the first of a series of potential regulatory approvals in 2028.
Pfizer shares closed at $29.45 on November 11, up 0.31% before the agreement was announced, and reached $29.48 in after-hours trading. Zacks Investment Research reported that Pfizer shares have risen 26.2% year to date compared to a 28.3% increase for its industry, while Zacks currently maintains a Rank #3 (Hold) on the stock.