New York, New York, U.S., and Cambridge, Massachusetts, U.S., November 11, 2026
Pfizer Inc. and Blackstone Life Sciences have announced a strategic co-funding agreement worth up to $1.5 billion to support the clinical development of berobenatide (PF’3944), an investigational, potential first-in-class monthly glucagon-like peptide-1 receptor (GLP-1) agonist peptide for chronic weight management and obesity-related conditions. Under the agreement, funds managed by Blackstone will cover eligible development costs through 2028, helping Pfizer advance its growing cardiometabolic research programme. The collaboration represents an important investment in the rapidly evolving obesity treatment and metabolic disease pharmaceutical market, where companies are increasingly exploring long-acting therapies and innovative drug combinations. Pfizer will retain full operational control and decision-making authority over the berobenatide development programme, while Blackstone will be eligible for milestone-based payments linked to regulatory approval and specified commercial sales achievements. The agreement is designed to strengthen Pfizer’s financial flexibility while supporting the development of a potentially differentiated treatment option for people living with obesity.
$1.5 Billion Strategic Agreement Supports Clinical Development
The funding agreement establishes a strategic partnership between Pfizer and Blackstone Life Sciences to accelerate the development of berobenatide. Under the terms, Blackstone-managed funds will provide up to $1.5 billion in development funding through 2028. In return, Blackstone will be eligible to receive milestone-based payments over multiple years, subject to U.S. regulatory approval of monthly injectable berobenatide monotherapy for chronic weight management and the achievement of certain commercial sales milestones. Importantly, Blackstone will not receive ownership or intellectual property rights in berobenatide. Pfizer will continue to control the drug candidate’s clinical development strategy, operational activities and related decision-making. Funds managed by Blackstone’s perpetual private equity strategy, BXPE, will invest alongside Blackstone Life Sciences as part of the transaction. The collaboration expands the existing relationship between the two organizations and reflects the increasing importance of external financial partnerships in supporting large-scale pharmaceutical research programmes. For Pfizer, the funding arrangement is expected to help manage the substantial costs associated with late-stage clinical development while maintaining resources for other therapeutic research priorities.
Berobenatide Targets Obesity Through Monthly GLP-1 Therapy
Berobenatide is an investigational long-acting GLP-1 receptor agonist peptide being developed as a once-monthly injectable treatment for chronic weight management. The medicine is designed to activate GLP-1 receptor pathways involved in appetite regulation, food intake and metabolic control. GLP-1-based therapies have become an important area of pharmaceutical innovation because of their potential to support weight reduction and improve certain obesity-related health conditions. Pfizer is positioning berobenatide as a potential differentiated treatment option through its monthly dosing approach. If clinical studies demonstrate favorable efficacy and safety, a once-monthly administration schedule could offer an alternative to more frequently administered injectable obesity medicines. However, the potential benefits of monthly dosing must be established through appropriate clinical evaluation. The company’s development strategy also includes investigating berobenatide for obesity-related comorbidities, including knee osteoarthritis and obstructive sleep apnea. These conditions can significantly affect the health and quality of life of individuals living with obesity. Pfizer is also exploring the medicine as a standalone therapy and in combination with other nutrient-stimulated hormone (NuSH) peptides, including amylin analogues, to investigate complementary metabolic mechanisms.
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Pfizer Expands Phase 3 Obesity Research Programme
The strategic funding agreement comes as Pfizer advances a comprehensive clinical development programme focused on obesity and associated metabolic conditions. The company plans to advance more than 20 clinical trials in 2026 across obesity and related comorbidities. This programme includes 10 ongoing and planned Phase 3 clinical trials evaluating berobenatide in different treatment settings. The late-stage clinical programme is intended to generate evidence regarding the medicine’s long-term effectiveness, safety and potential role in chronic weight management. Additional investigations will explore its use in combination with other metabolic therapies, reflecting the growing pharmaceutical industry interest in multi-mechanism obesity treatments. Cecile Guegan, Chief Financial Officer and Executive Vice President of Pfizer, highlighted the importance of combining internal research investments with targeted financial partnerships. According to the company, the agreement will help advance its comprehensive obesity programme while maintaining financial capacity and flexibility to invest across its broader pharmaceutical pipeline. Dr. Nicholas Galakatos, Global Head of Blackstone Life Sciences, also emphasized the importance of the collaboration in supporting the development of innovative medicines and technologies. The partnership highlights the growing role of strategic pharmaceutical financing in accelerating drug development. As demand for effective obesity treatments continues to drive investment in metabolic research, collaborations between pharmaceutical companies and specialist life sciences investors may help support complex clinical programmes. For Pfizer, the agreement provides additional financial resources to advance berobenatide while retaining control over its development. The medicine remains investigational and has not received marketing approval. Its future commercial potential will depend on clinical outcomes, regulatory decisions and its ability to demonstrate meaningful benefits for patients.
Source: Pfizer, Blackstone Life Sciences press release
