With an eye on entering the obesity market dominated by Eli Lilly, Pfizer has secured $1.5bn from Blackstone Life Sciences to spur clinical development of its monthly glucagon-like peptide-1 receptor agonist (GLP-1RA) berobenatide.
The private equity firm will bankroll the development costs of berobenatide through 2028. In exchange, Blackstone will be eligible to receive milestone-based payments, dependent on the drug making it to the US market and achieving certain sales figures. The funding does not give Blackstone any ownership rights to berobenatide.
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Pfizer is the latest pharma company to tap the financial services of Blackstone. MSD, J&J, and Apogee Therapeutics all have funding arrangements with the equity firm.
While Pfizer has trimmed parts of its obesity pipeline this year, berobenatide remains front and centre of the drugmaker’s efforts to join the weight loss market. Pfizer acquired the asset – formerly known as MET097i – as part of its $10bn takeover of Metsera in December 2025, a deal that only went through after a fierce bidding war with Novo.
Pfizer has an extensive clinical programme for berobenatide that spans 10 ongoing or planned Phase III studies. Alongside chronic weight management, the asset is also being evaluated for obesity-related comorbidities including knee osteoarthritis and obstructive sleep apnoea.
Pfizer’s chief financial officer Cecile Guegan said: “Today’s announcement helps us advance our comprehensive obesity programme and maintain the financial capacity and flexibility to invest in our broader pipeline across all therapeutic areas.”
In a research note, Citi analysts said: “The transaction improves the programme’s risk-adjusted economics and enables Pfizer to advance its broad Phase III obesity programme with less near-term financial burden.”
The analysts added that differentiation on efficacy, tolerability and monthly dosing from the late-stage trial remains the key value driver.
The cardiometabolic arena is dominated by Eli Lilly. In Q3, the pharma company’s tirzepatide brands Mounjaro and Zepbound continued their ascendancy. The type 2 diabetes and obesity medications generated $10.7bn and $5.4bn in global sales, respectively.
Tirzepatide’s total quarterly take-home of around $16.1bn meant the drug alone outperformed the total revenue of many other big pharma companies in Q3, including Novartis, GSK, and Bristol Myers Squibb (BMS), among others.
While not as dominant as it once was, Novo still occupies significant market share with its semaglutide franchise that now includes a daily pill. While Novo has raced to market its Wegovy pill in the US, Europe, and the UK first, Lilly is leaning on easier administration of its Foundayo (orforglipron) pill to close the gap. Unlike other territories, Lilly’s pill won approval first in China.
