Blackstone to Fund Up to $1.5 Billion of Pfizer’s Monthly Obesity Drug
Blackstone will cover up to $1.5 billion of development costs for Pfizer's monthly GLP-1 obesity shot through 2028 in return for milestone payments.
Pfizer said on Wednesday, Nov. 11, that funds managed by Blackstone will pay up to $1.5 billion of the development costs for berobenatide, an experimental once-a-month obesity injection, through 2028. Blackstone gets no ownership of the drug. Instead it can collect payments if the treatment wins U.S. approval and reaches certain sales targets. The deal lets the drugmaker share the cost of one of its most expensive late-stage programs as it tries to catch up in the weight-loss drug market.
What happened
In a joint announcement, the companies said the money will come from Blackstone Life Sciences, the investment firm’s unit that backs drug and medical-technology development, and from funds in Blackstone’s perpetual private equity strategy, known as BXPE, which will invest alongside it.
The structure is closer to a financing than a licensing deal. According to the announcement, Blackstone acquires no rights to or ownership of berobenatide, and Pfizer keeps full control of the program and all decisions about it. Blackstone’s return depends on two conditions: U.S. regulatory approval of berobenatide as a stand-alone monthly injection for chronic weight management, and the drug hitting certain commercial sales milestones. Any payments would be spread over several years. Neither company disclosed how large those milestone payments could be.
Reuters reported that Pfizer shares rose 0.2% to $29.52 in extended trading after closing slightly higher at $29.45. Seeking Alpha also covered the deal, describing berobenatide as Pfizer’s potential first-in-class monthly GLP-1 drug for weight loss.
What the drug is
Berobenatide, also known by the code PF’3944, is a GLP-1 receptor agonist, the same broad class of drugs as the blockbuster weight-loss and diabetes treatments already on the market. These medicines mimic a gut hormone that regulates appetite and blood sugar. Most current GLP-1 injections are taken weekly. Pfizer is betting that a monthly dose could set its product apart.
Pfizer calls the drug the anchor of its cardiometabolic pipeline. The company said it is studying berobenatide on its own and in combination with other peptides based on nutrient-stimulated hormones, a group that includes amylin analogs, which mimic a hormone that helps signal fullness. According to the announcement:
- Pfizer plans to run more than 20 trials in obesity and related conditions in 2026.
- Ten of those are ongoing or planned Phase 3 trials of berobenatide. Phase 3 is the large, late-stage testing usually required before a drug can be approved.
- Besides chronic weight management, the studies cover knee osteoarthritis and obstructive sleep apnea, two conditions closely tied to excess weight.
Why it matters
Running ten Phase 3 trials at once is costly. Splitting part of that bill with an outside investor lets Pfizer keep all the upside on the drug while freeing up cash for the rest of its research. Pfizer said the arrangement gives it more flexibility to invest across its pipeline, Reuters reported.
Cecile Guegan, Pfizer’s chief financial officer and executive vice president, said the company’s goal is to deliver new medicines “while taking a disciplined approach,” and Reuters quoted her as saying Pfizer aims to combine “internal research investments with targeted investment from capital partners.” Nicholas Galakatos, global head of Blackstone Life Sciences, said the deal shows the firm’s leadership in “providing capital solutions at scale.”
For Blackstone, the deal is a bet on a single regulatory and commercial result. If berobenatide fails in trials or is not approved for its main use, the milestone payments tied to approval would not be triggered.
Background
Pfizer got berobenatide when it bought Metsera, a U.S. obesity-drug developer, last year in a deal Reuters valued at up to $10 billion. The purchase came near the end of a run of acquisitions that, according to Reuters, was meant to replace falling revenue from Pfizer’s COVID-19 products and offset coming patent expirations on some of its biggest drugs.
This is not the first time the two companies have worked together this way. Reuters noted that in April 2023 Pfizer agreed to a deal under which Blackstone would provide up to $550 million through 2025 to help pay development costs for certain treatments.
What comes next
The funding runs through 2028, which covers the period when Pfizer’s late-stage berobenatide trials are expected to produce results. Any payout to Blackstone depends on the U.S. Food and Drug Administration approving the monthly injection for weight management, and then on how well it sells against established weekly treatments.
