Pfizer on Monday said it would buy weight loss drugmaker Metsera in an up to $7.3 billion deal, including future payments, as it scrambles to win a slice in the booming obesity drug market. 

Pfizer said it will pay an initial $47.50 a share in cash for Metsera, a nearly 43% premium to the biotech company’s Friday’s closing price of $33.32. That gives the deal an enterprise value of $4.9 billion. 

The pact also includes a contingent value right worth up to $22.50 a share based on potential clinical and regulatory achievements for Metsera’s medicines, which could bring the total value to $70 a share. 

The deal is expected to close at the end of the year. Shares of Metsera rose more than 60% in premarket trading on Monday, while Pfizer’s stock rose more than 1%. 

The move comes after a string of setbacks for Pfizer in the obseity space. The pharmaceutical giant struggled to develop its own lead obesity drug candidate, danuglipron, before deciding to scrap it entirely in April due to safety concerns. Pfizer also discontinued a different once-daily pill in June 2023 due to elevated liver enzymes in patients who received it. 

Pfizer has earlier-stage obesity drugs in its pipeline that work in different ways, but the company has faced mounting investor pressure to accelerate its push into the market.

The opportunity could be huge. Some analysts expect the weight loss drug space could be worth roughly $100 billion by the 2030s, with room for new rivals to compete with popular injections from Eli Lilly and Novo Nordisk.

Metsera, founded in 2022, brings a pipeline of both oral and injectable treatments with different targets that the company had picked up through its own licensing and acquisition deals. That includes a GLP-1 drug called MET-233i, which helped patients lose up to 8.4% of their weight in 36 days in a small, early-stage trial. Metsera is developing that treatment as a potential once-monthly injectable, meaning that patients can take it less frequently than existing weekly injections.

Metsera’s pipeline also includes a monthly drug targeting a hormone called amylin, along with two oral GLP-1 candidates “expected to begin trials imminently,” Pfizer said in a release. 

“The proposed acquisition of Metsera aligns with our focus on directing our investments to the most impactful opportunities and propels Pfizer into this key therapeutic area,” Pfizer CEO Albert Bourla said in a statement. “We are excited to apply our deep cardiometabolic experience and manufacturing and commercial infrastructure to accelerate a portfolio that includes potential best-in-class injectables.”

In a note on Monday, Leerink Partners analyst David Risinger said the firm estimates Metsera’s obesity candidates have the potential to generate more than $5 billion in combined peak annual sales. In a separate note on Monday, JPMorgan analyst Chris Schott said Metsera’s experimental drugs “should accelerate” Pfizer’s entry into the market. 

The New York-based Metsera went public this year in one of the biggest biotech listings of 2025. It is among several companies racing to develop next-generation obesity treatments following the success of weekly injections such as Eli Lilly’s obesity drug Zepbound and Novo Nordisk’s rival Wegovy.