Pfizer Jumps Back into the Weight-Loss Race With $4.9B Acquisition

Pfizer halted the development of its weight-loss medication in April after a patient fell ill. (Dreamstime)

Key Points

About This Summary

• Pfizer wants to acquire Metsera to enter the anti-obesity market after halting its own weight-loss drug development.
• The deal values Metsera at $7.3 billion, with Pfizer paying $47.50 per share in cash.
• Metsera’s stock surged following the announcement, as Pfizer aims to compete with Eli Lilly and Novo Nordisk.

Big pharma firm Pfizer is storming back into the weight-loss market after an embarrassing faceplant, announcing its biggest proposed acquisition in more than two years on Monday morning.

Pfizer said it would pay $4.9 billion up front for Metsera, a biotech with a diversified weight loss pipeline. Pfizer is paying $47.50 per share for Metsera, which closed Friday at $33.32. The company is also promising bonus payments worth up to $22.50 per share if Metsera’s drugs hit certain milestones.

Metsera shares were up 61% to $53.65 in Monday trading, well above the deal price, implying significant investor confidence in the company’s pipeline. Pfizer shares were up 2.3%, while Novo Nordisk and Eli Lilly , which currently dominate the weight-loss market, were down 1.8% and up 0.6%, respectively.

Created with Highcharts 9.0.1Source: FactSetAs of Sept. 22, 4 p.m. ET

Created with Highcharts 9.0.1MetseraEli LillyPfizerNovo NordiskSept. 2025-10010203040506070%

Pfizer’s obesity-drug flameout has dragged on for years and has been a significant overhang for the stock. In early 2023, as the company was looking to recover from the evaporation of the Covid-19 vaccine market, Pfizer CEO Albert Bourla boasted at an investment conference that the oral GLP-1 weight loss drug the company had under development at the time “could be a $10 billion product” and that Pfizer would be one of “very few players” in the oral GLP-1 market.

In the years that followed, nothing went right for Pfizer’s weight-loss hopes. After repeated disappointments, the company finally dropped development of its most closely watched pill early this year. That left Pfizer virtually alone among big pharma names without a high-profile weight-loss drug under development.

With experts widely anticipating global weight-loss drug sales to climb to $100 billion, investors didn’t think that Pfizer could afford to miss out. The stock is down 16% over the past 12 months.

The deal announced Monday amounts to a big swing at claiming a chunk of the weight-loss market, with Pfizer perhaps hoping to someday compete for share with Lilly and Novo. Metsera, which went public in January, has a handful of weight-loss drugs in clinical trials.

Metsera’s pipeline includes both GLP-1 injectables that are roughly similar to the Lilly and Novo blockbusters already on the market, and another type of experimental weight-loss treatment known as an amylin. Novo reported data last week on an amylin it plans to progress into Phase 3 trials.

Metsera’s most advanced program, MET-097i, is an injectable GLP-1 that the company is testing as a monthly injection in a Phase 2 trial. Lilly’s Zepbound and Novo’s Wegovy are both injected weekly. The company’s lead amylin is an injectable called MET-233i now in Phase 1 trials.

Wall Street had been waiting for data from the MET-097i trials. On an investor call early Monday, Pfizer executives said that they had seen “some of the data” from the trials, and that more data “will be coming out in the very near term.”

In their comments on the call, the Pfizer team—which didn’t include CEO Bourla—said that the ability to dose the Metsera GLP-1 monthly would give it an advantage over other weight-loss GLP-1 injections. They also said that they were interested in the ability to combine the company’s GLP-1 and amylin drugs into a single medicine.

Pfizer’s chief internal medicine officer, Jim List, said on the investor call that MET-097i, the long-lasting injectable GLP-1 drug, could enter Phase 3 trials next year.

“We believe these agents have the potential to deliver category-leading efficacy and competitive tolerability with monthly maintenance dosing,” List said of MET-097i and MET-233i.

If Pfizer is able to launch the drugs in coming years, they will be seeking to crack a market where Lilly, Novo, and perhaps other competitors will already have a many-year lead. On the Monday call, Pfizer executives said they expect Metsera drugs to launch in 2028 or 2029.

“Pfizer has a proven track record of entering competitive markets and emerging as a leader,” the company’s chief strategy and innovation officer, Andrew Baum, said on the call, citing the blood thinner Eliquis and the statin Lipitor, both Pfizer blockbusters that competed in crowded markets.

Analysts said that the Metsera deal will give Pfizer plenty of options as it seeks to bring a weight-loss drug to market.

“We viewed the Metsera portfolio as one of the more attractive smid-cap obesity portfolios, driven primarily by its amylin analog MET-233i, and complemented by a broad set of GLP-1s,” Cantor analyst Carter Gould wrote early Monday. “In that sense, the deal makes strategic sense, immediately makes Pfizer relevant in obesity again, and gives the company plenty of levers to pull as it contemplates late-stage development.”

The question is whether investors will give Pfizer much credit for the deal, given the competitive challenges that surely await.

If the Metsera drugs do translate into a success for Pfizer, it couldn’t come at a better time. The company is in the midst of a historic wave of patent expirations, which is set to peak later this decade, around when the Metsera drugs could launch.

Write to Josh Nathan-Kazis at josh.nathan-kazis@barrons.com and Elsa Ohlen at elsa.ohlen@barrons.com