Pfizer Sees Obesity Drugs Echoing Viagra’s Early Growth, CEO Says

Pfizer completed its acquisition of Metsera in 2025, paying up to $10 billion and ending a competitive bidding war for the obesity biotech company.

Pfizer CEO Albert Bourla in Davos, Switzerland, on May 25, 2022. Fabrice Coffrini/AFP

Pfizer is gearing up for a consumer-driven market for obesity drugs that could match the rapid growth it experienced after introducing erectile dysfunction drug Viagra more than 20 years ago, Chief Executive Albert Bourla said on Jan. 12.

Speaking during the J.P. Morgan Healthcare Conference in San Francisco, Bourla said Pfizer underestimated how quickly patients would be willing to pay out of pocket for obesity treatments, even without insurance coverage.

The obesity drug market is currently dominated by Eli Lilly and Novo Nordisk, whose drugs have seen soaring demand worldwide.

Bourla said Pfizer’s expectations changed as it moved toward acquiring clinical-stage obesity drugmaker Metsera, a deal first announced in September 2025.

“Both Lilly and Novo presented their sales and had significant sales outside the reimbursement system. Basically, outside the U.S., we were calculating very limited sales,” Bourla told reporters at the conference.

He said the willingness of patients to pay directly for obesity drugs now resembles the early years of Viagra, which Pfizer launched in 1998.

“Now we see that this operates almost like Viagra, where people were willing to pay and buy it, although it was not reimbursed at all,” he said.

Pfizer developed and sold Viagra for years before spinning off the business that controls the brand in 2020. Viagra is now sold mostly as a generic drug.

Pfizer completed its acquisition of Metsera on Nov. 13 last year, paying up to $10 billion and ending a competitive bidding war for the obesity biotech company.

Phase 3 Studies

Pfizer said on Jan. 12 that it plans to launch 10 Phase 3 studies of Metsera obesity compounds by the end of this year, including one that began in November 2025.

Bourla said the scale of those trials reflects how central obesity has become to Pfizer’s long-term plans.

“We are all in on obesity,” Bourla said. “We invested. We have good expertise in commercial, good expertise in development, and good expertise in discovery.”

Bourla has pointed to recent clinical progress as evidence that Pfizer’s strategy is beginning to take shape. In a post on X dated Jan. 5, he said the company ended 2025 with two key Phase 3 trial starts.

“We ended 2025 with two milestone Phase 3 trial starts: an investigational ultra-long-acting injectable peptide for obesity and an investigational antibody for advanced colorectal cancer,” Bourla said.

“Both joined our pipeline just last year. Both reached pivotal studies ahead of plan, with more to come in 2026.”

In an interview with Bloomberg’s Katie Greifeld published on Jan. 12, Bourla said investors are watching for clinical catalysts after Pfizer’s stock lagged peers.

“I think investors want to see catalysts, and this is a year that is very rich in catalysts,” Bourla said.

He highlighted upcoming obesity trial data, including 30-day dosing results for an ultra-long-acting treatment and a combination therapy using GLP-1 and amylin.

Pricing Balance

Pfizer was the first major drugmaker to strike a pricing agreement with the Trump administration.

On Sept. 30, 2025, officials announced a deal under which Pfizer agreed to cut Medicaid prices to match those in other developed nations in exchange for three years of tariff relief.

“I’m very proud of what we did. What we did opens the way for the entire industry,” Bourla said in the Bloomberg interview.

The move “puts to bed” the issue of big differences in pricing between the United States and other rich nations, he added, describing it as a “good deal.”

Following the Pfizer deal, the Trump administration announced 14 deals with major pharmaceutical manufacturers to bring prices in line with those paid in other developed nations, the White House said on Dec. 19. These include GSK, Merck, Novartis, Sanofi, Boehringer Ingelheim, Genentech, and Gilead Sciences.

Reuters contributed to this report.