Pfizer spent most of the past three years living off COVID-era revenue. That money is gone, and the company’s response tells investors something important about where pharmaceutical growth is heading next.

Pfizer’s R&D pipeline is becoming an increasingly important part of the investment story as the company tries to revive growth after the sharp decline in COVID-19 product revenues and address several upcoming patent expirations. The urgency behind that pivot is real: Pfizer has warned that 2026 through 2030 will bring a significant reduction in revenue as multiple in-line products face patent-based or regulatory exclusivity expirations, including products such as Eliquis and Ibrance.

To fill that gap, management made a calculated bet. In 2025, Pfizer invested approximately $8.8 billion in business development transactions, primarily reflecting the Metsera acquisition and the 3SBio in-licensing deal, to boost its pipeline in obesity and oncology. The result is a portfolio with genuine breadth. As of August 2026, Pfizer has described its pipeline as comprising 95 potential new treatments and indications across four therapeutic areas, with the most important assets concentrated in obesity and oncology.

The obesity angle is the one that deserves investor attention right now. Pfizer completed its acquisition of obesity drugmaker Metsera in November 2025, bringing Pfizer back into the obesity space after it discontinued development of danuglipron, a weight-loss pill, in April 2025. The new lead candidate, PF’3944, works differently from the drugs that failed before it. In the phase IIb VESPER-3 study, PF’3944 achieved up to 12.3% placebo-adjusted weight loss at 28 weeks, with patients continuing to lose weight even after transitioning from weekly to monthly dosing. Monthly maintenance dosing is a meaningful differentiator. The currently available and highly popular weight loss GLP-1 therapies, Eli Lilly’s Zepbound and Novo Nordisk’s Wegovy, are weekly injections. A patient who only needs one shot per month is a patient far more likely to stay on therapy.

On the cancer side, Pfizer is executing across two distinct strategies simultaneously. CEO Albert Bourla has said Pfizer now directs more than 40% of its annual R&D spend toward oncology. That capital is flowing into antibody-drug conjugates from the Seagen acquisition and a newer class of combination therapy. Pfizer has also in-licensed global rights outside of mainland China to develop and commercialize SSGJ-707 (PF-08634404), a dual PD-1 and VEGF inhibitor, from China’s 3SBio. Dual PD-1/VEGF inhibitors are designed to overcome the limitations of single-target cancer therapies like Merck’s blockbuster Keytruda and have the potential to become a new standard of care in oncology.

The risks are real and should not be dismissed. If Pfizer’s monthly GLP-1 fails in late-stage clinical trials, the company will have little path to competing in the obesity market, leaving it overly dependent on oncology. Separately, Depo-Provera litigation has continued to grow, with public court trackers and legal reporting in recent months placing the federal MDL in the low-thousands of filed cases, and additional claims pending in state courts, creating the risk of costly settlements.

For long-term investors, the valuation remains the overlooked part of this story. Pfizer’s shares recently traded at about 10 times forward earnings, well below many large-cap pharmaceutical peers. That discount prices in a lot of skepticism. If PF’3944 delivers in phase III and even one or two of the oncology readouts land well, the gap between where Pfizer trades and where it belongs could close faster than the market currently expects.