Pfizer History: Founding, Growth & Key Milestones

Pfizer pursued Warner-Lambert to acquire the Lipitor (atorvastatin) cholesterol-lowering statin franchise which was already on track to become the best-selling drug in history at the time of the acquisition. The deal was structured as a hostile takeover after Warner-Lambert had announced a competing merger agreement with American Home Products (later Wyeth), and Pfizer outbid with a $111 billion all-stock offer. The acquisition also brought significant consumer healthcare brands including Listerine, Benadryl, and Halls.

Pfizer acquired Pharmacia Corporation for approximately $60 billion in 2003 to add the Celebrex (celecoxib) COX-2 inhibitor franchise, the cancer drug Camptosar, ophthalmology products, and a substantial pipeline. The acquisition was also motivated by post-Lipitor diversification concerns and the need to add research capabilities and marketed products to offset anticipated future patent expirations across the combined portfolio.

Pfizer acquired Wyeth for $68 billion during the financial crisis of 2009, using the depressed asset valuations of the period to complete what was then one of the largest pharmaceutical acquisitions in history. The primary strategic targets were the Prevnar pneumococcal vaccine franchise, the Enbrel (etanercept) biologics franchise for rheumatoid arthritis and other inflammatory conditions, the Effexor and Pristiq antidepressants, and Wyeth's substantial consumer healthcare business.

Pfizer acquired Medivation for $14 billion in 2016 to secure Xtandi (enzalutamide), an androgen receptor inhibitor for prostate cancer that was among the most commercially promising oncology drugs of the decade. The acquisition was Pfizer's first major commitment to oncology as a primary strategic growth focus rather than a secondary therapeutic area, signaling a deliberate shift toward cancer treatment as an organizational priority.

Pfizer acquired Seagen for approximately $43 billion in December 2023 to secure leadership in antibody-drug conjugate technology, the fastest-growing drug modality in oncology. Seagen's four commercially approved ADC productsAdcetris, Padcev, Tivdak, and Tukysaprovided immediate revenue contribution while the ADC platform technology provided the foundation for Pfizer's oncology pipeline strategy through 2030. The acquisition represented Pfizer's response to the anticipated loss of exclusivity on Ibrance and the broader need to establish a new oncology platform capable of generating multi-billion-dollar revenues independent of CDK4/6 inhibitor franchise sustainability.

Re-enter the obesity market after Pfizer discontinued its in-house oral GLP-1 candidates danuglipron and lotiglipron. Metsera brought injectable and oral incretin and amylin candidates, including monthly-dosing programs.