Merck & Co., a pharmaceutical giant, is still riding a roller coaster.

The hotly anticipated Antibody-Drug Conjugates (ADCs) need no introduction. Merck’s much-watched potential merger with ADC leader Seagen was preempted by Pfizer’s $43 billion acquisition. This year alone, numerous pharmaceutical giants have announced ADC co-development deals. Moreover, mergers and acquisitions carry integration risks. For instance, Amgen—having just completed its record-breaking acquisition of Horizon Therapeutics in October—subsequently announced a layoff plan. Public data shows that among Merck’s more than 20 oncology drugs that have advanced beyond early development, 18 were acquired or developed through partnerships; of roughly 32 distinct compounds, only about eight originated from internal discovery. It is thus unsurprising that Merck relies heavily on acquisitions to consolidate its position—or even launch entirely new research areas. However, some analysts argue that these acquisitions have not been well integrated into Merck’s core operations. Over the next few years, Merck’s pipeline evolution will be further tested—especially as funding constraints limit the maneuverability of clinical-stage companies. Real-world challenges also include last year’s passage of the Inflation Reduction Act (IRA). Under the new rules, small-molecule inhibitors like nemtabrutinib—which Merck acquired for $2.7 billion—enter Medicare price negotiations nine years after FDA approval, while large-molecule biologics face negotiation after 13 years. This may significantly hinder subsequent indication development for newly approved drugs. In June, Merck filed a lawsuit in the U.S. District Court for the District of Columbia, arguing that the IRA’s drug pricing provisions violate the U.S. Constitution’s Fifth Amendment. Specifically, the amendment stipulates that even when the government takes private property for public use, it must provide ‘just compensation.’ Subsequently, many multinational corporations joined the litigation. Yet amid mounting public pressure for healthcare cost containment, can they truly challenge a far larger systemic framework? At least for now, Merck has yet to smoothly transition onto the second growth curve it envisioned. References: 1. Merck: Right On Time; Seeking Alpha 2. Merck Q3 2023 Earnings Preview: Keytruda LOE Continues To Dominate Narrative; Seeking Alpha 3. Merck: Still Fundamentally Undervalued Considering Keytruda's Prospects; Seeking Alpha 4. Merck & Co., Inc. (MRK) Q3 2023 Earnings Call Transcript; Seeking Alpha 5. When Will Keytruda Step Down from Merck’s Throne?; Drug Times 6. Prof. Xia Ningshao’s Team Publishes Head-to-Head Immunogenicity Comparison Study of China’s First Domestic 9-Valent HPV Vaccine vs. Imported 9-Valent HPV Vaccine in The Lancet Infectious Diseases; Xiamen University 7. China’s First Domestic HPV Vaccine Receives Market Authorization—How Advanced Is Xiamen University’s Core Technology?; Tongxieyi Biotech 8. Global Top 10 Vaccines, H1 2023; Sinobioway Biomedical Division 9. EASL 2023: After Obeticholic Acid’s Setback, a ‘Spring Renewal’ in the Liver Disease Pipeline; Tongxieyi 10. MSD Terminates Phase II Trials for Alzheimer’s Drug Due to Liver Toxicity; Clinical Trials Arena 11. $10 Billion Milestone Payment! A Biotech Licenses Out Seven ADC Programs to Merck; Tongxieyi 12. Founded Just One Year Ago, This Company Has Already Sold Assets Worth $7.1 Billion; Tongxieyi 13. Is the High-Return U.S. Innovative Drug Market in Peril? Merck Fires the First Shot in Its Defense Campaign; Tongxieyi

Overall review of global top pharmaceutical companies’ drug sales revenue (as of December 31, 2025).

Immunology: One product—AbbVie’s Rinvoq (upadacitinib), a JAK inhibitor approved in 2019 for rheumatoid arthritis, psoriasis, and other type-II inflammatory diseases. It has not yet reached peak sales; its 2025 revenue totaled $8.304 billion. Ophthalmology: One product—Bayer and Regeneron’s Eylea (aflibercept), a VEGFR fusion protein approved in 2011 for age-related macular degeneration. It peaked in 2022 at $9.703 billion and has since declined; its 2025 revenue stood at $8.037 billion. Eylea ranks among the top 20 best-selling drugs by peak revenue—a topic previously covered in detail. Cardiovascular and metabolic disease: Novartis’s Entresto (sacubitril/valsartan), a combination of a neprilysin inhibitor and an angiotensin receptor blocker, approved in 2015 for heart failure and hypertension. It peaked in 2024 at $7.822 billion and slightly declined to $7.748 billion in 2025. Entresto also belongs to the top 20 best-selling drugs by peak revenue—previously detailed as well. Summary of the Top 20 Best-Selling Drugs in 2025 Overall, the top 20 best-selling drugs in 2025 are dominated by oncology, diabetes/weight-loss, and immunology products. Oncology accounts for five entries. The highest-revenue drug in 2025 is Merck’s Keytruda (pembrolizumab), a PD-1 antibody approved in 2014 for multiple solid tumors. Thanks to its broad indications, its 2025 revenue exceeded $30 billion. Another competing PD-1 antibody, Bristol Myers Squibb’s Opdivo (nivolumab)—also approved in 2014 for multiple solid tumors—generated over $10 billion in 2025 revenue. Because PD-1 antibodies treat such a wide range of indications, their market potential remains exceptionally large. The remaining three oncology products include Johnson & Johnson’s Darzalex (daratumumab), a CD38 monoclonal antibody for multiple myeloma; Astellas and Pfizer’s Xtandi (enzalutamide), an androgen receptor inhibitor for prostate cancer; and AstraZeneca’s Tagrisso (osimertinib), a small-molecule TKI targeting EGFR-mutated non-small cell lung cancer. Among these, daratumumab is a monoclonal antibody therapy, enzalutamide is an endocrine therapy, and osimertinib is a small-molecule TKI inhibitor. Collectively, their narrower therapeutic scopes—compared to PD-1 antibodies—result in substantially lower revenues. As global obesity and diabetes prevalence rise—and given the proven efficacy of GLP-1 receptor agonists in diabetes treatment—these agents have recently demonstrated remarkable weight-loss benefits, fueling explosive commercial success. Diabetes and weight-loss drugs occupy four and two spots, respectively, among the top 20 best-selling drugs in 2025. Eli Lilly’s dual GIP/GLP-1 receptor agonist tirzepatide (for diabetes and weight loss) and Novo Nordisk’s GLP-1 receptor agonist semaglutide (also for diabetes and weight loss) both rank among the top 20 best-selling drugs in 2025.

Merck tops third-quarter estimates as Keytruda, Gardasil outperform

1 day ago

Merck beat Q3 earnings estimates driven by Keytruda and Gardasil sales, raising its full-year revenue forecast. Additionally, positive late-stage trial data was published for an mRNA cancer vaccine developed with Moderna.

reuters

2026-04-30

Merck beats quarterly sales expectations as Keytruda fuels growth

2026-10-29

Merck tops third-quarter estimates as Keytruda, Gardasil outperform

Merck tops third-quarter estimates as Keytruda, Gardasil outperform

FAQ