• The Pfizer of oncology and vaccines.
• The Procter & Gamble of prescription drugs and vaccines.

• Keytruda (pembrolizumab): An anti-PD-1 therapy used to treat various cancers, including melanoma, lung cancer, and certain head and neck cancers, by enhancing the immune system's ability to detect and fight tumor cells.
• Gardasil/Gardasil 9: Vaccines that help protect against diseases caused by Human Papillomavirus (HPV), including certain cancers like cervical, anal, and throat cancers, and genital warts.
• Januvia (sitagliptin) / Janumet: Medications used to improve blood sugar control in adults with type 2 diabetes by increasing insulin release and decreasing glucose production in the liver.
• Bridion (sugammadex): A medication used to reverse the effects of certain neuromuscular blocking agents used during surgery, helping patients recover muscle function more quickly.
• Lynparza (olaparib): An oral PARP inhibitor, co-developed with AstraZeneca, used to treat certain types of cancer, including ovarian, breast, prostate, and pancreatic cancers, particularly in patients with BRCA mutations.
• Vaxneuvance (Pneumococcal 15-valent Conjugate Vaccine): A vaccine designed to protect adults and children against invasive disease and pneumonia caused by 15 serotypes of the bacterium *Streptococcus pneumoniae*.

Merck (MRK) primarily sells its pharmaceutical products to other companies, specifically major wholesale drug distributors, rather than directly to individual consumers. These distributors then supply pharmacies, hospitals, and other healthcare providers with Merck's products.

Based on their financial filings, Merck's major customers are:

• AmerisourceBergen Corporation (Symbol: ABC)
• Cardinal Health, Inc. (Symbol: CAH)
• McKesson Corporation (Symbol: MCK)

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Robert M. Davis, Chairman and Chief Executive Officer

Rob Davis became Chairman and Chief Executive Officer of Merck in July 2021, and Chairman of the Board in December 2022. He joined Merck in 2014 as Chief Financial Officer, overseeing real estate operations, corporate strategy, business development, information technology, and procurement. Prior to Merck, Mr. Davis was corporate vice president and president of Baxter's medical products business. During his tenure at Baxter, he also held roles such as president of Baxter's renal business, chief financial officer, and treasurer. Before joining Baxter in 2004, he spent 14 years at Eli Lilly and Company, where he held various positions of increasing responsibility, including Director of Corporate Financial Planning. Mr. Davis serves on the board of directors for Duke Energy Corporation, Project HOPE, and Catalyst.

Caroline Litchfield, Executive Vice President and Chief Financial Officer

Caroline Litchfield has served as Executive Vice President and Chief Financial Officer for Merck since April 2021. In this role, she is responsible for the company's finance, procurement, and real estate operations. Ms. Litchfield joined Merck in its U.K. business in 1990 and has held numerous positions of increasing responsibility across the company's country, regional, and global finance functions. She previously served as the company's Treasurer. From 2014 to 2018, she led finance for Human Health, Merck's largest business. She was also instrumental in integrating Merck and Schering-Plough following their merger in 2009, serving as vice president and finance lead for the Emerging Markets region. Ms. Litchfield currently serves as a Director with Verizon.

Cristal N. Downing, Executive Vice President and Chief Communications & Public Affairs Officer

Cristal Downing joined Merck as Executive Vice President and Chief Communications & Public Affairs Officer in July 2021. She is responsible for the development, advancement, and execution of the company's communications and public affairs strategy, and Environmental, Social, and Governance (ESG) efforts. Before joining Merck, Ms. Downing spent six years at Johnson & Johnson, where she served as Vice President of Medical Devices and Global Communications and Public Affairs, and Vice President of Financial Communications. She also co-led the development and implementation of Johnson & Johnson's "Our Race to Health Equity" strategy. Her career spans over 20 years with leadership experience at various organizations, including American Express, JP Morgan Chase, and Wells Fargo.

Dean Y. Li, M.D., Ph.D., Executive Vice President and President, Merck Research Laboratories

Dean Y. Li is the Executive Vice President and President of Merck Research Laboratories. Dr. Li holds a Ph.D. in Biochemistry from the Massachusetts Institute of Technology and a Bachelor's Degree in Biochemistry and Molecular Biology from the University of California, Davis.

Dave Williams, Executive Vice President, Chief Information & Digital Officer

Dave Williams is the Executive Vice President, Chief Information & Digital Officer at Merck. In this role, he is responsible for the company's technology direction and organization. Prior to his current role, Mr. Williams served as the Chief Information Officer of Merck Animal Health and Executive Director of Enterprise Information Management. He has also held various IT leadership roles at Schering-Plough.

Key Risks to Merck (MRK)

1. Patent Expiration of Keytruda: Keytruda, Merck's leading immunotherapy drug, is projected to lose patent protection in the United States in 2028 and in Europe in 2031. This "patent cliff" is a critical concern, as Keytruda has accounted for a substantial portion of Merck's total revenue, estimated at 40-50% in recent years. The expiration is expected to lead to a significant decline in sales due to the entry of biosimilar competition, potentially causing substantial revenue erosion.
2. Pipeline Risks and Inability to Offset Revenue Decline: A major risk for Merck is the uncertainty surrounding the successful development and commercialization of new drugs in its pipeline to effectively offset the anticipated revenue loss from Keytruda's patent expiration. While Merck is actively investing in research and development and strategic acquisitions to diversify its portfolio, there is no guarantee that these new assets will generate sufficient revenue to compensate for Keytruda's decline.
3. Generic Erosion, Market Competition, and Regulatory/Pricing Pressures: Merck faces ongoing challenges from increasing competition, including lower-cost generic and biosimilar products for drugs other than Keytruda, which can lead to a loss of market share and revenue. Additionally, the pharmaceutical industry is subject to evolving and often more stringent regulatory requirements regarding drug pricing and reimbursement. These external pressures can impact Merck's pricing power, market share, and overall financial performance across its product portfolio.

Merck (MRK) operates in several significant addressable markets with its diverse portfolio of pharmaceutical products and services. The market sizes for some of its main products are outlined below.

Key Products and Addressable Markets:

• Keytruda (Pembrolizumab):
• The global market size for Keytruda is estimated at approximately $28.62 billion in 2025 and is projected to reach $33.08 billion by 2030, growing at a CAGR of 2.94% during this period.
• Other estimates for global Keytruda market size include $31 billion in projected global sales by 2025 and $32.2 billion in full-year 2025 sales.
• North America holds a substantial share of the global Keytruda market, accounting for 38.0%. The U.S. market specifically dominates the North American region.
• Gardasil (HPV Vaccine):
• The global Gardasil (HPV vaccine) market size is estimated at $6 billion in 2025 and is projected to exceed $8 billion by 2033, with a Compound Annual Growth Rate (CAGR) of 5% from 2019 to 2033.
• Another estimate for the global Gardasil market size was approximately $4.86 billion in 2024 and is projected to reach around $11.69 billion by 2034, with a CAGR of roughly 11.60% between 2025 and 2034.
• The global Human Papillomavirus Vaccine market size was $4.32 billion in 2024. North America held over 40% of this global revenue, with a market size of $1.73 billion in 2024.
• Januvia/Janumet (Sitagliptin/Sitagliptin and Metformin):
• The global diabetes care market, which includes Januvia/Janumet, is projected to reach approximately $128 billion by 2025.
• Januvia commands approximately 25-30% of the global DPP-4 inhibitor market share. Forecasts suggest potential global annual sales for Januvia of $4.8 billion - $5.3 billion by 2025-2026.
• Janumet holds the highest market share, about 37.4%, in the Combination Anti-Diabetes Drugs Market.
• Bridion (Sugammadex):
• Merck's global sales for Bridion were $439 million in Q3 2025. No specific addressable market size was provided in the search results beyond sales figures.
• Welireg:
• Merck's global sales for Welireg were $196 million in Q3 2025. No specific addressable market size was provided in the search results beyond sales figures.
• Winrevair:
• Merck's global sales for Winrevair were $360 million in Q3 2025. No specific addressable market size was provided in the search results beyond sales figures.
• Animal Health Products:
• Merck's Animal Health business reported global sales of $1.6 billion in Q2 2025, representing an 11% growth. No specific addressable market size was provided in the search results beyond sales figures.
• Vaxneuvance (Pneumococcal Vaccine, previously Capvaxive):
• Global sales for "Pepvexib" (likely referring to Vaxneuvance) were $244 million in Q3 2025. Capvaxive recorded sales of $236 million in the first half of 2025. No specific addressable market size was provided in the search results beyond sales figures.
• M-M-R II, Varivax, and ProQuad (Measles, Mumps, Rubella, and Varicella Vaccines):
• The global measles, mumps, rubella vaccine market size was estimated at $1.82 billion in 2024 and is expected to reach $2.95 billion by 2030, growing at a CAGR of 8.47% from 2025 to 2030. North America was the largest region in the M-M-R II market as of 2024.
• The global varicella vaccine market was valued at $3.4 billion in 2024 and is expected to grow from $3.5 billion in 2025 to $6.3 billion by 2034, at a CAGR of 6.5%. The North America varicella vaccine market dominated the global market with a share of 39.1% in 2024, and the U.S. market alone was valued at $1.21 billion in 2024.
• Isentress/Pifeltro (HIV Drugs):
• The global anti-HIV drugs market size was valued at $30.27 billion in 2024 and is projected to reach $52.01 billion by 2033, growing at a CAGR of 6.2% during the forecast period (2025-2033).
• Another estimate for the global HIV drugs market size was $36.22 billion in 2024 and is projected to hit around $66.16 billion by 2034, growing at a CAGR of 6.21% (2025-2034). The Americas dominated the HIV drugs market with the highest market share of 46% in 2024. The U.S. HIV drugs market size was $12.5 billion in 2024 and is projected to be worth around $23.23 billion by 2034. No specific addressable market size was provided for Isentress/Pifeltro alone.

Merck (MRK) is expected to drive future revenue growth over the next two to three years through a combination of existing product expansion, the rapid uptake of recently launched therapies, and strategic pipeline diversification. The following are 3-5 expected drivers:

1. Continued Expansion and New Indications for Keytruda: Keytruda remains a significant revenue driver for Merck. Its continued growth is anticipated through the expansion into earlier-stage cancer indications and the launch and adoption of its subcutaneous formulation, Keytruda Qlex. In the third quarter of 2025, Keytruda sales increased by 8% to $8.1 billion, driven by strong demand in metastatic indications and robust uptake in earlier-stage cancers. Merck is also running numerous Phase 3 trials for Keytruda in early-stage diseases, aiming to double its approved U.S. indications and potentially generate 25%-30% of its total revenue from early-phase settings by 2025. The recent FDA approval and launch of Keytruda Qlex are expected to further bolster Merck's bottom line.
2. Rapid Uptake and Label Expansion of Winrevair: Winrevair (sotatercept), a treatment for Pulmonary Arterial Hypertension (PAH), is poised for substantial revenue growth. Analysts project Winrevair to achieve strong uptake in 2025 and contribute significantly to sales, with forecasts reaching $1.5 billion in 2025 and potentially $5 billion by 2030. The drug is experiencing rapid adoption in Class II/III PAH patients due to the unmet need in the current standard of care. Positive data from the Phase 3 HYPERION trial in recently diagnosed PAH patients is expected to further accelerate its adoption, and Merck is pursuing label expansion into additional patient populations with ongoing Phase 3 trials. Winrevair sales increased by 141% to $360 million in the third quarter of 2025.
3. Successful Launch and Increasing Market Penetration of New Vaccines: Merck's new vaccine offerings, particularly Capvaxive (pneumococcal vaccine for adults) and Enflonsia (RSV antibody drug), are expected to contribute to future revenue growth. Capvaxive had a "very strong start," generating $244 million in sales in the third quarter of 2025, up from $129 million in the second quarter, and has a peak sales potential exceeding $2 billion. Enflonsia has also shown initial stocking sales, reflecting anticipated demand. Merck's management anticipates mid-to-high single-digit growth in its business outside of GARDASIL China in 2025, driven by the momentum from these new product launches.
4. Growth of Welireg in Renal Cell Carcinoma Combinations: Welireg, a treatment for certain tumors, is showing promising growth, particularly with its expanded indications in kidney cancer. Welireg sales more than doubled in 2024. In the third quarter of 2025, Welireg sales increased by 41% to $196 million, driven by increased use in previously treated advanced renal cell carcinoma in the U.S. and ongoing international launches. Recent Phase 3 trial successes for Welireg in combination with Keytruda in post-surgery clear cell renal cell carcinoma are expected to significantly boost its revenue contribution and inspire investor confidence beyond Keytruda's exclusivity period.
5. Strategic Diversification of the Pipeline: Merck is actively diversifying its pipeline beyond its core oncology focus, aiming to mitigate the impact of Keytruda's patent expiry. The company is investing heavily in general and specialty medicine, with a particular focus on cardiometabolic, immunology, neuroscience, and ophthalmology. Merck anticipates seven potential approvals from its cardiometabolic pipeline alone by 2030, with a peak revenue potential of over $15 billion by the mid-2030s. Recent acquisitions, such as EyeBio (ophthalmology), Prometheus Biosciences (immunology), and Caraway Therapeutics (neuroscience), along with a move into the GLP-1 space, underscore this strategic shift to expand its therapeutic areas. This diversification strategy aims to build a strong foundation for sustainable growth by introducing new products and expanding into new markets.

Share Repurchases

• In January 2025, Merck's board of directors authorized a new share repurchase program worth $10 billion, with no set expiration date.
• Merck repurchased approximately $1.306 billion in shares during 2024.
• Approximately $1.346 billion in shares were repurchased in 2023.

Outbound Investments

• Merck acquired Verona Pharma in July 2025 for $10 billion, a company focused on developing drugs for respiratory diseases.
• In April 2023, Merck acquired Prometheus Biosciences for $10.8 billion, a company specializing in precision medicine for immune-mediated diseases.
• Merck completed the acquisition of Acceleron Pharma for $11.5 billion in September 2021, focusing on therapies for rare diseases and pulmonary arterial hypertension.

Capital Expenditures

• Merck plans to invest approximately $21 billion in capital investments over the five-year period from 2025 to 2029, with over $11 billion allocated to the U.S., primarily for expanding manufacturing capacity in Oncology, Vaccines, and Animal Health.
• From 2020-2024, the company planned to invest more than $20 billion in new capital projects, mainly aimed at increasing manufacturing capacity for key products.
• In 2024, Merck made strategic investments in production and research and development, including €290 million for a biosafety testing facility in Rockville, Maryland, and €70 million for the expansion of ADC manufacturing capabilities in St. Louis, Missouri.