NYSE: MRK

All product or service marks appearing in type form different from that of the surrounding text are trademarks or service marks owned, licensed to, promoted or distributed by Merck, its subsidiaries or affiliates, except as noted. All other trademarks or service marks are those of their respective owners.

Product Sales

Total Company sales, including sales of the Company’s top pharmaceutical products, as well as sales of animal health products, were as follows:

($ in millions)202520242023

Total Sales$65,011 $64,168 $60,115

Pharmaceutical58,142 57,400 53,583

Keytruda/Keytruda Qlex
31,680 29,482 25,011

Gardasil/Gardasil 9
5,233 8,583 8,886

Januvia/Janumet2,544 2,268 3,366

ProQuad/M-M-R II/Varivax
2,451 2,485 2,368

Bridion1,841 1,764 1,842

Alliance revenue - Lynparza(1)
1,450 1,311 1,199

Winrevair
1,443 419 —

Alliance revenue - Lenvima(1)
1,053 1,010 960

Prevymis
978 785 605

Vaxneuvance
825 808 665

Capvaxive
759 97 —

Welireg
716 509 218

Animal Health6,354 5,877 5,625

Livestock3,896 3,462 3,337

Companion Animal
2,458 2,415 2,288

Other Revenues(2)
515 891 907

(1)Alliance revenue represents Merck’s share of profits, which are product sales net of cost of sales and commercialization costs.

(2)Other revenues are primarily comprised of miscellaneous corporate revenues, including revenue hedging activities, as well as revenue from third-party manufacturing arrangements.

Pharmaceutical

The Pharmaceutical segment includes human health pharmaceutical and vaccine products. Human health pharmaceutical products consist of therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. Human health vaccine products consist of preventive pediatric, adolescent and adult vaccines. Certain of the products within the Company’s franchises are as follows:

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Oncology

Keytruda (pembrolizumab) is an anti-PD-1 (programmed death receptor-1) therapy available for intravenous administration that has been approved as monotherapy for the treatment of certain patients with cervical cancer, classical Hodgkin lymphoma (cHL), cutaneous squamous cell carcinoma, esophageal or gastroesophageal junction (GEJ) carcinoma, head and neck squamous cell carcinoma (HNSCC), hepatocellular carcinoma (HCC), melanoma, Merkel cell carcinoma, microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors (including MSI-H/dMMR colorectal cancer and endometrial carcinoma), non-small cell lung cancer (NSCLC), primary mediastinal large B-cell lymphoma (PMBCL), tumor mutational burden-high (TMB-H) solid tumors, and urothelial cancer including non-muscle invasive bladder cancer. Keytruda is also approved as monotherapy for the adjuvant treatment of certain patients with melanoma, and for certain patients with renal cell carcinoma (RCC) post-surgery. Keytruda is approved for adjuvant treatment following resection and platinum-based chemotherapy for certain patients with NSCLC.

Additionally, in perioperative settings, Keytruda is approved for patients with certain types of resectable NSCLC in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery; for certain patients with high-risk early stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery; for certain patients with resectable locally advanced HNSCC as a single agent as neoadjuvant treatment, continued as adjuvant treatment in combination with radiotherapy with or without cisplatin chemotherapy and then as a single agent; and for certain patients with muscle invasive bladder cancer (MIBC), in combination with enfortumab vedotin, as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment.

In addition, Keytruda is approved in combination with chemotherapy for the treatment of certain patients with advanced NSCLC, advanced malignant pleural mesothelioma, HNSCC, advanced biliary tract cancer, advanced esophageal cancer, advanced TNBC, and advanced or recurrent endometrial carcinoma; in combination with chemotherapy with or without bevacizumab, and in combination with chemoradiotherapy, for the treatment of certain patients with advanced cervical cancer; in combination with trastuzumab and chemotherapy for the treatment of certain patients with advanced human epidermal growth factor receptor 2 (HER2)-positive gastric or GEJ adenocarcinoma, and in combination with chemotherapy for the treatment of certain patients with advanced HER2-negative gastric or GEJ adenocarcinoma; in combination with axitinib for the treatment of certain patients with advanced RCC; in combination with Lenvima (lenvatinib) for the treatment of certain patients with advanced RCC or advanced endometrial carcinoma; in combination with enfortumab vedotin for certain patients with locally advanced or metastatic urothelial cancer; and in combination with chemotherapy with or without bevacizumab for certain patients with platinum-resistant ovarian cancer.

Keytruda Qlex (pembrolizumab and berahyaluronidase alfa-pmph) is a subcutaneously-administered fixed combination of pembrolizumab, an anti-PD-1 therapy, and berahyaluronidase alfa, which enhances dispersion and permeability to enable subcutaneous administration of pembrolizumab. Keytruda Qlex is approved in the U.S. in solid tumor indications approved for Keytruda. In some markets, it is approved as a new subcutaneous route of administration and new pharmaceutical form of Keytruda and is marketed as Keytruda SC.

Welireg (belzutifan) is a medication for the treatment of adult patients with certain von Hippel-Lindau (VHL) disease-associated tumors not requiring immediate surgery, for the treatment of adult patients with advanced RCC following a PD-1 or programmed death-ligand 1 (PD-L1) inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (TKI) and for treatment of adult and pediatric patients 12 years and older with certain types of pheochromocytoma or paraganglioma.

In addition, the Company recognizes alliance revenue related to sales of Lynparza (olaparib), an oral poly (ADP-ribose) polymerase (PARP) inhibitor, for certain types of advanced or recurrent ovarian, early or metastatic breast, metastatic pancreatic, and metastatic castration-resistant prostate cancers; alliance revenue related to sales of Lenvima, an oral receptor TKI, for certain types of thyroid cancer, RCC, HCC, in combination with everolimus for certain patients with advanced RCC, and in combination with Keytruda for certain patients with advanced endometrial carcinoma or advanced RCC; and alliance revenue related to Reblozyl (luspatercept-aamt) for the treatment of certain types of anemia.

Vaccines

Gardasil (Human Papillomavirus Quadrivalent [Types 6, 11, 16 and 18] Vaccine, Recombinant)/Gardasil 9 (Human Papillomavirus 9-valent Vaccine, Recombinant), vaccines to help prevent certain cancers and diseases caused by certain types of human papillomavirus (HPV); ProQuad (Measles, Mumps, Rubella and Varicella Virus Vaccine Live), a pediatric combination vaccine to help protect against measles, mumps, rubella and varicella; M−M−R II (Measles, Mumps and Rubella Virus Vaccine Live), a vaccine to help prevent measles, mumps and rubella; Varivax

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(Varicella Virus Vaccine Live), a vaccine to help prevent chickenpox (varicella); Vaxneuvance (Pneumococcal 15-valent Conjugate Vaccine), a vaccine to help prevent invasive pneumococcal disease in individuals 6 weeks of age and older; RotaTeq (Rotavirus Vaccine, Live Oral, Pentavalent), a vaccine to help protect against rotavirus gastroenteritis in infants and children; Capvaxive (Pneumococcal 21-valent Conjugate Vaccine), a vaccine to help prevent invasive pneumococcal disease and pneumococcal pneumonia in adults; Enflonsia (clesrovimab-cfor), a long acting monoclonal antibody for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season; and Pneumovax 23 (pneumococcal vaccine polyvalent), a vaccine to help prevent pneumococcal disease.

Hospital Acute Care

Bridion (sugammadex), a medication for the reversal of two types of neuromuscular blocking agents used during surgery; Prevymis (letermovir) for the prophylaxis of cytomegalovirus (CMV) infection and disease, or of CMV disease, in certain high risk adult and pediatric recipients of an allogeneic hematopoietic stem cell transplant or of a kidney transplant, respectively; Zerbaxa (ceftolozane and tazobactam) for injection, a combination antibacterial and beta-lactamase inhibitor for the treatment of certain bacterial infections; and Dificid (fidaxomicin) for the treatment of C. difficile-associated diarrhea.

Cardiometabolic and Respiratory

Winrevair (sotatercept-csrk), an activin signaling inhibitor indicated for the treatment of adults with pulmonary arterial hypertension (PAH, Group 1 pulmonary hypertension) to improve exercise capacity and World Health Organization (WHO) functional class (FC), and reduce the risk of clinical worsening events including hospitalization for PAH, lung transplantation and death; Adempas (riociguat), a cardiovascular drug for the treatment of chronic thromboembolic pulmonary hypertension or PAH in certain patients; Verquvo (vericiguat), a medicine to reduce the risk of cardiovascular death and heart failure hospitalization following a hospitalization for heart failure or need for outpatient intravenous diuretics in certain adults with symptomatic chronic heart failure and reduced ejection fraction; and Ohtuvayre (ensifentrine), an inhaled PDE3/4 inhibitor indicated for the maintenance treatment of chronic obstructive pulmonary disease (COPD) in adults.

Virology

Lagevrio (molnupiravir), an investigational oral antiviral COVID-19 medicine available in the U.S. under Emergency Use Authorization; Isentress/Isentress HD (raltegravir), a human immunodeficiency virus (HIV) integrase inhibitor for use in combination with other antiretroviral agents for the treatment of HIV-1 infection; Delstrigo (doravirine/lamivudine/tenofovir disoproxil fumarate), a complete regimen for the treatment of HIV-1 infection in adult patients with no prior antiretroviral treatment history or to replace the current antiretroviral regime in certain patients who are virologically suppressed on a stable antiretroviral regimen; and Pifeltro (doravirine), a non-nucleoside reverse transcriptase inhibitor for use in combination with other antiretroviral agents for the treatment of HIV-1 infection in adult patients with no prior antiretroviral treatment history or to replace the current antiretroviral regime in certain patients who are virologically suppressed on a stable antiretroviral regimen.

Neuroscience

Belsomra (suvorexant), an orexin receptor antagonist, indicated for the treatment of insomnia, characterized by difficulties with sleep onset and/or sleep maintenance.

Diabetes

Januvia (sitagliptin) and Janumet (sitagliptin/metformin HCl) for the treatment of type 2 diabetes.

Animal Health

The Animal Health segment discovers, develops, manufactures and markets a wide range of veterinary pharmaceuticals, vaccines and health management solutions and services, as well as an extensive suite of digitally connected identification, traceability and monitoring products. Principal products in this segment include:

Livestock Products

Nuflor (Florfenicol) antibiotic range for use in cattle and swine; Bovilis/Vista vaccine lines for infectious diseases in cattle, including Bovilis Cryptium for protection against Cryptosporidium parvum; Banamine (Flunixin meglumine) bovine and swine anti-inflammatory; Estrumate (cloprostenol sodium) for the treatment of fertility disorders in cattle; Matrix (altrenogest) fertility management for swine; Resflor (florfenicol and flunixin meglumine), a combination broad-spectrum antibiotic and non-steroidal anti-inflammatory drug for bovine respiratory disease; Zuprevo (tildipirosin) for bovine respiratory disease; Revalor (trenbolone acetate and estradiol) to improve production efficiencies in beef cattle; Safe-Guard (fenbendazole) de-wormer for cattle; M+Pac (Mycoplasma Hyopneumoniae Bacterin) swine pneumonia vaccine; Porcilis (Lawsonia intracellularis baterin) and Circumvent (Porcine Circovirus Vaccine, Type 2, Killed Baculovirus Vector) vaccine lines for infectious diseases in swine; Nobilis/Innovax (Live

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Marek’s Disease Vector), vaccine lines for poultry; Paracox and Coccivac coccidiosis vaccines; Exzolt (fluralaner), a systemic treatment for poultry red mite and northern foul mite infestations; Exzolt 5% (fluralaner), for treatment and prevention of ticks, lice, horn flies and New World Screwworm on cattle; Slice (emamectin benzoate) parasiticide and Imvixa (lufenuron) for sea lice control in salmon; Clynav vaccine for protection against pancreas disease in salmon; Aquavac (Avirulent Live Culture)/Norvax vaccines against bacterial and viral disease in fish; Aquaflor (florfenicol) antibiotic for farm-raised fish; Flexolt (fluralaner) against lice in sheep; and Allflex Livestock Intelligence solutions for animal identification, monitoring and traceability.

Companion Animal Products

Bravecto, a line of oral, topical and injectable parasitic control products, including the original Bravecto (fluralaner) products for dogs and cats that last up to 12 weeks; Bravecto (fluralaner) One-Month, a monthly product for dogs, Bravecto (fluralaner) Injectable/Quantum, an injectable product for dogs that lasts up to one-year, Bravecto TriUNO (fluralaner/moxidectin/pyrantel), a one month dog product that covers internal and external parasites, and Bravecto Plus (fluralaner/moxidectin), a two-month product for cats; Sentinel, a line of oral parasitic products for dogs including Sentinel Spectrum (milbemycin oxime, lufenuron, and praziquantel) and Sentinel Flavor Tabs (milbemycin oxime, lufenuron); Numelvi (atinvicitinib), a once daily second-generation Janus kinase inhibitor for the treatment of pruritus associated with allergic dermatitis; Optimmune (cyclosporine), an ophthalmic ointment; Nobivac vaccine lines for flexible dog and cat vaccination, including Nobivac NXT for canine flu and feline leukemia virus; Gilvetmab, an immune checkpoint inhibitor monoclonal antibody conditionally licensed for melanoma and mastocytoma tumors; Otomax (gentamicin sulfate, USP; Betamethasone valerate USP; and Clotrimazole USP ointment)/Mometamax (gentamicin sulfate, USP, Mometasone Furoate Monohydrate and Clotrimazole, USP, Otic Suspension)/Mometamax Ultra (gentamicin sulfate, mometasone furoate monohydrate and posaconazole suspension)/Posatex (orbifloxacin, mometasone furoate monohydrate and posaconazole, suspension) ear ointments for acute and chronic otitis; Caninsulin/Vetsulin (porcine insulin zinc suspension) diabetes mellitus treatment for dogs and cats; Panacur (fenbendazole)/Safeguard (fenbendazole) broad-spectrum anthelmintic (de-wormer) for use in many animals; Regumate (altrenogest) fertility management for horses; Prestige vaccine line for horses; Scalibor (Deltamethrin)/Exspot for protecting against bites from fleas, ticks, mosquitoes and sandflies; and Sure Petcare products for companion animal identification and well-being, including the microchip and pet recovery system Home Again.

For a further discussion of sales of the Company’s products, see Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations” below.

Product Approvals

Set forth below is a summary of significant product approvals received by the Company in 2025 and, to date, in 2026.

ProductDateApproval

Keytruda

January 2025

China’s National Medical Products Administration (NMPA) approval in combination with enfortumab vedotin, an antibody-drug conjugate (ADC), for the treatment of adults with locally advanced or metastatic urothelial carcinoma, based on the KEYNOTE-A39 trial that was conducted in collaboration with Seagen (now Pfizer Inc., Pfizer) and Astellas.

April 2025

European Commission (EC) approval in combination with pemetrexed and platinum chemotherapy for the first-line treatment of adult patients with unresectable non epithelioid malignant pleural mesothelioma, based on the IND.227/KEYNOTE-483 trial.

May 2025

Japan’s Ministry of Health, Labor and Welfare (MHLW) approval in combination with trastuzumab and chemotherapy for the first-line treatment of patients with unresectable, advanced or recurrent HER2-positive gastric or GEJ adenocarcinoma, based on the KEYNOTE-811 trial.

May 2025
Japan’s MHLW approval in combination with pemetrexed and platinum chemotherapy for unresectable, advanced or recurrent metastatic malignant pleural mesothelioma, based on the IND.227/KEYNOTE-483 trial.

June 2025

U.S. Food and Drug Administration (FDA) approval for the treatment of adult patients with resectable locally advanced HNSCC whose tumors express PD-L1 Combined Positive Score (CPS) ≥ 1 as determined by an FDA-approved test, as a single agent as neoadjuvant treatment, continued as adjuvant treatment in combination with radiotherapy with or without cisplatin and then as a single agent, based on the KEYNOTE-689 trial.

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Keytruda

June 2025

China’s NMPA approval of Keytruda plus Lenvima in combination with transarterial chemoembolization for the treatment of patients with unresectable, non-metastatic HCC, based on the LEAP-012 clinical trial.

October 2025

EC approval as monotherapy for the treatment of resectable locally advanced HNSCC as neoadjuvant treatment, continued as adjuvant treatment in combination with radiation therapy with or without concomitant cisplatin and then as monotherapy in adults whose tumors express PD-L1 with a CPS ≥ 1, based on the KEYNOTE-689 trial.

November 2025

FDA approval in combination with Padcev (enfortumab vedotin-ejfv) as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment, for the treatment of adult patients with MIBC who are ineligible for cisplatin-based chemotherapy, based on the KEYNOTE-905 trial conducted in collaboration with Pfizer and Astellas.

February 2026

China’s NMPA approval for the first-line treatment of certain patients with primary advanced or recurrent endometrial cancer, based on the KEYNOTE-868 (NRG-GY018) trial.

February 2026

FDA approval in combination with paclitaxel, with or without bevacizumab, for the treatment of adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS ≥ 1) as determined by an FDA-authorized test, and who have received one or two prior systemic treatment regimens, based on the KEYNOTE-B96 trial.

February 2026

Japan’s MHLW approval for neoadjuvant and adjuvant treatment of locally advanced HNSCC, based on the KEYNOTE-689 trial.

Keytruda Qlex(1)

September 2025

FDA approval across most adult solid tumor indications for Keytruda.

October 2025

FDA approval for the treatment of adult patients with resectable locally advanced HNSCC whose tumors express PD-L1 CPS ≥ 1 as determined by an FDA-approved test, as a single agent as neoadjuvant treatment, continued as adjuvant treatment in combination with radiotherapy with or without cisplatin and then as a single agent, based on the KEYNOTE-689 trial.

November 2025

EC approval of new subcutaneous route of administration and a new pharmaceutical form of Keytruda for all adult indications approved in the European Union (to be marketed as Keytruda SC).

November 2025

FDA approval in combination with Padcev as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment, for the treatment of adult patients with MIBC who are ineligible for cisplatin-based chemotherapy, based on the KEYNOTE-905 trial conducted in collaboration with Pfizer and Astellas.

February 2026

FDA approval in combination with paclitaxel, with or without bevacizumab, for the treatment of adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS ≥ 1) as determined by an FDA-authorized test, and who have received one or two prior systemic treatment regimens, based on the KEYNOTE-B96 trial.

Capvaxive

March 2025

EC approval for the prevention of invasive pneumococcal disease and pneumococcal pneumonia caused by certain serotypes in individuals 18 years of age and older.

August 2025

Japan’s MHLW approval for the prevention of invasive pneumococcal disease and pneumococcal pneumonia caused by certain serotypes in individuals 18 years of age and older.

Enflonsia

June 2025

FDA approval for the prevention of RSV lower respiratory tract disease in neonates (newborns) and infants who are born during or entering their first RSV season

Gardasil/Gardasil 9

January 2025

China’s NMPA approval of Gardasil for use in males 9-26 years of age to help prevent certain HPV-related cancers and diseases.

April 2025

China’s NMPA approval of Gardasil 9 for use in males 16-26 years of age to help prevent certain HPV-related cancers and diseases.

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Gardasil/Gardasil 9

August 2025

Japan’s MHLW approval of nine-valent HPV vaccine for use in males nine years of age and older (marketed as Silgard 9).

Lynparza(2)

January 2025

China’s NMPA approval for the adjuvant treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated, HER2-negative high-risk early breast cancer who have been previously treated with neoadjuvant or adjuvant chemotherapy, based on the OlympiA trial.

Welireg

February 2025

EC conditional approval as monotherapy for the treatment of adult patients with VHL disease who require therapy for associated, localized RCC, central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors, and for whom localized procedures are unsuitable, based on the LITESPARK-004 trial.

February 2025

EC conditional approval for the treatment of adult patients with advanced clear cell RCC that progressed following two or more lines of therapy that included a PD-1 or PD-L1 inhibitor and at least two vascular endothelial growth factor targeted therapies, based on the LITESPARK-005 trial.

May 2025
FDA approval for the treatment of adult and pediatric patients (12 years and older) with locally advanced, unresectable, or metastatic pheochromocytoma and paraganglioma, based on the LITESPARK-015 trial.

June 2025
Japan’s MHLW approval as monotherapy for the treatment of adult patients with VHL disease-associated tumors, based on the LITESPARK-004 trial.

June 2025
Japan’s MHLW approval for the treatment of adults with radically unresectable or metastatic RCC that has progressed after chemotherapy, based on the LITESPARK-005 trial.

Winrevair

June 2025

Japan’s MHLW approval for the treatment of adults with PAH, based on the STELLAR trial (marketed as Airwin).

October 2025

FDA approval of expanded indication in adults with PAH (WHO Group 1 pulmonary hypertension) to improve exercise capacity and WHO FC, and reduce the risk of clinical worsening events, including hospitalization for PAH, lung transplantation and death, based on the ZENITH trial.

January 2026

EC approval of expanded indication in combination with other PAH therapies for the treatment of PAH in adult patients with WHO FC II, III and IV, based on the ZENITH trial.

Bravecto Quantum
July 2025
FDA approval for flea and tick treatment and protection in dogs using a once-yearly injectable form of Bravecto.

Numelvi

July 2025

EC approval of tablets for dogs for the treatment of pruritus associated with allergic dermatitis including atopic dermatitis and treatment of clinical manifestations of atopic dermatitis.

(1) Keytruda Qlex is available in some markets as Keytruda SC.

(2) Being jointly developed and commercialized in a worldwide collaboration with AstraZeneca.

Competition and the Health Care Environment

Competition

The markets in which the Company conducts its business and the pharmaceutical industry in general are highly competitive and highly regulated. The Company’s competitors include other worldwide research-based pharmaceutical companies, smaller research companies with more limited therapeutic focus, generic drug manufacturers, and animal health care companies. The Company’s operations may be adversely affected by generic and biosimilar competition as the Company’s products mature, as well as technological advances of competitors, industry consolidation, patents granted to competitors, competitive combination products, new products of competitors, the availability of generic or biosimilar versions of competitors’ branded products, and new information from clinical trials of marketed products or post-marketing surveillance. In addition, patent rights are increasingly being challenged by competitors, and the outcome can be highly uncertain. An adverse result in a patent dispute can preclude commercialization of products or negatively affect sales of existing products and could result in the payment of royalties or in the recognition of an impairment charge with respect to intangible assets associated with certain products.

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Pharmaceutical competition involves a rigorous search for technological innovations and the ability to market these innovations effectively. With its long-standing emphasis on research and development, the Company is well-positioned to compete in the search for technological innovations. The Company is active in acquiring and marketing products through external alliances, such as licensing arrangements and collaborations, and has been refining its sales and marketing efforts to address changing industry conditions. However, the introduction of new products and processes by competitors may result in price reductions and product displacements, even for products protected by patents. For example, the number of compounds available to treat a particular disease typically increases over time and can result in slowed sales growth or reduced sales of the Company’s products in that therapeutic category.

The highly competitive animal health business is affected by several factors including regulatory and legislative issues, scientific and technological advances, product innovation, the quality and price of the Company’s products as well as competitors’ products, effective promotional efforts and the frequent introduction of generic products by competitors.

Health Care Environment and Government Regulation

Global efforts toward health care cost containment continue to exert pressure on product pricing and market access. Changes to the U.S. health care system as part of health care reform, as well as increased purchasing power of entities that negotiate on behalf of Medicare, Medicaid, and private sector beneficiaries, have contributed to pricing pressure. In several international markets, government-mandated pricing actions have reduced prices of generic and patented drugs. In addition, the Company’s sales performance in 2025 was negatively affected by other cost-reduction measures taken by governments and other third parties to lower health care costs. In the U.S., the Executive Branch and Congress continue to discuss legislation designed to control health care costs, including the cost of drugs. The Company anticipates all of these actions and additional actions in the future will continue to negatively affect sales and profits.

In addressing global cost containment pressures, the Company engages in public policy advocacy with policymakers and continues to work to demonstrate that its medicines and vaccines provide value to patients and to those who pay for health care. The Company advocates with government policymakers to encourage a long-term approach to sustainable health care financing that ensures access to innovative medicines and does not disproportionately target pharmaceuticals as a source of budget savings. In markets with historically low rates of health care spending, the Company encourages those governments to increase their investments and adopt market reforms in order to improve their citizens’ access to appropriate health care, including medicines and vaccines.

Operating conditions have become more challenging under the global pressures of competition, industry regulation and cost containment efforts. Although no one can predict the effect of these and other factors on the Company’s business, the Company continually takes measures to evaluate, adapt and improve the organization and its business practices to better meet customer needs and believes that it is well-positioned to respond to the evolving health care environment and market forces.

United States

The Company faces increasing pricing pressure from managed care organizations, government agencies and programs that could negatively affect the Company’s sales and profit margins, including, through (i) practices of managed care organizations, federal and state exchanges, and institutional and governmental purchasers, and (ii) federal laws and regulations related to Medicare and Medicaid, including the Medicare Prescription Drug, Improvement, and Modernization Act of 2003, the Patient Protection and Affordable Care Act of 2010 (ACA), the American Rescue Plan Act of 2021 (American Rescue Plan Act), and the Inflation Reduction Act of 2022 (IRA). Additionally, increased utilization of the 340B Federal Drug Discount Program and restrictions on the Company’s ability to identify inappropriate discounts are having a negative impact on Company performance.

In the U.S., federal and state governments for many years have pursued methods to reduce the cost of drugs and vaccines for which they pay. For example, federal and state laws require the Company to pay specified rebates for medicines reimbursed by Medicaid and to provide discounts for medicines purchased by certain state and federal entities such as the Department of Defense, Veterans Affairs, Public Health Service entities and hospitals serving a disproportionate share of low income or uninsured patients.

In May 2025, the U.S. presidential administration issued an executive order intended to encourage or impose the use of “most-favored-nation” pricing to tie U.S. prescription drug prices to prices in selected comparably developed nations. In July 2025, the Company and other pharmaceutical companies received letters from the U.S. presidential administration with a request to agree to the administration’s “most-favored-nation” drug pricing goals by September 29, 2025. Further to the letter received from the administration, on December 19, 2025, the Company announced that it had entered into a three-year agreement (the MFN Agreement) with the U.S government that

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addressed the four policy goals of the administration’s July letter. Included within the MFN Agreement is an obligation by the Company to provide key products through a direct-to-patient program at affordable prices for eligible patients in the U.S. This will initially include Januvia, Janumet and Janumet XR, and will be expanded in the future to include enlicitide decanoate pending FDA approval. The Company also agreed to offer its existing medicines at discounted prices to Medicaid, excluding certain products. The Company has also agreed that products launched during the term of the MFN Agreement (with certain exceptions) will be subject to “most-favored-nation” pricing in reference to prices for such products in a specified group of countries (MFN Countries). Finally, the Company agreed to repatriate and share with the Federal government a portion of foreign revenue received by the Company as a result of the government’s successful trade policy efforts. Additionally, the Company reached an agreement with the U.S. Department of Commerce to delay Section 232 tariffs for three years, enabling the Company to make investments in the U.S. to reshore manufacturing for American patients.

In September 2025, the Advisory Committee on Immunization Practices (ACIP) of the U.S. Centers for Disease Control and Prevention (CDC) voted to recommend that children under the age of four years receive protection from chickenpox (varicella) as a standalone immunization rather than in combination with measles, mumps, and rubella (MMR) vaccination, eliminating a previous shared clinical decision-making recommendation that allowed parents to choose combined MMR and varicella vaccine (MMRV) first-dose administration. The ACIP also voted to align the Vaccines for Children (VFC) program with this change. The acting CDC Director adopted the recommendation in October 2025. MMR and varicella vaccines remain recommended and funded through the VFC program for both the first and second doses. The Company is the only manufacturer in the U.S. of MMRV vaccine (ProQuad) and varicella vaccine (Varivax). The Company anticipates that any negative effect of these recommendations on sales of ProQuad will not be material.

In December 2025, the CDC ended the universal birth-dose recommendation for hepatitis B vaccination, adopting an ACIP recommendation. For infants born to mothers who test negative for hepatitis B, vaccination is now based on individual decision-making, with the first dose recommended no earlier than 2 months of age. For infants born to mothers who are hepatitis B–positive or whose status is unknown, the CDC continues to recommend a birth dose of hepatitis B vaccine. The Company manufactures a hepatitis B vaccine (Recombivax HB, Hepatitis B Vaccine [Recombinant]) and, subject to a collaboration agreement with Sanofi Pasteur MSD, co-promotes a hexavalent vaccine that includes a hepatitis B component (Vaxelis, Diphtheria and Tetanus Toxoids and Acellular Pertussis, Inactivated Poliovirus, Haemophilus b Conjugate and Hepatitis B Vaccine). The Company anticipates that any negative effect of these recommendations on sales of Recombivax HB and Vaxelis will not be material.

In January 2026, the acting CDC Director announced changes to the child and adolescent immunization schedule (January announcement), reducing the number of routinely recommended vaccinations and creating three new categories: immunizations recommended for all children; immunizations recommended for certain high-risk groups or populations; and immunizations based on shared clinical decision-making. Immunizations recommended for all children include vaccines for measles, mumps, rubella, polio, pertussis, tetanus, diphtheria, Haemophilus influenzae type B (Hib), pneumococcal disease, HPV, and varicella. Immunizations recommended for certain high-risk groups or populations include RSV, hepatitis A, hepatitis B, and dengue. Immunizations recommended based on shared clinical decision-making include rotavirus, hepatitis A, and hepatitis B. The January announcement is the subject of litigation by third parties. The U.S. Department of Health and Human Services (HHS) has stated that immunizations for all of the diseases covered by the previous immunization schedule will still be available to anyone who wants them through Affordable Care Act insurance plans and federal insurance programs, including Medicaid, the Children’s Health Insurance Program, and the VFC program. Additionally, in September 2025, the trade association representing U.S. health insurers (AHIP) announced that its member health plans would continue to cover all immunizations that had been recommended by the CDC’s ACIP as of September 1, 2025, with no cost-sharing for patients through the end of 2026.

Among the changes in the January announcement was a reduction of the recommended doses for HPV vaccination of adolescents to a single dose. Gardasil 9 is currently indicated in the U.S. for a two-dose regimen in adolescents aged 9-14 and a three-dose regimen for those aged 15-45. Previous CDC recommendations for adolescents followed FDA-approved dosing. Many countries outside the U.S. have implemented a reduced dosing schedule for HPV vaccination in certain age groups. The Company anticipates that any negative effect of these recommendations or reduced dosing schedules on sales of Gardasil/Gardasil 9 will not be material.

Additionally in the U.S., consolidation and integration among health care entities is a major factor in the competitive marketplace for pharmaceutical products. Health plans and pharmacy benefit managers have been consolidating into fewer, larger entities, thus enhancing their purchasing strength and importance. Private third-party insurers, as well as governments, employ formularies to control costs by negotiating discounted prices in exchange for formulary inclusion. Failure to obtain timely or adequate pricing or formulary placement for Merck’s products or obtaining such placement at unfavorable pricing could adversely affect revenue. In addition to formulary tier co-pay

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differentials, private health insurance companies and self-insured employers have been increasing the cost-sharing required from beneficiaries, particularly for branded pharmaceuticals and biotechnology products. Private health insurance companies, as well as governments, also are increasingly imposing utilization management tools, such as clinical protocols, requiring prior authorization for a branded product or requiring the patient to first fail on one or more generic products before permitting access to a branded medicine. These same management tools are also used in treatment areas in which the payer has taken the position that multiple branded products are therapeutically comparable. As the U.S. payer market concentrates further, the Company may face greater pricing pressure from private third-party payers.

Legislative Changes

In 2022, Congress passed the IRA, which made significant changes to how drugs are covered and paid for under the Medicare program, including the creation of financial penalties for drugs whose prices rise faster than the rate of inflation, redesign of the Medicare Part D program to require manufacturers to bear more of the liability for certain drug benefits, which has taken effect in 2025, and government price setting for certain Medicare Part D drugs, starting in 2026, and Medicare Part B drugs starting in 2028. Government price setting may also impact pricing in the private market negatively affecting the Company’s performance. HHS, through the Centers for Medicare & Medicaid Services (CMS), selected Januvia in 2023 for the first year of the IRA’s “Drug Price Negotiation Program” (Program), and selected Janumet and Janumet XR in 2025 for the second year of the Program. Pursuant to the IRA’s Program, the government set a price for Januvia, which became effective on January 1, 2026, and set a price for Janumet and Janumet XR, which will become effective on January 1, 2027. In addition, in January 2026, HHS announced that Lenvima has been selected for government price setting, the set price for which will become effective on January 1, 2028. Furthermore, the Company expects that Keytruda will be selected in 2027 for government price setting, which would become effective on January 1, 2029, and the Company expects that, as a result, U.S. sales of Keytruda will decline materially after that time. The Company has sued the U.S. government regarding the IRA’s Program (see Item 8 “Financial Statements and Supplementary Data,” Note 10. “Contingencies and Environmental Liabilities” below). Furthermore, the Executive Branch and Congress continue to discuss legislation designed to control health care costs, including the cost of drugs.

The long-term implications of the IRA remain uncertain and subject to various factors, including the manner in which HHS decides to implement the statute. Many experts and analysts, both within the industry and outside, have predicted that the law will harm innovation in the pharmaceutical industry and result in fewer new treatments being developed and approved over time. Merck is working to mitigate the potentially harmful effects that the law could have, which could include a detrimental impact on innovation.

In addition, in 2021, Congress passed the American Rescue Plan Act, which included a provision that eliminated the statutory cap on rebates drug manufacturers pay to Medicaid. These rebates act as a discount off the list price and eliminating the cap means that manufacturer discounts paid to Medicaid can increase. Prior to this change, manufacturers have not been required to pay more than 100% of the Average Manufacturer Price (AMP) in rebates to state Medicaid programs for Medicaid-covered drugs. As a result of this provision, manufacturers may have to pay state Medicaid programs more in rebates than they received on sales of particular products. This change presents a risk to Merck for drugs that have high Medicaid utilization and rebate exposure that is more than 100% of the AMP.

The Company also faces increasing pricing pressure in the states, which are looking to exert greater influence over the price of prescription drugs. A number of states have passed pharmaceutical price and cost transparency laws. These laws typically require manufacturers to report certain product price information or other financial data to the state. Some laws also require manufacturers to provide advance notification of price increases. The Company expects that states will continue their focus on pharmaceutical pricing and will increasingly shift to more aggressive price control tools such as Prescription Drug Affordability Boards that have the authority to conduct affordability reviews and establish upper payment limits and that Company products may be selected for such reviews. In addition, in 2024, the FDA authorized, for a two-year period, Florida’s application to import prescription drugs from Canada.

Regulatory Changes

The pharmaceutical industry also could be considered a potential source of savings via other legislative and administrative proposals that have been debated but not enacted. These types of revenue generating or cost saving proposals include additional direct price controls.

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European Union

Efforts toward health care cost containment remain intense in the European Union (EU). The Company faces competitive pricing pressure resulting from generic and biosimilar drugs. In addition, a majority of countries in the EU attempt to contain drug costs by engaging in reference pricing in which authorities examine pre-determined markets for published prices of drugs. Reference pricing may either compare a product’s prices in other markets (external reference pricing), or compare a product’s price with those of other products in a national class or group (internal reference pricing). The authorities then use the price data to set new local prices for brand-name drugs, including the Company’s drugs. Reference pricing mechanisms are usually set at the national level and can be changed pursuant to local regulations or guidance.

Some EU Member States have established free-pricing systems, but regulate the pricing for drugs through profit control plans. Others seek to negotiate or set prices based on the cost-effectiveness of a product or an assessment of whether it offers a therapeutic benefit over other products in the relevant class.

The downward pressure on health care costs in general, particularly prescription drugs, has become intense. As a result, increasingly high barriers are being erected to the entry of new products. In some EU Member States, cross-border imports from low-priced markets also exert competitive pressure that may reduce pricing within an EU Member State.

Additionally, EU Member States have the power to restrict the range of pharmaceutical products for which their national health insurance systems provide reimbursement. In the EU, pricing and reimbursement plans vary widely from Member State to Member State. Some EU Member States provide that drug products may be marketed only after a reimbursement price has been agreed. Some EU Member States may require the completion of additional studies that compare the cost-effectiveness of a particular product candidate to already available therapies or a so-called health technology assessment (HTA), in order to obtain reimbursement or pricing approval. The HTA of pharmaceutical products is becoming an increasingly common part of the pricing and reimbursement procedures in most EU Member States. The HTA process, which is currently governed by the national laws of these countries, involves the assessment of the cost-effectiveness, public health impact, therapeutic impact and/or the economic and social impact of use of a given pharmaceutical product in the national health care system of the individual country in which it is conducted. Ultimately, an HTA measures the added value of a new health technology compared to existing ones.

The EU Health Technology Assessment Regulation 2021/2282 (HTAR) now applies. This provides for the conduct of an EU level comparative Joint Clinical Assessment (JCA) of a new product versus relevant comparators identified by the EU Member States. JCAs will be carried out in parallel with the review of a marketing authorization application, so that a JCA report is available shortly after the product is authorized. The HTAR applies to all new active substance oncology products and advanced therapy medicinal products, including cell and gene therapies, beginning January 2025; to new active substance orphan medicinal products beginning January 2028; and to all products approved via the centralized procedure beginning in 2030.

EU Member States remain responsible for pricing and reimbursement decisions but must take “due consideration” of JCA reports when making national market access decisions. This means that EU Member State pricing and reimbursement processes are likely to evolve and more EU Member States may use HTAs as part of their decision-making.

The outcome of HTAs regarding specific pharmaceutical products will increasingly influence the pricing and reimbursement status granted to these pharmaceutical products by the market access authorities of individual EU Member States. A negative HTA of one of the Company’s products may mean that the product is not reimbursable or may force the Company to reduce its reimbursement price or offer discounts or rebates.

A negative HTA by a leading and recognized HTA body could also undermine the Company’s ability to obtain reimbursement for the relevant product outside a jurisdiction. For example, EU Member States that have not yet developed HTA mechanisms may rely to some extent on JCAs under the HTAR or an HTA performed in other countries with a developed HTA framework, to inform their pricing and reimbursement decisions. HTA procedures require additional data, reviews and administrative processes, all of which increase the complexity, timing and costs of obtaining product reimbursement and exert downward pressure on available reimbursement.

To obtain reimbursement or pricing approval in some EU Member States, the Company may be required to conduct studies that compare the cost-effectiveness of the Company’s product candidates to other therapies that are considered the local standard of care. There can be no assurance that any EU Member State will allow favorable pricing, reimbursement and market access conditions for any of the Company’s products, or that it will be feasible to conduct additional cost-effectiveness studies, if required.

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In December 2025, the EU Parliament and the Council reached political agreement on a new directive and a new regulation that will result in a major update to the EU’s pharmaceutical laws. The final text of the legislation has yet to be released but it will include measures designed to increase availability of medicines across the EU. In particular, the new legislation is expected to allow a Member State to request that marketing authorization holders supply their medicines in sufficient quantities to meet patient needs in that Member State. The request must be within one year of marketing authorization. A failure to commence supplies within four years of marketing authorization can result in a two-year reduction in regulatory exclusivity in that Member State. If the final text of the legislation includes such provisions, there is a risk that Member States may seek to exploit the threat of loss of exclusivity to further pressure pharmaceutical prices.

Japan

In Japan, the pharmaceutical industry is subject to government-mandated annual price reductions of pharmaceutical products and certain vaccines. The next government-mandated price reduction is scheduled to occur in April 2026. Furthermore, the government can order re-pricings for specific products if it determines that use of such product will exceed certain thresholds defined under applicable re-pricing rules.

China

The Company’s business in China experienced significant contraction in 2025 due to lower sales of Gardasil/Gardasil 9. Recovery of the Company’s business in China is dependent upon ongoing development of a favorable environment for innovative pharmaceutical products and vaccines, sustained access for the Company’s currently marketed products, and the absence of trade impediments or adverse pricing controls. In recent years, the Chinese government has introduced and implemented a number of structural reforms to accelerate the shift to innovative products and reduce costs. There have been multiple new policies introduced by the government to improve access to new innovation, reduce the complexity of regulatory filings, and accelerate the review and approval process. This has led to a significant increase in the number of new products being approved each year. While the mechanism for drugs being added to the government’s National Reimbursement Drug List (NRDL) evolves, inclusion may require a price negotiation which could impact the outlook in the market for selected brands. A new NRDL was recently completed in which new entries averaged approximately 60% price reductions. While pricing pressure has always existed in China, health care reform has increased this pressure in part due to the acceleration of generic substitution through volume-based procurement (VBP). The government has implemented the VBP program through a tendering process for mature products which have generic substitutes with a Generic Quality Consistency Evaluation approval. Mature products that have entered into the latest rounds of VBP had, on average, a price reduction of more than 50%. The Company expects that the VBP process will have a significant impact on mature products moving forward.

Emerging Markets

The Company’s focus on emerging markets, in addition to China, has continued. Governments in many emerging markets are also focused on constraining health care costs and have enacted price controls and measures impacting intellectual property, including in exceptional cases, threats of compulsory licenses, that aim to put pressure on the price of innovative pharmaceuticals or result in constrained market access to innovative medicine. The Company anticipates that pricing pressures and market access challenges will continue in the future to varying degrees in the emerging markets.

Beyond pricing and market access challenges, other conditions in emerging market countries can affect the Company’s efforts to continue to grow in these markets, including potential political instability, changes in trade sanctions and embargoes, significant currency fluctuation and controls, financial crises, limited or changing availability of funding for health care, credit worthiness of health care partners, such as hospitals, and other developments that may adversely impact the business environment for the Company. Further, the Company may engage third-party agents to assist in operating in emerging market countries, which may affect its ability to realize continued growth and may also increase the Company’s risk exposure.

Regulation

The pharmaceutical industry is also subject to regulation by regional, country, state and local agencies around the world focused on standards and processes for determining drug safety and effectiveness, as well as conditions for sale or reimbursement.

Of particular importance is the FDA in the U.S., which administers requirements covering the testing, approval, safety, effectiveness, manufacturing, labeling, and marketing of prescription pharmaceuticals. In some cases, the FDA requirements and practices have increased the amount of time and resources necessary to develop new products and bring them to market in the U.S. At the same time, the FDA has committed to expediting the development and review of products bearing the “breakthrough therapy” designation, which has accelerated the

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regulatory review process for medicines with this designation. The FDA has also undertaken efforts to bring generic competition to market more efficiently and in a more timely manner.

The EU has adopted directives and other legislation concerning the classification, approval for marketing, labeling, advertising, manufacturing, wholesale distribution, integrity of the supply chain, pharmacovigilance and safety monitoring of medicinal products for human use. These provide mandatory standards throughout the EU, which may be supplemented or implemented with additional regulations by the EU Member States. In particular, EU regulators may approve products subject to a number of post-authorization conditions. Examples of typical post-authorization commitments include additional pharmacovigilance, the conduct of clinical trials, the establishment of patient registries, physician or patient education and controlled distribution and prescribing arrangements. Non-compliance with post-authorization conditions, pharmacovigilance and other obligations can lead to regulatory action, including the variation, suspension or withdrawal of the marketing authorizations, or other enforcement or regulatory actions, including the imposition of financial penalties. The Company’s policies and procedures are already consistent with the substance of these directives; consequently, the Company believes that they will not have any material effect on the Company’s business.

The Company believes that it will continue to be able to conduct its operations, including launching new drugs, in this regulatory environment. (See “Research and Development” below for a discussion of the regulatory approval process.)

Access to Medicines

As a global health care company, Merck’s primary role is to discover and develop innovative medicines and vaccines. The Company also recognizes that, in collaboration with key stakeholders, it has a role to play in helping to ensure that its science advances health care, and its products are accessible and affordable globally. The Company is committed to ensuring a high-quality, safe, reliable, supply of its medicines and vaccines, and to implementing innovative solutions that address barriers to care and sustainable access to its products.

Merck’s approach is designed to enable it to serve the greatest number of patients today, while meeting the needs of patients in the future. The Company's wide-ranging efforts to expand access to health encompass a set of principles embedded in its business strategies and operations. These principles guide its global approach to addressing significant public health burdens. The Company systematically evaluates its pipeline candidates to assess their potential to address unmet medical needs, particularly in low- and middle-income countries. The insights from the assessment inform product development and access strategies, with a focus on expanding the availability of the Company’s medicines and vaccines in an economically sustainable manner.

Throughout the life cycle of its products, Merck seeks to evaluate their potential and adapt to changes in the external environment. Collaborating with various stakeholders, including private, governmental, multilateral, and non-profit organizations, the Company seeks to design and deliver sustainable access solutions at the payer, provider, and patient levels. Furthermore, the Company incorporates access to health metrics in its scorecard, making it a component of calculating annual incentive pay for the majority of its global employees.

In addition, through social investments, including philanthropic programs and impact investing, Merck is helping to strengthen health systems and reduce barriers for communities with limited access to quality care. The Merck Patient Assistance Program provides certain medicines and adult vaccines for free to people in the U.S. and U.S. territories who do not have prescription drug or health insurance coverage and who, without the Company’s assistance, cannot afford their Merck medicines and vaccines. Globally, Merck has made substantial contributions to access to health through key initiatives, including product donations for humanitarian assistance in low-income countries through the Medical Outreach Program. The Mectizan Donation Program, the longest running disease-specific drug donation program of its kind, supports the elimination of two neglected tropical diseases – onchocerciasis and lymphatic filariasis. Additionally, through Merck for Mothers, the Company provides funding, and scientific and business acumen to help global health partners strengthen health systems, expand access to critical maternal health services, and end preventable deaths from complications of pregnancy and childbirth. Merck also supports the Merck Foundation, an independent grantmaking organization helping to address systemic barriers to access to health care.

Privacy and Data Protection

The Company is subject to numerous privacy and data protection laws and regulations globally. These laws and regulations, which often vary, may impact how the Company collects, processes and shares data across borders, including in clinical research, manufacturing, and commercial activities, and corporate functions. The legislative and regulatory landscape for privacy and data protection continues to evolve and enforcement and litigation in this space continue to increase.

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In the U.S., the number of state privacy laws to which the Company is subject is increasing, with a particular focus on the regulation of consumer health data and sensitive personal information, often broadly defined. At the federal level, while there is no single comprehensive federal privacy law, the Federal Trade Commission (FTC) uses several mechanisms to support consumer privacy in the U.S., including Section 5 of the Federal Trade Commission Act, and other sector-specific laws and rules. The Data Security Program, established by the U.S. Department of Justice in 2025 in response to Executive Order 14117, introduced new restrictions on certain types of data sharing to prevent foreign adversaries from accessing bulk U.S. sensitive personal data and U.S. government-related data. Failure to comply with these laws and regulations can result in significant monetary fines and other administrative penalties, as well as reputational harm and civil liability claims from individuals whose personal data was processed.

Outside of the U.S., the Company is subject to the General Data Protection Regulation (GDPR) in the EU and related implementing laws in individual EU Member States. In China, the privacy and data protection framework is complex and imposes stringent compliance requirements on companies, particularly with respect to transferring certain types of personal data outside of China. The Company also is subject to other privacy and data protection laws and regulations in Europe, Asia, Canada, Central and South America, Africa, and the Middle East. Although specific obligations vary by region and country, in general, these laws increase the Company’s responsibility and potential liability in relation to processing personal data, including using data globally and moving data across country borders. Compliance with these laws, which are rapidly evolving in scope and interpretation, introduces significant complexity in Company business operations.

Failure to comply with the requirements of the GDPR and other data related protection frameworks also may result in significant monetary fines, administrative penalties, litigation, and reputational harm.

Distribution

The Company sells its human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers, such as health maintenance organizations, pharmacy benefit managers and other institutions. Human health vaccines are sold primarily to physicians, wholesalers, distributors and government entities. The Company’s professional representatives communicate the effectiveness, safety and value of the Company’s pharmaceutical and vaccine products to health care professionals in private practice, group practices, hospitals and managed care organizations. The Company sells its animal health products to veterinarians, distributors, animal producers, farmers and pet owners.

Raw Materials

The Company obtains raw materials essential to its business from numerous suppliers worldwide. Most of the principal materials the Company uses in its manufacturing operations are available from more than one source. However, the Company obtains certain raw or intermediate materials primarily from only one source. The Company attempts, if possible, to mitigate the potential risk associated with raw materials, components and supplies through inventory and appropriate supplier management.

Patents, Trademarks and Licenses

Patent protection is considered, in the aggregate, to be of material importance to the Company’s marketing of its products in the U.S. and in most major foreign markets. Patents may not only cover a product per se, but also pharmaceutical formulations of a product, processes for making a product, including intermediates useful in those processes, and methods of treatment or other uses of a product. Patent protection for individual products extends for varying periods in accordance with the legal life of patents in individual countries. The protection afforded, which may also vary from country to country, depends upon the type of patent and its scope of coverage.

Patent portfolios developed for products introduced by the Company normally provide varying degrees of market exclusivity. Key patents, which generally cover the product per se, may be subject to a patent term restoration (also known as patent term extension or PTE) of up to five years in the U.S., Japan, and certain other jurisdictions. In Europe, up to five years of extended term may be available in the form of a Supplementary Protection Certificate (SPC). PTEs and SPCs are awarded to offset a portion of the patent term lost during the clinical testing and regulatory review process of a product prior to approval. The Food and Drug Administration Modernization Act includes a Pediatric Exclusivity Provision that may provide an additional six months of market exclusivity (added to the patent term for all Orange Book-listed patents, and to the regulatory data exclusivity term for small molecule and biologic products) in the U.S. for indications of new or currently marketed drugs if certain agreed upon pediatric studies are completed by the applicant. The EU also provides an additional six months of pediatric market exclusivity attached to a product’s SPC term for both small molecule and biologic products. Japan attaches the additional term for pediatric studies to market exclusivity and this extension is unrelated to patent term. In some countries, one or more regulatory exclusivities, including data exclusivity, may provide parallel market protection that is complementary

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to patent protection and, in some cases, may provide more effective or longer lasting marketing exclusivity than a product’s patent portfolio. In the U.S., the regulatory data/marketing protection term generally runs five years from first marketing approval of a new chemical entity, extended to seven years for an orphan drug indication, and twelve years from first marketing approval of a biological product.

The table below provides a list of expiration dates, which include any pending PTE and SPC periods where indicated, for the key patent protection in the U.S., the EU, Japan and China for the following marketed products:

ProductYear of Expiration (U.S.)
Year of Expiration (EU)(1)

Year of Expiration (Japan)(2)

Year of Expiration (China)

Januvia
2026(3)
Expired
2026
Expired

Janumet
2026(3)
ExpiredN/AExpired

Janumet XR

2026(3)
N/AN/A
N/A

Lenvima(4)

2026(5)

2027
2026Expired

Bridion
2026

Expired

Expired
Expired

Bravecto
2027

2029
2029
Expired

Lynparza(6)

2027(7)

2029(7)
2028-2029
Expired

Winrevair

2027(8)

2026(8)

2031 (with pending PTE)(8)

2026

Gardasil2028ExpiredExpired
Expired

Gardasil 9
2028
2030(9)

2030(9)

Expired

Keytruda
2028(10)
20312032-20332028

Adempas(11)

N/A(12)

2028(7)
2027-2028
Expired

Prevymis
2029

2029(13)
2029
Expired

Vaxneuvance

2031(9)(14)

No Patent(15)

No Patent(15)
N/A

Welireg2035 (with pending PTE)
2034 (patent), 2039 (SPCs)

2039 (with pending PTE)

2034

Ohtuvayre

2035 (with pending PTE)(16)

N/A

N/A

N/A(17)

Capvaxive

2038(9)

2038 (patent)(9)(18)

2040 (with pending PTE)(9)

N/A

Enflonsia

2039 (with pending PTE)

N/A

N/A

N/A

Keytruda Qlex

2043

2031(19)

N/A

N/A

Note: Compound patent unless otherwise noted. Certain of the products listed may be the subject of patent litigation. See Item 8. “Financial Statements and Supplementary Data,” Note 10. “Contingencies and Environmental Liabilities” below.

N/A: Currently no marketing approval.

(1)The EU date represents the expiration date for the following four countries: France, Germany, Italy, and Spain (Major EU Markets). If SPC applications have been filed but have not been granted in all Major EU Markets, both the patent expiry date and the SPC expiry date are listed.

(2)The PTE system in Japan allows for a patent to be extended more than once provided the later approval is directed to a different indication from that of the previous approval. This may result in multiple PTE approvals for a given patent, each with its own expiration date.

(3)As a result of settlement agreements related to a patent directed to the specific sitagliptin salt form of the products, exclusivity will extend through May 2026 for Januvia and Janumet, and through July 2026 for Janumet XR.

(4)Part of a global strategic oncology collaboration with Eisai Co., Ltd.

(5)As a result of settlement agreements related to an additional product-related patent, generic entry is not expected until July 2030; however, litigation is ongoing.

(6)Part of a global strategic oncology collaboration with AstraZeneca.

(7)Eligible for six months pediatric market exclusivity.

(8)Eligible for 12 years of data exclusivity in the U.S. (expires in 2036), 11 years in the EU (expires in 2035), and 10 years in Japan (expires in 2035). Granted patents covering methods of treating PAH with Winrevair, which will expire in 2037 (absent PTE or SPC), may provide additional exclusivity.

(9)Composition patent.

(10)The compound patent family contains two additional patents that expire in 2029 due to patent term adjustment resulting from patent office delay. These patents are based on the initial discovery of the active ingredient in Keytruda. While these patents may provide additional protection, the Company expects that they will be the subject of litigation in the future.

(11)Commercialized under a worldwide collaboration with Bayer AG.

(12)The Company has no marketing rights in the U.S.

(13)Data exclusivity expires in January 2030.

(14)PTE is pending but is not included in the listed patent expiry date. Data exclusivity has been granted in the U.S. and expires in July 2033.

(15)Data exclusivity has been granted in the EU and Japan, which expires in December 2031 and September 2030, respectively.

(16)Ensifentrine polymorph patent.

(17)The Company has no marketing rights in China.

(18)SPC applications will be filed in 2026.

(19)A patent application is currently pending, which if granted, will expire in 2040.

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The Company has the following key U.S. patent protection for drug candidates under review in the U.S. by the FDA:

Under Review in the U.S. Currently Anticipated

Year of Expiration (in the U.S.)

MK-8591A (doravirine + islatravir)
2032

The Company also has the following key U.S. patent protection for drug candidates in Phase 3 development:

Phase 3 Drug CandidateCurrently Anticipated

Year of Expiration (in the U.S.)

V181

2029

MK-2400 (ifinatamab deruxtecan)(1)
2034

MK-1022 (patritumab deruxtecan)(1)
2035

MK-1308A (quavonlimab + pembrolizumab)
2035

MK-1026 (nemtabrutinib)
2035

MK-8527
2035

V940 (intismeran autogene)(1)
2036

MK-3543 (bomedemstat)
2036

MK-5684 (opevesostat)
2037

MK-8591D (islatravir + lenacapavir)(1)(2)
2037

MK-2140 (zilovertamab vedotin)
2038

MK-4482 Lagevrio(1)(3)
2038

MK-5909 (raludotatug deruxtecan)(1)
2038

MK-1406(4)
2039

MK-2870 (sacituzumab tirumotecan)(1)
2040

MK-0616 (enlicitide decanoate)
2040

MK-7240 (tulisokibart)
2040

MK-1084 (calderasib)(1)
2041

MK-3000(5)
2041

(1)Being developed in a collaboration.

(2)On partial clinical hold for higher doses of islatravir than those in current clinical trials.

(3)Available in the U.S. under Emergency Use Authorization.

(4)Formerly CD388.

(5)Program is in a Phase 2/3 study.

Unless otherwise noted, the patents in the above tables cover the product per se (also known as compound patents). For those drug candidates under review or in development, the key U.S. patents may be subject to a future PTE of up to five years and/or six months of pediatric market exclusivity. In addition, depending on the circumstances surrounding any final regulatory approval of the product, there may be other granted patents or pending patent applications that could have relevance to the product as finally approved.

While the expiration of the compound patent generally results in loss of market exclusivity for the covered pharmaceutical product, other patents may provide additional market exclusivity associated with certain aspects of the product that extends beyond the compound patent expiration, including those derived from the initial discovery of the product’s active ingredient(s) or from product-related innovation that occurs after this initial discovery. These include later-expiring patents directed to (i) processes and intermediates related to methods of manufacture of the active ingredient(s), (ii) use(s) of the product, and (iii) novel compositions and formulations of the product. The effect of product patent expiration on pharmaceutical product sales may also depend upon many other factors such as the nature of the market and the position of the product in it, the growth of the market, the complexities and economics of the process for manufacture of the active ingredient(s) of the product and the requirements of new drug provisions of the Federal Food, Drug and Cosmetic Act or similar laws and regulations in other countries. In addition, in the U.S. and certain other countries, a variety of different regulatory exclusivities that impact market exclusivity may be available under relevant law.

For further information with respect to the Company’s patents, see