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As filed with the Securities and Exchange Commission on February 26, 2024

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D. C. 20549
_________________________________
FORM 10-K

 
Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the Fiscal Year Ended December 31, 2023

OR
Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the transition period from                  to                 

Commission File No. 1-6571
02852_Merck_Logo_Horizontal_Teal&Grey_RGB.jpg
Merck & Co., Inc.
126 East Lincoln Avenue
RahwayNew Jersey07065
(908740-4000
New Jersey22-1918501
(State or other jurisdiction of incorporation)
(I.R.S. Employer Identification No.)
Securities Registered pursuant to Section 12(b) of the Act:
Title of Each ClassTrading Symbol(s)Name of Each Exchange on which Registered
Common Stock ($0.50 par value)MRKNew York Stock Exchange
0.500% Notes due 2024MRK 24New York Stock Exchange
1.875% Notes due 2026MRK/26New York Stock Exchange
2.500% Notes due 2034MRK/34New York Stock Exchange
1.375% Notes due 2036MRK 36ANew York Stock Exchange
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.     Yes ☒    No
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes ☐    No 
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes   No  
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).    Yes   No  
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Large accelerated filerAccelerated filer
Non-accelerated filerSmaller reporting company
Emerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.
If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.
Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes    No  
Number of shares of Common Stock ($0.50 par value) outstanding as of January 31, 2024: 2,532,643,872.
Aggregate market value of Common Stock ($0.50 par value) held by non-affiliates on June 30, 2023 based on the closing price on June 30, 2023: $292,929,000,000.
Documents Incorporated by Reference:
Document Part of Form 10-K
Proxy Statement for the Annual Meeting of Shareholders to be held May 18, 2024, to be filed with the
Securities and Exchange Commission within 120 days after the close of the fiscal year covered by this report
 Part III


Table of Contents
Table of Contents
   Page
Item 1.
Item 1A.
Item 1B.
Item 1C.
Item 2.
Item 3.
Item 4.
Item 5.
Item 6.
   43
Item 7.
Item 7A.
Item 8.
(a)
Item 9.
Item 9A.
Item 9B.
Item 9C.
Item 10.
Item 11.
Item 12.
Item 13.
Item 14.
Item 15.
Item 16.


Table of Contents
PART I
 
Item 1.Business.
Merck & Co., Inc. (Merck or the Company) is a global health care company that delivers innovative health solutions through its prescription medicines, including biologic therapies, vaccines and animal health products. The Company’s operations are principally managed on a product basis and include two operating segments, Pharmaceutical and Animal Health, both of which are reportable segments.
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. The Company sells these 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 vaccine products consist of preventive pediatric, adolescent and adult vaccines. The Company sells these human health vaccines primarily to physicians, wholesalers, distributors and government entities.
The Animal Health segment discovers, develops, manufactures and markets a wide range of veterinary pharmaceutical and vaccine products, as well as health management solutions and services, for the prevention, treatment and control of disease in all major livestock and companion animal species. The Company also offers an extensive suite of digitally connected identification, traceability and monitoring products. The Company sells its products to veterinarians, distributors, animal producers, farmers and pet owners.
On June 2, 2021, Merck completed the spin-off (the Spin-Off) of products from its women’s health, biosimilars and established brands businesses into a new, independent, publicly traded company named Organon & Co. (Organon) through a distribution of Organon’s publicly traded stock to Company shareholders. The established brands included in the transaction consisted of dermatology, non-opioid pain management, respiratory, select cardiovascular products, as well as the rest of Merck’s diversified brands franchise.
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 services 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)202320222021
Total Sales$60,115 $59,283 $48,704 
Pharmaceutical53,583 52,005 42,754 
Keytruda25,011 20,937 17,186 
Gardasil/Gardasil 9
8,886 6,897 5,673 
Januvia/Janumet3,366 4,513 5,288 
ProQuad/M-M-R II/Varivax
2,368 2,241 2,135 
Bridion1,842 1,685 1,532 
Lagevrio1,428 5,684 952 
Alliance revenue - Lynparza(1)
1,199 1,116 989 
Alliance revenue - Lenvima(1)
960 876 704 
RotaTeq769 783 807 
Vaxneuvance
665 170 
Animal Health5,625 5,550 5,568 
Livestock3,337 3,300 3,295 
Companion Animal
2,288 2,250 2,273 
Other Revenues(2)
907 1,728 382 
(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.
1

Table of Contents
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:
Oncology
Keytruda is an anti-PD-1 (programmed death receptor-1) therapy that has been approved as monotherapy for the treatment of certain patients with cervical cancer, classical Hodgkin lymphoma, 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, 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. Keytruda is also approved for 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. In addition, Keytruda is approved in combination with chemotherapy for the treatment of certain patients with advanced NSCLC, in combination with chemotherapy for certain types of advanced biliary tract cancer, in combination with chemotherapy with or without bevacizumab for advanced cervical cancer, in combination with chemotherapy for advanced esophageal cancer, in combination with trastuzumab and chemotherapy for certain patients with advanced human epidermal growth factor receptor 2 (HER2)-positive gastric or GEJ adenocarcinoma with PD-L1 (CPS ≥1) and in combination with chemotherapy for advanced HER2-negative gastric or GEJ adenocarcinoma, in combination with chemotherapy for HNSCC, in combination with chemotherapy for advanced TNBC, in combination with axitinib for advanced RCC, in combination with Lenvima (lenvatinib) for patients with advanced RCC or certain types of advanced endometrial carcinoma, and in combination with enfortumab vedotin for adult patients with locally advanced or metastatic urothelial cancer. Welireg (belzutifan) is a medication for the treatment of adult patients with certain von Hippel-Lindau disease-associated tumors and 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. 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 tyrosine kinase inhibitor, 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 (Varicella Virus Vaccine Live), a vaccine to help prevent chickenpox (varicella); RotaTeq (Rotavirus Vaccine, Live Oral, Pentavalent), a vaccine to help protect against rotavirus gastroenteritis in infants and children; Vaxneuvance (Pneumococcal 15-valent Conjugate Vaccine), a vaccine to help prevent invasive pneumococcal disease in individuals 6 weeks of age and older; Pneumovax 23 (pneumococcal vaccine polyvalent), a vaccine to help prevent pneumococcal disease; and Vaqta (hepatitis A vaccine, inactivated) indicated for the prevention of disease caused by hepatitis A virus in persons 12 months of age and older.
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 recipients of an allogeneic hematopoietic stem cell transplant or of a kidney transplant, respectively; Dificid (fidaxomicin) for the treatment of C. difficile-associated diarrhea; Zerbaxa (ceftolozane and tazobactam) for injection, a combination antibacterial and beta-lactamase inhibitor for the treatment of certain
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bacterial infections; Noxafil (posaconazole), an antifungal agent for the prevention of certain invasive fungal infections; and Primaxin (imipenem and cilastatin) for injection, an antibiotic for the treatment of certain bacterial infections.
Cardiovascular
Adempas (riociguat), a cardiovascular drug for the treatment of chronic thromboembolic pulmonary hypertension or pulmonary arterial hypertension 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.
Virology
Lagevrio, an investigational oral antiviral COVID-19 medicine available in the U.S. under Emergency Use Authorization (EUA); Isentress/Isentress HD (raltegravir), an HIV integrase inhibitor for use in combination with other antiretroviral agents for the treatment of HIV-1 infection.
Neuroscience
Belsomra (suvorexant), an orexin receptor antagonist, indicated for the treatment of insomnia, characterized by difficulties with sleep onset and/or sleep maintenance.
Immunology
Simponi (golimumab), a once-monthly subcutaneous treatment for certain inflammatory diseases; and Remicade (infliximab), a treatment for inflammatory diseases, both of which the Company markets in Europe, Russia and Türkiye.
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; 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 Marek’s Disease Vector), vaccine lines for poultry; Paracox and Coccivac coccidiosis vaccines; Exzolt, a systemic treatment for poultry red mite infestations; Slice (Emamectin benzoate) parasiticide for sea lice 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 and topical 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, 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); Optimmune (cyclosporine), an ophthalmic ointment; Nobivac vaccine lines for flexible dog and cat vaccination; 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
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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 2023 and, to date, in 2024.
ProductDateApproval
Keytruda
January 2023
U.S. Food and Drug Administration (FDA) approval as a single agent for adjuvant treatment following surgical resection and platinum-based chemotherapy for adult patients with stage IB (T2a ≥4 cm), II, or IIIA NSCLC, based on the KEYNOTE-091 trial.
March 2023
FDA full approval for the treatment of adult and pediatric patients with unresectable or metastatic MSI-H or dMMR solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options. The conversion from an accelerated to a full (regular) approval is based on the KEYNOTE-158, KEYNOTE-164 and KEYNOTE-051 trials.
April 2023
FDA accelerated approval in combination with Padcev (enfortumab vedotin-ejfv) for the treatment of adult patients with locally advanced or metastatic urothelial carcinoma who are not eligible for cisplatin-containing chemotherapy, based on the KEYNOTE-869 trial dose escalation cohort, Cohort A and Cohort K, which was conducted in collaboration with Seagen (now Pfizer Inc. (Pfizer)) and Astellas.
June 2023
Japan’s Ministry of Health, Labor and Welfare (MHLW) approval for the treatment of patients with relapsed or refractory PMBCL, based on the KEYNOTE-170 and the KEYNOTE-A33 trials.
August 2023
European Commission (EC) approval in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of locally advanced unresectable or metastatic HER2-positive gastric or GEJ adenocarcinoma in adults whose tumors express PD-L1, based on the KEYNOTE-811 trial.
September 2023
China’s National Medical Products Administration (NMPA) approval as monotherapy for the treatment of adult patients with advanced unresectable or metastatic MSI-H or dMMR solid tumors, including patients with colorectal cancer that have progressed following treatment with fluoropyrimidine, oxaliplatin or irinotecan, or those with other solid tumors that have progressed following prior therapy and who have no satisfactory alternative treatment options, based on the KEYNOTE-158 and KEYNOTE-164 trials.
October 2023

EC approval as a monotherapy for the adjuvant treatment of adults with NSCLC who are at high risk of recurrence following complete resection and platinum-based chemotherapy, based on the KEYNOTE-091 trial.
October 2023

FDA approval for the treatment of patients with resectable (tumors >=4cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery, based on the KEYNOTE-671 trial.
October 2023
FDA full approval for the treatment of adult and pediatric patients with recurrent locally advanced or metastatic Merkel cell carcinoma. The conversion from an accelerated to a full (regular) approval is based on the KEYNOTE-913 and KEYNOTE-017 trials.
October 2023

FDA approval in combination with gemcitabine and cisplatin for the treatment of patients with locally advanced unresectable or metastatic biliary tract cancer, based on the KEYNOTE-966 trial.
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Keytruda
November 2023
FDA approval in combination with fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or GEJ adenocarcinoma, based on the KEYNOTE-859 trial.
December 2023
FDA full approval in combination with Padcev (enfortumab vedotin-ejfv), an antibody-drug conjugate, for the treatment of adult patients with locally advanced or metastatic urothelial cancer. The conversion from an accelerated to a full (regular) approval is based on the KEYNOTE-A39 trial that was conducted in collaboration with Seagen (now Pfizer) and Astellas.
December 2023
EC approval in combination with fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of locally advanced unresectable or metastatic HER2-negative gastric or GEJ adenocarcinoma in adults whose tumors express PD-L1, based on the KEYNOTE-859 trial.
December 2023
EC approval in combination with gemcitabine and cisplatin for the first-line treatment of locally advanced unresectable or metastatic biliary tract carcinoma in adults, based on the KEYNOTE-966 trial.
December 2023
China’s NMPA approval in combination with fluoropyrimidine- and platinum-containing chemotherapy for the first-line treatment of patients with locally advanced unresectable or metastatic HER2-negative gastric or GEJ adenocarcinoma, based on the KEYNOTE-859 trial.
January 2024
FDA approval in combination with chemoradiotherapy for the treatment of patients with FIGO (International Federation of Gynecology and Obstetrics) stage III-IVA cervical cancer, based on the KEYNOTE-A18 trial.
January 2024
FDA full approval for the treatment of patients with HCC secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1 containing regimen. The conversion from an accelerated to full (regular) approval is based on the KEYNOTE-394 trial.
February 2024
China’s NMPA approval in combination with gemcitabine and cisplatin for the first-line treatment of patients with locally advanced or metastatic biliary tract carcinoma, based on the KEYNOTE-966 trial.
Lynparza(1)
May 2023
FDA approval in combination with abiraterone and prednisone or prednisolone for the treatment of adult patients with deleterious or suspected deleterious BRCA-mutated (BRCAm) metastatic castration-resistant prostate cancer (mCRPC), based on the PROpel trial.
August 2023
Japan’s MHLW approval in combination with abiraterone and prednisolone for treatment of adult patients with BRCAm mCRPC with distant metastasis, based on the PROpel trial.
Prevymis
June 2023
FDA approval for CMV prophylaxis in Donor CMV-seropositive/Recipient CMV-seronegative adult kidney transplant recipients, based on the P002 trial.
November 2023
EC approval for CMV prophylaxis Donor CMV-seropositive/Recipient CMV-seronegative adult kidney transplant recipients, based on the P002 trial.
Ervebo
August 2023
FDA approval of an expanded indication for the prevention of disease caused by Zaire ebolavirus in individuals 12 months of age and older. The vaccine was previously approved for use in individuals 18 years of age and older.
September 2023
EC approval of an expanded indication for active immunization of individuals one year of age or older to protect against Ebola Virus Disease caused by Zaire ebolavirus. The vaccine was previously approved for use in the EU for individuals 18 years of age or older.
Welireg
December 2023
FDA approval for the treatment of adult patients with advanced RCC following both a PD-1 or PD-L1 inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor, based on the LITESPARK-005 trial.
Bravecto
January 2024
EC approval of injectable formulation for dogs for the persistent killing of fleas and ticks for 12 months after treatment.
(1)    Being jointly developed and commercialized in a worldwide collaboration with AstraZeneca.
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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 generic availability 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.
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 enacted in prior years, 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 2023 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 Biden Administration 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.
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).
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.
Additionally in the U.S., consolidation and integration among health care providers is a major factor in the competitive marketplace for pharmaceutical products. Health plans and pharmacy benefit managers (PBMs) 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
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tier co-pay 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 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 payor has taken the position that multiple branded products are therapeutically comparable. As the U.S. payor market concentrates further, the Company may face greater pricing pressure from private third-party payors.
In order to provide information about the Company’s pricing practices, the Company annually posts on its website its Pricing Transparency Report for the U.S. The report provides the Company’s average annual list price, net price increases, and average discounts across the Company’s U.S. portfolio dating back to 2010. In 2023, the Company’s gross U.S. sales were reduced by 37% as a result of rebates, discounts and returns.
Legislative Changes
In 2022, Congress passed the IRA, which makes 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, and government price-setting for certain Medicare Part D drugs, starting in 2026, and Medicare Part B drugs starting in 2028. In August 2023, the U.S. Department of Health and Human Services (HHS), through the Centers for Medicare & Medicaid Services (CMS), announced that Januvia will be included in the first year of the IRA’s “Drug Price Negotiation Program” (Program). Pursuant to the IRA’s Program, discussions with the government occurred in 2023 and will continue in 2024, with government price setting becoming effective on January 1, 2026. The Company has sued the U.S. government regarding the IRA’s Program (see Item 8 “Financial Statements and Supplementary Data,” Note 11. “Contingencies and Environmental Liabilities” below). Furthermore, the Biden Administration 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 the U.S. Department of Health and Human Services 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 eliminates the statutory cap on rebates drug manufacturers pay to Medicaid beginning in January 2024. 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, beginning in 2024, 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. In addition, recently, the FDA authorized, for a two-year period, Florida’s application to import prescription drugs from Canada.

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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.
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 (internal reference pricing). The authorities then use the price data to set new local prices for brand-name drugs, including the Company’s drugs. Guidelines for examining reference pricing are usually set in local markets and can be changed pursuant to local regulations. 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 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 outcome of HTAs regarding specific pharmaceutical products will often influence the pricing and reimbursement status granted to these pharmaceutical products by the regulatory 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 the 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.
Japan
In Japan, the pharmaceutical industry is subject to government-mandated annual price reductions of pharmaceutical products and certain vaccines. 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. In addition, if a Merck product has the same medical action or composition of another product that is subject to market expansion re-pricing, the Merck product could also be subject to re-pricing unless it meets exception criteria. The next government-mandated price reduction will occur in April 2024.

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China
The Company’s business in China has grown rapidly in the past few years, and the importance of China to the Company’s overall pharmaceutical and vaccines business has increased accordingly. Continued growth 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. Since 2017, 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 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). In 2019, the government 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 last five rounds of VBP had, on average, a price reduction of more than 50%. The Company expects VBP to be a semi-annual process that 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.
In addressing global cost containment pressures, the Company engages in public policy advocacy with policymakers and continues to work to demonstrate that its medicines 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.
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.
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, it is believed 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. The