Merck Data at ACC.25 Highlight Innovative Advancements and Commitment to Improving Outcomes for People Living with Cardiovascular Disease

Data from Phase 3 ZENITH trial evaluating WINREVAIR™ (sotatercept-csrk) when added to background therapy in adults with pulmonary arterial hypertension (PAH, Group 1 PH) WHO* functional class (FC) III or IV at high risk of mortality to be featured as a late-breaking presentation

New research highlights gaps and barriers for patients to achieve low-density lipoprotein cholesterol (LDL-C) goals and the impact on patient outcomes and healthcare utilization, underscoring the urgency to treat to LDL-C goals

Merck (NYSE:MRK), known as MSD outside of the United States and Canada, today announced that new clinical and outcomes research data will be presented at the American College of Cardiology's Annual Scientific Session and Expo (ACC.25) in Chicago from March 29-31. Data being shared at the meeting highlights how Merck is advancing research focused on improving outcomes for even more patients living with cardiovascular disease, through the evaluation of approved treatments, as well as data supporting opportunities for improved disease management in a real-world setting.

Merck will present results from the Phase 3 ZENITH trial evaluating WINREVAIR™ (sotatercept-csrk) when added to background therapy in adults with pulmonary arterial hypertension (PAH, Group 1 PH) WHO* functional class (FC) III or IV at high risk of mortality. These results will be shared as an oral presentation in a late-breaking session on Monday, March 31 during the Clinical and Investigative Horizons I session from 10:00-11:00 a.m. ET/9:00-10:00 a.m. CT (LBA402-16).

"Merck has a long legacy of making an impact in cardiovascular disease, and since we introduced our first therapy more than 60 years ago, we have remained committed to advancing innovative research to better understand and help improve the lives of patients with cardiovascular disease," said Dr. Eliav Barr, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories. "We are particularly thrilled to share research from the Phase 3 ZENITH trial evaluating WINREVAIR in PAH as a late-breaking presentation. ZENITH is the first study in PAH in which the interim analysis led to an early conclusion due to overwhelming efficacy and adds to the growing body of data evaluating WINREVAIR in a broad spectrum of patients with PAH."

Four outcomes research presentations focused on cholesterol management from Merck will also be shared during the meeting. These include two presentations evaluating real-world data: the first highlights healthcare utilization and costs among patients treated for dyslipidemia in a U.S. integrated delivery system and the second provides insights into low-density lipoprotein (LDL-C) measurement patterns. Two additional presentations include a model to estimate the impact of treatment patterns for adults on lipid lowering therapy (LLT), as well as a systematic literature review and meta-analysis of residual atherosclerotic cardiovascular disease (ASCVD) risk among those treated with statin therapy.

"Our commitment to improving the lives of patients includes driving analyses of observational data to provide valuable insights into the barriers to achieving LDL-C goals in order to manage atherosclerotic cardiovascular disease," said Dr. Bjorn Oddens, senior vice president and head of value and implementation, Merck Research Laboratories. "Low-density lipoprotein cholesterol is an established and modifiable risk factor for the development of atherosclerotic cardiovascular disease, a disease which accounts for 85 percent of cardiovascular deaths, but nearly two-thirds of individuals do not reach their LDL-C goals. Research presented at ACC aims to provide the cardiovascular community with insights into existing gaps in management, the impact on patient outcomes and healthcare systems and opportunities for improvement, with the ultimate goal of helping more patients better manage their LDL-C."

Key data from Merck to be presented at ACC.25:

• First presentation of results from the Phase 3 ZENITH trial evaluating WINREVAIR when added to background therapy in patients with PAH FC III or IV at high risk of mortality (Abstract #LBA402-16; Clinical and Investigative Horizons I);
• A systematic review and meta-analysis evaluating the residual ASCVD risk in statin users in the real-world setting (Abstract #1062-36; Cardiovascular Disease Prevention 03);
• Real-world data evaluating the frequency of LDL-C measurement and its association with patient characteristics among adults prescribed LLT in the U.S. (Abstract #1062-19; Cardiovascular Disease Prevention 03);
• Presentation of a model to estimate the benefits of non-statin LLT use in terms of clinical (LDL-C and ASCVD event reduction) and economic (cost reduction) impact on the U.S. health system (Abstract #977-03; Costs of Cardiovascular Preventive Care: Implications Across Stakeholders);
• Poster presentation estimating the association between healthcare resource use and treatment patterns among adults on LLT across various levels of risk in a large U.S. health system (Abstract #977-15; Costs of Cardiovascular Preventive Care: Implications Across Stakeholders).

Details on key abstracts for Merck:

*World Health Organization

About WINREVAIR^™ (sotatercept-csrk) for injection, for subcutaneous use, 45 mg, 60 mg

WINREVAIR is FDA-approved for the treatment of adults with pulmonary arterial hypertension (PAH, Group 1 PH) to increase exercise capacity, improve WHO functional class (FC) and reduce the risk of clinical worsening events. WINREVAIR is the first activin signaling inhibitor therapy approved to treat PAH. WINREVAIR improves the balance between pro-proliferative and anti-proliferative signaling to modulate vascular proliferation. In preclinical models, WINREVAIR induced cellular changes that were associated with thinner vessel walls, partial reversal of right ventricular remodeling, and improved hemodynamics.

WINREVAIR is the subject of a licensing agreement with Bristol Myers Squibb.

Selected Safety Information for WINREVAIR in the U.S.

WINREVAIR may increase hemoglobin (Hgb). Severe erythrocytosis may increase the risk of thromboembolic events or hyperviscosity syndrome. Monitor Hgb before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter, to determine if dose adjustments are required.

WINREVAIR may decrease platelet count. Severe thrombocytopenia may increase the risk of bleeding. Thrombocytopenia occurred more frequently in patients also receiving prostacyclin infusion. Do not initiate treatment if platelet count is <50,000/mm3. Monitor platelets before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter to determine whether dose adjustments are required.

In clinical studies, serious bleeding (e.g., gastrointestinal, intracranial hemorrhage) was reported in 4% of patients taking WINREVAIR and 1% of patients taking placebo. Patients with serious bleeding were more likely to be on prostacyclin background therapy and/or antithrombotic agents, or have low platelet counts. Advise patients about signs and symptoms of blood loss. Do not administer WINREVAIR if the patient is experiencing serious bleeding.

WINREVAIR may cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use an effective method of contraception during treatment with WINREVAIR and for at least 4 months after the final dose. Pregnancy testing is recommended for females of reproductive potential before starting WINREVAIR treatment.

Based on findings in animals, WINREVAIR may impair female and male fertility. Advise patients on the potential effects on fertility.

The most common adverse reactions occurring in the phase 3 clinical trial (≥10% for WINREVAIR and at least 5% more than placebo) were headache (24.5% vs 17.5%), epistaxis (22.1% vs 1.9%), rash (20.2% vs 8.1%), telangiectasia (16.6% vs 4.4%), diarrhea (15.3% vs 10.0%), dizziness (14.7% vs 6.2%), and erythema (13.5% vs 3.1%).

Because of the potential for serious adverse reactions in the breastfed child, advise patients that breastfeeding is not recommended during treatment with WINREVAIR, and for 4 months after the final dose.

Merck's focus on cardiovascular disease

Merck has a long history of making an impact in cardiovascular disease. More than 60 years ago, we introduced our first cardiovascular therapy – and our scientific efforts to understand cardiovascular-related disorders have continued. Cardiovascular disease continues to be one of the most serious health challenges of the 21st century. Approximately 19 million people across the globe die every year, and in the United States one person dies every 36 seconds from cardiovascular disease.

Advancements in the treatment of cardiovascular disease can make a critical difference for patients around the world. At Merck, we strive for scientific excellence and innovation in all stages of research, from discovery through approval and life cycle management. We work with experts throughout the cardiovascular and pulmonary community to advance research that can help improve the lives of patients globally.

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on X (formerly Twitter), Facebook, Instagram, YouTube and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Rahway, N.J., USA

This news release of Merck & Co., Inc., Rahway, N.J., USA (the "company") includes "forward-looking statements" within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company's management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline candidates that the candidates will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company's patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company's Annual Report on Form 10-K for the year ended December 31, 2024 and the company's other filings with the Securities and Exchange Commission (SEC) available at the SEC's Internet site (www.sec.gov).

Please see Prescribing Information for WINREVAIR (sotatercept-csrk) at http://www.merck.com/product/usa/pi_circulars/w/winrevair/winrevair_pi.pdf , Patient Information for WINREVAIR at http://www.merck.com/product/usa/pi_circulars/w/winrevair/winrevair_ppi.pdf , and Instructions for Use for WINREVAIR (1-vial kit, 2-vial kit) at https://www.merck.com/product/usa/pi_circulars/w/winrevair/winrevair_ifu_1-vial_2-vial_kits.pdf.

View source version on businesswire.com: https://www.businesswire.com/news/home/20250319014096/en/

Media Contacts:

Julie Cunningham

(617) 519-6264

Nikki Lupinacci

(718) 644-0730

Investor Contacts:

Peter Dannenbaum

(732) 594-1579

Steven Graziano

(732) 594-1583