Press release: Extension of Mectizan Donation for Triple Therapy Advances Fight Against Lymphatic Filariasis Through 2030

November 17, 2025 6:45 am EST

Extension of Mectizan Donation for Triple Therapy Advances Fight Against Lymphatic Filariasis Through 2030

RAHWAY, N.J., November 17, 2025 – Merck (NYSE: MRK), known as MSD outside of the United States and Canada, is extending the donation of up to 100 million ivermectin treatments annually through 2030, reinforcing its longstanding commitment to the global elimination of lymphatic filariasis (LF) through the World Health Organization’s (WHO) recommended triple drug therapy strategy.

This renewed pledge is driven by the strong progress reported by the WHO, including the milestone achievement of Timor-Leste becoming the first country in 2024 to eliminate LF using this approach.

“By extending our commitment, we aim to ensure that national LF elimination programs in endemic countries continue to have reliable access to the treatments needed to protect vulnerable populations and strengthen health systems,” said Robert M. Davis, chairman and chief executive officer, Merck. “This work is essential to achieving the WHO’s Neglected Tropical Disease Road Map, which targets global elimination by 2030.”

Merck’s donation supports the co-administration of ivermectin (Mectizan), diethylcarbamazine and albendazole — commonly referred to as “triple therapy” — in countries where onchocerciasis (river blindness) is not co-endemic. LF, also known as elephantiasis, is a mosquito-borne parasitic disease that severely damages the lymphatic system. It can lead to extreme swelling of the limbs and genitals, resulting in lifelong disability, pain and social stigma.

“WHO is deeply grateful to Merck for its generosity and solidarity with communities affected by LF,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “In a time of declining resources for global health, in-kind commitments and public-private partnerships are more important than ever. These partnerships have brought us so far in the fight against LF and are the foundation for eliminating many neglected tropical diseases. Together, we can finish the job.”

Merck first pledged in 1987 to provide Mectizan for the treatment of river blindness, a leading cause of preventable blindness worldwide, transmitted through the bite of black flies that breed near fast-flowing streams and rivers, for as much as needed, as long as needed. The Mectizan Donation Program was established that same year as an independent body to oversee Merck’s donation. In 1998, the program expanded to support LF elimination in African countries and Yemen, where LF and river blindness are co-endemic.

In 2017, Merck further strengthened its support by adding up to 100 million additional treatments annually through 2025 to accelerate LF elimination with triple therapy. Research shows that the use of triple therapy reduces the parasites in the blood significantly longer than two-drug regimens, requiring fewer number of treatment rounds needed to interrupt LF transmission. The new five-year extension builds on demonstrated success in countries implementing triple therapy to eliminate LF.

Once endemic in 72 countries, LF has now been eliminated as a public health threat in 21 countries across five WHO regions, with the disease remaining endemic and requiring mass treatment in just 39 countries.

To date, Merck has donated more than 5 billion Mectizan treatments to 62 countries, resulting in the successful elimination of river blindness or LF in nine countries by incorporating Mectizan into national public health strategies. In addition, more than 340 million people no longer require treatment in subnational regions of several African countries as disease transmission is believed to have been eliminated.

About the Mectizan® Donation Program

The Mectizan Donation Program (MDP) was established at the Task Force for Global Health in 1987 to provide medical, technical and administrative oversight of the donation of MECTIZAN® by Merck for the treatment of onchocerciasis. In 1998, the MDP expanded its mandate to include coordination of the donation of albendazole by GSK to be distributed in conjunction with Mectizan for the elimination of lymphatic filariasis in onchocerciasis co-endemic areas. In 2017 the mandate was further extended to oversee the donation of Mectizan for IDA in eligible countries.

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. 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).