Innovation

We’re researching ADCs with a focus on both ends of bifunctional linkers

To develop next-generation ADCs, our scientists are committed to finding the right chemistry

October 15, 2026

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What are antibody-drug conjugates (ADCs)?

Antibody-drug conjugates (ADCs) are a class of drugs designed to deliver a cancer-killing drug to tumor cells while reducing harm to normal or healthy cells. They work by binding to a target expressed on a tumor cell and then delivering its payload once it arrives. For years, much of ADC research and development has centered on finding the right antibody and the right payload to treat a variety of different tumor types.

But the linker that connects the two plays a critical role in how safely and effectively ADCs perform — and optimizing that linker is a complex chemistry problem that requires finding the right balance between stability in circulation and payload release at the target cell.

Every ADC contains three main parts:

• An antibody that helps target specific cells
• A payload that carries the cancer-fighting therapy
• A linker that connects the two and controls payload release

What is a linker in an ADC?

A linker is a specialized chemical connector that attaches to an antibody at one end and a cancer-fighting payload on the other.

The bifunctional linkers do more than connect the antibody and payload; they help determine when and where the payload is released. The goal is to protect heathy tissue by keeping the potent payload contained while circulating in blood, only releasing it once it gets to the target cell or tumor cell.

Some ADCs have prioritized speedy payload release, ensuring the most cancer-killing drug possible gets released but potentially exposing healthy cells in the process. Others have focused on maximizing the stability of the connection to both antibody and payload, increasing the chance to kill cancer cells but also potentially impacting healthy cells that also express the target. There isn’t a one-size-fits-all approach, and depending on the ADC’s target, the optimal level of stability can differ.

What are the different types of ADC targets?

There are many different examples of ADC targets. The ideal targets are overexpressed on cancer cells compared to healthy tissue. The more a target is selectively expressed on a tumor, the more precisely the payload will affect cancerous cells as opposed to healthy cells.

Learn more about our ADC research.

Both ends matter: the linker’s balancing act

Our scientists are researching linker stability with the goal of striking the right balance between attacking the tumor and minimizing damage to healthy cells. Both ends of these bifunctional linkers are important to achieving the desired stability.

• Connection to the antibody: The stability of the linker’s connection to the antibody controls how the payload stays intact while circulating in the body in hopes of reducing harm to healthy cells.
• Connection to the drug: Meanwhile, the linker’s connection to the drug controls the amount of chemotherapy that gets released into the tumor, which powers the ADC to target tumor cells.

“We believe ADCs will be a cornerstone of the future of precision oncology, offering the chance to combine powerful therapies with targeted delivery to treat patients with many common cancer types,” said Alan Northrup, vice president of discovery chemistry, Merck Research Laboratories.

“Our research in bifunctional linkers is focused on finding the right balance to both enable the drug to find its target and also to optimize the timing and release of its payload, ideally killing the tumor in a targeted way that minimizes the damage to healthy cells elsewhere in the body.”

• Alan Northrup
  Vice president of discovery chemistry, Merck Research Laboratories

Could linker innovations enable more precision in oncology?

When a linker system is optimized, it can help researchers explore different combinations of antibodies and payloads for different tumor types and patient needs. In that way, linker innovation can enable next-generation ADC designs that are promising for the future of precision medicine in oncology.

By advancing bifunctional linker design, our scientists aim to help drive ADC research and expand what’s possible in cancer care.

Learn more about our work in oncology.

Innovation

Understanding blood cancers

How Merck is helping advance research with new approaches for people living with these challenging conditions

June 10, 2026

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Blood cancers develop when changes in DNA cause blood‑forming cells to grow abnormally. Instead of producing healthy blood cells that support the immune system and carry oxygen through the body, these altered cells multiply in an uncontrolled way. Over time, this can weaken the immune system and make it harder for the body to fight infection and perform essential functions.

Types of blood cancer: leukemia, lymphoma and myeloma

The most common types of blood cancer are leukemia, lymphoma and myeloma. Together, they account for the majority of hematologic malignancies, with more than 190,000 new cases projected each year in the U.S.   

• Leukemia forms in the blood and bone marrow and is caused by the rapid production of abnormal white blood cells. There are several types of leukemia, which include acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia and chronic myeloid leukemia. 
• Lymphoma develops in the lymphatic system, a network of organs, vessels and tissues that helps protect the body from infection. It is often classified as either Hodgkin lymphoma or non‑Hodgkin lymphoma, depending on the type of lymphocyte involved and specific cellular features.
• Myeloma, also known as multiple myeloma, forms in plasma cells found in the bone marrow. Unlike cancers that first appear in one location, myeloma can occur in multiple areas of the bone marrow at the same time.

Rare blood cancers: myeloproliferative neoplasms (MPNs) and myelodysplastic syndromes (MDS)

In addition to the previously listed more common blood cancers, there are rarer related blood cancers, such as myeloproliferative neoplasms (MPNs) and myelodysplastic syndromes (MDS). About 20,000 new cases of MPNs and MDS are diagnosed each year in the U.S. MPNs occur when the bone marrow produces too many blood cells, while MDS develops when blood cells do not mature properly and are unable to become healthy cells.  The main types of MPNs include essential thrombocythemia, primary myelofibrosis and polycythemia vera.

As the number of people affected by blood cancers and disorders continues to rise, scientists at Merck are exploring innovative strategies aimed at improving outcomes for patients living with these complex and challenging conditions. These approaches focus on enhancing the body’s response to cancer, targeting cancer cells more precisely and addressing pathways that drive cancer growth.

Merck is currently investigating several potential targets for hematologic malignancies across a broad range of different disease pathways, including:

Targeting ROR1, a protein that is overexpressed in multiple hematologic malignancies

Evaluating the inhibition of Bruton’s tyrosine kinase to address common mechanisms of resistance for patients with certain hematologic malignancies

Targeting lysine-specific demethylase 1 (LSD1), an enzyme that is potentially important for regulating the rapid reproduction of blood stem cells and the maturation of blood cells in the bone marrow

Evaluating the role of the BCR::ABL novel protein in preventing white blood cells from proliferating

Researching T-cell engagement for certain types of leukemia and lymphoma

“Our team is building on our legacy in oncology to understand how various mechanisms and modalities could address blood cancers in innovative ways,” said Dr. Shweta Jain, vice president, oncology clinical research, Merck Research Laboratories.

“By exploring multiple potential novel mechanisms of action across a broad range of blood cancers and disorders, we hope to help address longstanding unmet needs for patients with hematologic malignancies.”

• Dr. Shweta Jain

Through ongoing studies and clinical trials, Merck is working to advance clinical research for patients living with blood cancers and disorders. Learn more about Merck’s hematology research and clinical trials.

Innovation

What are individualized neoantigen therapies?

How scientists are harnessing the specific mutations of each person’s cancer to evaluate therapies that would be tailored to their own tumor

May 20, 2026

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Over the past decade, immunotherapy has transformed our understanding of how the immune system can be used to help fight certain types of cancer. As the treatment of cancer continues to evolve, researchers are focusing on more individualized approaches.

What makes each person’s cancer different — and why does it matter?

Cancer develops when the body’s own cells undergo mutations that create abnormal proteins in cancer cells, known as neoantigens. These mutations are not found in normal cells and are specific to each person’s tumor. That helps explain why people diagnosed with the same type of cancer — and treated in similar ways — could respond differently.

What if the immune system can be trained to recognize each person’s cancer?

To explore the idea of one medicine for one patient, we’re evaluating individualized neoantigen therapies as a potential way to help train the immune system to identify and destroy cancer cells unique to each individual.

Merck scientists, with colleagues at Moderna, are studying this approach to deepen our understanding of how mutations vary across different cancers — insights that could help advance more personalized approaches to cancer care.

How are individualized neoantigen therapies designed to work?

• To predict each patient’s mix of neoantigens, or tumor mutations, scientists analyze the genetic code of a person’s tumor cells.
• The analysis helps predict which neoantigens are most likely to appear on the surface of cancer cells and which may be the most promising targets for a personalized therapy.
• This tailoring could potentially allow an individualized neoantigen therapy to effectively train the immune system to find and kill specific cancer cells.
• Because healthy cells don’t have cancer neoantigens on their surface, this approach may also help avoid harming healthy tissue.

“Building on our past learnings from cancer trials involving the immune system, we’re investigating a new approach to individualized cancer care based on each patient’s specific tumor mutations. No two individualized neoantigen therapies will be alike, because no two cancers are the same.”

• Dr. Vassiliki Karantza
  AVP, global clinical development, Merck Research Laboratories

Clinical studies are ongoing to explore the safety and effectiveness of individualized neoantigen therapies when combined with other cancer treatments. There are currently no U.S. FDA-approved individualized neoantigen therapies. 

Learn more about our work in oncology.