Discovery Could Make Immune Checkpoint Inhibitors Safer

Experts report proof-of-concept results that may reduce risk of lethal side effect from cancer immunotherapies.

Published on Feb. 23, 2026

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Researchers at Cincinnati Children's Hospital have discovered a way to dramatically reduce the risk of a potentially lethal side effect from immune checkpoint inhibitor (ICI) cancer treatments. The team found that blocking the tumor necrosis factor (TNF) signaling pathway through the TNFR2 gene product prevented the inflammatory cycle that leads to life-threatening heart issues in some patients receiving ICIs.

Why it matters

Immune checkpoint inhibitors have revolutionized cancer treatment, but about 2% of patients receiving these therapies develop a dangerous side effect called myocarditis, which is inflammation of the heart muscle. This complication has a 50% mortality rate, significantly limiting the use of these otherwise transformative cancer immunotherapies. This discovery could make ICIs safer and more accessible for a wider range of cancer patients.

The details

The researchers engineered a mouse model that accurately mimics ICI-induced myocarditis. They found that the complication is not caused by tumors exhausting the body's cancer-fighting T cells, but rather through the production of new "autoreactive" T cells that attack healthy cardiac muscle cells in addition to cancer cells. Blocking the TNF signaling pathway through TNFR2 prevented this inflammatory cycle in the mouse models, suggesting a potential targeted approach to preventing cardiac toxicity without compromising the anti-tumor benefits of ICIs.

  • The study results were published on February 20, 2026 in the Journal of Experimental Medicine.
  • The first ICI drug, Yervoy, was approved in the U.S. for treating metastatic melanoma in 2011.

The players

Chandrashekhar Pasare

Director of the Division of Immunology at Cincinnati Children's Hospital and co-corresponding author on the study.

Jeffery Molkentin

Director of the Division of Molecular Cardiovascular Biology at Cincinnati Children's Hospital and co-corresponding author on the study.

Kathrynne Warrick

MD-PhD student who led the research work.

James Allison

One of the inventors of immune checkpoint inhibitors, who received the Nobel Prize in Medicine in 2018 for the discovery.

Tasuku Honjo

One of the inventors of immune checkpoint inhibitors, who received the Nobel Prize in Medicine in 2018 for the discovery.

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What they’re saying

“This study makes a very important discovery that shows how to uncouple anti-tumor efficacy from cardiac toxicity. These findings have major implications for treating or avoiding immune related adverse events in cancer patients receiving immune check point blockade.”

— Chandrashekhar Pasare, Director, Division of Immunology at Cincinnati Children's

“Checkpoint inhibitors allow TNF signaling to trigger CD8 T-cells that are specific to antigens on cardiac myocytes, which in turn leads to life-threatening arrythmias. We used a targeted TNF blockade method to prevent this cycle in our mouse models. If these results can be replicated in humans, TNF blockade should prevent cardiac toxicity without compromising the anti-tumor benefits of ICIs.”

— Jeffery Molkentin, Director, Division of Molecular Cardiovascular Biology at Cincinnati Children's

What’s next

More research is needed to determine if a narrowly focused TNF inhibitor would be safe for human use, and how long a patient might need to take such a drug. The team also wants to determine whether similar approaches can also prevent immune-related adverse events affecting other organs.

The takeaway

This discovery could make immune checkpoint inhibitors, a transformative cancer treatment, safer and more accessible for a wider range of patients by preventing a potentially lethal side effect. If the findings can be replicated in humans, it would be a major advancement in cancer immunotherapy.