Genetic Inheritance May Predict Resistance to Immunotherapy in Advanced Skin Cancer

Recent research has uncovered a significant genetic factor that could influence the effectiveness of immunotherapy treatments for metastatic melanoma, a severe form of skin cancer that claims nearly 10,000 lives annually in the United States. In a study led by NYU Langone Health and its Perlmutter Cancer Center, scientists analyzed blood samples from over 1,200 patients participating in the landmark CheckMate-067 Phase III trial across multiple international centers.

The findings reveal that individuals carrying a specific mitochondrial DNA mutation, known as mitochondrial haplogroup T (HG-T), are approximately 3.5 times less likely to respond to immune checkpoint inhibitors, such as nivolumab and ipilimumab. These treatments work by blocking immune system checkpoints, which tumors manipulate to evade immune attack. However, the genetic mutation in mitochondrial DNA, inherited maternally, seems to confer resistance by affecting mitochondrial function, specifically within cell powerhouse structures called mitochondria.

Researchers focused on mitochondrial DNA because it has a distinct inheritance pattern and has been linked to immune cell development. They discovered that patients resistant to immunotherapy with HG-T showed underdeveloped T cells, possibly due to enhanced resilience against reactive oxygen species (ROS)—chemicals involved in inflammatory responses—thus impairing the immune cells’ ability to attack cancer cells effectively.

To validate their initial results, the team examined additional blood samples from a complementary cohort of 397 melanoma patients, confirming the strong association between HG-T and immunotherapy resistance. Lead investigators emphasized that identifying this genetic marker enables more personalized treatment approaches, guiding clinicians to consider alternative therapies for patients unlikely to benefit from checkpoint inhibitors.

This research opens the door for further studies on how mitochondrial genetics influences immune response and cancer treatments. The next step involves prospective clinical trials to evaluate whether patients without HG-T respond better to immunotherapy, aiming to improve outcomes for those with resistant genetic profiles.

Understanding and testing mitochondrial inheritance could ultimately help revolutionize cancer treatment strategies, ensuring patients receive the most effective therapies based on their genetic makeup.