Montelukast targets CysLTR1 to improve immunotherapy response

A common asthma medication may hold promise for improving cancer immunotherapy, according to new research. Scientists have discovered that tumors can exploit a molecule targeted by the drug to suppress the body's immune defenses, and blocking it could help overcome treatment resistance.

The study, published in the journal Nature Cancer, focuses on a molecule called cysteinyl leukotriene receptor 1 (CysLTR1), which is well-known for its role in asthma and allergies. Drugs like montelukast, widely prescribed for decades, work by blocking this molecule. Researchers found that many aggressive cancers appear to hijack this same pathway to evade the immune system.

Specifically, the research indicates tumors can increase a group of white blood cells called neutrophils and reprogram them to support cancer growth instead of fighting it. This process is controlled by CysLTR1. In experiments using mouse models of several cancers—including triple-negative breast cancer, melanoma, ovarian, colon, and prostate cancer—blocking CysLTR1 genetically or with drugs like montelukast slowed tumor growth, improved survival, and restored the effectiveness of immunotherapy. This was even observed in...