Applying this discovery to patients, Dr. Marron initiated a clinical trial using dupilumab, a drug that blocks the protein receptor for IL-4—in combination with a PD1 /PD-L1 checkpoint blockade—to treat patients with relapsed or refractory non-small cell lung cancer (NSCLC). The trial showed promising results, with one of the six patients treated with the drug combination showing near complete response.

This study highlights the role of IL-4 in controlling the development of immune cells that suppress the immune system in cancer. The study also discovered a new way to combine treatments to block immune checkpoints in patients.

These findings are important because myeloid cells play a crucial role in shaping tumor progression, at times by suppressing the body’s anti-tumor immune response. In the case of NSCLC, the tumor is infiltrated by macrophages that actively contribute to tumor development through various means. Unfortunately, these macrophages create a resistant environment, making current immunotherapies less effective in treating the tumor. The introduction of any therapy or drug capable of safely managing these tumor-associated macrophages could revolutionize the field, especially when combined with existing immunotherapies.