Prophetic Proteins: Predicting Patient Response to Melanoma Immunotherapy

Researchers from the Mayo Clinic have identified a protein marker, Bim, which can help effectively predict patients’ responses to PD-1 blockade immunotherapy for melanoma.

The Bim protein helps coordinate programmed cell death.

As tumors can potentially evade the immune system, researchers generated biological molecules blocking interaction between PD-1 and PD-L1 to thereby preventing T cell elimination.

Furthermore, according to the researchers, the melanoma patients who responded to PD-1 blockade with pembrolizumab actually had more tumor-targeting T cells expressing Bim and PD-1 in their blood before therapy than those patients who didn’t respond.

The experts realized responders have higher levels of soluble PD-L1 in their blood prior to treatment, signifying that PD-1 blockade could be the most effective method during PD-1 and PD_L1 interaction.

Rosana Dronca, MD, hematologist at the Mayo Clinic, presented these findings at the American Association for Cancer Research International Cancer Immunotherapy Conference in NY. “The discovery of biomarkers of sensitivity are vital not only for informing clinical decisions, but also to help identify which patients with melanoma, and possibly other malignancies, who are most likely to benefit from PD-1 blockade,” she said.