Triple negative breast cancer (TNBC) accounts for 15-20% of all breast cancers and it is highly aggressive, accounting for a disproportionate amount of metastatic disease cases and breast cancer deaths. Cancer cells evolve and develop protective mechanisms to hide themselves from cancer killing T-cells. Immune checkpoint inhibitors block these protective mechanisms by targeting PD-1, unhiding cancer cells so that they can be killed by T-cells. Immune checkpoint inhibitors such as pembrolizumab have significantly improved the time to progression in patients with PD-1+ metastatic TNBC when combined with chemotherapy, resulting in an FDA approval. However, TNBC is often called a “cold” tumor where there are very few immune cells, limiting the efficacy of the immune checkpoint inhibitors. Thus, there is an unmet need to identify drugs capable of priming breast tumors (turning “cold” tumors “hot”) to enhance the immune checkpoint inhibitor’s effectiveness. Recent studies have demonstrated that ivermectin, an inexpensive drug, induces a robust infiltration of T-cells into breast tumors, thus turning “cold” tumors “hot”. This phase I study will assess the safety of ivermectin in combination with pembrolizumab in patients with metastatic TNBC.
Trial Registration: ClinicalTrials.gov Identifier: NCT05318469