Blocking PD-1/PD-L1 Immune Checkpoints in Breast Cancer: Research Findings and Ways to Improve Response

The effectiveness of PD-1/PD-L1 immunotherapy may depend on tumor-intrinsic factors and cell interactions within the tumor microenvironment.

• Combining PD-1/PD-L1 immune checkpoint blockade with chemotherapy has shown promising efficacy in early and metastatic triple-negative breast cancer.
• Only a subset of patients experiences durable responses to this treatment.
• Identifying responders is critical for optimizing immune drug selection.
• Key findings from clinical trials indicate that the regulation of PD-L1 expression is influenced by various mechanisms.
• Recent advances suggest that tumor-infiltrating lymphocytes' quantity, type, and spatial arrangement could serve as promising biomarkers for therapy.
• Strategies to enhance the effectiveness of immune checkpoint blockers are being explored to support personalized treatment approaches.

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