Immune Checkpoint Blockade Augments Lymphodepleting Chemotherapy-Induced Antitumor Immunity by Expanding Effector CD8+ T-cell Clones.

Combining cyclophosphamide with immune checkpoint blockade expands effector CD8+ T cell clones, delaying tumor progression in multiple cancer models.

• Why it matters: Overcoming resistance to immune checkpoint therapies remains a challenge in cancer treatment, necessitating strategies to enhance anti-tumor immune responses and improve patient outcomes.
• What they did: Researchers administered a single dose of cyclophosphamide prior to anti-PD-1 and anti-CTLA-4 therapy in mouse models, observing effects on tumor growth and T cell responses across various cancers.
• The result: The combination significantly delayed tumor progression and extended survival by promoting clonal expansion of tumor-specific effector CD8+ T cells, suggesting a promising approach for resistant tumors.