Boiling histotripsy and in-situ CD40 stimulation improve the checkpoint blockade therapy of poorly immunogenic tumors

Background: Advanced stage cancers with a suppressive tumor microenvironment (TME) are often refractory to immune checkpoint inhibitor (ICI) therapy. Recent studies have shown that focused ultrasound (FUS) TME-modulation can synergize ICI therapy, but enhancing survival outcomes in poorly immunogenic tumors remains challenging. Here, we investigated the role of based boiling histotripsy (HT) and in-situ anti-CD40 agonist antibody (?CD40) combinatorial therapy therapeutic efficacy against murine melanoma. Methods: Unilateral bilateral large (~330-400 mm3) B16F10 melanoma were established flank regions mice. Tumors exposed single local HT followed by an administration ?CD40 (HT+ ?CD40: HT40). Inflammatory signatures post treatment assessed using pan-cancer profiling flow cytometry. The ability HT40 ± enhance systemic effects was determined immunological characterization harvested tissues, growth delay distant untreated 4-6 weeks treatment. Results: Immune revealed upregulated variety inflammatory markers tumors. Immunologically, treated showed increased population granzyme B+ expressing functional CD8+ T cells (~4-fold) as well M1 M2 macrophage ratio (~2-3-fold) T: regulatory cell (~5-fold) compared control. Systemically, proliferation rates melanoma-specific memory significantly enhanced Finally, combination (anti-CTLA-4 anti-PD-L1) caused superior inhibition tumors, prolonged Conclusions: Data suggest reprograms immunologically cold sensitizes them This approach may be clinically useful for treating advanced cancers.