Posted: Monday, December 5, 2022
According to Angel Arnaout, MD, of the Ottawa Hospital Research Institute, Canada, and colleagues, intratumoral injection with INT230-6 may convert traditionally immune-quiescent breast cancers into immunogenic tumors. The results of the phase II INVINCIBLE trial, which were presented at the 2022 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 545) and published in the Journal for ImmunoTherapy of Cancer, suggested this well-tolerated formulation may serve as an immunotherapeutic option in early-stage disease.
“Local therapies that induce cell death and expose tumor antigens [may] potentially increase responsiveness to immunotherapies,” the investigators remarked. “Intratumoral INT230-6, [which is] composed of a dispersion enhancer molecule in solution with…vinblastine and cisplatin, [is] designed to cause tumor necrosis by dispersion throughout the tumor and diffusion into cancer cells.”
The trial enrolled 87 patients with newly diagnosed intermediate- or high-grade stage T1–T2 invasive breast cancer who were awaiting surgery. In part I of the study, they were randomly assigned in a 2:1 ratio to receive either one to three weekly doses of the INT230-6 injection or no treatment prior to surgery. In part II of the study, patients were randomly assigned in a 2:1 ratio to receive either one dose of the INT230-6 injection or a saline injection.
Injection-site pain, injection-site reaction, and nausea/vomiting were the most frequently reported adverse events. Treatment with INT230-6 was found to induce necrosis of up to 95% of the tumor in various breast cancer subtypes and histologies, including invasive lobular carcinoma. Gene-expression analysis revealed significant differential gene expression between the baseline biopsy and surgical specimens. Based on a pathway analysis, genes associated with T-cell receptor signaling, B cells, T cells, chemokine signaling, and NF-κB signaling were significantly changed in the samples post treatment. A relative increase in CD4 and CD8 T cells, B cells, and natural killer cells was observed within the tumor and tumor microenvironment.
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