Repeated intratumoral administration of ONCOS-102 leads to systemic antitumor CD8⁺T-cell response and robust cellular and transcriptional immune activation at tumor site in a patient with ovarian cancer

Abstract

Adenoviruses are excellent immunotherapeutic agents with a unique ability to prime and boost immune responses. Recombinant adenoviruses cause immunogenic cancer cell death and subsequent release of tumor antigens for antigen presenting cells, resulting in the priming of potent tumor-specific immunity. This effect may be further enhanced by immune-stimulating transgenes expressed by the virus. We report a case of a 38-year-old female with Stage 3 metastatic micropapillary serous carcinoma of the ovary. She was treated in a Phase I study with a granulocyte-macrophage colony stimulating factor (GMCSF)-expressing oncolytic adenovirus, Ad5/3-D24-GMCSF (ONCOS-102). The treatment resulted in progressive infiltration of CD8+ lymphocytes into the tumor and concomitant systemic induction of several tumor-specific CD8+ T-cell populations. The patient was alive at the latest follow up more than 20 months after initiation of the study.