Efficacy and Safety of Oncolytic Viruses Immunotherapy in Advanced Malignancies

To provide insight into the efficacy and safety of oncolytic viruses (OVs) in advanced malignancies.

We reviewed 188 clinical trials, including 5410 patients. This review mainly summarized the clinical landscape of OVs, including the immune response, clinical response, and treatment-related adverse events (TRAEs).

We found that the most common tumor type targeted was melanoma (1586/541029.3%) and most patients were treated with OVs monotherapy (2893/541053.5%) via intratumoral (2917/541054.4%) or intravenous (1686/541061.2) delivery. Sixty-eight (68/18836.2%) and 74 (74/18836.4%) studies evaluated the tumor microenvironment and systemic immune response, respectively. Importantly, an increase in tumor-specific cytotoxic T lymphocytes was reported in 15 (8.0%) trials. There were 103 (54.8%) and 13 (6.9) studies reporting humoral and cellular virus-specific immune responses, respectively. 129 (129/18868.6%) studies evaluated clinical efficacy in 3536 patients, with objective response and disease control of 870 (24.6%) and 2615 (59.1%), respectively. Subgroup analysis revealed an objective response in 522 (34.5%) and disease control in 953 (62.9%) of the 1514 patients in the herpes simplex virus (HSV) subgroup. The percentages of patients with objective response and disease control for different administration routes, including intratumoral (29.3%; 63.1%) and intravenous (18.1%; 52.8%) injections, and for different treatments including combination (31.8%; 65.1%) and monotherapy (17.3%; 55.1%), were summarized. Immunotherapy may be a promising combination therapy, with objective response and disease control occurring in high proportions of patients (35.9%; 59.9%). Moreover, OVs demonstrated a manageable safety profile, with most TRAEs being Grades 1-2.

This study provides a general overview of the status of OVs clinical trials, but further research is needed to determine the optimal treatment regimen and combination strategy.