Efficacy of oncolytic virus in the treatment of intermediate-to-advanced solid tumors: a systematic review and meta-analysis

Abstract

This meta-analysis assessed oncolytic virus therapy's efficacy for intermediate-to-advanced solid tumors. We systematically searched PubMed, Cochrane Library, and Embase databases until March 6, 2025. Our review included 87 studies, involving 5,385 individuals, encompassing 75 clinical trials and 12 retrospective studies. Patient response rates were as follows: complete response (CR) 11%, partial response (PR) 18%, stable disease (SD) 32%, and progressive disease (PD) 32%. The overall response rate (ORR) was 29%, and the durable response rate (DRR) was 39%. Comparing oncolytic virus therapy to alternatives, the odds ratio (OR) for overall response was 1.62, and the hazard ratio (HR) for overall survival (OS) was 0.86. This analysis emphasizes the effectiveness of oncolytic virus therapy for intermediate-to-advanced solid tumors, highlighting its promise as a treatment option. These findings offer vital insights into cancer therapy researchers and practitioners.IMPORTANCEAlthough previous meta-analyses on this topic have been published, our research addresses the limitations of previous studies by including missed and newly published studies, updating the results, and conducting extensive subgroup analyses. Our study fills a gap in the literature by providing a comprehensive evaluation of the therapeutic potential of oncolytic viruses for solid tumors.

Keywords: intermediate-to-advanced solid tumor; meta-analysis; oncolytic virus.

Fig 1

Flow chart illustrating the process of study selection. Inclusion/exclusion criteria can be seen in Table S2.

Fig 2

Forest plot demonstrating the CR (a, n = 62), PR (b, n = 61) SD (c, n = 57), and PD (d, n = 55) of patients treated with OVs. CR: complete response, PR: partial response, SD: stable disease, PD: progressive disease, OV: oncolytic viruses, CI: confidence intervals.

Fig 3

Forest plot presenting the ORR (a, n = 81) and DRR (b, n = 9) of patients treated with OVs. The ORR of patients was 29% (95% CI = 23%–35%, P < 0.01) using the random effects model. The DRR of patients was 39% (95% CI = 24%–56%, P < 0.01) using the random effects model. ORR: overall response rate, DRR: durable response rate, CI: confidence intervals.

Fig 4

Subgroup analysis of ORR of patients by virus species, country, study phase, OV types, and cancer types. HSV: herpes simplex virus, ORR: overall response rate, OV: oncolytic viruses, CI: confidence intervals, HCC: hepatocellular carcinoma.

Fig 5

(a)Forest plot of OR of ORR in patients treated with OVs versus no OVs (n = 19). The OR of ORR was 1.72 (95%CI = 1.19–2.50, P < 0.01) using the random effects model. (b) Subgroup analysis of OR of ORR based on virus species, country, OV types, study types, and cancer types. HSV: herpes simplex virus, OR: odds ratio, ORR: overall response rate, OV: oncolytic viruses, HCC: hepatocellular carcinoma.

Fig 6

(a) Forest plot of HR of OS in patients treated with OVs versus no OVs (n = 14). The HR of OS was 0.85 (95%CI = 0.71–1.02, P < 0.01) using random effects model. (b) Subgroup analysis of HR of OS based on virus species, country, OV types, study types, and cancer types. (c) Forest plot of HR of PFS in patients treated with OVs versus no OVs (n = 11). The HR of PFS was 0.89 (95%CI = 0.74–1.08, P < 0.01) using random effects model. HSV: herpes simplex virus, HR: hazard ratio, OS: overall survival, OV: oncolytic viruses, PFS: progression-free survival, HCC: hepatocellular carcinoma.