Drugdu.com expert's response:

Oncolytic virus (OV) therapy demonstrates outstanding performance in terms of broad-spectrum efficacy, cost-effectiveness, and the ability to reverse the tumor immune microenvironment. However, it faces limitations in administration methods and infection efficiency, necessitating combination with other therapies to overcome single-agent constraints. CAR-T therapy exhibits remarkable efficacy in hematological malignancies but is associated with high costs, limited effectiveness in solid tumors, and elevated risks of side effects. PD-1 inhibitors offer convenience and maturity in application but suffer from low response rates and are constrained by tumor immune phenotypes. Below is a detailed comparison of oncolytic virus therapy with other immunotherapies, such as CAR-T and PD-1 inhibitors:

Advantages of Oncolytic Virus Therapy

Broad-Spectrum Efficacy and Tumor Microenvironment Remodeling: Oncolytic viruses can target a variety of solid tumors, including liver cancer, melanoma, and ovarian cancer, and are particularly adept at transforming "cold tumors" (with low immune cell infiltration) into "hot tumors." By lysing tumor cells, they release antigens that activate dendritic cells and T cells, while expressing immunostimulatory factors (such as IL-12 and IL-15) to reverse the immunosuppressive microenvironment.

Cost-Effectiveness and Accessibility: The production cost of oncolytic viruses is significantly lower than that of CAR-T therapy. For example, the cost of a single dose of NDV-GT cultured in chicken embryos is approximately 140,withanannualtreatmentcostoflessthan4,200; in contrast, a single dose of CAR-T therapy in China costs around $140,000.

Overcoming Drug Resistance and Combination Potential: Oncolytic viruses are less prone to developing drug resistance and can significantly enhance efficacy when combined with PD-1 inhibitors. For instance, Binhui Biotech's OH2, in combination with a PD-1 inhibitor, extended patient survival in melanoma treatment; VG161 expresses immune checkpoint blockade peptides to reverse immune evasion in liver cancer.

Disadvantages of Oncolytic Virus Therapy

Administration Limitations: Oncolytic viruses are primarily administered via intratumoral injection, requiring image guidance for deep-seated tumors; intravenous administration is prone to immune clearance. The in vivo infection rate of oncolytic viruses is only about 20%, necessitating optimization of the delivery system.

Limited Efficacy as Monotherapy: Although oncolytic viruses have shown efficacy in various solid tumors, their therapeutic effect as monotherapy may not be as significant as that of combination therapies.

Comparison with Other Immunotherapies

Comparison with CAR-T Therapy: 

Advantages: Oncolytic viruses excel in broad-spectrum efficacy, cost-effectiveness, and the ability to reverse the tumor immune microenvironment; whereas CAR-T therapy is highly effective in hematological malignancies but is costly, has limited efficacy in solid tumors, and poses high risks of side effects (such as cytokine release syndrome and neurotoxicity).

Combination Potential: Oncolytic viruses can carry specific antigens (such as CD19T) for expression in tumor cells, enhancing the targeting of CAR-T therapy. For example, the combination of oncolytic virus OV-CD19T with CD19-CAR-T significantly improves the killing effect on solid tumors.

Comparison with PD-1 Inhibitors:

Advantages: Oncolytic viruses can release antigens and activate the immune system, forming a "dual immune activation" effect when combined with PD-1 inhibitors; whereas PD-1 inhibitors have an effectiveness rate of only 20% in non-selected populations and are largely ineffective against "cold tumors" (such as pancreatic cancer and MSS-type colorectal cancer).

Limitations: PD-1 inhibitors offer the advantages of convenience and mature application, with intravenous or oral administration being straightforward. They have become the standard therapy for "hot tumors" (such as those with high PD-L1 expression), covering a variety of indications including lung cancer and melanoma.