Review: Oncolytic virotherapy, updates and future directions

Area of Science:

• Oncolytic virology
• Cancer immunotherapy
• Viral oncology

Background:

• Oncolytic viruses (OVs) selectively infect and lyse cancer cells, sparing normal tissues.
• IMLYGIC™ (T-VEC) is the first approved oncolytic virus for advanced melanoma.
• OVs demonstrate potent anticancer activity in vitro and in vivo but often have limited clinical efficacy as monotherapy.

Purpose of the Study:

• To explore the rationale for combining oncolytic viruses with other cancer therapies.
• To investigate the potential of oncolytic viruses to enhance anti-tumor immune responses.
• To evaluate the synergistic effects of oncolytic viruses and immune checkpoint inhibitors.

Main Methods:

• Review of mechanisms of oncolytic virus action, including direct cell lysis and immune stimulation.
• Analysis of clinical data and preclinical studies on oncolytic virus therapy.
• Examination of the interplay between oncolytic viruses, tumor microenvironment, and immune checkpoints.

Main Results:

• Oncolytic viruses can induce an anti-tumor immune response, creating an inflamed tumor microenvironment.
• Intratumoral administration of OVs can improve direct tumor access and reduce systemic side effects.
• Immune checkpoint stimulation is observed post-OV therapy, suggesting potential for combination strategies.

Conclusions:

• Oncolytic viruses offer a favorable toxicity profile and direct/indirect tumor-killing mechanisms.
• Combination therapy with oncolytic viruses and immune checkpoint inhibitors is a promising strategy for cancer treatment.
• Further clinical trials are warranted to investigate the efficacy of combining OVs with other cancer therapies.