Oncolytic Virus Encoding a Master Pro-Inflammatory Cytokine Interleukin 12 in Cancer Immunotherapy

Area of Science:

• Oncolytic virotherapy
• Cancer immunotherapy
• Molecular virology

Background:

• Oncolytic viruses (OVs) selectively destroy cancer cells and stimulate anti-tumor immunity.
• Interleukin 12 (IL-12) is a cytokine that enhances T-cell responses against tumors but causes systemic toxicity.
• Genetically engineered OVs expressing IL-12 (OV-IL12s) aim to deliver IL-12 locally to tumors, mitigating toxicity.

Purpose of the Study:

• To review the efficacy and safety of OV-IL12s, focusing on oncolytic herpes simplex virus encoding IL-12 (OHSV-IL12).
• To discuss the potential of OV-IL12s for local IL-12 production in cancer treatment.
• To explore OHSV-IL12 as a monotherapy and in combination treatments.

Main Methods:

• Preclinical testing of 25 different IL-12 expressing OVs (OV-IL12s) in various cancer models.
• Focus on genetically engineered oncolytic herpes simplex virus encoding IL-12 (OHSV-IL12) due to its clinical advancement.
• Review of studies evaluating safety, tumor specificity, and anti-tumor immune/anti-angiogenic effects.

Main Results:

• Local IL-12 expression via OVs avoids systemic toxicity associated with IL-12 therapy.
• OV-IL12s induce potent anti-tumor immunity and can synergize with other therapies.
• OHSV-IL12 demonstrates promising preclinical results and is the most advanced OV-IL12 in clinical trials.

Conclusions:

• OV-IL12s, particularly OHSV-IL12, represent a promising strategy for localized IL-12 delivery in cancer therapy.
• These engineered viruses offer a safer alternative to systemic IL-12, enhancing anti-tumor immunity and potentially improving treatment outcomes.
• Further clinical investigation of OHSV-IL12 and other OV-IL12s is warranted to fully exploit their therapeutic potential.