Oncolytic Therapy: Delivery System and New Therapeutic Strategies for Cancer

Area of Science:

• Oncology
• Immunotherapy
• Virology

Background:

• Oncolytic viruses (OVs) are an emerging cancer immunotherapy combining tumor cell lysis with immune activation.
• While OVs show promise, clinical efficacy is limited by biological barriers like immune clearance, poor tumor targeting, and the immunosuppressive tumor microenvironment (TME).

Purpose of the Study:

• To review the mechanisms of OV infection, tumor selectivity, and virus-induced antitumor immune responses.
• To explore factors limiting OV therapeutic efficacy, including host immunity, tumor barriers, and TME networks.
• To examine strategies for optimizing OV delivery and combination therapies to enhance efficacy.

Main Methods:

• Review of current literature on oncolytic virotherapy mechanisms, challenges, and therapeutic strategies.
• Analysis of viral delivery systems (e.g., cell-based, extracellular vesicles, nanomaterials).
• Examination of combination therapies (e.g., immune checkpoint blockade, chemoradiotherapy, metabolic modulation).

Main Results:

• Key mechanisms of OV infection, tumor selectivity, and immune responses are detailed.
• Significant barriers to OV efficacy include host antiviral immunity, tumor structural constraints, and TME immunosuppression.
• Advanced delivery systems and combination therapies are crucial for overcoming these limitations.

Conclusions:

• Oncolytic viruses are evolving into adaptable immunotherapeutic platforms, not just cytolytic agents.
• Optimized delivery methods, TME modulation, and strategic therapeutic integration are key to maximizing OV effectiveness.
• Future research should focus on refining these strategies for improved clinical outcomes in cancer treatment.