Toll-like receptor agonists as cancer therapeutics: a patent review (2014-2024)

Toll-like receptors (TLRs) play a key role in cancer immunotherapy by harnessing the immune system's natural response to target and fight tumors. Among the various TLRs, mainly TLR3, TLR4, TLR7, TLR8, and TLR9, have been investigated for their ability to modulate immune responses, improve tumor recognition, and enhance the efficacy of conventional treatments like chemotherapy and radiotherapy.

This review provides an in-depth analysis of patents filed from 2014 to 2024 that explored TLR-targeting strategies in cancer therapy. TLRs trigger the release of pro-inflammatory cytokines such as IFN-γ, TNF-α, IL-12, and IL-6, which promote anti-tumor immunity by enhancing T-cell activation and dendritic cell maturation. TLR-based therapies have shown promise by stimulating innate and adaptive immunity, leading to increased tumor cell death.

TLR agonists have been shown to, reduce treatment-related side effects, and inhibit tumor growth. However, challenges such as immune-related adverse events, including cytokine storms, and limited efficacy in specific tumor types persist. Advances in delivery systems, such as nanoparticles, liposomes, and conjugates, further enhance the targeting and effectiveness of TLR-based therapies while minimizing toxicity. The ongoing exploration of TLR agonists and their integration into combination therapies holds significant promise for improving cancer immunotherapy and patient outcomes.