Research progress in bifunctional small molecules for cancer immunotherapy

Area of Science:

• Oncology
• Immunology
• Medicinal Chemistry

Background:

• Immunotherapy using anti-PD-L1/PD-1 monoclonal antibodies (mAbs) has revolutionized cancer treatment, but faces challenges like limited efficacy (∼20%), poor pharmacokinetics, and immune resistance.
• The limitations of current immunotherapies necessitate the development of novel therapeutic strategies, including combination therapies and bifunctional small molecules.

Purpose of the Study:

• To summarize the latest advancements in bifunctional small molecules for cancer immunotherapy.
• To review PD-L1-based and other dual-acting compounds targeting various pathways involved in tumorigenesis and immune response.
• To discuss the mechanisms of action, synergy, challenges, and future directions of these novel therapeutics.

Main Methods:

• Literature review of recent developments in bifunctional small molecule immunotherapy.
• Analysis of PD-L1-based and other dual-acting compounds targeting key cancer-related pathways.
• Summary of tumorigenesis and synergy mechanisms for various molecular targets.

Main Results:

• Significant progress has been made in developing PD-L1-based bifunctional small molecules targeting pathways such as HDAC, CXCL12, Tubulin, IDO1, PARP, STING, and NAMPT.
• Other promising dual-acting compounds based on A2AR, IDO1, TLR, SHP2, and HPK1 have also emerged.
• These compounds aim to enhance anti-tumor immunity by modulating the tumor microenvironment and overcoming resistance mechanisms.

Conclusions:

• Bifunctional small molecules represent a promising next generation of cancer immunotherapy, offering potential to overcome the limitations of current antibody-based treatments.
• Further research into their mechanisms, clinical efficacy, and safety is crucial for their successful translation into patient care.
• These novel agents hold significant potential for improving treatment outcomes in various cancers.