Molecularly targeted therapy and immunotherapy for hormone receptor‑positive/human epidermal growth factor receptor...

Area of Science:

• Oncology
• Pharmacology
• Immunology

Background:

• Hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (HR+/HER2− aBC) has limited treatment options beyond endocrine therapy.
• Targeted signaling pathways and immune checkpoints are implicated in HR+/HER2− aBC proliferation and growth.

Purpose of the Study:

• To review targeted biological therapies and immunotherapies for HR+/HER2− aBC.
• To discuss mechanisms of action, clinical efficacy, and safety profiles of these novel treatments.

Main Methods:

• Literature review of approved and investigational targeted therapies and immunotherapies.
• Analysis of clinical trial data regarding efficacy and toxicity.

Main Results:

• Phosphoinositide 3-kinase/AKT/mammalian target of rapamycin pathway inhibitors show clinical activity.
• CDK4/6 inhibitors, alone or with endocrine therapy, demonstrate promising tumor response and acceptable toxicity.
• Programmed death 1/programmed death ligand 1 (PD1/PD-L1) and cytotoxic T lymphocyte antigen-4 inhibitors show potential for antitumor immune response.

Conclusions:

• Targeted therapies, including CDK4/6 inhibitors, represent a significant advancement in HR+/HER2− aBC treatment.
• Immunotherapies offer a proof-of-principle for their use in breast cancer, warranting further investigation.
• Comprehensive understanding of efficacy and safety is crucial for integrating these novel therapies into clinical practice.