Beyond Neoantigens: Antigens Derived from Tumor Drivers as Cancer Vaccine Targets

Area of Science:

• Oncology
• Immunology
• Vaccine Development

Background:

• HER2 (human epidermal growth factor receptor 2) is a tumor antigen that is overexpressed in certain cancers, including breast cancer.
• Targeting overexpressed tumor antigens with vaccines is a promising strategy in cancer immunotherapy.

Purpose of the Study:

• To evaluate the safety and efficacy of a HER2-targeting vaccine in patients with metastatic breast cancer.
• To assess the vaccine's ability to prime T cells for adoptive transfer and induce an immune response.

Main Methods:

• Administration of a vaccine targeting HER2.
• Ex vivo expansion of T cells.
• Adoptive transfer of primed T cells.
• Monitoring for toxicity and immune response, including epitope spreading.

Main Results:

• The HER2 vaccine successfully primed T cells for ex vivo expansion and adoptive transfer.
• The treatment regimen exhibited minimal toxicity in patients.
• Intramolecular epitope spreading was observed in a majority of patients, indicating an enhanced immune response.

Conclusions:

• A vaccine targeting HER2 is a viable treatment modality for patients with metastatic breast cancer expressing HER2.
• This vaccine-based approach has the potential to improve outcomes for HER2-positive breast cancer patients.
• The induction of epitope spreading suggests a robust and potentially durable anti-tumor immune response.