An investigational HER-2 vaccine, ES2B-C001, has demonstrated strong immune responses and therapeutic benefits when administered concurrently with monoclonal antibody therapy. This new generation vaccine, based on virus-like particles, elicited robust antibody and T cell responses in preclinical models.
Crucially, the simultaneous administration of the anti-HER-2 monoclonal antibody 4D5 did not impede the vaccine's immunogenicity. Antibody concentrations remained high for over six months, indicating durable immune activation even during ongoing antibody treatment.
The vaccine also retained its therapeutic efficacy in mice with human HER-2 transgenic mammary carcinomas. When combined with the antibody 4D5, a significant percentage of mice remained tumor-free long-term, comparable to antibody treatment alone. These findings suggest the HER-2 vaccine can maintain anti-tumor activity despite concurrent monoclonal antibody therapy.
ES2B-C001 has entered clinical development, with these preclinical results supporting its feasibility as part of combination treatment strategies for HER-2-positive diseases. This offers promise for expanding treatment options for patients already undergoing established anti-HER-2 therapies.