PGV001, a multi-peptide personalized neoantigen vaccine platform: Phase I study in patients with solid and hematological malignancies in the adjuvant setting

Abstract Immunotherapies like immune checkpoint inhibitors (ICIs) have changed the standard of care for cancer patients, often leading to durable responses. However, many patients remain or become refractory to ICIs owing to factors such as a lack of primed neoantigen-reactive T cells. We developed a peptide-based vaccination platform that utilizes fully personalized genome vaccines (PGV) and targets neoantigens predicted by our OpenVax computational pipeline. Here we report results from PGV001 study (NCT02721043) targeting up to 10 neoantigens, administered in the adjuvant setting to patients with both solid and hematological malignancies who have high risk of recurrence. Our data indicates that PGV001 is feasible and safe, with 13 out of 14 enrolled patients receiving the vaccine and 11 completing the treatment. 100% of vaccinated patients developed targeted T cell and B cell responses highlighting the capacity of OpenVax to predict immunogenic neoantigens and the potential of PGV001 for safely inducing targeted immunity.