Conclusions
Cancer peptide vaccines in combination with intravesical BCG therapy demonstrated good immunogenicity and safety, and may provide benefit for preventing recurrence of NMIBC.
Methods
127 patients were enrolled in a multicenter, non-randomized phase II clinical trial. The primary endpoint was recurrence-free survival (RFS) rate, and secondary endpoints were safety and immunological response. HLA-A24-restricted peptides were subcutaneously administered in addition to intravesical BCG therapy. The exploratory endpoint evaluated differences of RFS rate between HLA-A*2402-positive (A24(+)) and -negative (A24(-)) groups.
Purpose
A phase I study using two peptide vaccines derived from M phase phosphoprotein 1 (MPHOSPH1) and DEP domain containing 1 (DEPDC1) demonstrated promising
Results
A 2-year RFS rate in all patients was 74.0%. The RFS rate in the A24(+) group (n = 75) and in the A24(-) group (n = 52) were 76.0 and 71.2%, respectively. This vaccine therapy was well-tolerated and feasible. MPHOSPH1 and DEPDC1 peptide-specific cytotoxic T lymphocyte responses were observed in 75.8 and 77.5% of the A24(+) group, respectively. Patients having both peptide-specific CTL responses showed significantly better RFS than patients without CTL response (P = 0.014). In the A24(+) group, patients who had positive reaction at the injection sites (RAI) had significantly lower rates of recurrence than RAI-negative patients (P = 0.0019). Conclusions: Cancer peptide vaccines in combination with intravesical BCG therapy demonstrated good immunogenicity and safety, and may provide benefit for preventing recurrence of NMIBC.