Pembrolizumab, Temozolomide and HSPPC-96 Vaccine in Newly Diagnosed Glioblastoma Post-Chemoradiation: Results from a Multi-institutional, Phase 2, Randomized, Placebo-Controlled Trial

The study examined the efficacy of a combination of pembrolizumab, temozolomide, and HSPPC-96 vaccine in patients with newly diagnosed glioblastoma, one of the most common and aggressive brain tumors in adults. The study enrolled 32 patients (8 in the vaccine group, 9 receiving placebo, and 15 in an ancillary group), of which 26 were evaluable for radiographic responses. The primary objective was overall survival at one year, which reached 65.5% in the vaccine group and 75% in the placebo group. The study did not demonstrate statistically significant improvement in progression-free survival or response rates. The treatment regimen was well-tolerated and safe. The results do not support the combination of pembrolizumab and HSPPC-96 vaccine with standard care therapy.