Buffalo, New York-based MimiVax said its Phase IIb SURVIVE trial of the cancer vaccine SurVaxM in newly diagnosed glioblastoma did not meet the primary overall survival (OS) endpoint in the full trial population, with median OS of 22.8 months versus 20.3 months for placebo (HR 0.75; 95% CI 0.54–1.03; p=0.076).
The randomized, double-blind, placebo-controlled SURVIVE trial (NCT05163080) evaluated SurVaxM plus standard of care versus placebo plus standard of care in 233 evaluable patients across 11 US cancer centers. MimiVax noted that median OS in the placebo arm, at 20.3 months, was longer than the 16-month historical benchmark used in the trial’s design assumptions.
A prespecified subgroup of patients aged 65 and under showed a statistically significant OS benefit, with median survival of 24.2 months for SurVaxM versus 20.2 months for placebo (HR 0.64; 95% CI 0.44–0.93; p=0.019). Progression-free survival also favored SurVaxM in that subgroup (HR 0.64; p=0.018). MimiVax said approximately 42% of SurVaxM-treated patients aged 65 and under were alive at 30 months or longer, compared with 18% in the placebo arm, with no additional deaths reported in the SurVaxM group between 30 and 54 months.
Grade 3 or higher adverse events occurred in 48% of SurVaxM-treated patients and 46% of placebo recipients, while serious adverse events occurred in 25% and 21%, respectively. No treatment-related deaths were reported in either group.
SurVaxM, also known as SVN53-67/M57-KLH, is a conjugated survivin peptide-mimic vaccine designed to stimulate survivin-specific immune responses. The vaccine comprises a synthetic peptide spanning amino acids 53–67 of human survivin with an M57 substitution and is linked to keyhole limpet hemocyanin.