RTID-04. A MULTICENTER, RANDOMIZED, CONTROLLED PHASE 2B TRIAL OF SURVIVIN VACCINE SURVAXM PLUS ADJUVANT TEMOZOLOMIDE FOR NEWLY-DIAGNOSED GLIOBLASTOMA (SURVIVE)

Abstract BACKGROUND Glioblastoma cells express high levels of survivin protein, whose presentation by MHC class I gets recognized by antibodies and cytotoxic T-lymphocytes (CTLs). A phase 2a trial (NCT02455557) demonstrated a median overall survival (OS) of 25.9 months in newly-diagnosed glioblastoma (nGBM) patients with 15-amino-acid-peptide-conjugate survivin vaccine (SurVaxM), which also stimulated production of survivin-directed antibodies and anti-tumor CTL. This phase 2b trial aims to further investigate efficacy and safety of SurVaxM plus adjuvant temozolomide (TMZ) for nGBM. METHODS SURVIVE is an ongoing, multicenter, randomized, placebo-controlled, investigator- and patient-blinded, phase 2b trial that randomizes nGBM patients receiving standard-of-care therapies to either SurVaxM (SurVaxM arm) or saline (control arm) in 3:2 ratio at 15 sites. Included patients have age ≥18 years, normal organ function, KPS≥70, and receive surgical resection with ≤1cm3 residual MRI contrast enhancement within 72 hours post-resection plus TMZ. Patients with recurrent, multicentric, brainstem- or cerebellar-origin GBM are excluded as well as patients on TTFields or other immunotherapies. All patients undergo 3 phases: (1) vaccine priming (VP) phase, starting ≤4 weeks after completing chemoradiation – 4 doses of SurVaxM or placebo administered q2weeks; (2) TMZ phase, started after ≥1 VP dose; and (3) vaccine maintenance phase, started 8 weeks after VP, with SurVaxM or placebo given q8weeks. TMZ phase overlaps with VP and VM phases. Primary endpoint is median OS. Assuming 1-year-OS of 75% in SurVaxM arm, based on prior trials, and 60% for control, the required sample size is N=228; 137 in SurVaxM and 91 in control arm. Accounting for dropouts, we aimed to enroll 239 patients. A log-rank test stratified by KPS (70-80 vs 90-100), MGMT methylation status, and IDH mutation status will be used for analysis. Secondary endpoints are OS and PFS at 15, 18, and 24 months, median PFS, and toxicity. A single sequential OS-driven interim analysis is planned when 50% of deaths occur. Trial is fully enrolled (NCT05163080).