A glioblastoma vaccine called SurVaxM extended survival in patients 65 and under by about four months in a randomized trial, according to results announced Oct. 7 by the company MimiVax and Roswell Park Comprehensive Cancer Center in Buffalo, New York. The trial missed its main goal for all patients combined.
The companies posted the figures in a press release on the SURVIVE trial, which enrolled adults with newly diagnosed glioblastoma, an aggressive brain cancer. The release does not cite a journal publication, and SurVaxM is investigational and not approved by the Food and Drug Administration.
SurVaxM trial results: what the numbers show
SURVIVE (NCT05163080) is a Phase 2b trial, meaning it was randomized, double-blind and placebo-controlled. Patients received standard care plus either SurVaxM or a placebo. The release says 233 evaluable patients took part at 11 cancer centers in the United States and the trial has run since 2022.
The primary endpoint was overall survival. Across all 233 patients, median survival was 22.8 months with SurVaxM and 20.3 months with placebo, according to the release. The hazard ratio was 0.75, and the p-value was 0.076. A p-value below 0.05 is the usual threshold for statistical significance, so the overall result did not meet it.
The prespecified key subgroup, patients 65 and under, fared better. Median survival was 24.2 months with SurVaxM and 20.2 months with placebo, with a hazard ratio of 0.64 and a p-value of 0.019, the release says. Progression-free survival in that group had a hazard ratio of 0.64 and a p-value of 0.018. At 12 months, 44% of vaccinated patients had no progression, compared with 24% on placebo.
The release also reports that about 42% of SurVaxM patients in the younger group were alive at 30 months or longer, compared with 18% on placebo. It says no further deaths occurred in the SurVaxM group between 30 and 54 months.
Onsite! arithmetic from the release’s figures: the gain was 2.5 months in the full group (22.8 minus 20.3) and 4.0 months in the 65-and-under group (24.2 minus 20.2). The younger group’s placebo median of 20.2 months sat nearly level with the whole placebo arm’s 20.3 months, so the subgroup’s gain came from the vaccine arm doing better, not from the placebo arm doing worse.
Ajay Abad, M.D., the trial’s principal investigator at Roswell Park, said in the release that “an improvement in survival of this magnitude is noteworthy.” He framed the result against what the release describes as limited progress in the field over 20 years.
Safety data for the SurVaxM vaccine
The release reports similar rates of serious problems in both arms. Adverse events of grade 3 or higher occurred in 48% of SurVaxM patients and 46% of placebo patients. Serious adverse events occurred in 25% and 21%. Four percent of SurVaxM patients stopped treatment because of side effects, and one of those cases was attributed to the study treatment. No treatmentrelated deaths occurred in either arm.
The most common reactions were mild to moderate and occurred where patients received injections. The release lists injection-site reactions in 48% of patients, pain in 41%, redness in 39%, itching in 38% and swelling in 29%. Flu-like illness occurred in 13%.
Why the placebo group matters in this glioblastoma trial
The placebo group lived longer than the trial planned for. The release says the placebo arm’s 20.3-month median exceeded the 16-month historical benchmark used to design the study. MimiVax says that made it harder to show a gap between the two arms.
That benchmark explains why the earlier results looked so different. In 2018, Roswell Park reported interim data from a 63-patient Phase 2 study without a placebo group. It said 91% of patients were alive at 12 months, compared with 61% in a historical group on standard therapy. Robert Fenstermaker, M.D., a Roswell Park neurosurgeon, said at the time, “We believe this drug has the potential to change the glioblastoma treatment paradigm.”
Randomized trials compare patients treated at the same time with the same care, and historical comparisons cannot. By the release’s own numbers, the contemporary control group outlived the historical benchmark by 4.3 months (20.3 minus 16). Some of what looked like vaccine benefit in the single-arm study may have come from improvements in standard care over time. The randomized difference is the figure that accounts for that.
MimiVax’s own Phase 2a median survival, which its website lists as 25.9 months, is also longer than the 22.8 months in the all-patient arm of the randomized study.
How SurVaxM works and what comes next
SurVaxM targets survivin, a cell-survival protein that Roswell Park said in 2018 is found in about 95% of glioblastomas. The 2018 release says the vaccine stimulates the patient’s T-cell response and also produces antibodies that inhibit the survivin pathway.
In 2023, the FDA granted the vaccine Fast Track designation, which allows more frequent agency meetings and, if the data support it, accelerated approval and priority review. At that time, the trial planned to enroll about 270 patients. The Oct. 7 release reports 233 evaluable patients.
MimiVax said it will ask the FDA for a meeting in the coming months to discuss the data, a Breakthrough Therapy designation and faster approval routes. Michael Ciesielski, Ph.D., the company’s chief executive and co-founder, said in the release that the data make a compelling case for the vaccine. The release said the path forward would be set in consultation with the FDA.
The release credits donors to the Roswell Park Alliance Foundation and two fundraising rides, Ride for Roswell and Empire State Ride, with seed funding that moved the therapy into clinical trials. It gives no dollar figures for the trial. MimiVax holds the exclusive global license to commercialize SurVaxM, and the release lists the availability of additional funding among its business risks.
The release says enrollment in the SurVaxM glioblastoma studies is complete and no such studies are currently enrolling, so patients cannot join a trial now. Patients and families deciding what to do should know that the benefit appears in a subgroup, and the study’s primary analysis did not reach significance. The release does not say when full results will be submitted for publication.
