MimiVax and Roswell Park Announce Results from Phase 2b SURVIVE Trial of SurVaxM in Newly Diagnosed Glioblastoma

MimiVax Inc., a clinical-stage biotechnology company dedicated to the development of innovative cancer immunotherapies, in collaboration with Roswell Park Comprehensive Cancer Center, today announced results from the SURVIVE trial (NCT05163080), the Company’s Phase 2b randomized, double-blind, placebo-controlled clinical trial evaluating its novel cancer vaccine, SurVaxM, in patients with newly diagnosed glioblastoma.

The data reflect the first reportable results from the fully enrolled clinical trial, which has been underway since 2022 at 11 U.S. cancer centers.

Across all 233 evaluable patients, SurVaxM improved median overall survival (OS), the primary endpoint, to 22.8 months versus 20.3 months for placebo (hazard ratio [HR] 0.75; 95% CI 0.54 to 1.03; log-rank p=0.076 adjusted for MGMT & KPS stratification), a clinically meaningful result that did not quite reach the traditional threshold for statistical significance (p=0.05).

Importantly, among a prespecified key subpopulation of patients aged 65 and under, SurVaxM demonstrated a statistically significant benefit, with median OS of 24.2 months versus 20.2 months (HR 0.64; 95% CI 0.44 to 0.93; p=0.019 adjusted for MGMT & KPS stratification). A significant benefit was seen in progression-free survival (PFS) in the same subgroup of patients 65 and under (HR 0.64; p=0.018), including improvement in progression-free survival at 12 months (44% SurVaxM vs 24% placebo).

“Every patient with glioblastoma is facing one of the hardest diagnoses in medicine. To see many of our study patients living longer, and several of them living years longer, is deeply meaningful to every one of us who has participated in the work to develop and study this new treatment approach,” said Ajay Abad, M.D., study principal investigator and Assistant Professor of Oncology and Neurology in the Department of Neuro-Oncology at Roswell Park. “In a disease where we’ve had limited progress over the last 20 years, an improvement in survival of this magnitude is noteworthy.”

Robert Fenstermaker M.D., co-principal investigator of the SURVIVE trial, Chair Emeritus of Neurosurgery at Roswell Park and Chief Medical Officer and Co-founder of MimiVax, added, “For patients 65 and under, this is one of the strongest signals we have seen in newly diagnosed glioblastoma in a long time. We designed the trial to provide a good comparison to our earlier Phase 2a study, while adding a placebo arm to account for improvements in standard of care that may have occurred over time. In a disease where progress has often been measured in weeks, results like these can be enormously meaningful.”

Long-Term Survival

The new analysis also shows that approximately 42% of SurVaxM-treated patients 65 and under were alive through 30 months or longer, with no further deaths reported at 30 through 54 months. This durable, long-term survival represents a doubling of survival compared to placebo (42% SurVaxM vs. 18% Placebo). This level of long-term survival is uncommon in people with newly diagnosed glioblastoma and warrants continued follow-up and investigation.

“These initial results from the SURVIVE trial give us a clear and coherent picture. SurVaxM showed a consistent survival signal, with a substantial group of patients living well past what we typically see in this disease,” said Michael Ciesielski, Ph.D., Chief Executive Officer and Co-Founder of MimiVax. “We believe these data make a compelling case for SurVaxM, and we look forward to discussing these robust findings with the FDA.”

The Control Arm’s Strong Results

The placebo arm in SURVIVE outperformed the trial’s design assumptions, with a median overall survival of 20.3 months versus an expected 16-month historical benchmark. The contemporary standard of care performed better than historical references would have predicted, raising the bar against which SurVaxM was measured. The longer survival in the control arm made a statistically significant separation in the overall population more difficult to achieve and provides important context for interpreting the primary endpoint.

Safety

SurVaxM was well tolerated. Observed responses were predominantly Grade 1 or 2 injection-site reactions (injection-site reaction 48%, pain 41%, erythema 39%, pruritus 38%, swelling 29%) and influenza-like illness (13%). Rates of Grade 3 or higher adverse events were similar between arms (48% with SurVaxM versus 46% with placebo), as were overall serious adverse event rates (25% versus 21%). Adverse events led to treatment discontinuation in 4% of SurVaxM patients, with one discontinuation attributed to study treatment. There were no treatment-related deaths in either arm.

Regulatory Next Steps

MimiVax plans to request a meeting with the U.S. Food and Drug Administration in the coming months to review the SURVIVE data and align on the path forward for SurVaxM in newly diagnosed glioblastoma.

“We want to discuss Breakthrough Therapy Designation with the FDA, along with other expedited pathways, including accelerated approval,” said Dr. Ciesielski. “The path to making SurVaxM available to patients will be determined in consultation with the agency.”

A Serious Unmet Need

Glioblastoma is a deadly disease that strikes about 15,000 Americans every year. With few effective therapies and a standard of care that has not changed in more than 20 years, patients and families are desperate for new options.

About the SURVIVE Trial

SURVIVE (NCT05163080) is a Phase 2b, randomized, double-blind, placebo-controlled, multicenter clinical trial evaluating SurVaxM in combination with standard of care in patients with newly diagnosed glioblastoma. The fully enrolled trial included 233 evaluable patients at 11 leading U.S. cancer centers. The primary endpoint was overall survival (OS), with patients aged 65 and under prespecified as a key subpopulation for the primary endpoint. Secondary endpoints included progression-free survival (PFS), landmark survival, safety, and survivin-specific immune responses.

About SurVaxM

SurVaxM is a first-in-class, patented peptide-mimic immunotherapeutic vaccine that targets survivin, a cell-survival protein present in approximately 95% of glioblastomas and many other cancers. Delivered by subcutaneous injection, SurVaxM is designed to stimulate the patient’s own immune system to recognize and attack survivin-expressing cancer cells, with the goal of controlling tumor growth and preventing recurrence. SurVaxM holds FDA Orphan and Fast Track Designations for newly diagnosed glioblastoma and is being evaluated across multiple cancer indications, including glioblastoma, neuroendocrine tumors, multiple myeloma, and pediatric brain cancers. SurVaxM is for investigational use only and has not yet been approved by the FDA or any other regulatory authority for any indication.

The late-stage SURVIVE study for glioblastoma has completed enrollment and is no longer open to additional patients. There are no SurVaxM studies currently enrolling for glioblastoma.

About MimiVax

MimiVax Inc. is a Delaware-incorporated, clinical-stage biotechnology company formed as a spinoff from Roswell Park Comprehensive Cancer Center in Buffalo, New York. The Company is dedicated to the development of innovative immunotherapies designed to improve survival for patients with cancer. MimiVax holds an exclusive global license to commercialize SurVaxM, along with an extensive worldwide patent portfolio.