SurVaxM extended median survival by 2.5 months across the full study population, while patients aged 65 and under recorded a statistically significant benefit. The company plans to discuss expedited approval pathways with the FDA.

 

An experimental cancer vaccine has delivered a promising survival signal in patients with newly diagnosed glioblastoma, extending median overall survival by 2.5 months in a Phase 2b clinical trial, although the benefit across the full study population fell short of the conventional threshold for statistical significance.

 

MimiVax and Roswell Park Comprehensive Cancer Center announced the results of the SURVIVE trial on October 7, reporting that patients treated with SurVaxM lived a median of 22.8 months, compared with 20.3 months among those who received a placebo alongside standard treatment.

 

The difference did not meet the traditional statistical significance threshold of p=0.05, with the trial reporting an adjusted p-value of 0.076. However, a prespecified subgroup analysis found a statistically significant survival benefit among patients aged 65 and under, offering a stronger signal for the investigational immunotherapy.

 

The randomized, double-blind, placebo-controlled trial included 233 evaluable patients across 11 US cancer centers. The study, which began in 2022, evaluated SurVaxM in combination with standard care for newly diagnosed glioblastoma, an aggressive brain cancer with few effective treatment options.

 

Among patients aged 65 and under, median overall survival reached 24.2 months with SurVaxM, compared with 20.2 months in the placebo group. The difference was statistically significant, with an adjusted p-value of 0.019.

 

The same subgroup also recorded a significant improvement in progression-free survival, which measures how long patients live without their disease worsening. The hazard ratio was 0.64, with a p-value of 0.018.

 

At 12 months, 44% of patients treated with SurVaxM remained progression-free, compared with 24% of patients receiving 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, 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, co-principal investigator of the SURVIVE trial, Chair Emeritus of Neurosurgery at Roswell Park and Chief Medical Officer and Co-founder of MimiVax, said the results offered an encouraging signal in a disease where treatment advances have been limited.

 

“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.”

 

The trial also reported a notable long-term survival signal among patients aged 65 and under.

 

Approximately 42% of patients treated with SurVaxM were alive at 30 months or longer, compared with 18% in the placebo group. The company reported no further deaths among SurVaxM-treated patients in this subgroup between 30 and 54 months.

 

The findings suggest a potentially durable benefit for a subset of patients, although continued follow-up and further investigation will be needed to establish the significance and durability of the results.

 

“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, 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 placebo group performed better than anticipated, recording median overall survival of 20.3 months against the 16-month historical benchmark used in the trial's design assumptions.

 

The stronger-than-expected results in the control arm narrowed the gap between the two groups, making it more difficult for the study to demonstrate a statistically significant survival advantage across the entire population.

 

The findings underscore the importance of interpreting the overall results alongside the prespecified subgroup analysis. While the full population did not meet the primary endpoint's conventional significance threshold, patients aged 65 and under showed statistically significant improvements in both overall and progression-free survival.

 

SurVaxM was generally well tolerated, with most reported treatment-related reactions involving the injection site or flu-like symptoms.

 

Reported injection-site reactions included reactions in 48% of patients, pain in 41%, redness in 39%, itching in 38% and swelling in 29%. Influenza-like illness was reported in 13%.

 

Grade 3 or higher adverse events occurred in 48% of patients receiving SurVaxM and 46% of those receiving placebo. Serious adverse events were reported in 25% and 21%, respectively.

 

Treatment discontinuation because of adverse events occurred in 4% of SurVaxM patients, with one discontinuation attributed to the study treatment. No treatment-related deaths were reported in either group.

 

MimiVax said it plans to request a meeting with the US Food and Drug Administration in the coming months to discuss the results and determine the next steps for SurVaxM's development.

 

The company intends to explore Breakthrough Therapy Designation and other expedited regulatory options, including accelerated approval. However, the trial results do not themselves establish eligibility for these pathways or guarantee regulatory approval.

 

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