Measuring the blood levels of certain proteins before treatment may help identify patients more likely to benefit from Advaxis‘ immunotherapy vaccine candidate axalimogene filolisbac (axal).
In the GOG/NRG-0265 Phase 2 trial (NCT01266460), patients with persistent or recurrent metastatic carcinoma of the cervix treated with axal were 77 percent more likely to survive if they had low serum levels of a cluster of four proteins at the study’s start.
The findings will be presented at the European Society of Gynecologic Oncology (ESGO) 2017 Congress Nov. 4-7 in Vienna, Austria.
Sandy Hayes, PhD, associate director of research and biomarker lead at Advaxis, will be presenting the poster, titled “Baseline Serum Protein Levels Associated with Survival in Axalimogene Filolisbac (Axal)-Treated Metastatic Cervical Cancer Patients: The GOG/NRG-0265 Trial.”
Axalimogene filolisbac is a live strain of Listeria monocytogenes that has been manipulated to produce cancer-fighting T-cells that work to destroy cancer cells. At the same time, this bacteria strain neutralizes the tumor’s natural protections, which makes it more susceptible to an immunologic attack.
Researchers at Advaxis determined the pre-treatment levels of specific serum proteins that were found to have a strong correlation with overall survival in a group of 45 patients with persistent or recurrent metastatic cervical carcinoma in a Phase 2 clinical study. Patients were then treated with axalimogene filolisbac.
Results from this trial showed a strong correlation between levels of four specific proteins and overall survival. The patients were stratified according to the levels of the four proteins in each patient. The first group of 25 patients had relatively low levels of all four proteins, and had an overall survival of 56%. The second group of 20 patients had relatively high levels of all four proteins, and had an overall survival of 15%. The 12-month overall survival of all patients in this trial was 38%.
Therefore, this data, which was statistically significant, suggests that the pre-treatment levels of these four proteins have a prognostic value for the determination of overall survival as higher levels indicate lower survival in this group of patients.
This prognostic correlation was mostly attributed to the levels of one particular protein, which was found to have the strongest correlation to overall survival in this study. Interestingly, this protein has never been associated with overall survival in the context of cervical carcinoma before.
Advaxis will continue its research into this particular protein as a potential biomarker for patients who could benefit from treatment with axalimogene filolisbac.
“In the field of cancer immunotherapy, biomarkers have been playing an increasing role in guiding patient selection and identifying early indicators of treatment response,” Robert Petit, chief scientific officer of Advaxis, said in a press release.
“The discovery of this potential biomarker, which previously has not been known to be associated with survival in cervical cancer, is significant and could be a biomarker to predict efficacy, similar to how PD-L1 expression is used as a biomarker for checkpoint inhibitors,” he said. “PD-L1 testing has become an important and routine strategy to guide treatment, and this biomarker has the promise to do the same for axalimogene filolisbac.”
Axalimogene filolisbac is an immunotherapy that has received fast track and orphan drug designation from the U.S. Food and Drug Administration for treatment of high-risk locally advanced cervical cancer.