Experimental Immunotherapy Extends Bladder Cancer Survival

Experimental personalized peptide cancer vaccine found to extend overall survival.

An investigational immunotherapy exhibited promising results in the treatment of bladder cancer, a recent study found.

The experimental personalized peptide cancer vaccine was found to extend overall survival in patients with metastatic bladder cancer compared with patients receiving best-supportive care alone in a randomized, phase 2 clinical trial.

“Recently, immunotherapy has emerged as a viable and attractive strategy for the treatment of advanced cancer,” said Masanori Noguchi, MD, PhD, professor in the Clinical Research Division of the Kurume University Research Center for Innovative Cancer Therapy. “In this study, we assessed whether a novel immunotherapeutic approach that we have devised, called personalized peptide vaccination, could improve outcomes for patients who have advanced bladder cancer that has progressed after platinum-based chemotherapy. This is a disease for which the prognosis is poor; median survival is just 13 to 15 months from the time of starting platinum-based chemotherapy.”

The trial enrolled 80 patients with bladder cancer that progressed following platinum-based chemotherapy, with 39 patients randomly assigned to the personalized peptide vaccine and best-supportive care group, while 41 patients were administered best-supportive care. This treatment approach includes palliative radiotherapy, antibiotics, and pain relief.

Patients in the peptide vaccination group received 2 to 4 peptides once per week for 8 weeks, followed by 4 doses once every 2 weeks.

These peptides were chosen from a group of 31 peptides, with each of the peptides selected for each patient based on the form of human leukocyte antigen (HLA) class IA marker expressed and based on signs of immune response to peptides in the patient’s blood.

Researchers found 9 patients in the personalized peptide vaccine group had a partial response, 2 of whom were alive with no disease progression at the data cutoff date of April 20, 2014. No patients in the supportive care group achieved partial response.

Median overall survival in the personalized peptide vaccine group was 7.9 months compared with 4.1 months in the supportive care group.

There was no significant difference found in median progression-free survival, which may be due to the time it for peptide vaccination to achieve an effective antitumor immune response.

“We were excited to see that personalized peptide vaccination led to a significant improvement in overall survival,” Dr. Noguchi said. “This suggests that this immunotherapeutic approach might become a treatment option for advanced bladder cancer after failure of platinum-based regimens. However, large-scale, randomized clinical trials are needed to confirm our results.”