In the study, three patients were given the highest dose of the vaccine. Two have exhibited stable disease for 6 months and the third patient has maintained stable disease for 9 months. The vaccine is directed at a protein found on RCC cells called carbonic anhydrase IX (CAIX). The vaccine is developed using the patient’s own dendritic cells (immune cells), which are infused back into the patient. It has taken the researchers 10 years of experimentation to get this far.
The phase I study was designed to determine if infusing the cells into the patients was safe. So far, 9 patients have received treatment with the vaccine. There were no serious adverse events. Other adverse event included fatigue, joint pain, fever, headache and back pain. The immune response to the vaccine was positive.
“CAIX is a potential target for clear cell carcinoma,” said Dr Alexandra Drakaki, assistant professor of haematology/oncology and urology at the University of California. “Dendritic cell-CAIX vaccination at the highest dose is feasible, safe, and triggers a CAIX specific immune response. CAIX vaccine monotherapy in the highest dose is associated with stable disease.”
Dr Drakaki said the next step in the project is to complete the ongoing phase I study, including treating the expansion cohort with the highest dose. After that, the researchers are posing combination therapy with checkpoint inhibitors or tyrosine kinase inhibitors.