A new personalized immunotherapy treatment called a cancer vaccine has shown promising results in a phase I trial in people with kidney cancer.
The results from nine patients treated at Dana-Farber Cancer Institute in Boston, MA were published in Nature and showed that all patients remain cancer-free three years after treatment.
Cancer vaccines do not work like vaccines for infectious diseases such as Covid-19 or measles, which are generally given to people pre-emptively to reduce the chance of them getting sick, or seriously ill from viruses, bacteria or other microorganisms. Cancer vaccines are given to people who already have cancer and prompt the immune system to attack the tumor.
There have been cancer vaccines which have shown promising results in other types of tumors, but this is one of the first significant results in kidney cancer, which is often difficult to treat and has a high rate of recurrence after treatment.
In the case of the Dana-Farber trial, all patients had surgery to remove the bulk of their tumors. Samples from these tumors were analyzed in a laboratory and a cancer vaccine developed for each individual patient focused on specific characteristics of their tumor that should provoke the immune system called neoantigens. The patients were then infused with the vaccines, causing their immune systems to attack any remnants of tumor left after surgery.
“This approach is truly distinct from vaccine attempts in kidney cancer,” said David A. Braun, MD, PhD first author of the paper in a press release. “We pick targets that are unique to the cancer and different from any normal part of the body, so the immune system can be effectively “steered” towards the cancer in a very specific way. We learned which specific targets in the cancer are most susceptible to immune attack and demonstrated that this approach can generate long-lasting immune responses, directing the immune system to recognize cancer,” added Braun.
Although the results should be interpreted with caution as the trial only involved a small number of patients, people with later stage kidney cancers have a high risk of their tumors recurring. So that all patients in the trial remain cancer free three years after treatment is a promising sign.
Unlike many standard chemotherapies which work for a certain amount of time that the patient is taking the drug, immunotherapies such as cancer vaccines train the immune system to continue recognizing tumor cells, minimizing the risk of recurrence as the immune system retains memory of the tumor and remains poised to attack should cancer cells start growing again.
Cancer treatments also often come with a host of short and long-term side effects, some which can be serious. But the trial reported no significant side effects from the treatment, another positive sign.
“We believe this work can form a foundation for the development of neoantigen vaccines in kidney cancer,” said Braun.
