Vaccines are an area full of promise for lung cancer patients. A big difference between the lung cancer vaccines being developed and a common existing vaccine, the flu shot, is timing. Flu shots are preventive: they are given to people before they are sick to train the immune system on what to look for, so the immune system can quickly attack the virus if it appears in the body. The lung cancer vaccines being developed are therapeutic: they are intended to treat lung cancer after the immune system has already allowed the tumor to stay and grow in the body.
“This creates a unique type of challenge that researchers have been grappling with,” explains Edward Garon, MD, professor of Medicine at the Jonsson Comprehensive Cancer Center at UCLA and a member of LUNGevity’s Scientific Advisory Board. “We have to find ways to “re-teach” the immune system that the cancer cells shouldn’t be there.”
Generally, there are two types of lung cancer vaccines being studied right now. One approach is to develop a standard vaccine that is loaded with the most common lung cancer-related antigens (protein sequences from lung cancer cells that alert the immune system to disease) to stimulate the immune response against lung cancer cells. Once lung cancer patients receive this vaccine, their bodies would get a boost in their immune system’s ability to find and then fight the most common lung cancer cells. “Several lung cancer vaccines of this type are already being tested in clinical trials,” notes Dr. Garon.
Another approach for lung cancer vaccines is cell therapy that is tailored to the requirements of each patient. In this approach, a specific vaccine is developed for each individual with the goal of training their immune system to destroy their specific lung cancer cells. Several researchers, including Dr. Garon, are working on developing personalized vaccines for lung cancer.
Dr. Garon’s approach uses dendritic cells, a specific type of cell that is known to infiltrate tumors and to present antigens to the immune system to help the body fight disease. His team has developed a personalized vaccination approach that involves harvesting dendritic cells from patients, modifying the dendritic cells to present peptides that are most relevant to the cancer, and then injecting the dendritic cells back into the tumor. Dr. Garon is studying this dendritic cell vaccine in combination with pembrolizumab, an approved immunotherapy, to encourage increased immune response to the vaccine. “We have treated a few patients with this approach. It’s still very much in early stages, but the results are exciting,” notes Dr. Garon.
There are challenges facing the development of personalized vaccines. “When you have one thing to test in a large population—one drug or one standard vaccine, such as a vaccine for COVID-19—the path forward is clear. The medical community knows how to evaluate the efficacy of the treatment,” explains Dr. Garon. “But when the treatment gets more complex, such as with individualized vaccines, we need to develop a new framework to help us evaluate how effective the treatment is.”
As individualized therapies begin to emerge, the U.S. Food and Drug Administration (FDA) will likely require updates to its protocols. “LUNGevity is well-positioned to help guide the conversation between pharmaceutical companies, the FDA and other key stakeholders, to develop regulatory frameworks for this new era of medicine,” says Dr. Garon.
“I am hopeful” says Dr. Garon, “that the more we learn about how lung cancer interacts with the immune system, the more the therapies will evolve and the better the survival rates will become.”
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Juhi Kunde, MA, is a science writer for LUNGevity.