Clinical Trial Offering Personalized Immunotherapy for Mesothelioma
August 14, 2019
Patients with mesothelioma are now eligible for a multicancer clinical trial studying the effectiveness of personalized immunotherapy at the University of California, San Diego Medical Center.
The phase I clinical trial involves a combination of Keytruda (pembrolizumab), a proven immunotherapy drug, and an individualized vaccine based upon the genetic mutations found in each patient’s cancer.
“This is the future of cancer treatment,” Dr. Ezra Cohen, principal investigator and director of the San Diego Center for Precision Immunotherapy, told The Mesothelioma Center at Asbestos.com. “Now, we still have a lot to learn, and will continue to do so, but this is the future. We’re convinced.”
Cohen has collaborated with Stephen Schoenberger, Ph.D., professor at the La Jolla Institute for Immunology, in developing a technology that can identify the foreign protein fragments specific to an individual and their tumor. A vaccine is then used to induce a stronger, more sustainable immune response.
“The immune system really is the answer to beating the cancer,” Cohen said. “The problem is usually that it is not strong enough. It’s a matter of giving the immune system the right signals. And those signals have to be individualized.”
Early Results Encouraging
The trial, which began in 2018, is expected to run through 2022. It is aimed at advanced cancers and patients who are not candidates for potentially curative standard therapy.
Gastrointestinal cancers, head-and-neck cancers and pancreatic neuroendocrine cancers already are being treated in the clinical trial.
Cohen now is encouraging patients with mesothelioma, a rare and aggressive cancer with no definitive cure, to enroll.
“Patients have responded well to this point. It’s been exciting to see,” he said. “Only time will tell to be sure, but we think we’re on the right track. It’s the biology of the disease, and if we’re ignoring that, we’ll never take those big leaps forward in advancing treatment.”
No Two Cancers the Same
The personalized vaccine has not been approved by the FDA and is considered experimental.
It can take up to eight weeks to produce the vaccine in the laboratory while a tumor biopsy is sequenced and the T-cells from the blood samples are reprogramed to better fight the cancer.
Each vaccine produced applies only to one individual.
“We may see two patients with mesothelioma with the same diagnosis, but when you look at it on the molecular level, they are two different cancers,” Cohen said. “The vaccine is for only one person on the planet. No two cancers are the same, and no two immune systems are alike.”
Keytruda is FDA approved for various cancers, including melanoma, non-small cell lung cancer, Hodgkin lymphoma and gastric cancer. For other cancers in the trial — including mesothelioma — Keytruda would be considered experimental.
Cohen believes that combining the vaccine and Keytruda will unleash the full potential of the T-cells to attack tumor cells.
Keytruda alone has shown outstanding effectiveness recently with pleural mesothelioma, but only for a small percentage of patients who have tried it.
“What that tells you is, that the immune system can do it,” he said. “If we stimulate the right way.”
Patients in the study will receive the personalized vaccine and Keytruda together to start. They will receive the Keytruda every three weeks and the vaccine every six weeks.
The study will measure treatment-related adverse events, T-cell effectiveness, an overall response rate, progression-free survival and overall survival times.
Although this clinical trial includes only patients who are not candidates for curative therapy, Cohen believes that eventually the combination will be used for those who undergo surgery with a curative intent but for a cancer with a high risk of recurrence.
“The principle is the same,” he said. “If you know there is a significant chance of the cancer coming back, you could use it there. It’s taken five years to get to this point, but we really believe in it. We believe this is the way forward.”
Unfortunately, without FDA approval, funding for further studies has been difficult to secure.
The current study was funded through individual philanthropy. There is no pharmaceutical giant behind it yet.
“If we’re going to take the next big step toward curing cancer, we have to do it with an individualized and personalized approach,” Cohen said. “We need to stop taking patients and trying to fit them into drugs. We need to start making drugs, and fitting them to what we’re seeing biologically in a patient’s cancer.”