A new personalized cancer vaccine has raised no safety concerns and has shown potential benefit to patients with different cancers, including lung and bladder cancer that has a high chance of recurrence. That's according to the results of a phase 1 clinical trial presented by researchers during the virtual American Association for Cancer Research (AACR) Annual Meeting 2021, which is currently underway.
"While immunotherapy has revolutionized the treatment of cancer, the vast majority of patients do not experience a significant clinical response with such treatments," said study author Thomas Marron, MD, PhD, assistant director for Early Phase and Immunotherapy Trials at the Tisch Cancer Institute and assistant professor of medicine at the Icahn School of Medicine at Mount Sinai, in a statement. "Cancer vaccines, which typically combine tumor-specific targets that the immune system can learn to recognize and attack to prevent recurrence of cancer. The vaccine also contains an adjuvant that primes the immune system to maximize the efficacy."
In the trial, 13 patients received the personalized vaccine; 10 patients had solid tumors, while three had multiple myeloma.
Marron's team developed the vaccine by sequencing a patient's specific tumor genetics and germline DNA. They then identified specific targets on the tumor, which helped them predict whether the patient's immune system would recognize the vaccine's targets. The researchers then used a computational system called OpenVax from Mount Sinai to help narrow down which of the targets would be viable options to incorporate into a personalized vaccine.
"Most experimental personalized cancer vaccines are administered in the metastatic setting, but prior research indicates that immunotherapies tend to be more effective in patients who have less cancer spread," said study author Nina Bhardwaj, also of the Tisch Cancer Institute at Mount Sinai. "We have therefore developed a neoantigen vaccine that is administered after standard-of-care adjuvant therapy, such as surgery in solid tumors and bone marrow transplant in multiple myeloma, when patients have minimal – typically microscopic – residual disease."
Although the primary focus of the phase 1 trial is to test the safety of the vaccine, which the researchers note "was well tolerated", the trial did also show some encouraging results regarding long-term positive outcomes in some patients.
It is worth noting however that it is too early to make firm conclusions as the patient size of the phase 1 trial was considerably small and the vaccine has therefore not been tested for safety and efficacy in a diverse population group with different tumor etiologies and post-operative treatment courses yet.
"Our results demonstrate that the OpenVax pipeline is a viable approach to generate a safe, personalized cancer vaccine, which could potentially be used to treat a range of tumor types," Bhardwaj said.