A team used the gene editing tool CRISPR to alter immune cells drawn from 16 patients who had a variety of solid cancers, including colon, breast and lung.
According to a report in the journal Nature, the genes of these immune cells were edited to add 175 newly isolated cancer-specific immune receptors. That would allow the cells to recognize and target mutations in the patients’ own cancer cells, researchers said.
“This is a leap forward in developing a personalized treatment for cancer, where the isolation of immune receptors that specifically recognize mutations in the patient’s own cancer are used to treat the cancer,” said co-author Dr. Antoni Ribas. He’s a professor at the University of California, Los Angeles and director of the Tumor Immunology Program at the UCLA Jonsson Comprehensive Cancer Center.
“The generation of a personalized cell treatment for cancer would not have been feasible without the newly developed ability to use the CRISPR technique to replace the immune receptors in clinical-grade cell preparations in a single step,” Ribas said in a center news release.
Every cancer patient has different and specific receptors on their immune cells that seek out and target tumors.
Because these receptors are different within every patient, researchers have been looking for an efficient way to isolate these targets and insert them back into immune cells, creating a personalized immunotherapy to treat individual cancers.
In this study, up to three preparations of gene-edited immune cells were infused back into patients after they’d received chemotherapy, for a total of 37 infusions for the 16 patients.
The immune cells successfully attacked the patients’ tumors, researchers said, preferentially targeting the cancers over all other immune challenges within their bodies.
Biopsies revealed that the genetically altered cells frequently represented the top 20% of immune cells in the cancer.
Two patients had side effects from the immunotherapy, one coming down with fever and chills and the other with confusion, researchers said. Both recovered promptly.
CRISPR has been previously used to remove specific genes so the immune system could ramp up its attack on cancer cells. This is the first time the technique has been used to insert new cancer-specific targets into immune cells, the researchers said.
The findings will also be presented Thursday at the annual meeting of the Society for Immunotherapy of Cancer, in Boston and virtually.