Scientists at UC San Francisco announced on Mar. 19 a new technique that allows cancer-fighting immune cells, known as CAR-T cells, to be engineered directly inside the body. This approach could make advanced cancer therapies more accessible by removing the need for complex and costly cell manufacturing outside the patient.
The development is significant because current CAR-T therapies require extracting a patient’s immune cells, modifying them in specialized facilities, and then reinfusing them—a process that can take weeks and cost hundreds of thousands of dollars. Many patients are unable to access these treatments due to time, expense, or health limitations.
According to Justin Eyquem, Ph.D., associate professor of medicine at UCSF and senior author of the study published in Nature, “I think this is just the beginning of a big wave of new therapies that will be truly transformational and save a lot of lives. I’m incredibly excited to be part of it.” The research team used a two-particle system: one particle delivered CRISPR-Cas9 gene-editing tools directly to T cells in the body; the other carried new DNA instructions for targeting cancer. This method allowed precise genetic changes without removing cells from the patient.
In experiments with mice carrying humanized immune systems, a single injection cleared aggressive leukemia within two weeks in nearly all cases. The approach also worked against multiple myeloma and solid sarcoma tumors—types historically resistant to CAR-T therapy. Eyquem said, “What was especially remarkable was that the cells we’re generating in vivo actually look better than what we make in the lab.” He added that this could lead to off-the-shelf treatments similar to vaccines.
Clinical trials are needed before human use. Eyquem and collaborators have founded Azalea Therapeutics to advance clinical development. “If we can translate this to humans, we could dramatically reduce costs, eliminate waiting times, and potentially allow community hospitals—not just major cancer centers—to offer these life-saving therapies,” he said. “That would truly democratize access to CAR-T cell therapy.”
The study involved researchers from UCSF, Gladstone Institutes, Duke University, and Innovative Genomics Institute. Funding came from organizations including the Parker Institute for Cancer Immunotherapy and Pew Charitable Trust.
