The University of Pennsylvania’s pioneering cell therapy physician Carl June shared new data Monday that showed the risk of secondary cancers following CAR-T therapy was very low.
In over 1,500 patients treated at UPenn and Stanford University, only a small percentage had a second cancer after treatment, June reported Monday morning at a Friends of Cancer Research and Parker Institute for Cancer Immunotherapy joint event in Washington.
None could be directly attributed to CAR-T therapy, according to June.
The two universities are major cell therapy research sites on the two US coasts.
The FDA in January told drug companies to add boxed warnings for the risk of T cell cancers to all six commercial CAR-T cell therapies. The warning labels came after the FDA began an investigation in November into the risk of these blood cancers following treatment with CAR-T therapy. At last count, the agency was investigating 22 cases of blood cancer developing after CAR-T cell therapy treatment.
FDA officials also shared in January that in three cases with genetic sequencing, the CAR transgene was detected in the cancer cells, which suggested that “the CAR-T product was most likely involved in the development of the T-cell cancer.”
At Penn, data from 783 patients treated in clinical trials were analyzed, “beginning with HIV CAR patients 20 years ago, and up to where we currently are,” according to June.
Eighteen patients developed a secondary cancer — making up 2.3% of all patients — and solid tumors were most common, June said. The studies spanned cell therapies using gammaretroviruses and lentiviruses.
“We found that [in] none of the cases was there insertion of the CAR molecule into a secondary malignancy, so nothing where we could directly attribute the CAR to a secondary cancer that occurred in a patient after treatment with gene modified T cells,” June said.
The cases occurred a median of roughly two years after treatment.
At Stanford, researchers analyzed a group of 725 patients and found 25 cases of secondary cancers: 11 were solid tumor cancers; 13 were acute myeloid leukemia or its precursor disease myelodysplastic syndromes; and one was a T cell lymphoma.
For that one case of T cell lymphoma, there was no CAR transgene insertion, June reported.
The results from both universities shared Monday have yet to be published in scientific journals.
In January, researchers from Penn previously reported one case of T cell lymphoma in a Nature Medicine analysis of 449 patients treated at the university.