An experimental gene therapy that turns a patient’s own blood cells into cancer killers worked in a major study, with more than one-third of very sick lymphoma patients showing no sign of disease six months after a single treatment, Kite Pharma Inc. said Tuesday.
In all, 82% of patients had their cancer shrink at least by half at some point in the study.
Shares of Santa Monica-based Kite soared 24.5% to close at $70.77.
Kite is racing Novartis AG to become the first to win approval of the treatment, called CAR-T cell therapy, in the U.S. It could become the nation’s first approved gene therapy.
A hopeful sign: The number in complete remission at six months — 36% — is barely changed from partial results released after three months, suggesting this one-time treatment might give lasting benefits for those who do respond well.
“This seems extraordinary … extremely encouraging,” said one independent expert, Dr. Roy Herbst, cancer medicines chief at the Yale Cancer Center.
The worry has been how long Kite’s treatment would last and its side effects, which he said seem manageable in the study. Follow-up beyond six months is still needed to see if the benefit wanes, Herbst said, but added, “this certainly is something I would want to have available.”
The therapy is not without risk. Three of the 101 patients in the study died of causes unrelated to worsening of their cancer, and two of those deaths were deemed due to the treatment.
It was developed at the government’s National Cancer Institute and then licensed to Kite. The Leukemia and Lymphoma Society helped sponsor the study.
Results were released by the company and have not been published or reviewed by other experts. Full results will be presented at the American Assn. for Cancer Research conference in April.
The company plans to seek approval from the U.S. Food and Drug Administration by the end of March and in Europe later this…