(Reuters) - Kite Pharma Inc on Monday said its experimental CAR T-cell therapy, which helps the immune system fight cancer, was highly effective in treating aggressive non-Hodgkin lymphoma, although two deaths were related to the drug, according to interim data from a midstage trial.
Shares of Kite, which had been halted before the release of the news, rose 11 percent when trading resumed.
Some 76 percent of patients taking the drug, called KTE-C19, showed significant tumor shrinkage, including 47 percent who had no remaining signs of cancer at least three months after receiving the treatment, Kite said.
CAR T-cell drugs are made by genetically altering a patients’ own T-cells to add a component of antibodies that makes them better able to spot and kill cancer cells.
Other companies developing CAR T-cell therapies include Juno Therapeutics Inc and Novartis.
Kite said it will provide more details of the interim analysis at an upcoming medical meeting and expects to have data with six months of follow-up from 101 patients in the first quarter of 2017.
It will be important to note whether the complete response rates remain durable at six months and beyond or whether patients begin to relapse.
The company said it will use the data to seek regulatory approval of KTE-C19, but did not specify when that would happen.
RBC Capital Markets analyst Michael Yee, in a research note, called the complete response rate strong and above expectations.
“It is important to note that this CR rate is very supportive of FDA approval,” Yee said.
Serious neurological toxicity was reported in 34 percent of patients, with serious cytokine release syndrome (CRS) seen in 18 percent, the company said.
CRS, one of the most worrisome side effects of CAR T-cell therapy, involves severe inflammation and a buildup of toxic debris in the bloodstream caused by destruction of cancer cells. It is typically subdued with steroids and other treatments.
The two deaths involved cardiac arrest related to CRS, the company said.
Kite shares were up more than 7 percent to $59 in after-hours trading, after initially jumping 11 percent. Juno shares rose about 6 percent.
Reporting by Ransdell Pierson and Bill Berkrot; Editing by Leslie Adler