Kite Pharma (NASDAQ: KITE) has dipped into a highly anticipated clinical trial of its cancer treatment, KTE-C19, to release a partial set of data.
Although not complete, the data bolster the view that Kite could be the first among its peers, all developing cutting-edge cancer treatments from a patient’s own white blood cells, to win the FDA’s green light.
Kite examined results in 62 non-Hodgkin’s lymphoma patients whose cancer had returned or not responded to chemotherapy. It’s a group of patients who generally aren’t expected to live more than a few months. Kite will eventually report results from more than 100 patients. But for now, the partial data show that three months after treatment, 39 percent of the patients saw their cancer disappear, what’s known as a “complete response.”
Kite shares are up more than nine percent, or $5.02, in after-hours trading.
Part of the full data release, scheduled for early next year, will show how patients fared six months after treatment. Those timelines are important. Doctors and researchers are concerned that patients, as has happened with many new drugs through the years, will respond well at first, only to have their cancers return as they evolve resistance.
Kite chief medical officer David Chang said on a conference call Monday that an earlier Kite study, with seven patients, and early studies at the National Cancer Institute, which licensed KTE-C19 to Kite, showed that “patients who maintain a complete response at three months tend to remain in complete response.”
Kite will share more details about the 62-patient group, including a deeper analysis of responses, at a scientific meeting later this year, Chang said.
Another wrinkle that will be worth watching: the 62 non-Hodgkin’s lymphoma patients are divided into two subsets of the disease. The larger group, 51, has the more common diffuse large B-cell lymphoma, and the other, 11, has less common forms. The smaller group had much better response rates, both immediately following treatment and after three months. Kite wants to combine all the patients into one data set when it asks the FDA and European regulators for approval. Agencies on both sides of the Atlantic have said previously they might be willing to speed the process if Kite’s data are positive.
Kite is racing Novartis (NYSE: NVS) and Juno Therapeutics (NASDAQ: JUNO) to turn a cutting-edge idea—that a cancer patient’s own white blood cells can be extracted, juiced up with genetic engineering, and put back into the patient to recognize and kill the cancer—into an approved product.
These treatments, known as CAR-T cell therapy, have shown remarkable results in early tests in people suffering from advanced blood-borne cancers. But Novartis said last month it would break up its division in charge of CAR-T work, leaving the future of its program in question. (The firm says it will keep developing the product, CTL-019, that is competing with Kite’s KTE-C19.) And Juno reported in July that three patients taking its most advanced CAR-T treatment died during its ongoing trial. The FDA halted the trial for several days. In light of those developments, Kite has been tabbed as the frontrunner.
As Juno’s setback demonstrated this summer, CAR-T treatments pose a safety risk. The engineered cells, put back into the patient’s body, can work so furiously that the patient has a serious immune reaction, called cytokine release syndrome. Kite reported today that two patients died in the midst of cytokine release syndrome, one from a rare immune malfunction, the other from cardiac arrest. Kite and others administering CAR-T cells treat the syndrome with steroids or with the immunosuppressive drug tocilizumab (Actemra). Chang called the ratio of risk to benefit “favorable.”
Overall, 18 percent of the patients examined had cytokine release syndrome, and 34 percent had neurological problems, such as hallucinations or temporary vision loss, related to the therapy. The highest rate of safety problem was in two thirds (66 percent) of patients, who had neutropenia, a precipitous reduction of white blood cells that fight off infection.
Other safety problems, according to Kite, were anemia (in 40 percent of patients), febrile neutropenia (29 percent), thrombocytopenia (29 percent), and encephalopathy (26 percent).
The trial is dubbed Zuma-1. Kite is testing KTE-C19 in three other types of blood-borne cancer. Those trials are called Zuma-2, Zuma-3, and Zuma-4.
Image of lymphoma tumor cells courtesy of the National Cancer Institute.