NEW YORK (FRONTLINE MEDICAL NEWS) – Should the first chimeric antigen receptor (CAR) T-cell treatment receive Food and Drug Administration approval for refractory, aggressive non-Hodgkin lymphoma, possibly before the end of 2017, several thousand U.S. patients will be potential candidates for the treatment, Jeremy S. Abramson, MD, predicted at a conference held by Imedex.

Dr. Abramson has led studies using a CAR T cell that differs from the one furthest along in development. He based his predicted timetable for an approved biologics license of the process, with which he can engineer patient-specific T cells that are under development by Kite Pharma, on the “remarkable” level of complete responses the intervention produced in a pivotal phase II study.

Results from the ZUMA-1 study, first reported in December 2016 at the American Society of Hematology annual meeting, showed superior responses in 101 patients who received infusions of the modified and expanded CAR T cells, a process that Kite calls axicabtagene ciloleucel. Comparatively, the existing chemotherapy treatment results for the types of non-Hodgkin lymphoma patients who were enrolled in the trial were bleak. Of the treated patients, 77 had a diffuse large B-cell lymphoma, and 24 had primary mediastinal B-cell lymphoma or transformed follicular lymphoma.

“Seeing a complete response rate of close to 40% that is sustained for more than 3 months and a complete response rate of close to a third at 6 months is light years beyond what is now available for patients” with these chemotherapy refractory B-cell lymphomas, said Dr. Abramson , clinical director of the Center for Lymphoma at Massachusetts General Hospital in Boston. “This is the first treatment to show a significant impact on large B-cell lymphoma, and that makes me optimistic” that the FDA will grant license approval later in 2017, he said in an interview.

Dr. Abramson acknowledged that some patients developed grade 3 or 4 cytokine-release syndrome and neurologic events, but the events were reversible and manageable if treated with the immunosuppressant tocilizumab (Actemra) or a corticosteroid.

At the end of March, Kite reported the completion of its FDA application, and, on April 2, the ZUMA-1 investigators presented an updated report on their results, with a 36% complete response rate across all enrolled patients at 6 month follow-up and a 39% complete response rate in all patients out to a median follow-up of 8.7 months.

Annually, in U.S. practice, perhaps 3,000 new patients with diffuse large B-cell lymphoma would meet the enrollment criteria for ZUMA-1, Dr. Abramson estimated. Once axicabtagene ciloleucel becomes commercially available in the United States, several thousand U.S. patients might initially seek the treatment.

Kite Pharma has a Los Angeles–area facility capable of processing T-cell specimens from 4,000 to 5,000 patients a year, according to Christine Cassiano , the company’s senior vice president for investor relations and corporate communications. This should continue to allow the average 17-day turnaround time seen in ZUMA-1, timed from when T cells were withdrawn from patients to the time when the engineered T cells were infused back. The single facility will handle all U.S. patients. So far, only the 101 patients from ZUMA-1 have received treatment with axicabtagene ciloleucel, but the facility has also produced other types of engineered T cells for testing in other trials, she said in an interview.

Dr. Abramson has been a consultant to Kite Pharma and to AbbVie, Genentech, Gilead, and Seattle Genetics.

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