A new treatment approach for B-Cell lymphoma patients developed at the National Cancer Institute (NCI) and licensed to Kite Pharmaceuticals is showing dramatic results in pilot clinical trials. The treatment, which involves extracting specific white blood cells from a patient and modifying them before infusion back into the patient, is currently involved in a phase I clinical trial.
The therapy entails removing a type of white blood cell, T cells, and then engineering them with a process called chimeric antigen receptor (CAR). With the CAR process, a receptor is added to the T cell that targets an antigen—termed CD19—found on the malignant cells. Once attached to the cancerous lymphoma cells, the T cells destroy the malignant cells. The process of re-engineering the T cells in this way takes about 10 days of laboratory work and results in what is referraed to as anti-CD19 CAR expression.
At the 2013 American Society of Hematology Meeting, researchers from the NCI presented results on 15 patients with advanced B cell lymphomas. Thirteen of the patients could be evaluated for response to treatment; of those 12 responded. Seven had complete remissions and five had partial remissions. The remaining patients had stable disease. Many of the patients who responded had previously exhausted all other treatment options.
The researchers reported that the treatment did cause severe but reversible side effects in many of the patients. They experienced acute toxicity, which manifested itself with high fever, hypotension, breathing difficulties, delirium, aphasia, and neurological toxicity. Most patients, however, recovered within two days and symptoms were gone after three weeks.
A similar approach is being explored at the University of Pennsylvania to treat chronic lymphocytic leukemia and acute lymphocytic leukemia.
Reference: American Society of Hematology (ASH) 55th Annual Meeting: Abstracts 67, 163, and 168 presented 8 December; abstract 4162 presented on December 9; and abstract 873 presented on December 10, 2013.