In a recent study published in the New England Journal of Medicine, 90% of patients with acute lymphoblastic leukemia (ALL) who were treated with CTL019, an investigational personalized cellular therapy, achieved complete remission 1 month after infusion. After 6 months, 78% of those treated remained living. These findings build on previously reported preliminary data from 25 children and young adults (aged 5 to 22 years) and 5 adults (aged 26 to 60 years) with ALL who had experienced prior relapse or were refractory to standard treatment.
“The patients who participated in these trials had relapsed as many as four times, including 60% whose cancers came back after stem cell transplants. Their cancers were so aggressive they had no treatment options left,” noted the study’s senior author, Stephan Grupp, MD, PhD. “The durable responses we have observed with CTL019 therapy are unprecedented.”
CTL019 comprises re-engineered T cells that contain an antibody-like chimeric antigen receptor protein that binds to CD19 proteins found on the surface of B cells, including cancerous B cells. Similar to dialysis, CTL019 synthesis begins with collection of the patients’ own T cells by apheresis, which are then “reprogrammed” with a gene transfer technique that teaches the reprogrammed T cells to hunt and kill CD19-expressing B cells characteristic of certain leukemias. Once infused back into the patient each re-engineered T cell can multiply as many as 10,000 times.
One of the patients in the study, a 9-year-old child who more than 2 years ago was the first patient with ALL to receive CTL019 therapy, currently remains in remission, as do 18 other study participants. While all patients experienced the expected side effects known to be associated with activated re-engineered T cells, these were effectively treated. In July 2014 the US Food and Drug Administration granted CTL019 Breakthrough Therapy designation; it is the first personalized cellular therapy to receive this designation.
Study results have been published in the October 16, 2014, issue of the New England Journal of Medicine.
Contributed by William Yarnall, RPh, CCP
Medical Writer, Connexion Healthcare