Nine of twelve leukemia patients who received infusions of their own T cells after the cells had been genetically engineered to attack the patients' tumors responded to the therapy, which was pioneered by scientists in the Perelman School of Medicine at the University of Pennsylvania. Penn Medicine researchers will present the latest results of the trial today at the American Society of Hematology's Annual Meeting and Exposition.
The clinical trial participants, all of whom had advanced cancers, included 10 adult patients with chronic lymphocytic leukemia treated at the Hospital of the University of Pennsylvania (HUP) and two children with acute lymphoblastic leukemia treated at the Children's Hospital of Philadelphia. Two of the first three patients treated with the protocol at HUP - whose cases were detailed in the New England Journal of Medicine and Science Translational Medicine in August 2011 - remain healthy and in full remissions more than two years after their treatment, with the engineered cells still circulating in their bodies. The findings reveal the first successful and sustained demonstration of the use of gene transfer therapy to turn the body's own immune cells into weapons aimed at cancerous tumors.
"Our results show that chimeric antigen receptor modified T cells have great promise to improve the treatment of leukemia and lymphoma," says the trial's leader, Carl June, MD, the Richard W. Vague Professor in Immunotherapy in the department of Pathology and Laboratory Medicine and director of Translational Research in Penn's Abramson Cancer Center. "It is possible that in the future, this approach may reduce or replace the need for bone marrow transplantation."
The results pave the way for a potential paradigm shift in the treatment of these types of blood cancers, which in advanced stages have the possibility of a cure only with bone marrow transplants. That procedure requires a lengthy hospitalization and carries at least a 20 percent mortality risk -- and even then offers only a limited chance of cure for patients whose disease has not responded to other treatments.
Three abstracts about the new research will be presented during the ASH meeting. David Porter, MD, director of Blood and Marrow Transplantation in the Abramson Cancer Center, will give an oral presentation of Abstract #717 on Monday, Dec. 10, at 5 PM in the Thomas Murphy Ballroom 4, Level 5, Building B of the Georgia World Congress Center. Michael Kalos, PhD, director of the Translational and Correlative Studies Laboratory at Penn, will give an oral presentation on Abstract #756 on Monday, Dec. 10, at 5:45 PM in C208-C210, Level 2, Building C. Stephan Grupp, MD, PhD, director of Translational Research in the Center for Childhood Cancer Research at the Children's Hospital of Philadelphia, will present a poster of Abstract #2604 on Sunday, Dec. 9, at 6 PM in Hall B1-B2, Level 1, Building B.