WASHINGTON, Feb. 19 (Xinhua) -- U.S. researchers on Wednesday reported "more encouraging news" about an experimental therapy against a deadly form of leukemia, called B cell acute lymphoblastic leukemia (B-ALL).
A clinical study involving 16 B-ALL patients found that 88 percent of them achieved "complete remissions" after being treated with genetically modified versions of their own immune cells, according to the research report published in the U.S. journal Science Translational Medicine.
"These extraordinary results demonstrate that cell therapy is a powerful treatment for patients who have exhausted all conventional therapies," said Michel Sadelain of Memorial Sloan Kettering Cancer Center and one of the study's senior authors. " Our initial findings have held up in a larger cohort of patients, and we are already looking at new clinical studies to advance this novel therapeutic approach in fighting cancer."
B-ALL, a type of blood cancer that develops in B cells, is difficult to treat because the majority of patients relapse. Patients with relapsed B-ALL have few treatment options and only 30 percent respond to salvage chemotherapy. Without a successful bone marrow transplant, few have any hope of long-term survival.
In the current study, 16 patients with relapsed B-ALL were given an infusion of their own genetically modified immune cells, called T cells, which were "reeducated" to recognize and destroy cancer cells that contain the protein CD19.
Overall, 14 patients, or 88 percent, of the 16 patients experienced a "complete remission," with no detectable cancer cells in their bodies, and seven were healthy enough to undergo a bone-marrow transplant, the researchers said.
Historically, only 5 percent of patients with relapsed B-ALL have been able to transition to bone marrow transplantation.
In a statement, the researchers identified two of the 16 patients: Dennis Billy of Wynnewood, Pennsylvania, one of the first patients to receive this treatment more than two years ago, was able to successfully undergo a bone marrow transplant and has been cancer-free and back at work teaching theology since 2011. Paolo Cavalli, a restaurant owner from Oxford, Connecticut, remains in complete remission eight months after receiving his personalized T cell treatment.
"Patients without any hope gained complete remission after receiving the engineered cells," Wang Xiuyan, one of the authors at the Memorial Sloan-Kettering Cancer Center, told Xinhua. " Although engineered T cells are still experimental, adoptive cell therapy, or immunotherapy in general, has been becoming a paradigm shifting modality in cancer patient care."
The researchers also said that additional studies to determine whether cell therapy can be applied to other types of cancer such as prostate cancer and lymphoma are already underway.