A landmark new study published in the New England Journal of Medicine shows that 90 percent of leukemia patients treated with a groundbreaking form of cellular therapy achieved complete responses.
Led by The Children’s Hospital of Philadelphia’s Stephan M. Grupp, MD, PhD, the study is the latest to validate Dr. Grupp and colleagues’ work with CTL019 therapy, in which patients’ immune cells are engineered to multiply and fight against acute lymphoblastic leukemia (ALL) and other B cell cancers. The cells are designed to proliferate in patients’ bodies, continuing to fight and protect against cancer. Children’s Hospital’s Shannon Maude, MD, PhD, and the University of Pennsylvania’s Noelle Frey, MD, were the study’s co-first authors.
The most common form of leukemia found in children, ALL is largely curable, with a roughly 85 percent cure rate. However, the remaining 15 percent of ALL cases resist standard therapy. In conjunction with the University of Pennsylvania’s Carl H. June, MD, last year Dr. Grupp reported the results of early work that showed the promise of their immune therapy approach. In that study, also published in the New England Journal of Medicine, they showed two children with acute lymphoblastic leukemia achieved a complete response after being treated with an innovative cell therapy.
One of those patients was then 7-year-old Emily Whitehead, who was the subject of a media frenzy when the experimental therapy led to her dramatic recovery after she relapsed following conventional treatment. Since receiving the CTL019 therapy, Emily remains healthy and cancer-free.
In the recent New England Journal of Medicine paper, 30 children and adults were treated at Children’s Hospital and UPenn with CTL019 therapy. Of those, 27 patients — 90 percent — experienced complete remissions, or a complete lack of detectable disease. Sustained remissions were seen in 67 percent of patients, and CTL019 cell proliferation was seen in 68 percent of patients.
Aside from the high percentage of complete remissions seen, the study’s findings are remarkable because many of the patients who took part had already experienced relapses or had treatment-refractory acute lymphoblastic leukemia. “Relapsed ALL is a considerable therapeutic challenge, particularly in patients who do not have a second complete remission or have a relapse after stem-cell transplantation,” the authors note. According to the study, of the 27 patients who had complete remissions, 19 remained in remission, some for as long as two years.
Advocacy organizations were quick to praise the CHOP-Penn team’s work. The Leukemia & Lymphoma Society (LLS), which has funded Dr. Grupp since 1992, called the work an “important advance.”
“This study comes almost exactly 70 years after Robert Roesler de Villiers, the son of the founders of LLS, died from ALL,” said the Leukemia & Lymphoma Society’s Louis J. DeGennaro, PhD. “At the time, the chance of surviving ALL was less than five percent of patients. Today nearly 90 percent of pediatric patients with ALL survive more than five years, and the findings announced today suggest that we may see even more patients surviving this blood cancer.”
“The patients who participated in these trials had relapsed as many as four times, including 60 percent whose cancers came back even after stem cell transplants,” said Dr. Grupp. “The durable responses we have observed with CTL019 therapy are unprecedented.”
To read more about CTL019 therapy, see The Children’s Hospital of Philadelphia’s page about the trial.