In a landmark development for cellular immunotherapy, researchers at Baylor College of Medicine have reported an unprecedented 18-year remission in a neuroblastoma patient treated with chimeric antigen receptor (CAR) T-cell therapy, marking the longest documented survival for this treatment approach.
The groundbreaking results, published in Nature Medicine, emerge from a follow-up analysis of a phase 1 clinical trial conducted at Texas Children's Cancer Center between 2004 and 2009. The study evaluated a novel CAR T-cell therapy engineered to target GD2, a surface antigen highly expressed in neuroblastoma cells.
The trial enrolled 19 pediatric patients with relapsed or refractory neuroblastoma, yielding remarkable long-term outcomes. Among 11 patients with active disease at treatment initiation, two achieved sustained complete responses, including the milestone 18-year remission case. Additionally, five out of eight patients who entered the trial with no evidence of disease remained cancer-free during the 10-15 year follow-up period.
Sustained Therapeutic Response
Dr. Helen Heslop, director of the Center for Cell and Gene Therapy and study's corresponding author, noted the significance of these sustained responses: "Our findings suggest that even with this early study some patients can have long-lasting benefit."
The research team detected persistent low levels of CAR T cells in patients throughout the follow-up period, with higher persistence observed in long-term survivors. Notably, these remarkable results were achieved using first-generation CAR T cells that lacked the co-stimulatory molecules common in current therapeutic designs.
Implications for Solid Tumor Treatment
"We're encouraged that it's not just patients with certain malignancies of blood cells who can have sustained responses to CAR T cells, but also some patients with advanced solid tumors who can still be disease free almost two decades later, with normal quality of life," explained Dr. Malcom Brenner, professor and founding director of the Center for Cell and Gene Therapy.
The study represents a crucial milestone in demonstrating the feasibility of cell therapy for solid tumors. According to first author Che-Hsing Li, this trial's success, even with first-generation technology, establishes a promising foundation for future developments in cellular immunotherapy for solid tumors.
Future Therapeutic Potential
The research team aims to build upon these encouraging results, with Dr. Brenner expressing hope to "extend this success to a higher percentage of patients in more types of cancer." The long-term survival data provides compelling evidence for the potential of CAR T-cell therapy in treating solid tumors, opening new avenues for research and therapeutic development.
