In a single-institution Italian phase I/II trial reported in The New England Journal of Medicine, Del Bufalo et al found that treatment with chimeric antigen receptor (CAR) T cells targeting the disialoganglioside GD2 expressed on tumor cells (GD2-CART01) produced responses in pediatric patients with relapsed or refractory high-risk neuroblastoma.
In the study, 27 patients with heavily pretreated disease were enrolled and treated at the IRCCS Ospedale Pediatrico Bambino Gesu, Rome, between January 2018 and October 2021. In a dose-escalation phase, doses of 3 × 106, 6 × 106, and 10 × 106 CAR-positive T cells/kg were tested. No dose-limiting toxicities were observed, and the recommended phase II dose was 10 × 106 CAR-positive T cells/kg. The G2-CAR T cells expressed the inducible caspase 9 suicide gene, to allow for clearance of GD2-CART01 in case of severe toxicity.
Key Findings
GD2-targeted CAR T cells expanded in vivo and had median persistence in peripheral blood of 3 months (range = 1–30 months).
Cytokine-release syndrome occurred in 20 (74%) of 27 patients and was grade 1 or 2 in 19 (95%) of 20. No central neurotoxic events were observed.
In one patient, the suicide gene was activated by two infusions of the dimerizing agent rimiducid, with rapid elimination of GD2-CART01.
Objective response was observed in 17 (63%) of 27 patients, with complete response in 9 (33%). An additional five patients (19%) had stable disease. At a median follow-up of 1.7 years, complete response was maintained in five of nine patients.
Among 21 patients who received the recommend phase II dose, 3-year overall survival was 60% and 3-year event-free survival was 36%.
The investigators concluded, “The use of GD2-CART01 was feasible and safe in treating high-risk neuroblastoma…. GD2-CART01 may have a sustained antitumor effect.”
Franco Locatelli, MD, PhD, of the Department of Pediatric Hematology and Oncology and of Cell and Gene Therapy, IRCCS Ospedale Pediatrico Bambino Gesu, Rome, is the corresponding author for The New England Journal of Medicine article.
Disclosure: The study was funded by the Italian Medicines Agency and others. For full disclosures of the study authors, visit nejm.org.
