Blinatumomab, a bispecific T-cell engager molecule targeting CD19, was safe and had a high level of efficacy in infants with newly diagnosed KMT2A-rearranged acute lymphoblastic leukemia (ALL) compared with historical controls from the Interfant-06 trial, researchers report. “Longer follow-up is awaited, but the low incidence of relapse after treatment with blinatumomab is remarkable, given that in historical controls relapses occur frequently and early during therapy,” the investigators write. “It may be useful to focus future work on identifying whether additional courses of blinatumomab will improve outcomes further and whether [allogeneic hematopoietic stem-cell transplantation (HSCT)] will continue to be necessary to cure high-risk patients.”
A total of 30 infants younger than 1 year of age with newly diagnosed KMT2A-rearranged ALL were given the Interfant-06 trial chemotherapy plus a postinduction course of blinatumomab. Based on a primary end point of clinically relevant toxic effects (any toxic effect possibly or definitely attributable to blinatumomab that resulted in permanent discontinuation of blinatumomab or death), the study shows: “The median follow-up was 26.3 months (range, 3.9 to 48.2). All 30 patients received the full course of blinatumomab. No toxic effects meeting the definition of the primary end point occurred. Ten serious adverse events were reported (fever [4 events], infection [4], hypertension [1], and vomiting [1]). The toxic-effects profile was consistent with that reported in older patients. A total of 28 patients (93%) either were MRD-negative (16 patients) or had low levels of MRD (<5×10−4 [i.e., <5 leukemic cells per 10,000 normal cells], 12 patients) after the blinatumomab infusion. All the patients who continued chemotherapy became MRD-negative during further treatment. Two-year disease-free survival was 81.6% in our study (95% confidence interval [CI], 60.8 to 92.0), as compared with 49.4% (95% CI, 42.5 to 56.0) in the Interfant-06 trial; the corresponding values for overall survival were 93.3% (95% CI, 75.9 to 98.3) and 65.8% (95% CI, 58.9 to 71.8).”