Inotuzumab ozogamicin may offer a safe and efficacious therapeutic option for pediatric patients with relapsed acute lymphoblastic leukemia (ALL), according to results recently published in Leukemia.
Approximately 10% to 15% of pediatric patients with ALL will relapse. Inotuzumab ozogamicin has been shown to be safe and efficacious in adults with relapsed ALL, but its role in pediatric relapsed ALL is less explored.
Researchers assessed the use of inotuzumab ozogamicin in 51 pediatric patients with relapsed or refractory ALL who received treatment in the compassionate use program. The patients were heavily pretreated, with 16% having received 2 to 3 prior lines of therapy, 55% having received 4 to 6 prior lines of therapy, and 29% having received at least 7 prior lines of therapy.
After treatment with inotuzumab ozogamicin, complete remission occurred in 67% of patients with overt marrow disease. Most responders (71%) were negative for minimal residual disease. Responses to inotuzumab ozogamicin occurred regardless of cytogenetic subtype or number or type of prior lines of treatment.
Inotuzumab ozogamicin was safe and well tolerated. Grade 3 hepatic transaminitis or hyperbilirubinemia occurred in 12% of patients. Grade 3 or 4 infections occurred in 22% of patients. None of the patients developed sinusoidal obstruction syndrome during treatment with inotuzumab ozogamicin, but 11 of the 21 patients (52%) who underwent hematopoietic stem cell transplantation after inotuzumab ozogamicin developed sinusoidal obstruction syndrome.
In 3 of 12 patients who developed a subsequent relapse after treatment with inotuzumab ozogamicin, downregulation of surface CD22 was determined to be a possible mechanism of escape.
Inotuzumab ozogamicin was efficacious and well-tolerated in pediatric patients with relapsed ALL, warranting prospective studies. Identification of risk factors affecting the development of post-HSCT sinusoidal obstruction syndrome could improve outcomes, concluded the researchers.
1. Bhojwani D, Sposto R, Shah NN, et al. Inotuzumab ozogamicin in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [published online September 28, 208]. Leukemia. doi: 10.1038/s41375-018-0265-z