Decitabine and Vorinostat with Chemotherapy in Relapsed Pediatric Acute Lymphoblastic Leukemia: A TACL Pilot Study.
Purpose: Treatment failure from drug resistance is the primary reason for relapse in acute lymphoblastic leukemia (ALL). Improving outcomes by targeting mechanisms of drug resistance is a potential solution.
Patients and methods: We report results investigating the epigenetic modulators decitabine and vorinostat with vincristine, dexamethasone, mitoxantrone, and PEG-asparaginase for pediatric patients with relapsed or refractory B-cell ALL (B-ALL). Twenty-three patients, median age 12 years (range, 1-21) were treated in this trial.
Results: The most common grade 3-4 toxicities included hypokalemia (65%), anemia (78%), febrile neutropenia (57%), hypophosphatemia (43%), leukopenia (61%), hyperbilirubinemia (39%), thrombocytopenia (87%), neutropenia (91%), and hypocalcemia (39%). Three subjects experienced dose-limiting toxicities, which included cholestasis, steatosis, and hyperbilirubinemia (n = 1); seizure, somnolence, and delirium (n = 1); and pneumonitis, hypoxia, and hyperbilirubinemia (n = 1). Infectious complications were common with 17 of 23 (74%) subjects experiencing grade ≥3 infections including invasive fungal infections in 35% (8/23). Nine subjects (39%) achieved a complete response (CR + CR without platelet recovery + CR without neutrophil recovery) and five had stable disease (22%). Nine (39%) subjects were not evaluable for response, primarily due to treatment-related toxicities. Correlative pharmacodynamics demonstrated potent in vivo modulation of epigenetic marks, and modulation of biologic pathways associated with functional antileukemic effects.
Conclusions: Despite encouraging response rates and pharmacodynamics, the combination of decitabine and vorinostat on this intensive chemotherapy backbone was determined not feasible in B-ALL due to the high incidence of significant infectious toxicities. This study is registered at http://www.clinicaltrials.gov as NCT01483690.
Clinical cancer research : an official journal of the American Association for Cancer Research
Burke MJ, Kostadinov R, Sposto R, et al. Decitabine and Vorinostat with Chemotherapy in Relapsed Pediatric Acute Lymphoblastic Leukemia: A TACL Pilot Study. Clin Cancer Res. 2020;26(10):2297-2307. doi:10.1158/1078-0432.CCR-19-1251