Magnesium supplementation therapy to prevent cisplatin-induced acute nephrotoxicity in pediatric cancer: a randomized phase-2 trial.

BACKGROUND: The present study aimed to examine the effect of magnesium (Mg) supplementation on cisplatin-induced nephrotoxicity (CIN) in pediatric cancer patients. METHODS: The present phase-2, open-label, multicenter, randomized controlled trial enrolled patients aged less than 20 years who were scheduled to receive cisplatin-containing chemotherapy and randomly allocated them at a ratio of 1:1 to a Mg supplementation arm with even-numbered chemotherapy courses (arm AB) or another arm with odd-numbered courses (arm BA). Analysis objects were reconstructed into two groups depending on whether the chemotherapy course had Mg supplementation (group B) or not (group A). The primary outcome was the proportion of chemotherapy courses resulting in elevated serum creatinine per chemotherapy course. The secondary outcomes included efficacies evaluated using other biomarkers and the safety of the Mg supplementation. RESULTS: Twenty-eight patients were randomly allocated to either group (16 to arm AB and 12 to arm BA). The baseline characteristics of the groups were similar. There was no significant difference in the proportion of courses with increased serum creatinine between the groups (group A: 10% vs. group B: 6%; P = 0.465) nor was any significant difference observed in other biomarkers during any chemotherapy course. The Mg value during chemotherapy was significantly higher in group B than that in group A. No adverse events related to magnesium administration were observed. CONCLUSIONS: The study design, which treated a single chemotherapy course as a study object, failed to detect a statistically significant benefit of Mg supplementation for preventing CIN in pediatric cancer patients. TRIAL REGISTRATION: JRCT ( https://jrct.niph.go.jp/ ) Identifier UMIN000029215 jRCTs031180251. UMIN-CTR ( http://www.umin.ac.jp/icdr/index.html ) Identifier UMIN000029215.

Acute lymphoblastic leukemia in infants: A quarter century of nationwide efforts in Japan.

Acute lymphoblastic leukemia (ALL) with KMT2A gene rearrangement (KMT2A-r) in infants is a biologically and clinically unique disease and one of the most difficult to cure forms of pediatric leukemia. Multicenter clinical trials have been carried out in Japan since the mid-1990s by introducing allogeneic hematopoietic stem cell transplantation (HSCT) in first remission, which led to a modest improvement in outcome of infants with KMT2A-r ALL. Because of the emerging evidence that HSCT does not benefit every infant with KMT2A-r ALL, the Japanese Pediatric Leukemia/Lymphoma Study Group trial MLL-10 introduced risk stratification using age and presence of central nervous system leukemia, and introduced intensive chemotherapy, including high-dose cytarabine in early consolidation; indication of HSCT was restricted to the patients with high-risk features. The trial resulted in excellent 3-year event-free survival of 66.2% (standard error, 5.6%) and overall survival of 83.9% (standard error, 4.3%) for 75 patients with KMT2A-r ALL recruited between 2011 and 2015. This Japanese experience and the results of the infant ALL trials worldwide suggest the importance of introducing effective therapy in the early phase of therapy, thus clearing minimal residual disease as rapidly as possible. However, further improvement in outcome is unlikely with conventional treatment approaches. Introduction of biology-driven novel agents and/or immunotherapies through international collaboration would be key solutions to overcome the disease.

Magnesium supplementation therapy to prevent cisplatin-induced acute nephrotoxicity in pediatric cancer: A protocol for a randomized phase 2 trial.

Although cisplatin is one of the most effective agents against various pediatric cancers, it is sometimes difficult to manage due to its dose-limiting nephrotoxicity. Magnesium sulfate (Mg) showed a kidney-protective effect against cisplatin-induced nephrotoxicity (CIN) by regulating renal platinum accumulation both in vitro and in vivo, and the body of clinical data demonstrating the efficacy of this drug in adult cancer patients is increasing.In this open, multicenter, phase-2, randomized trial, patients under age 18 years who are scheduled to receive cisplatin-containing chemotherapy will be enrolled and randomly allocated either to an Mg supplementation arm in even-numbered chemotherapy courses (arm AB) or to another arm in odd-numbered courses (arm BA), with a 1:1 allocation. Analysis objects will be reconstructed into two groups depending on whether the chemotherapy course has Mg supplementation (group B) or not (group A). The primary endpoint is the proportion of chemotherapy courses resulting in elevated serum creatinine equal to or greater than 50% of the prechemotherapy value. For the secondary endpoints, various parameters for measuring kidney function, such as serum cystatin-C, B2M, L-FABP, NGAL, and urinary NAG in the two groups will be compared. A sample size based on alpha = 5% and 80% power requires at least 40 samples per group (ideally, 60 samples per group).If Mg demonstrates efficacy, a phase-3 study to confirm the prophylactic effect of Mg supplementation in both acute and chronic CIN will be developed using novel and better biomarkers. TRIAL REGISTRATION: UMIN-CTR (http://www.umin.ac.jp/icdr/index.html) Identifier UMIN000029215.

Preclinical evaluation of NUDT15-guided thiopurine therapy and its effects on toxicity and antileukemic efficacy.

Thiopurines (eg, 6-mercaptopurine [MP]) are highly efficacious antileukemic agents, but they are also associated with dose-limiting toxicities. Recent studies by us and others have identified inherited NUDT15 deficiency as a novel genetic cause of thiopurine toxicity, and there is a strong rationale for NUDT15-guided dose individualization to preemptively mitigate adverse effects of these drugs. Using CRISPR-Cas9 genome editing, we established a Nudt15-/- mouse model to evaluate the effectiveness of this strategy in vivo. Across MP dosages, Nudt15-/- mice experienced severe leukopenia, rapid weight loss, earlier death resulting from toxicity, and more bone marrow hypocellularity compared with wild-type mice. Nudt15-/- mice also showed excessive accumulation of a thiopurine active metabolite (ie, DNA-incorporated thioguanine nucleotides [DNA-TG]) in an MP dose-dependent fashion, as a plausible cause of increased toxicity. MP dose reduction effectively normalized systemic exposure to DNA-TG in Nudt15-/- mice and largely eliminated Nudt15 deficiency-mediated toxicity. In 95 children with acute lymphoblastic leukemia, MP dose adjustment also directly led to alteration in DNA-TG levels, the effects of which were proportional to the degree of NUDT15 deficiency. Using leukemia-bearing mice with concordant Nudt15 genotype in leukemia and host, we also confirmed that therapeutic efficacy was preserved in Nudt15-/- mice receiving a reduced MP dose compared with Nudt15+/+ counterparts exposed to a standard dose. In conclusion, we demonstrated that NUDT15 genotype-guided MP dose individualization can preemptively mitigate toxicity without compromising therapeutic efficacy.