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Purpose: Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL. Patients and Methods: In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations. Results: Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021–0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011–0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection. Conclusions: NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Supplementary Fig. 1 Treatment schema & Sampling Timepoints

Supplementary Fig. 4 Evaluation of long-term storage of serum specimens (NAC assay)

Supplementary Fig. 3 Change in serum glutathione concentrations following NAC infusion

Supplementary Fig. 5 Progression-free survival in NAC treated and observation patients

Supplementary Fig. 2 Cumulative incidence of SIOP Grade ≥2 hearing loss

Supplemental Tables and Files

Purpose:Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.Patients and Methods:In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.Results:Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021–0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011–0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.Conclusions:NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Anthracycline chemotherapies cause heart failure in a subset of cancer patients. Emerging evidence suggests that genetic factors might contribute to the interindividual variations in cardiac sensitivity to anthracyclines. We previously reported that the anthracycline doxorubicin (DOX) induces cardiotoxicity through activation of cyclin-dependent kinase 2 (CDK2). The aim of this study was to determine whether retinoblastoma-like 2 (RBL2/p130), an emerging CDK2 inhibitor, regulates CDK2 activity and anthracycline sensitivity in the heart. Here, we showed that loss of endogenous Rbl2 increased basal cardiac CDK2 activity. Mice lacking Rbl2 were more sensitive to DOX-induced cardiotoxicity, as evidenced by rapid deterioration of heart function and loss of heart mass. Disruption of Rbl2 exacerbated DOX-induced mitochondrial damage and cardiomyocyte apoptosis. Mechanistically, Rbl2 deficiency enhanced CDK2-dependent activation of forkhead box O1 (FOXO1), leading to upregulation of the pro-apoptotic protein Bim. Inhibition of CDK2 desensitized Rbl2-depleted cardiomyocytes to DOX. In wild-type cardiomyocytes, DOX exposure induced Rbl2 expression in a FOXO1-dependent manner. Importantly, human RBL2 gene single nucleotide polymorphism (rs17800727) was also associated with anthracycline cardiotoxicity in childhood cancer survivors. In conclusion, loss of Rbl2 provokes cardiac CDK2 activation, resulting in increased sensitivity to DOX-induced cardiotoxicity. Rbl2 is an endogenous CDK2 inhibitor in the heart and represses FOXO1-mediated pro-apoptotic gene expression. Our findings suggest that RBL2 could be used as a biomarker to predict the risk of cardiotoxicity in individual patient prior to initiation of anthracycline-based chemotherapy.

Background: Ondansetron is a highly effective antiemetic for the treatment of nausea and vomiting. However, this medication has also been associated with QT prolongation. Pharmacogenomic information on therapeutic response to ondansetron exists, but no investigation has been performed on genetic factors that influence the cardiac safety of this medication. Methods: Three patient groups receiving ondansetron were recruited and followed prospectively (pediatric post-surgical patients n = 101; pediatric oncology patients n = 98; pregnant women n = 62). Electrocardiograms were conducted at baseline, and 5- and 30-min post-ondansetron administration, to determine the effect of ondansetron treatment on QT interval. Pharmacogenomic associations were assessed via analyses of comprehensive CYP2D6 genotyping and genome-wide association study data. Results: In the entire cohort, 62 patients (24.1%) met the criteria for prolonged QT, with 1.2% of the cohort exhibiting unsafe QT prolongation. The most significant shift from baseline occurred at five minutes post-ondansetron administration (P = 9.8 × 10−4). CYP2D6 activity score was not associated with prolonged QT. Genome-wide analyses identified novel associations with a missense variant in TLR3 (rs3775291; P = 2.00 × 10−7) and a variant linked to the expression of SLC36A1 (rs34124313; P = 1.97 × 10−7). Conclusions: This study has provided insight into the genomic basis of ondansetron-induced cardiac changes and has emphasized the importance of genes that have been implicated in serotonin-related traits. These biologically-relevant findings represent the first step towards understanding this adverse event with the overall goal to improve the safety of this commonly used antiemetic medication.

Supplemental material, sj-pdf-5-pdp-10.1177_10935266211001986 for Histologic Correlates of Molecular Group 4 Pediatric Medulloblastoma: A Retrospective Canadian Review by Joanna Triscott, Stephen Yip Donna Johnston, Jean Michaud, Shahrad R. Rassekh, Juliette Hukin, Sandra Dunn and Christopher Dunham in Pediatric and Developmental Pathology

Supplemental material, sj-pdf-4-pdp-10.1177_10935266211001986 for Histologic Correlates of Molecular Group 4 Pediatric Medulloblastoma: A Retrospective Canadian Review by Joanna Triscott, Stephen Yip Donna Johnston, Jean Michaud, Shahrad R. Rassekh, Juliette Hukin, Sandra Dunn and Christopher Dunham in Pediatric and Developmental Pathology

Children with acute lymphoblastic leukemia receive vincristine, a chemotherapy drug known to cause peripheral neuropathy. Yet, few studies have examined the association of vincristine to fine motor function.This study will describe the fine motor skills and function of children with acute lymphoblastic leukemia on maintenance vincristine.A prospective case series design assessed manual dexterity and parent-reported fine motor dysfunction of 15 children with acute lymphoblastic leukemia in relation to cumulative vincristine exposure.Almost half of the participants had below-average fine motor skills compared to age-related norms, and 57% of parents observed functional motor problems in their children. No significant associations were found between vincristine, manual dexterity, and functional motor skills.Early detection and intervention for fine motor difficulties is suggested. Research with a larger sample is necessary to further explore the association of vincristine and fine motor function in this clinical population.