Search

Background: Hearing is essential in child development. Cisplatin which is a common chemotherapy used in many pediatric solid-tumor protocols cause various degrees of ototoxicity. Several risk factors for cisplatininduced ototoxicity have been reported, including race and age. This study aimed to evaluate the incidence of ototoxicity and its long-term outcome in Thai pediatric solid-tumor patients receiving cisplatin and to determine the risk factors associated with hearing impairment., Methods: A retrospective study was conducted in solid-tumor patients < 15 years old from 2007 to 2019 at Siriraj Hospital, Bangkok, Thailand. Hearing was evaluated by an audiogram and/or auditory steady-state response and the impairment was graded according to the Common Terminology Criteria for Adverse Events version 5. Grade 2 and above was considered significant hearing loss., Results: In total, the hearing of 47 patients was evaluated. At the end of treatment, hearing impairment and significant hearing loss were found in 66% and 48.9% of patients, respectively. A high median cumulative cisplatin dose was significantly associated with worse hearing impairment (p = 0.039) and a more progressive grading of ototoxicity (p = 0.005). A risk factor for significant hearing loss was a cumulative dose ≥400 mg/m2 (p = 0.014). All 9 patients who received a cumulative dose > 600 mg/m2 and 5 patients who received aminoglycoside developed significant hearing loss. One patient had progressive hearing impairment at 8 months after the end of treatment and 1 patient developed grade 3 ototoxicity which required a hearing aid after bone marrow transplantation. The latter patient received a total cisplatin dose of 708.2 mg/m < sup > 2 < /sup > and carboplatin 1400 mg/m < sup > 2 < /sup > ., Conclusions: The incidence of hearing impairment in pediatric patients receiving cisplatin is high. Regular hearing evaluation is essential for the early detection of ototoxicity. Long-term follow-up is recommended, especially in patients who have a combination of other risk factors for hearing loss.

Although patients diagnosed as Langerhans cell histiocytosis (LCH) with bone lesion initially respond well to treatment, some may experience relapse or refractory disease. Pamidronate, a potent N-bisphosphonate, has been used in several primary bone diseases, benign bone tumors, and metastatic bone cancers. The mechanism includes an inhibitory effect on osteoclast activity by decreasing development and recruitment of osteoclast progenitors and promoting osteoclast apoptosis. Herein, we introduce a seven-month-old Thai girl who was diagnosed as multiple-relapse LCH with refractory bone lesions and was treated with standard and salvage steroid-based therapies. After receiving two courses of intravenous pamidronate, she had marked clinical and radiographical improvement without any adverse events. She has been in remission for two years after receiving six courses of therapy. This report supports the efficacy ofpamidronate in LCH-related bone lesions, but further studies in large cohort are warranted.

FLT3 kinase internal tandem duplication (ITD) mutations are common in acute myeloid leukemia (AML) and are associated with poor clinical outcomes. Although initial responses to FLT3 tyrosine kinase inhibitors (TKIs) are observed in FLT3-ITD-positive patients, subsequent relapse often occurs upon acquisition of secondary FLT3 kinase domain (KD) mutations, primarily at residues D835 and F691. Using biochemical assays, we determined that crenolanib, a novel TKI, demonstrates type I properties and is active against FLT3 containing ITD and/or D835- or F691-activating mutations. Potent activity was observed in FLT3-ITD-positive AML cell lines. Crenolanib delayed the outgrowth of MV4-11 cells in a xenograft mouse model, whereas in combination with the type II TKI sorafenib, a significant decrease in leukemic burden (P < .001) and prolonged survival (P < .01) was observed compared with either type I or II TKI alone. Crenolanib was active against Ba/F3 cells harboring FLT3-ITD and secondary KD mutations and sorafenib-resistant MOLM-13 cells containing FLT3-ITD/D835Y both in vitro and in vivo. In addition, crenolanib inhibited drug-resistant AML primary blasts with FLT3-ITD and D835H/Y mutations. These preclinical data demonstrate that crenolanib is effective against FLT3-ITD containing secondary KD mutations, suggesting that crenolanib may be a useful therapeutic agent for TKI-naive and drug-resistant FLT3-ITD-positive AML.

Purpose: Investigate antileukemic activity of artemisinins, artesunate (ART), and dihydroartemisinin (DHA), in combination with cytarabine, a key component of acute myeloid leukemia (AML) chemotherapy using in vitro and in vivo models.Methods: Using ten human AML cell lines, we conducted a high-throughput screen to identify antimalarial agents with antileukemic activity. We evaluated effects of ART and DHA on cell viability, cytotoxicity, apoptosis, lysosomal integrity, and combination effects with cytarabine in cell lines and primary patient blasts. In vivo pharmacokinetic studies and efficacy of single-agent ART or combination with cytarabine were evaluated in three xenograft models.Results: ART and DHA had the most potent activity in a panel of AML cell lines, with selectivity toward samples harboring MLL rearrangements and FLT3-ITD mutations. Combination of ART or DHA was synergistic with cytarabine. Single-dose ART (120 mg/kg) produced human equivalent exposures, but multiple dose daily administration required for in vivo efficacy was not tolerated. Combination treatment produced initial regression, but did not prolong survival in vivo.Conclusions: The pharmacology of artemisinins is problematic and should be considered in designing AML treatment strategies with currently available agents. Artemisinins with improved pharmacokinetic properties may offer therapeutic benefit in combination with conventional therapeutic strategies in AML. [ABSTRACT FROM AUTHOR]