Online Articles: Clinical and Laboratory ObservationsTrametinib-induced Left Ventricular Dysfunction in a Child With Relapsed NeuroblastomaModak, Shakeel MD*; Asante-Korang, Alfred MD†; Steinherz, Laurel J. MD*; Grana, Nanette MD‡Author Information *Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY Divisions of †Cardiology ‡Hematology-Oncology, All Children’s Hospital, St Petersburg, FL The authors declare no conflict of interest. Reprints: Shakeel Modak, MD, Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 (e-mail: firstname.lastname@example.org). Received October 21, 2014 Accepted April 21, 2015 Journal of Pediatric Hematology/Oncology: August 2015 - Volume 37 - Issue 6 - p e381-e383 doi: 10.1097/MPH.0000000000000364 Buy Metrics Abstract The MEK inhibitor trametinib is globally approved for metastatic melanoma harboring BRAF mutations. There are no reports thus far on its use in children. Exome sequencing on a relapsed tumor sample from an 11-year-old male with progressive, multiply relapsed stage 4 neuroblastoma revealed NRASQ61K mutation. After demonstration of normal cardiac function, he was started on oral trametinib. On day 13 of treatment, echocardiogram showed moderate left ventricular dysfunction. Trametinib was discontinued on day 15 and oral lisinopril was started. Left ventricular function recovered to baseline 37 days after discontinuing trametinib. However, neuroblastoma showed further progression. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.