Trametinib-induced Left Ventricular Dysfunction in a Child With Relapsed Neuroblastoma

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.