Severe, reversible alectinib-induced acute kidney injury requiring dialysis in an elderly patient with metastatic non-small cell lung cancer.

Alectinib is a first-line tyrosine kinase inhibitor (TKI) for anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) and is generally well tolerated. Severe renal toxicity is rare and evidence guiding management in elderly patients is limited. We describe a severe, reversible, dialysis-requiring nephrotoxicity confirmed by drug rechallenge, with successful subsequent treatment using an alternative ALK inhibitor.An elderly patient with advanced ALK-rearranged NSCLC developed kidney injury (AKI) shortly after initiation of alectinib, which progressed to dialysis-requiring renal failure. Renal function improved after treatment discontinuation but deteriorated again on alectinib rechallenge, strongly supporting drug-related causality. Urine sediment findings were consistent with acute tubular necrosis. Alectinib was permanently discontinued and treatment was switched to brigatinib, resulting in stable renal function and sustained oncological response.This case highlights that severe alectinib-induced nephrotoxicity, although rare, can occur and may be life-threatening, particularly in elderly patients with comorbidities and polypharmacy. Importantly, effective disease control can still be achieved through alternative ALK inhibitors.