Nivolumab after recurrent pembrolizumab-associated hepatotoxicity in PD-L1-high metastatic squamous non-small cell lung cancer: a case report.

Immune-related hepatitis can interrupt effective PD-1 therapy, and evidence guiding within-class retreatment after recurrent toxicity remains limited. An 82-year-old woman with remote resected lung cancer later developed PD-L1-high metastatic squamous non-small cell lung cancer with thoracic and hepatic disease. After 4 pembrolizumab doses, mixed liver injury developed despite normal baseline liver chemistries. Viral hepatitis serologies were negative, liver ultrasound was unrevealing, and acetaminophen exposure remained a non-significant competing factor. Liver tests improved with corticosteroids but recurred after 2 pembrolizumab rechallenges, including a grade 3 event, prompting permanent discontinuation. Nivolumab was started after biochemical recovery and was tolerated for more than 3 years without recurrent hepatotoxicity. Follow-up PET-CT demonstrated durable metabolic resolution of thoracic and hepatic disease.