Unexpected Acute Pancreatitis After Tarlatamab in Small Cell Lung Cancer: A Case Report

Tarlatamab is a bispecific T-cell engager (BiTE) targeting delta-like ligand 3, recently approved for relapsed extensive-stage small cell lung cancer.Its toxicity profile is primarily characterized by cytokine release syndrome and neurotoxicity.Pancreatitis has not been well described.We report a case of acute pancreatitis occurring approximately eight hours after the first dose, followed by completion of subsequent scheduled doses without recurrence.A 62-year-old man developed severe epigastric pain on cycle 1, day 1, after receiving tarlatamab.Lipase was elevated, and imaging confirmed acute interstitial pancreatitis.There was no history of alcohol use, and evaluation did not demonstrate gallstones, biliary obstruction, hypertriglyceridemia, hypercalcemia, or autoimmune disease.The patient improved with supportive care.After recovery, he proceeded with the remaining scheduled doses of cycle 1, which were completed without recurrence of symptoms.This case highlights a possible early, transient pancreatic toxicity and suggests that treatment may be completed in selected patients after resolution of symptoms.