A case report published in Respirology Case Reports described fatal tumor lysis syndrome after a single 1-milligram starter dose of tarlatamab in a woman with relapsed small cell lung cancer. The reaction occurred six days after the initial dose, despite only mild early symptoms. While the report is limited by its design, it raises immediate questions for clinicians about baseline tumor burden, monitoring intensity, and how early dosing schedules may need adjustment. As tarlatamab continues to move through development and real-world use, the case underscores the importance of standardized TLS risk mitigation and rapid escalation protocols.