A cancer case report described a rare but severe complication after one dose of an immunotherapy combination in a patient with stage IV lung adenocarcinoma. Clinicians reported four organ crises following a regimen combining the anti-PD-L1 antibody atezolizumab with tiragolumab, an experimental anti–T-cell receptor antibody. While checkpoint inhibitors can cause immune-related adverse events, the report illustrates how rapidly serious toxicity can emerge and the importance of early clinical vigilance when combining agents that amplify immune activity. For developers running combination studies, the update supports a continuing focus on safety surveillance and rapid management pathways in addition to efficacy signals.