Ivonescimab monotherapy in an elderly patient with EGFR-TKI-resistant advanced lung adenocarcinoma and pericardial effusion: a case report and literature review.

Background: Ivonescimab is a first-in-class bispecific antibody targeting PD-1 and VEGF, showing promise in non-small cell lung cancer (NSCLC). This case report aims to explore the feasibility and efficacy of ivonescimab monotherapy in an elderly patient with EGFR-TKI-resistant advanced lung adenocarcinoma complicated by malignant pericardial effusion. Case presentation: A 77-year-old female with a 19-year history of postsurgical left lung adenocarcinoma was admitted with dyspnea and edema. Disease progression was observed after four cycles of chemotherapy (docetaxel plus nedaplatin) and subsequent EGFR-TKI therapy (icotinib and later furmonertinib combined with anlotinib). Upon readmission in February 2025 due to aggravated dyspnea, imaging revealed significant mediastinal tumor enlargement and a large pericardial effusion. Cytopathological examination of the pericardial fluid confirmed the presence of malignant cells, indicating TKI resistance. Given her advanced age and poor performance status precluding further chemotherapy, the patient was started on ivonescimab monotherapy (800 mg intravenously every 3 weeks). After six cycles of treatment, a follow-up CT scan demonstrated a marked reduction in the mediastinal tumor size and resolution of the pericardial effusion. Serum tumor markers, such as CYFRA 21-1 and proGRP, showed a decreasing trend. The treatment was well-tolerated with no significant adverse events observed during the follow-up periodstoryliter. Conclusion: This case suggests that ivonescimab monotherapy can achieve disease control with an acceptable safety profile in an elderly, heavily pretreated NSCLC patient with EGFR-TKI resistance and malignant pericardial effusion. It may represent a viable treatment option for this challenging population.