Ivonescimab combined with radiotherapy in the treatment of advanced lung adenocarcinoma with high expression of PD-L1: A case report.

The optimal sequencing of immunotherapy and radiotherapy in non-small cell lung cancer (NSCLC) remains unclear. The present study reports a case of advanced lung adenocarcinoma (cT4N2bM1a, stage IVa) with a programmed death-ligand 1 (PD-L1) tumor proportion score of 90% and TP53 mutation. The patient received first-line ivonescimab monotherapy (900 mg, every 3 weeks) for four cycles, achieving a partial response (47% reduction per Response Evaluation Criteria in Solid Tumors 1.1). Sequential thoracic radiotherapy (5,000 cGy/25 fractions) was then administered for consolidation. Serum tumor markers (carcinoembryonic antigen, cancer antigen 125, cytokeratin 19 fragment and neuron-specific enolase) exhibited markedly decreased levels from baseline. Grade I radiation pneumonitis occurred post-radiotherapy but resolved rapidly with low-dose glucocorticoids. At the last follow-up (8 months), the patient remained progression-free with the Eastern Cooperative Oncology Group performance status improving from 2 to 0. This case provides real-world evidence for the 'immunotherapy induction followed by radiotherapy consolidation' strategy in an individual with high PD-L1 expression. The presence of TP53 mutation may predict an enhanced synergistic response to combined immunotherapy and radiotherapy, warranting further investigation.