Successful Treatment of Switching EGFR-TKIs for Advanced Lung Adenocarcinoma Due to Interstitial Lung Disease: A Case Report.

Introduction: Icotinib and almonertinib are efficacious for non-small cell lung cancer (NSCLC) factor patients with epidermal growth receptor (EGFR)-mutation. Patients who previously used EGFR tyrosine kinase inhibitor (EGFR TKI) may switch to another one due to the adverse events.

Case presentation: Here, we report a case of a 73-year-old male patient with advanced lung adenocarcinoma in which an EGFR (exon 21 L858R substitution) was found. Icotinib (125mg three times daily) was administered initially. He achieved partial response two months later but developed acute interstitial lung disease (grade 2) with dry cough and chest tightness five months later. Icotinib was discontinued, and treatment with methylprednisolone improved the interstitial lung disease. Chemotherapy with pemetrexed, carboplatin, and bevacizumab was initiated as subsequent therapy. Considering the effectiveness of EGFR-TKIs, we decided cautiously to rechallenge the third-generation TKI almonertinib administration. The patient successfully received almonertinib for almost one year without the recurrence of interstitial lung disease and tumor progression. ILD was an infrequent but often life-threatening reaction associated with icotinib.

Conclusion: This is the first reported case of successful switching from icotinib to another EGFR TKI because of interstitial lung disease associated with icotinib, suggesting that EGFR-TKIs rechallenge because of adverse events rather than progression might provide a significant benefit in patients with EGFR driver positive NSCLC.