Interstitial Lung Disease due to Tepotinib after Durvalumab in a Patient with Lung Adenocarcinoma Harbouring MET Exon 14 Skipping Mutation: A Case Report.

Introduction: Tepotinib is a targeted agent for patients with advanced non-small cell lung cancer (NSCLC) with MET exon 14 skipping mutation (METex14). Whereas durvalumab is an immune-checkpoint inhibitor (ICI), which has been administered to those with unresectable stage III NSCLC. The efficacy and safety of sequential treatment in patients with METex14 are unclear. Reports have suggested that the administration of tyrosine kinase inhibitors after ICIs could potentially increase the incidence of drug-induced lung injury. Case Presentation: A 76-year-old female patient was diagnosed NSCLC harbouring METex14 with clinical stage IIIA (cT2aN2M0). Chemoradiotherapy and consolidation therapy with durvalumab were initiated to achieve a cure. Durvalumab was discontinued due to interstitial lung disease (ILD). After systemic disease progression was observed, tepotinib was initiated 7 weeks after the last dose of durvalumab. She developed ILD due to the sequential treatment of tepotinib after durvalumab. Conclusion: It is unclear whether tepotinib is safe in patients with METex14 after durvalumab administration. Considering the residual period of ICIs in the body, caution should be exercised when initiating molecular-targeted drugs after ICI administration in patients with NSCLC with METex14.