Central nervous system effectiveness of selpercatinib retreatment in heavily pretreated NSCLC patient with RET rearrangement: A case report.

INTRODUCTION

RET-rearranged non-small cell lung cancer (NSCLC) is a rare molecular subtype, accounting for 1-2% of all lung cancers. Selpercatinib, a selective RET tyrosine kinase inhibitor (TKI), has demonstrated efficacy in this oncogene-addicted population, but data on rechallenge after disease progression are lacking.

CASE DESCRIPTION: A 70-year-old male was diagnosed with a metastatic RET-positive adenocarcinoma of the lung. At the time of systemic progressive disease on first-line chemo-immunotherapy, he received selpercatinib for 22 months before further central nervous system (CNS) progression. After whole-brain radiotherapy and third-line chemotherapy, selpercatinib was resumed due to further CNS progression and lack of other therapeutic options. Remarkably, the patient achieved an almost complete CNS remission.

CONCLUSION

This case suggests that selpercatinib rechallenge may be effective in difficult-to-treat RET-positive NSCLC patients, including those with uncontrolled CNS disease.