USE OF OSIMERTINIB 160mg FOR TREATMENT OF NSCLC: CASE REPORT

Abstract

Introduction: Lung cancer is the most prevalent cancer in the world, and it is also the cancer with the highest mortality. Non-small cell lung cancer (NSCLC) accounts for 85% of cases, and is related to bone metastases in the central nervous system (CNS), and liver. It is known that a large part of the mutations involved in the development of NSCLC is the mutation in the epidermal growth factor receptor (EGFR) gene, leading to the production of EGFR with permanent activation, and thus, generating a lack of control over cell growth pathways. Thus, drugs capable of blocking the mutated EGFR receptor and reversing the constitutive activation of the receptor have been developed. Currently, the drugs available with this capacity are tyrosine kinase inhibitors (TKIs), including osimertinib (third-generation TKI), which has the ability to act on EGFR T790M mutations, and penetrate the blood-brain barrier, allowing the treatment of leptomeningeal and brain metastases. Currently, osimertinib is used in doses of 80 mg for the treatment of NSCLC with CNS metastasis resistant to first- and second-generation TKIs, and there are few studies on therapeutic and side effects at higher doses. Thus, the present case report seeks to elucidate the effects caused by osimertinib 160mg on NSCLC associated with meningeal metastasis and to understand the side effects observed with the increase in the dose of the drug. Case report: A 53-year-old female patient diagnosed in 2018 with NSCLC with EGFR mutation and meningeal metastasis. She used osimertinib 80 mg, with tumor growth in the lung and meninges. In 2020, the dose was increased to 160 mg after developing meningeal syndrome and observing the presence of tumor cells in cerebrospinal fluid. The patient developed adverse reactions to the medication and dose increases. She presented clinical worsening at the end of 2021, evolving to death in 2022. Conclusion: Osimertinib 160mg has high efficacy for the control of neoplasms and metastases with EGFR mutations, and more intense side effects than the usual dose, and further studies are needed to understand the efficacy of the drug in meningeal metastases in the long term.

DOI: https://doi.org/10.56238/sevened2024.039-026