Abstract
This case report examines the effectiveness of osimertinib in a 64-year-old non-smoking female diagnosed with stage IV lung adenocarcinoma and an epidermal growth factor receptor (EGFR) exon 19 mutation, focusing on the treatment's impact on bone metastasis. Despite initial responsiveness to osimertinib, the patient's bone lesions remained largely unresponsive, prompting a comprehensive exploration of alternative treatments and clinical trials. This report highlights the patient's clinical journey, from diagnosis through various treatment phases, culminating in palliative care, and underscores the need for further research into targeted treatments for bone metastasis in lung cancer.