Osimertinib-Induced Myositis in a Patient With Metastatic Non-small Cell Lung Cancer With Epidermal Growth Factor Receptor Mutation.

Publication/Presentation Date

8-1-2024

Abstract

Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) that has emerged as a standard treatment in non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation. While it is generally well tolerated, milder side effects of diarrhea, cytopenia, and cutaneous rashes are common. Osimertinib-induced myositis and rhabdomyolysis are exceedingly rare, and only a few cases have been documented in the literature to date. In this report, we present a case of a 59-year-old female with metastatic NSCLC who experienced myalgia following the initiation of osimertinib. Blood work revealed elevated creatine kinase (CK), serum creatinine (Cr), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Initially, her myalgia improved, and lab work normalized after drug discontinuation and supportive care. However, rechallenge with a 50% dose resulted in recurrence of symptoms and elevated serum CK, Cr, ALT, and AST. MRI findings suggested diffuse inflammation and a muscle biopsy revealed necrotizing myopathy. Symptoms ameliorated upon complete cessation of the drug and use of steroids. This case highlights the importance of recognizing this rare adverse effect of osimertinib and a guide for managing these associated symptoms.

Volume

16

Issue

8

First Page

67597

Last Page

67597

ISSN

2168-8184

Disciplines

Medicine and Health Sciences

PubMedID

39310509

Department(s)

Department of Medicine, Department of Pathology and Laboratory Medicine, Hematology-Medical Oncology Division, Lehigh Valley Topper Cancer Institute

Document Type

Article

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