Oral administration of osimertinib mesylate induced multiple peripheral neuropathy of a non-small-cell lung cancer patient and treated with traditional Chinese medicine - A case report

Osimertinib mesylate (OM) is a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) for the targeted treatment of non-small-cell lung cancer (NSCLC). To date, some adverse effects of OM (such as rhabdomyolysis, severe rash, etc.) have been reported in clinic, but no cases of OM-induced multiple peripheral neuropathy (MPN) have been documented. Here we report a rare case about oral administration of OM-induced MPN in a NSCLC patient and its treatment with traditional Chinese medicine (TCM) decoction. After taking OM orally to treat NSCLC for 2 months, a 70-year-old man experienced MPN symptoms including numbness in hand and foot, weakness in both lower limbs, limited mobility, and eventually the loss of the ability to stand and walk. Meanwhile, other known causes of MPN were ruled out. His symptoms did not improve after 24 days of discontinuing oral administration of OM. Subsequently, he received daily oral TCM decoction based on syndrome differentiation. One month later, his symptoms of MPN were relieved and the Total Neuropathy Score (TNS) was significantly reduced. He was able to stand and walk with the aid of a walker. The use of dialectical TCM decoction is a feasible treatment protocol to alleviate and even eliminate MPN symptoms. Further study is needed to investigate the mechanisms and preventive strategies of OM-induced MPN.