2049P - Osimertinib-related muscle cramps as a common adverse event: A real-world data analysis in the post-approval setting

Background

Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) that is the standard of care treatment for non-small cell lung cancer (NSCLC) with EGFR driver mutation. Some of the most common treatment-related adverse events (TRAEs) are rash, diarrhea, nausea, paronychia, and stomatitis. This abstract aims to describe muscle cramps as TRAEs associated with osimertinib use.

Methods

EGFR mutant NSCLC patients using osimertinib were included. Data were collected during pharmaceutical consultations and remote telemonitoring between January 2016 and April 2023. In all consultation modalities, drug interactions, drug reconciliation, adherence to treatment using the Morisky Medication Adherence Scale (MMAS) tool, classification and grading of TRAEs according to Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 were evaluated.

Results

A total of 88 patients were included. Mean age was 68 years and 71% were female. The pharmacist performed medication reconciliation and analysis of drug interactions in all patients and 99% of them showed good adherence to treatment. In the evaluation of TRAEs, 29% reported muscle cramps, with 19% of the sample developing grade 2. The median onset of the event was 2 months after starting osimertinib. Around 57% of the patients had diarrhea, which was managed early after the initial symptoms. Therefore, the occurrence of muscle cramps was not related to hydroelectrolytic unbalance due to diarrhea. The main osimertinib registration studies did not report muscle cramps as TRAEs.

Conclusions

In our cohort muscle cramps were very common TRAEs associated with osimertinib use and have not been directly related to diarrhea. It is an underreported adverse event that can impact on quality of life. Pharmaceutical follow-up is strategic for post-marketing surveillance, playing an important role in identifying new TRAEs. Update on muscle cramps as a very common TRAEs for osimertinib is required to develop supportive measures in conjunction with the multidisciplinary team, support clinical data and add to regulatory agency records.

Clinical trial identification

Research Ethics Committee approval CAAE: 19918319.1.0000.5533.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.