381P - Real-world experience of treatment with afatinib in advanced non-small cell lung cancer (NSCLC) in Vietnam

Background

Afatinib is a second-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), which has demonstrated significantly improved clinical results relative to chemotherapy and gefitinib. This study was conducted with the aim of evaluating the efficacy and safety profile of afatinib in the real-world practice.

Methods

This is a single center observational study of NSCLC harboring EGFR mutations at Ho Chi Minh Oncology hospital, started first-line afatinib from Jan 1st, 2018, to Jun 1^st, 2021. The primary endpoint of the study is time on treatment (TOT).

Results

Among 66 patients enrolled in this study, EGFR mutation analyzed from the tumors includes exon 19 deletion, L858R and uncommon mutations in 55%, 15%, and 30%, respectively. Among them, 14 patients featured baseline brain metastases, majority of patients has ECOG performance status of 0-1, and current or former smokers accounted for 35% of patients. Afatinib 30mg once daily was the most common either initiating or maintenance doses. At the time of analysis, 64% patients (42/66) have discontinued the treatment of afatinib with median TOT of 16.13 months (95% CI, 12.3 - 19.9 months). Patients with baseline brain metastases has an encouraging TOT with median value of 16.03 months. Only four patients without CNS metastases baseline, who discontinued afatinib, detected newly developed lesion of brain. Additionally, multivariate analysis demonstrated that there was no statistically significant difference on median TOT among subtypes of EGFR mutation with median TOT of 16.03 months, 20.7 months, and 19.83 months for del19, L858R, and uncommon mutations, respectively. The overall survival data was not mature at the time of cut-off data. In term of safety data, primary side effects included diarrhea, rash/acne, stomatitis and paronychia, with only five patients who developed severe adverse events during the course of treatment.

Conclusions

In the single center study, afatinib demonstrated an encouraging clinical activity in the first-line settings of advanced NSCLC harboring EGFR mutation with impressive TOT regardless of mutation subtypes and very low incidence of intracranial progression. Additionally, treatment with afatinib was generally well-tolerated.

Clinical trial identification

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.