Clinical analysis of patients treated with afatinib for advanced non-small cell lung cancer: A Nagano Lung Cancer Research Group observational study.

BACKGROUND: Afatinib has been available in Japan for the treatment of epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) since May 2014. We conducted an observational study in patients treated with afatinib in Nagano prefecture, focusing on response and associated toxicities.

METHODS: We analyzed the clinical records of NSCLC patients treated with afatinib between May 2014 and February 2015.

RESULTS: The records of a total of 73 patients (27 men, 46 women) with a median age of 69 years (range: 42-85 years) were analyzed. Afatinib was administered to 11 patients as a first-line therapy, but it was predominantly administered as a fifth-line or beyond therapy (32 cases, 43.8%). The overall response rates for afatinib as a first-line therapy and beyond second-line therapy were 80% (95% confidence interval [CI]: 55.2-100.0%) and 27.1% (95% CI: 14.5-39.7%), respectively. The main toxicities grade >3 included diarrhea (8.2%), skin rash (6.8%), nausea (6.8%), and appetite loss (6.8%). A low body surface area (BSA) (<1.5m(2)) was significantly associated with a higher frequency of diarrhea grade >2, compared with a higher BSA (≥ 1.5m(2)). Forty-eight patients (63.0%) were treated without a dose reduction of afatinib.

CONCLUSIONS: Although the survival benefit with afatinib remains unclear, our observational analysis demonstrated the feasibility of using afatinib for EGFR-mutated NSCLC in clinical practice. In particular, a relatively high level of drug delivery is possible. In addition, a lower BSA may be a predictor of diarrhea in patients treated with afatinib.