Real-World Clinical Experience Of The Galician Lung Cancer Group: Afatinib In Patients With Egfr Positive Mutation.

e20654 Background: Treatment with tyrosine kinasa inhibitors has been a revolution for the patients with non-small cell lung cancer and EGFR positive mutation, especially in patients with exon 19 deletions. Afatinib seems one of the best options of treatment. Methods: Retrospective study on patients from differents hospitals in Galicia (Spain) diagnosed of metastasic lung adenocarcinoma with EGFR positive mutation who have received first line treatment with afatinib between July 2015 and September 2018 were included. The main objective was to compare our clinical experience concerning response rate, progression free survival and toxicity with published data. Results: 45 caucasians patients were included in our analysis (33 women, 12 men). Median age was 71.2 years (range 39-91 years) and 29 patients had never smoked. Exon 19 deletion was the most common mutation (41 patients, 91.1%). The objective overall response was 68.9% (95% CI: 82.4-55.3), complete responses were observed in 6 patients (13.3%) and partial responses were found in 25 patients (55.6%). Stable disease was observed in 8 patients (17.8%) and disease progression in 1 patient (2.2%), 5 patients have not been re-evaluated (11.1%). Median progression free survival (PFS) was 27 months (95% CI: 14.8-39.1) and overall survival was not reached. Common adverse events grade 3/4 were mucositis and skin toxicity in 11 patients (24.4%) and diarrhea in 6 patients (13.3%), respectively. The dose was reduced in 28 patients (62.2%) and treatment was discontinued in 8 patients (17.8%) owing to adverse events. Conclusions: Median PFS in our patients is 15 months longer than the information retrieved from differents studies with similar response rates and toxicity. This might be due to a majority of population with exon 19 deletion which, according to published data, seems to benefit more from afatinib than from other EGFR mutations.