P84.19 A Review of Clinical Outcomes of Irish Patients With ALK Rearranged NSCLC

Abstract

Chromosomal rearrangements of the anaplastic lymphoma kinase (ALK) gene are found in approximately 4% of non-small cell lung cancer (NSCLC). Patients can have substantial and durable responses to tyrosine kinase inhibitors (TKIs), with median overall survival measured in years. Little has been studied of ALK NSCLC in Irish patients. The medical records of patients diagnosed with ALK rearranged NSCLC between 2010 to 2018 were identified and analysed in four Irish cancer centres. Patient demographics, treatment, toxicity and survival were assessed. 23 patients were identified, 37% male, 96% Caucasian, 100% adenocarcinoma histology and 74% never smokers. Median age at diagnosis was 51 years (range 27-87). 7 (30%) had brain metastases de novo. The median number of treatment lines received was 2 (range 1-7). 16 (70%) received crizotinib as first line treatment, the objective response rate (ORR) was 75% and median progression free survival (mPFS) was 9 months (range 2-43). Of these patients, 62% required a dose reduction of crizotinib and 25% discontinued crizotinib due to toxicity. 10 patients subsequently received alectinib as second line therapy, ORR 80%, mPFS 7.5 months (range 6-18). 60% required a dose reduction and 40% discontinued alectinib due to toxicity. Median overall survival was not reached, 78% of patients were alive one year from diagnosis of advanced disease. The patient characteristics, ORRs and the mPFS observed in this cohort of Irish patients with ALK rearranged NSCLC were similar to international results. Crizotinib-led sequences were most common, reflecting the approval history of ALK inhibitors in Ireland during the study period. In this real-world experience, there were more treatment discontinuations and dose reductions of TKIs than the phase 3 clinical trials that led to their approval.