1546P - Treatment patterns and outcomes for patients (pts) with anaplastic lymphoma kinase-positive (ALK+) advanced non-small cell lung cancer (NSCLC) in US clinical practice

ALK inhibitors (ALKi) have shown substantial benefit in pts with advanced ALK+ NSCLC. We describe real-world treatment patterns and outcomes in pts with ALK+ advanced NSCLC in the US. This retrospective cohort study utilised US electronic health record data from Flatiron Health. Pts diagnosed with stage IIIB-IV ALK+ NSCLC from 1 Jan 2011 to 30 Sep 2018 were included. Treatment patterns and outcomes (real-world progression-free survival [rwPFS] and overall survival [OS]) were extracted for first- or second-line therapy. Time to treatment discontinuation (TTTD) was used as a surrogate for real-world treatment duration accounting for treatment beyond progression. Time-to-event analyses were performed using Kaplan-Meier methods. Data were available for 620 pts with ALK+ advanced NSCLC. An ALKi was given to 420/620 (67.7%) pts as first-line therapy and 273/359 (76.0%) pts who received second-line therapy. Among non-ALKi treatments, platinum-based regimens were the most common. Crizotinib was the preferred first-line ALKi up to 2016, and then alectinib. As second-line therapy, crizotinib was the preferred ALKi up to 2013, followed by ceritinib from 2014–2015, and then alectinib to the end of the follow-up period. TTTD, rwPFS and OS were longest with alectinib, followed by crizotinib and non-ALKi (Table). The use of ALKi in the US reflects current clinical guidelines. Despite the choice and established benefit of individual ALKi as first-line therapy, more than 25% of pts received a non-ALKi as first-line therapy, even in recent years (2017/2018). Furthermore, in clinical practice, treatment beyond progression with an ALKi is relatively common. OS for non-ALKi was comparable to some ALKi, but OS is also reflective of treatment received in later lines of therapy.Table1546PTable1LOutcomeStatisticsAlectinib (n=98)Ceritinib (n=4)Crizotinib (n=318)non-ALKi (n=200)rwPFSMedian (95% CI), monthsNR5.06 (0.72, NR)6.41 (5.92, 8.16)8.26 (6.25, 9.9)6-month probability (95% CI)0.83 (0.75, 0.91)0.5 (0.19, 1)0.55 (0.49, 0.6)0.59 (0.52, 0.66)12-month probability (95% CI)0.68 (0.58, 0.79)0.25 (0.05, 1)0.32 (0.27, 0.38)0.37 (0.3, 0.44)TTTDMedian (95% CI), monthsNR6.1 (0.72, NR)7.57 (6.97, 9.14)3.12 (2.76, 4.38)6-month probability (95% CI)0.85 (0.78, 0.92)0.5 (0.19, 1)0.61 (0.56, 0.67)0.35 (0.29, 0.43)12-month probability (95% CI)0.73 (0.64, 0.84)0.25 (0.05, 1)0.36 (0.31, 0.42)0.21 (0.16, 0.28)OSMedian (95% CI), monthsNR6.1 (0.72, NR)23.06 (16.51, 30.86)27.99 (21.6, 36.51)6-month pro