Several ALK inhibitors, including 2nd and 3rd generation agents are available for patients with ALK+ NSCLC. Treatment patterns and outcomes with use of multiple sequential ALK inhibitors is limited. A retrospective observational cohort study of patients with ALK+ NSCLC treated with 1st generation (crizotinib) and 2nd generation (alectinib, brigatinib, ceritinib) ALK inhibitors from 1 September 2011 to 31 December 2017. Structured data were obtained via programmatic extraction from the iKnowMed EHR database of the US Oncology Network. Patient demographics and treatment sequences were characterized. Index was the start date of the first ALK. Duration of therapy (DOT) from index to end of the last ALK, and overall survival (OS) were assessed using the Kaplan-Meier method. A total of 410 ALK+ NSCLC patients were included. Median age at index was 62 years, 54% were female, 78% Caucasian, 87% adenocarcinoma histology, and 54% never smokers. 233 (57%), 144 (35%), and 33 (8%) patients received 1, 2, or 3-4 different ALK inhibitors, respectively. Crizotinib monotherapy (50%) was most common. Among patients that received 2 or more ALK inhibitors (n=177), most were crizotinib-led sequences. In 59% of patients, chemotherapy was given prior to the first ALK (median time from start of chemo to index 6.64 mo), and 53% of patients ended their ALK sequence and received subsequent chemo. Median cumulative ALK DOT in the full study population, regardless of line of therapy or sequence was 16 mo (95% CI 6-19). Median OS from index for the full study population was 28 mo (95% CI 24, 36). Median OS among patients who received 1, 2, or 3-4 ALK inhibitors was 15 mo (95% CI 10, 22), 42 mo (95% CI 38, 60) and 56 mo (95% CI 31, 72). Patients received a range of 1 to 4 ALK inhibitors. Crizotinib-led sequences were most common, likely reflecting the approval history of ALK inhibitors during the study period. Longer DOT and OS were observed in patients receiving multiple ALK inhibitors. This study provides an initial view of treatment patterns following the emergence of new ALK inhibitors and suggests feasibility of sequential ALK therapies. Follow-up studies will help improve understanding of outcomes of patients treated with 2nd generation-led sequences.