Background: Non-small cell lung cancer (NSCLC) is the leading cause of cancer death in the US. Treatment choices in the first-line setting are critical as only half of all patients will receive second-line (2L) therapy. This study describes the real-world treatment patterns and outcomes in metastatic NSCLC patients treated with a first line (1L) therapy. Methods: A retrospective cohort analysis of IBM MarketScan@ Commercial and Medicare Supplemental Claims Databases was conducted. The analysis included adult patients diagnosed with mNSCLC who initiated nab-paclitaxel, sb-paclitaxel, or PD-L1 based 1L therapy from 1/1/2011 to 12/31/2017. Patients were continuously enrolled (CE) with medical and pharmacy benefits ≥6 months prior to mNSCLC diagnosis date to the start of 1L treatment (index date) and for ≥6 months after the index date. End of 1L was defined by treatment change, discontinuation (>60-day gap), or inpatient death or hospice. Patient follow-up was from index date to the end of CE or end of the study period, 6/30/2018. Baseline demographic, clinical characteristics, treatment patterns, and outcomes were analyzed descriptively. Results: 3533 patients meeting eligibility criteria were identified. Mean age was 65 years, 86.3% were older than 55, and 52% were men. Mean Charlson Comorbidity Index score was 10.3. Of the 1L treatments, 10.3%, 74.6%, and 15.1% patients had a nab-paclitaxel-based, sb-paclitaxel-, or PD-L1-based treatment, respectively. Observed median follow-up time was 363 days. 18.2% of patients remained on 1L treatment for at least 6 months. Mean 1L DOT was 126 days (SD, 113 days). Overall, 92.2% of patients stopped 1L treatment during follow-up, including death in 2.8% of patients; 52.0% of patients received a 2L therapy Outcomes varied among the 84.9% patients who received taxane-based treatment. Mean DOT was 143 (SD 104) and 108 (SD 97) days for nab-paclitaxel- and sb-paclitaxel-based treatments, respectively. The proportion of patients who remained on 1L treatment was greater for those receiving a nab-paclitaxel-based compared to sb-paclitaxel-based treatment (23.5% vs. 11.7%). Mean TTNT was 210 and 181 days for nab-paclitaxel- and sb-paclitaxel-based treatments, respectively. Conclusion: Given half of patients do not receive 2L, it is important to administer a 1L treatment that allows longer time on treatment and delayed progression. Results suggest nab-paclitaxel offers an early treatment option for patients.