Treatment patterns for advanced non-small cell lung cancer in the US: A systematic review of observational studies

•The advent of new therapies has transformed the treatment landscape in advanced NSCLC.•This systematic review captures the evolving first-line treatment patterns in the US.•A total of 18 observational studies published from 2012 to 2020 were included.•Chemotherapy remained the most preferred frontline treatment until 2017. Thereafter, immunotherapies have emerged as the first-line treatment of choice. The advent of immunotherapies (I-O) and targeted therapies has transformed the treatment landscape in advanced non-small cell lung cancer (NSCLC). However, adoption of new treatment guidelines and evolving treatment patterns in clinical practice are largely unknown. The aim of this systematic literature review (SLR) was to capture real-world first-line treatment patterns in advanced (staged IIIB–IV) or recurrent NSCLC patients in the US. Electronic databases were systematically searched for observational studies published 2012–2020 that reported on adult patients receiving first-line therapy for advanced NSCLC. Included studies were reviewed and treatment patterns were summarized descriptively. Eighteen studies were included. Platinum-doublet (PD) chemotherapy and unspecified chemotherapy regimens were the most commonly used first-line treatments (up to 71% and 96%, respectively). Chemotherapy as monotherapy was mainly utilized in patients ≥65 years. While chemotherapy use was continuously high, I-O became the preferred front-line treatment in 2018 (32.9%). I-O monotherapy was more prevalent among patients with PD-L1 ≥50%, compared to patients with lower levels. First-line use of tyrosine kinase inhibitors and bevacizumab-based therapies was common in 2010 (33.4% and 21.7%, respectively), but gradually declined to