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

Background: 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. Methods: 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. Results: 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 <1% in 2018. Conclusion: Consistent with the evolving first-line NSCLC treatment landscape in the US, this SLR captures the increasing use of I-O in recent years. While the brief lag in I-O use from the time of authorization may be attributable to an initial resistance to treatment adoption or publication delays, continued use of chemotherapy regimens may reflect an unmet treatment need, which warrants further research.