P1.16-42 Real-World Trends in Systemic Anticancer Therapy (SACT) for Squamous Advanced NSCLC (aNSCLC) in the US, 2011–2018

Abstract

The SACT options for aNSCLC continue to increase each year with approvals of more effective therapies that improve long-term outcomes, as seen with immunotherapies (IO). Our aim was to examine real-world trends in SACT distribution and sequence from first- to second-line (1L-2L) for squamous aNSCLC from 2011-2018 at US community oncology practices. This study used the nationwide Flatiron Health de-identified, EHR-derived database (cutoff: 31Jan2019). Eligible patients were adults who initiated 1L SACT from Jan2011-Jun2018 for aNSCLC with squamous histology, excluding patients with known EGFR/ALK-positive tumors. Descriptive analyses included patients receiving ≥1 SACT dose, assigning all SACT regimens to mutually exclusive classes in hierarchical order (combination regimens assigned by highest component), from highest to lowest: (1) PD1/PD-L1 inhibitor (anti-PD1/L1)-based, (2) EGFR/ALK TKI-based, (3) platinum-based chemotherapy combination with vascular endothelial growth factor inhibitor (PBC+VEGF), (4) PBC only, (5) single agent chemotherapy, (6) others. The 2L regimens were examined for patients with 1L SACT initiation only through 2017 to enable sufficient follow-up. Results were stratified by years and by pre-IO and post-IO years of 1L initiation, defined as 2011-2014 and 2015-2018, respectively, based on the earliest IO approval for 2L therapy in Mar2015. For 1L therapy, in the pre-IO period, most patients were prescribed PBC (80%), and post-IO, most patients were prescribed PBC (68%) or anti-PD1/L1 (21%). Among patients prescribed 1L therapy, the percentages who received 2L therapy were 44%-53% following 1L PBC and 25%-37% following 1L anti-PD1/L1, with 19% of 2017 1L anti-PD1/L1 starts still on 1L therapy (table). PBC remain the most common 1L SACT prescribed through mid-2018 for patients with squamous aNSCLC at US community oncology practices. Prescribing of PD1/PD-L1 inhibitors as 1L has gradually increased since regulatory approval starting in 2015. Approximately one-half of patients with squamous aNSCLC prescribed 1L PBC are treated with 2L therapy.