First-Line Pembrolizumab Plus Chemotherapy for Advanced Squamous NSCLC: Real-World Outcomes at U.S. Oncology Practices.

Introduction: Pembrolizumab plus carboplatin and (nab-)paclitaxel (pembrolizumab-chemotherapy) is currently an approved and recommended systemic therapy for patients with previously untreated advanced squamous NSCLC. This retrospective study evaluated real-world time on treatment (rwToT) and overall survival (OS) among patients with advanced squamous NSCLC treated with first-line pembrolizumab-chemotherapy at oncology practices in the United States.

Methods: Using a real-world database, we selected adult patients with newly diagnosed or recurrent advanced squamous NSCLC (unresectable stages IIIB, IIIC, or IV) and good performance status (Eastern Cooperative Oncology Group 0-1) who initiated first-line pembrolizumab-chemotherapy from November 1, 2018, to May 31, 2020. The Kaplan-Meier method was used to determine rwToT and OS overall and by programmed death-ligand 1 (PD-L1) expression. Data cutoff was October 31, 2021.

Results: Of 364 eligible patients, 243 (67%) were men; median age was 70 (range: 43-84) years; and PD-L1 expression was greater than or equal to 1%, less than 1%, and unknown for 172 (47%), 94 (26%), and 98 patients (27%), respectively. Median follow-up from pembrolizumab-chemotherapy initiation to data cutoff was 26.2 months. Overall, median pembrolizumab rwToT was 6.5 months (95% confidence interval [CI]: 5.6-7.6), with on-treatment rates of 29.3% and 15.9% at 12 and 24 months, respectively. Median OS was 15.3 months (95% CI: 11.7-18.6), with 12- and 24-month OS rates of 54.9% and 37.3%, respectively. Median OS did not differ with PD-L1 expression: 16.2 months (95% CI: 10.3-20.6) for PD-L1 greater than or equal to 1% and 17.2 months (95% CI: 10.8-20.6) for PD-L1 less than 1%.

Conclusions: For patients with advanced squamous NSCLC and good performance status treated with first-line pembrolizumab-chemotherapy, rwToT and OS are similar to clinical trial findings for treatment duration and OS.