Real-World Data of Combined Immunochemotherapy in Patients With Nonsquamous Advanced NSCLC. A Single-Center Retrospective Study

INTRODUCTION: On the basis of the landmark trial KEYNOTE-189 (KN-189), pembrolizumab plus chemotherapy has become the standard-of-care first-line treatment for patients with advanced nonsquamous NSCLC without oncogenic driver alterations. KN-189 included a selected patient population and lacks external validity. In clinical practice, many patients do not meet the inclusion criteria of KN-189, although they are treated accordingly. It is unknown whether these patients benefit equally as the trial population. METHODS: We retrospectively analyzed all patients with advanced nonsquamous NSCLC without targetable oncogenic alterations who received the KN-189 treatment regimen between April 2018 and May 2021 at the University Hospital Basel, Switzerland. Patients were grouped into those who retrospectively met the inclusion criteria of KN-189 (group A) and those who did not (group B). Outcome parameters included progression-free survival (PFS), overall survival (OS), and objective response rate. Multivariate subgroup analyses were performed. RESULTS: We identified 75 patients, including 29 patients in group A and 46 patients in group B. Median PFS was 9.2 and 4.6 months in group A and B, respectively (p = 0.12). Median OS was 16.5 and 6.5 months in group A and B, respectively (p = 0.11). Objective response rate was 59% in group A and 33% in group B (p = 0.03). Eastern Cooperative Oncology Group performance status greater than or equal to 2 and active infections were significantly associated with shorter PFS and OS. CONCLUSIONS: We report real-world data for patients treated according to the KN-189 regimen with inferior outcomes in patients who did not meet the KN-189 inclusion criteria. Better treatment options for this vulnerable patient population are needed.