Emulation of the KEYNOTE-042 (NCT02220894) Trial Using Specialty Oncology Electronic Health Records Databases

Study Period: ENCORE database 1 (EDB1): Patient identification period: 01/01/2011-04/30/2024 with follow-up information through data cut-off date on 04/30/2024 ENCORE database 2 (EDB2): Follow-up information through February 2023 (there is no specific time period restrictions for patient eligibility) ENCORE database 4 (EDB4): Patient identification period: 10/01/2018-09/30/2023 with follow-up information through data cut-off date on 09/30/2023. Inclusion Criteria: * Age ≥18 years at treatment initiation * Subjects with histologically or cytologically confirmed advanced or metastatic NSCLC that is not amenable to curative-intent treatment * ECOG 0 or 1 * Line of therapy setting classified as "advanced" (EDB1) or "metastatic" (EDB2), or evidence of metastatic disease at treatment initiation (EDB4) * PD-L1 ≥ 50% Exclusion Criteria: * Patients with documentation of prior chemotherapy administration for advanced/metastatic NSCLC * Pembrolizumab group: patients with documented EGFR/ALK positivity * Chemotherapy group: patients with documented EGFR/ALK positivity or missing/unknown EGFR/ALK status * Missing/unknown or PD-L1 \< 50% * Patients with any documentation of an investigational agent within 4 weeks prior to initiation of first-line pembrolizumab/chemotherapy * Squamous patients with any documentation of prior carboplatin plus paclitaxel * Patients with any documentation of chemotherapy or biologic therapy within 3 weeks prior to initiation of first-line pembrolizumab/…