Analysis of Treatment Patterns and Outcomes Among Patients with Third-Line or Later (3L+) Diffuse Large B-Cell Lymphoma (DLBCL) with Multiple Qualifying Index Dates Treated in the United States

Background/Objectives: Diffuse large B-cell lymphoma (DLBCL) is an aggressive hematologic malignancy with a defined, first-line (1L) standard of care (SOC). Several novel agents have been approved for the treatment of relapsed/refractory (R/R) disease in recent years, leading to a heterogeneous treatment landscape in later lines of therapy (LOTs). Our study aimed to characterize real-world treatment patterns for patients who received third-line or later (3L+) therapy using a multiple index date qualification methodology to enable a comparison to clinical trials. Methods: This observational, retrospective study identified eligible patients in the COTA (now Verana Health) electronic health record-based, DLBCL dataset. Patients were assessed for eligibility at the initiation of each 3L+ LOT. The results were summarized overall and by qualification methodology, and the Kaplan–Meier method was used to evaluate real-world overall survival (rwOS). Results: Among 476 unique patients, 716 index-LOTs were identified, and 3L+ index therapies were variable. The Eastern Cooperative Oncology Group (ECOG) score was 0–2 for 57% of qualifying-LOTs and missing/unknown (M/U) for 43%. The median rwOS among all-qualifying, first-qualifying, and last-qualifying index-LOTs was 8.0 (95% CI: 6.9, 10.6), 11.4 (95% CI: 9.7, 13.6), and 6.3 months (95% CI: 5.3, 8.0), respectively. Patients with M/U ECOG did not experience worse outcomes compared to those with ECOG 0–2. Conclusions: The outcomes in our study are similar to those from comparator arms of contemporary clinical trials, demonstrating a continued unmet need for effective, SOC therapy for patients with 3L+ DLBCL. Additionally, the variable outcomes based on qualifying index-LOTs underscores the criticality of appropriate patient identification and comparison for clinical trials.