Real‐world treatment patterns and clinical outcomes among follicular lymphoma patients in the SEER‐Medicare population

Introduction: Follicular lymphoma (FL) is the second most common lymphoma with annual estimated new cases of approximately 14,000 in the US. Survival outcomes in FL patients vary depending on various risk factors. Patients generally respond well to anti-CD20 monoclonal antibody (mab) with or without chemotherapy. However, majority of patients require multiple lines of therapy and treatment sequencing is very heterogeneous (Casulo et al., Lancet Haematol 2022). Progression of disease within two years (POD24) of first-line chemoimmunotherapy (CIT) and receiving third-line therapy within three years of diagnosis (3L36) have shown to be associated with shorter overall survival (OS). The aim of the study was to characterize the real-world evidence of treatment patterns and outcomes in FL patients in the US. Methods: Patients aged ≥65 who were diagnosed with FL between 2000 and 2017 were identified from the SEER-Medicare database based on ICD-O-3 codes (9695/3, 9691/3, 9698/3, 9690/3). A new line of therapy (LOT) was defined when next lymphoma directed treatment was started (including retreatment of anti-CD20 mab) after 180 days from completion of previous treatment. Event-free survival (EFS) was used as a proxy of treatment success in this study and an event was defined as initiation of next lymphoma treatment, transformation or death from any cause. OS by POD24 and 3L36 were estimated by landmark analysis (Casulo et al., Blood 2022), which included patients with ≥24 months of follow-up from 1L CIT (for POD24 analysis) or ≥36 months from diagnosis (for 3L36 analysis). Cox models were conducted to evaluate the association between prognostic factors and OS. Results: Of 14,077 patients with incident FL (median age: 76 years), 64%, 23%, 9%, and 4% received at least 1, 2, 3, and 4 LOTs, respectively. CIT, the most common treatment regimen across all LOTs, was used in 60%, 45%, 42% and 42% of patients in 1L, 2L, 3L, and 4L, respectively. Anti-CD20 mab monotherapy was used in 31%, 40%, 38%, and 36% of patients in 1L, 2L, 3L, and 4L, respectively. Median follow-up time was 56.8 months after 1L initiation and decreased to 23.6 months following 4L. The median EFS was 33.9, 20.0, 15.9 and 13.4 months for patients in 1L, 2L, 3L and 4L, respectively. The median OS was 81.9, 49.6, 35.1, and 27.1 months for patients in 1L, 2L, 3L, and 4L, respectively. Patients experiencing POD24 showed shorter OS than other patients (median OS: 67.5 vs. 103.8 months; hazard ratio [HR] 1.61; 95% CI: 1.46, 1.79). The median OS was 38.2 and 88.2 months in patients with or without receiving 3L36 (HR 1.78; 95% CI: 1.57, 2.02). Conclusions: This study confirmed the negative impact of POD24 and 3L36 on survival in older patients with FL. The median EFS becomes shorter with later lines of treatment, indicating unmet needs for effective and tolerable therapies in patients with FL. The research was funded by: Genmab A/S and AbbVie Keywords: Cancer Health Disparities, Indolent non-Hodgkin lymphoma Conflicts of interests pertinent to the abstract. S. Yang Employment or leadership position: Genmab S. Bains Chawla Employment or leadership position: Genmab G. Zhang Employment or leadership position: Genmab A. Wang Employment or leadership position: AbbVie J. Yu Employment or leadership position: AbbVie D. Arnette Employment or leadership position: AbbVie F. Rivas Navarro Employment or leadership position: Genmab J. Blaedel Employment or leadership position: Genmab A. Mutebi Employment or leadership position: Genmab