OBJECTIVES: To describe clinical characteristics, treatment patterns, and overall survival (OS) in patients with follicular lymphoma (FL).

METHODS: This retrospective analysis identified incident FL patients from the Surveillance, Epidemiology, and End Results (SEER) database based on ICD-O-3 codes (9695/3, 9691/3, 9698/3) in the time period 1/1/2000 to 12/31/2017. The first recorded FL diagnosis date was set as the index date. Patients were required to be continuously enrolled in Medicare Parts A and B for ≥12 months prior to index date. From the Medicare database linked with SEER, NCCN-recommended treatment regimens (version 5.2022) were identified and lines of therapy (LOTs) were derived. OS was estimated from initiation of each LOT until death, end of eligible insurance enrollment, or study end (12/31/2019).

RESULTS: Overall, 9164 incident FL patients were identified. Median age at diagnosis was 75 years; most were female (56%), had FL grade 1/2 (74.7%), and Ann Arbor stage III/IV (51.9%). During the mean [median(maximum)] follow-up period of 73.1 [61.1(240)] months from index date, 6006 (65.5%), 1976 (21.6%), 693 (7.6%), and 261 (2.9%) patients were treated with 1L+, 2L+, 3L+, and 4L+, respectively. Across different LOTs, the most used regimens were rituximab or obinutuzumab (R/O) + chemotherapy (61.3% in 1L, 52.4% in 2L, 52.7% in 3L) and R/O monotherapy (30.7% in 1L, 30.1% in 2L, 21.8% in 3L). As patients progressed to later LOTs, median OS declined (87.0 months for 1L+, 43.5 months for 2L+, 28.6 months for 3L+, 22.3 months for 4L+). Accordingly, the estimated 2-year OS was 80%, 65%, 56%, and 47% for 1L+, 2L+, 3L+, and 4L+, respectively. Sensitivity analyses exploring different LOT definitions showed consistent results.

CONCLUSIONS: This retrospective analysis showed that FL patients experience worsening survival outcomes as they progress through later LOTs, demonstrating the high unmet need of FL patients with relapsed/refractory disease.