IBCL-425 Disease Burden and Treatment Patterns of Relapsed/Refractory Follicular Lymphoma: A Systematic Literature Review

Abstract

Follicular lymphoma (FL) is among the most common forms of indolent non-Hodgkin lymphoma, accounting for 22% of all lymphomas. FL invariably relapses and becomes refractory to available therapies. Treatment options are limited for relapsed/refractory (R/R) FL. To assess the treatment patterns, disease, and economic burden of R/R FL utilizing a systematic literature review (SLR). MEDLINE, Embase, EconLit, and APA PsycInfo databases were searched from 2015-2021 for US-based observational studies on treatment patterns, humanistic and economic burden of R/R FL. The SLR identified 11 real-world observational studies for R/R FL: 6 reported on treatment patterns, 6 on clinical outcomes, 1 on humanistic burden, and 3 on economic burden. Among observed systemic treatments in 2008-2021, rituximab (R) monotherapy or in combination with bendamustine (BR) or with cyclophosphamide, hydroxydaunorubicin, vincristine, prednisone (R-CHOP) were the most reported regimens in 2L (R: 18.9%-52.7%; BR: 15.9%-25.9%; R-CHOP: 4.6%-10.5%) and 3L (R: 11.1%-38.4%; BR: 16.6%-20.0%; R-CHOP: 7.8%-15.6%). Targeted therapies like anti-CD20+lenalidomide and phosphoinositide 3-kinase inhibitors (PI3Ki) were infrequent across lines of therapy (LOT) but more common in ≥3L (anti-CD20+lenalidomide: 2.2%-19.2%; PI3Ki: 21.6%). Among patients on later LOT across all treatments, median treatment duration (2L: 3.6-8.5 months; 3L: 2.8 months) and median time to next treatment (2L: 38.3 months; 3L+: 14.1 months) became shorter. Progression-free survival (2L vs. 3L vs. 4L: 1.5 vs. 1.1 vs. 0.9 years) and overall survival (2L vs. 3L vs. 4L: 11.7 vs. 8.8 vs. 5.3 years) worsened with later LOT. One ex-US study showed lower health-related quality of life in later LOT (1L vs. 3L, EQ-5D-5L: 0.82 vs. 0.59; Functional Assessment of Cancer Therapy-Lymphoma: 109 vs. 88; P<0.0001). The estimated all-cause US healthcare costs increased from $10,466-$16,806 per-patient-per-month in 2L to $16,101-$22,879 in 3L and $28,420-$30,883 in 4L. FL systemic treatments and medical services contributed the most to costs. Chemoimmunotherapy is frequently used for R/R FL in the US real-world setting. Trends of worsening clinical and humanistic outcomes and increasing healthcare cost in later LOT were consistently observed, highlighting the need for innovative options to increase the percentage of patients who benefit from extended treatment duration and response.