Differences in patient-reported time toxicity between bispecific antibody (BsAb) options: Impact of treatment duration and dosing frequency on patient-reported time burden in relapsed/refractory (R/R) follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL)

Abstract

Abstract Background Several BsAbs with different treatment (Tx) approaches have been approved by the FDA for Tx of lymphoma, including: fixed-duration and less frequently dosed mosunetuzumab (mosun) and glofitamab (glofit) (Option 1 Tx approach); and treat to progression and more frequently dosed epcoritamab (epcor) (Option 2 Tx approach). Differences in Tx approaches have implications for time spent receiving care, known as “time toxicity”. We previously reported that mosun and glofit were associated with about 2 weeks lower time toxicity vs epcor over the first year in R/R FL and DLBCL, based on registrational trial protocols (Torka et al. Blood 2024; Ma et al. Value in Health 2025). In this study, we assessed time toxicity from the perspective of patients (pts) receiving BsAbs for R/R FL or DLBCL. Methods An online survey was conducted aiming for input from 120 pts with R/R FL or DLBCL, who have received BsAb for ≥1 month in the US. Time toxicity was measured by pts recalling time spent on healthcare contacts related to BsAb Tx, cancer management, and any other reasons in the past 30 days. Pts' preferences were assessed through direct elicitation of choice between 2 hypothetical Tx profiles with different Tx approaches and time toxicity, assuming the same efficacy and safety. The survey was pre-tested and refined based on input from 3 BsAb pts with R/R DLBCL to ensure relevance and comprehension. Descriptive analyses were performed on pts characteristics, mean and standard deviation (SD) of time spent per pt per month, and the proportion of pts preferring the convenience of different Tx profiles. Results At this interim analysis, 101 pts receiving BsAbs responded to the survey: 48 pts with R/R FL (mosun n=28; epcor n=20) and 53 pts with R/R DLBCL (glofit n=32; epcor n=21). Most pts with R/R FL lived in urban/suburban areas (87.5% vs 12.5% in rural areas) and had a shorter one-way travel time to receive care vs pts in rural areas (mean±SD: 28.2±13.5 vs 60.3±30.2 minutes). The median age was 58 years for both mosun and epcor. Mean±SD Tx duration was 6.2±1.8 months for mosun vs 4.5±1.3 months for epcor. In the past 30 days, pts on mosun had fewer BsAb Tx visits vs epcor (mean±SD: 1.0±0.2 vs 2.0±1.2), and fewer all-cause healthcare contacts vs epcor (mean±SD: 1.7±0.8 vs 3.5±2.0). The mean±SD time spent per BsAb Tx visit was 5.0±1.4 hours for mosun vs 3.8±1.8 hours for epcor. Less time was spent per pt per month on recovery at home after Tx visit for mosun vs epcor (22.7±16.5 vs 43.2±47.6 hours). Less time was spent per pt per month on Tx and cancer management for mosun vs epcor (mean±SD: 30.5±16.9 vs 56.9±59.3 hours). Most pts with R/R DLBCL lived in urban/suburban areas (88.7% vs 11.5% in rural areas) and had a shorter one-way travel time to receive care vs pts in rural areas (mean±SD: 31.4±14.1 vs 103.3±19.4 minutes). The median age was 67 years for glofit and 66 years for epcor. The mean±SD Tx duration was 6.1±2.0 months for glofit vs 5.9±1.8 months for epcor. In the last 30 days, pts on glofit had fewer BsAb Tx visits vs epcor (mean±SD: 1.1±0.2 vs 1.7±0.5), and fewer all-cause healthcare contacts vs epcor (mean±SD: 2.2±1.3 vs 3.0±1.1). Irrespective of the route of administration, the time spent per BsAb Tx visit was similar (mean±SD: 5.1±1.6 hours for mosun; 5.6±1.2 hours for epcor). Less time was spent per pt per month on recovery at home after Tx visit for glofit vs epcor (mean±SD: 34.3±23.8 vs 69.3±39.4 hours). Less time was spent per pt per month on Tx visits and cancer management for glofit vs epcor (mean±SD: 43.0±25.9 vs 85.0±44.2 hours). Regardless of which BsAb pts received, most pts (93%) preferred the convenience of Option 1 Tx approach with less time required over Option 2 Tx approach with more time required. Conclusions This is the first study to directly measure pt-reported time toxicity from pts with R/R FL and DLBCL receiving BsAbs in a real-world setting. Fixed-duration less frequently dosed mosun and glofit (Option 1 Tx approach) had less pt-reported time toxicity, with less healthcare contact and less time spent per pt per month vs treat to progression more frequently dosed epcor (Option 2 Tx approach). Over 90% of pts preferred the convenience of a fixed-duration, less frequently dosed, and less time required Tx option, suggesting that time toxicity is a significant factor in shared Tx decision-making for pts with R/R FL and DLBCL. Analysis is ongoing to comprehensively measure pt-reported time toxicity.