Infection burden among patients with triple-class–exposed RRMM receiving non–T-cell–redirecting therapies: a US claims study

Triple-class–exposed (TCE) relapsed/refractory multiple myeloma (RRMM) is associated with cumulative immunosuppression and heightened infection risk. In this longitudinal, retrospective, observational study, US claims data from the Komodo Healthcare Map (KHM; n = 2702; median follow-up, 9.5 months) and the All-Payer Claims Data (APCD; n = 1755; median follow-up, 14.9 months) were used to assess infection burden in patients with TCE RRMM receiving non-bispecific antibody therapies after ≥4 prior lines of therapy (LOTs). The study period was from 1/1/2016 through 10/31/2024. Median (range) index LOT number was 5 (5–5; KHM) and 5 (5–6; APCD); median (interquartile range) age was 67.0 (60–75; KHM) and 71.0 (64–77; APCD) years. Across datasets, the weighted average rate for any infection was 63.5% (95% confidence interval [CI], 61.2–65.8), with the most common infection type being bacterial (58.2%), then viral (27.4%) and fungal (8.2%). Severe infections occurred in 46.1% of patients (95% CI, 44.1–48.1). Cumulative infection rates increased from 49.5 (26 weeks) to 66.4% (52 weeks); cumulative severe infection rates increased from 31.5 to 44.9%, respectively. These findings demonstrate substantial real-world infection burden in heavily pretreated patients with TCE RRMM receiving non-bispecific antibody and non–CAR-T therapies, underscoring the need for infection prophylaxis and supportive care.