Infection risk and management in patients with relapsed/refractory multiple myeloma treated with linvoseltamab in the LINKER-MM1 study

Patients with multiple myeloma are at increased risk of infection, highlighting the importance of evidence-based strategies for prevention, monitoring, and management of infections. In this post hoc analysis, we characterized infection events in 117 patients treated with linvoseltamab 200 mg in the Phase 1/2 LINKER-MM1 study (NCT03761108). Infection protection evolved during LINKER-MM1 in line with current guidelines to include mandated PJP prophylaxis and recommended antiviral prophylaxis and immunoglobulin replacement therapy (IgRT). At median follow-up of 14.3 months, infections were reported in 74.4% (Grade ≥ 3: 45.3%) of patients. The infection event rate (assessed in 3-month windows) during the first 6 months of treatment was 7.3–12.9 events/1000 patient-days (PD; Grade ≥ 3: 4.2–5.0/1000 PD), then declined and remained relatively stable after 6 months at 4.6–5.1/1000 PD (Grade ≥ 3: 0.5–1.0/1000 PD). The most common infection types during the first 6 months were coronavirus (any grade: 1.2–1.8/1000 PD; Grade ≥ 3: 0.6–0.9/1000 PD), upper respiratory tract (1.1–1.9/1000 PD; 0.0–0.1/1000 PD), and lower respiratory tract and lung infections (1.2–1.4/1000 PD; 1.0–1.0/1000 PD). Any grade infections resolved within a median (interquartile range) of 14.0 (8.0–29.0) days. A post hoc exploratory landmark analysis showed a trend towards lower risk of Grade ≥ 3 infections in patients receiving IgRT vs. those not having received IgRT during the first 3 months of follow-up (adjusted HR: 0.39 [95% CI: 0.11–1.32]). In summary, infection risk in patients treated with linvoseltamab notably decreases after 6 months of treatment and may be further mitigated by IgRT.