Objective:

To analyze the incidence and risk factors for infections among patients with relapsed/refractory multiple myeloma treated with bispecific antibodies.

Approach:

• Study Design: A retrospective, single-center study involving 50 RRMM patients treated with anti-BCMA or anti-GPRC5D bispecific antibodies.
• Data Collection: Clinical and biological data were extracted from electronic medical records, including demographics, disease characteristics, treatment history, and vaccination history.

Key Findings:

• 78% of patients received prior vaccinations, with those having ≥3–4 vaccines showing lower infection-related mortality (23.4% vs 6.7%).
• 121 infectious episodes were recorded, with 45.5% classified as severe (grade ≥3).
• The respiratory tract was the most affected site (65%), with viral (43%) and bacterial (45%) infections.
• Anti-BCMA BsAbs were linked to a higher incidence and severity of infections compared to anti-GPRC5D therapy (2.3 vs 3.8 months to first infection).
• Infection-related mortality accounted for 34% of deaths, making it the second leading cause after disease progression.

Interpretation:

Limitations:

• The study was conducted at a single center, which may limit generalizability.
• No subgroup analysis was performed for patients receiving both anti-BCMA and anti-GPRC5D therapies.

Conclusion: