Pre-Treatment Strategies Prior to CAR-T for Multiple Myeloma: EBMT Survey Insights

Overview

A multinational survey of 48 centers across 11 countries reveals highly heterogeneous bridging therapy practices prior to anti-BCMA CAR-T in multiple myeloma. Most centers use bridging in over 85% of patients, favor proteasome inhibitors and immunomodulatory drugs, and initiate bridging promptly after apheresis with typical durations of 1–2 months. Despite variability, over 95% proceed to CAR-T infusion even after progression on bridging therapy.

Background

Anti-BCMA CAR-T therapies have transformed treatment for relapsed/refractory multiple myeloma, but patients often require bridging therapy to control disease while awaiting infusion. Bridging regimens vary widely due to differences in disease tempo, prior treatments, comorbidities, and center experience. Pivotal trials have restricted bridging options, creating a gap between trial protocols and real-world practice. Understanding current bridging strategies is critical to optimize outcomes and inform consensus guidelines.

Data Highlights

Key Findings

• Bridging therapy is widely used (>85% of patients) with proteasome inhibitors and IMiDs as the most common agents.
• Bridging regimens are highly individualized, driven primarily by prior therapies and refractory disease patterns rather than cytogenetics or marrow involvement.
• Most centers initiate bridging promptly within one week after apheresis and continue for 1–2 months.
• Despite progression during bridging, over 95% of centers proceed to CAR-T infusion, with some pausing to reassess timing.
• Monitoring during bridging relies mainly on serum free light chains and M-protein, supplemented by imaging and clinical assessment.
• Wash-out periods for bispecific antibodies before CAR-T vary widely, with common practice being 2–4 weeks, reflecting uncertainty and need for standardization.

Clinical Implications

Clinicians should anticipate the need for bridging therapy in most multiple myeloma patients undergoing CAR-T and tailor regimens based on prior treatment history and disease burden. Prompt initiation post-apheresis and close monitoring with serum markers and imaging are essential. Awareness of variable wash-out practices for bispecific antibodies is important to optimize timing and preserve CAR-T efficacy. Standardized guidelines are needed to harmonize bridging approaches and improve patient outcomes.

Conclusion

This EBMT survey highlights significant heterogeneity in bridging therapy practices prior to CAR-T for multiple myeloma, underscoring the need for prospective studies and consensus guidelines. Optimizing bridging strategies will be critical to maximize CAR-T benefits while managing disease control and treatment-related risks.

References

1. EBMT CMWP and CTIWP 2024 -- Pre-Treatment Strategies Prior to CAR-T Administration for Multiple Myeloma