EFFICACY AND SAFETY OF BCMA-DIRECTED BISPECIFIC ANTIBODIES IN RELAPSED/REFRACTORY MULTIPLE MYELOMA PATIENTS WITH RENAL IMPAIRMENT: A REVIEW

Renal impairment is frequent in relapsed/refractory multiple myeloma (RRMM) due to light chain–mediated tubular injury, hypercalcemia, infection, and treatment-related toxicity. Patients with moderate/severe chronic kidney disease, especially on dialysis, are underrepresented in trials, limiting evidence for therapeutic decisions. BCMA-directed bispecific antibodies, such as teclistamab and elranatamab, show high response rates in heavily pretreated RRMM, but data in renal impairment remain scarce. This review synthesizes available evidence to guide treatment selection, monitoring, and supportive care. The objective was to evaluate efficacy and safety of BCMA-directed bispecific antibodies in RRMM with renal impairment, including dialysis. Outcomes included overall response rate (ORR), progression-free survival (PFS), acute kidney injury (AKI), cytokine release syndrome (CRS), and ICANS. A PubMed search (to August 2025) used the terms “teclistamab,” “elranatamab,” “bispecific antibody,” “BCMA,” “multiple myeloma,” “renal impairment,” and “hemodialysis.” Eligible studies reported outcomes in RRMM with creatinine clearance <40 mL/min or on dialysis. Three were included: a multicenter real-world teclistamab analysis, a retrospective teclistamab vs CAR-T AKI comparison, and an elranatamab dialysis case report. In the largest cohort, 384 RRMM patients received teclistamab; 21% had renal impairment (<40 mL/min), 18% severe (<30 mL/min), and 5% dialysis. ORR was 52% in renal impairment vs 56% without (NS). Median PFS was 4.6 vs 6.5 months (NS). Safety was similar: CRS in 51% vs 59% (grade ≥3: 1.2% vs 1.0%), ICANS in 16% vs 13% (grade ≥3: 2.5% vs 2.6%). Hematologic toxicity was more frequent with renal impairment, but renal worsening was mainly disease- related. A retrospective study of 64 RRMM patients (34 teclistamab, 30 CAR-T) found AKI in 22% overall: 10 teclistamab vs 4 CAR-T. AKI-free survival at 180 days was 68% vs 90% (HR 3.38; p = 0.065), suggesting a non-significant trend toward higher AKI risk with teclistamab. In a case report, an elranatamab-treated dialysis patient achieved a very good partial response within 7 weeks. CRS grade 1 during step-up dosing was managed with tocilizumab and dexamethasone. Treatment was otherwise well tolerated; available data suggest moderate renal impairment does not significantly alter pharmacokinetics. These findings suggest that BCMA-directed bispecific antibodies maintain efficacy in RRMM with renal impairment, including dialysis, with ORR and PFS comparable to patients with preserved renal function. Toxicities, including high-grade CRS and ICANS, are not increased, though hematologic events are more common. A possible higher AKI risk with teclistamab than with CAR-T warrants monitoring. Limitations include the small number of severe renal impairment cases, predominance of retrospective data, and lack of robust pharmacokinetic analyses. Prospective studies stratifying by renal function and dialysis status are needed to refine dosing, monitoring, and supportive care. In conclusion, teclistamab and elranatamab appear effective and safe in RRMM with renal impairment, including dialysis. While efficacy is preserved and major toxicities manageable, careful monitoring for hematologic complications and AKI is advisable, particularly with teclistamab. Further prospective research is essential to optimize treatment protocols and confirm safety in this population.