Bold Claim: Even in the toughest real-world settings, elranatamab still delivers meaningful responses for frail, heavily pretreated patients with relapsed/refractory multiple myeloma—and the data invite a closer look at how supportive care can sharpen outcomes.
But here’s where it gets controversial: real-world performance shows shorter progression-free survival (PFS) on average, yet higher response rates compared with another BCMA-targeted bispecific in similar patients. These nuances stem from different patient characteristics across real-world cohorts, making direct cross-trial comparisons tricky but nonetheless informative for practice beyond the trial population.
Real-world activity and what it means for patients
A retrospective, multi-center analysis of elranatamab-bcmm (Elrexfio) in the United States enrolled 130 patients across nine centers from August 2023 to March 2025. The cohort’s median age was 71, with a substantial burden of prior therapies and high-risk features. The overall response rate (ORR) reached 65% (81 of 125 patients), with 46% achieving a very-good partial response (VGPR) or better and 36% attaining a complete response (CR) or better. By comparison, early data from the MagnetisMM-3 phase 3 trial (cohort A) reported an ORR of 61%, VGPR or better of 56.1%, and CR or better of 35%. These figures suggest solid activity in real-world practice, though differences in baseline risk complicate direct comparisons.
Treatment duration and discontinuation varied: the median time on therapy was 4.0 months overall, extending to 7.9 months for those with VGPR or better. Toxicity or non-relapse mortality led to treatment discontinuation in 12% of patients. Intravenous immunoglobulin (IVIg) users had a notably lower discontinuation rate (5%) compared with non-users (17%).
Survival and duration of response paint a more nuanced picture. With a median follow-up of 7.5 months in this real-world dataset and 28.4 months in MagnetisMM-3 cohort A, median overall survival (OS) was 14.6 months versus 24.6 months, respectively. Median PFS was 4.27 months in the real-world group and 17.2 months in MagnetisMM-3 cohort A. Median duration of response (DOR) was 12.2 months in the real-world group and not reached in MagnetisMM-3 cohort A.
Early, small-sample benchmarks from other settings aligned with these observations. A French compassionate-use cohort showed about 42% one-year OS versus 58% in the real-world elranatamab group, and similar one-year PFS and DOR figures, though this cohort had shorter follow-up. These comparisons underscore that real-world outcomes can parallel trial results while reflecting patient heterogeneity.
Equivalence in outcomes across trial-eligible and trial-ineligible patients emerged in several key measures. Hazard ratios for OS, PFS, and DOR indicated similar effectiveness regardless of trial eligibility, though performance status and prior therapies still shaped the magnitude of benefit.
Impact of patient characteristics on outcomes
Performance status mattered. When stratified by ECOG 0–1, ECOG 2, and ECOG ≥3, median OS and PFS varied markedly: ECOG 0–1 yielded longer survival and care-free periods, while ECOG ≥3 correlated with substantially shorter PFS and DOR. The BCMA exposure history also influenced outcomes; patients with prior BCMA exposure had a lower CR or better rate and a shorter OS if the exposure occurred within a year, suggesting prior therapies shape response durability.
Biomarkers and lab values offered additional predictive clues. Higher hemoglobin levels correlated with better outcomes, whereas elevated ferritin and LDH linked to poorer results. LDH, in particular, stood out as a consistent predictor of shorter PFS and OS after adjusting for other factors. Lower hemoglobin independently predicted worse PFS and reduced odds of achieving CR or better.
Prior BCMA therapy presented a meaningful impact. Prior exposure was associated with a lower likelihood of CR or better and a higher risk of shorter OS when the prior exposure occurred within the year preceding elranatamab treatment.
Safety snapshot
Cytokine release syndrome (CRS) occurred in 39% of patients, with 12% experiencing grade 2 or higher CRS and 2.3% experiencing grade 3 or higher. Immune-effector cell-associated neurotoxicity syndrome (ICANS) occurred in 17% overall, with 7.7% grade 2 or higher. Compared with MagnetisMM-3 cohort A, these rates were higher, signaling a need for vigilant monitoring in real-world practice.
CRS typically began around day 2 and lasted about 1–2 days. Tocilizumab and steroids were used in 36% and 23% of cases, respectively. Intensive care unit admission occurred in 6.2% of patients.
Infections affected 38% of patients, and a majority of these were severe. IVIg prophylaxis correlated with a lower infection risk, with 46% of patients receiving IVIg. Bacterial infections dominated the severe infection landscape, followed by viral and fungal cases.
Infection-free survival favored IVIg users, with the hazard ratio indicating a meaningful reduction in infection risk when IVIg was employed.
Clinical implications and takeaway
The real-world evidence supports elranatamab as a active therapy for a frail, heavily pretreated multiple myeloma population, extending beyond the controlled environment of clinical trials. However, clinicians should recognize that real-world outcomes can diverge from trial data due to patient heterogeneity, prior therapies, and baseline risk factors. Tailoring supportive care, including IVIg prophylaxis and proactive infection management, may improve overall outcomes.
Open questions for clinicians and readers
- How should prior BCMA exposure influence sequencing decisions and expectations for elranatamab in relapsed/refractory disease?
- In which patients does IVIg prophylaxis offer the most meaningful protection against infections, and what are the cost-benefit considerations?
- How can real-world practice adapt to mitigate higher CRS/ICANS rates observed outside of clinical trials while preserving therapeutic benefits?
References (selected)
- Real-world outcomes with elranatamab in multiple myeloma: A multi-center analysis from the United States multiple myeloma immunotherapy consortium. Blood. 2025.
- Elranatamab in relapsed or refractory multiple myeloma: phase 2 MagnetisMM-3 trial results. Nat Med. 2023.
- Long-term survival and safety of elranatamab in relapsed or refractory multiple myeloma: MagnetisMM-3 update. Hemasphere. 2024.
- Bispecific antibodies targeting BCMA or GPRC5D in relapsed myeloma after CAR T-cell therapy. Blood Cancer J. 2024.
- Cubic splines to model relationships between continuous variables and outcomes: clinician guide. Bone Marrow Transplant. 2020.
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