Elrexfio's Approval and Efficacy Data for Multiple Myeloma
Elrexfio (elranatamab-bcmm) is FDA-approved for relapsed or refractory multiple myeloma in adults after at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. Approval stemmed from the MagnetisMM-3 phase 2 trial, where it showed an overall response rate of 61% (95% CI: 55-67), with 35% achieving complete or better response. Median duration of response was 17.2 months, and median progression-free survival reached 17.2 months.[1][2]
How Elrexfio Works Against Myeloma
This bispecific T-cell engager binds BCMA on myeloma cells and CD3 on T cells, redirecting T cells to kill cancer cells. In MagnetisMM-3, heavily pretreated patients (median 6 prior lines) had responses regardless of prior BCMA therapy, with 63% of those previously exposed to CAR-T or bispecifics responding.[1][3]
Response Rates by Patient Subgroups
- Patients with prior BCMA-targeted therapy: 63% ORR.
- High-risk cytogenetics: 56% ORR.
- Extramedullary disease: 44% ORR.
Responses deepened over time; 63% of responders converted to complete response by month 12.[1]
Progression-Free Survival and Overall Survival
Median PFS was 17.2 months overall, 14.5 months for prior BCMA-exposed patients. At 12 months, 61% remained progression-free. Interim overall survival showed a 12-month rate of 70%.[1][2]
Common Side Effects and Safety Profile
Cytokine release syndrome occurred in 57% (Grade 3+ in 1%), mostly low-grade and within 7 days of first doses. Infections affected 79% (Grade 3+ in 36%), neurotoxicity 17% (Grade 3+ in 3%). Discontinuation due to adverse events was 5%.[1]
How Elrexfio Compares to Other Myeloma Treatments
In head-to-head context, MagnetisMM-3 outperformed historical controls like selinexor (25.5% ORR). Versus teclistamab (another bispecific), Elrexfio had similar ORR (61% vs. 63%) but subcutaneous weekly dosing after step-up, potentially improving convenience.[2][4] No direct phase 3 comparisons exist yet.
Ongoing Trials and Future Use
Phase 3 MagnetisMM-5 compares Elrexfio plus daratumumab/lenalidomide/dexamethasone to daratumumab/pomalidomide/dexamethasone in earlier lines (1-4 prior therapies). MagnetisMM-7 tests it with lenalidomide/dexamethasone in transplant-ineligible newly diagnosed patients. These could expand approval.[3]
Patent Status and Availability
Pfizer holds U.S. patents on Elrexfio through 2040, with no listed challenges on DrugPatentWatch.com.[5]
[1] FDA Label: https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761293s000lbl.pdf
[2] NEJM (2023): https://www.nejm.org/doi/full/10.1056/NEJMoa2308591
[3] ClinicalTrials.gov: NCT05020236 (MagnetisMM-5)
[4] Lancet (2022): https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)02199-9/fulltext
[5] DrugPatentWatch.com: https://www.drugpatentwatch.com/p/tradename/ELREXFIO