Pfizer has announced topline results from the phase 3 MagnetisMM-32 study evaluating ELREXFIO (elranatamab) as monotherapy in adults with Relapsed or Refractory Multiple Myeloma (RRMM) who received at least 1 prior line of treatment with anti-CD38 therapy (daratumumab or isatuximab) and lenalidomide.

At the pre-specified interim analysis for efficacy, the study met its primary endpoint of Progression-Free Survival (PFS) as assessed by Blinded Independent Central Review (BICR).

ELREXFIO demonstrated a statistically significant and clinically meaningful reduction in the risk of disease progression or death versus investigator’s choice of elotuzumab, pomalidomide and dexamethasone (EloPd); pomalidomide, bortezomib and dexamethasone (PVd); or carfilzomib and dexamethasone (Kd).

MagnetisMM-32 used one of the broadest Standard of Care (SoC) comparators in a phase 3 BCMA bispecific trial in this setting, with investigator’s choice of 3 established regimens.

More than 75 percent of patients receiving ELREXFIO had not experienced disease progression or death from any cause at the time of the analysis, with an estimated 68 percent PFS at 18 months. Data for Overall Survival (OS), a key secondary endpoint, remain immature, and follow-up will continue to the next pre-specified OS analysis.

The safety profile of ELREXFIO in MagnetisMM-32 was consistent with its known profile and no new safety signals were identified. Infection prophylaxis measures instituted from the beginning of the study helped mitigate infection risk, including Grade 3 or higher infections.

Grade ≥3 infections were observed in 27.5 percent of patients receiving ELREXFIO vs. 18.1 percent of patients on investigator’s choice, and Grade 5 infections were observed in 0.8 percent of patients receiving ELREXFIO vs 1.6 percent of patients on investigator’s choice.

Jeff Legos, Chief Oncology Officer, Pfizer, said, “The treatment landscape for multiple myeloma continues to evolve as anti-CD38-based regimens and lenalidomide are increasingly used earlier in care. Yet many patients ultimately experience disease progression, with limited treatment options available following these commonly used therapies. MagnetisMM-32 demonstrates that ELREXFIO, an off-the-shelf, fixed-dose monotherapy, delivers a significant and clinically meaningful Progression-Free Survival benefit and an encouraging safety profile in this increasingly important treatment setting, with median PFS not yet reached and a high percentage of patients remaining progression-free at the time of analysis. These findings further strengthen the rationale for moving BCMA-directed therapy earlier in the treatment journey and underscore ELREXFIO's potential to help redefine outcomes for patients.”

Pfizer plans to submit these data to global health authorities, with detailed results to be shared at a future medical meeting and submitted for publication.

C. Ola Landgren, Professor of Medicine, Chief of Myeloma Division and Director, Sylvester Myeloma Institute, University of Miami Miller School of Medicine, said, “The MagnetisMM-32 results are particularly compelling given the rigorous and clinically relevant benchmark of 3 established Standard of Care regimens. Demonstrating a significant Progression-Free Survival benefit against this active control highlights the potential of elranatamab-bcmm to provide an important treatment option for patients whose disease has progressed following anti-CD38 therapy and lenalidomide.”