Phase 3 MagnetisMM-5 Trial Shows Statistically Significant and Clinically Meaningful Improvement in Primary Endpoint of Progression-Free Survival Using Elranatamab vs Daratumumab Plus Pomalidomide and Dexamethasone (DPd), as Evaluated by Blinded Independent Central Review (BICR)

On Wednesday, April 29, Pfizer Inc. announced “positive topline results from the Phase 3 MagnetisMM-5 study evaluating Elrexfio® (elranatamab) as monotherapy in adults with relapsed/refractory multiple myeloma (RRMM) who received at least one prior line of treatment,” in a press release.

According to Pfizer, “the study demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of progression‑free survival (PFS), as assessed by blinded independent central review (BICR), versus standard-of-care daratumumab plus pomalidomide and dexamethasone (DPd).”  

Safety and tolerability also remained consistent with elranatamab’s known safety profile, “with no new safety signals identified.”

PFS results showed that elranatamab exceeded the study’s early benchmark for treatment efficacy, with most treated patients not experiencing disease progression. The trial is still ongoing and will be evaluating overall survival as a key secondary endpoint (data was not yet available at the time of the interim analysis). These findings will be discussed with global health authorities, and results from the MagnetisMM-5 trial will be presented at a future medical congress.

These interim efficacy results “further strengthen confidence in development strategy for Elrexfio as monotherapy and in combination, across multiple lines of therapy,” stated Pfizer.  

What is Elrexfio? 

Elrexfio (elranatamab) is “a subcutaneously delivered B-cell maturation antigen (BCMA)-cluster of differentiation CD3-directed bispecific antibody immunotherapy that binds to BCMA on myeloma cells and CD3 on T cells, activating the T cells to kill myeloma cells,” as stated by the press release.

The BCMA-targeted bispecific antibody has been approved in over 35 countries worldwide. In the U.S., Elrexfio “received accelerated approval from the U.S. Food and Drug Administration (FDA) for use in adults with RRMM who have received at least four prior lines of therapy” on August 14, 2023.

In the European Union (EU), Elrexfio was “granted conditional marketing authorization for adults with RRMM who have received at least three prior therapies and have demonstrated disease progression on the last therapy” on December 7, 2023. 

 

The MagnetisMM-5 Trial 

The MagnetisMM-5 trial is “an open-label, multicenter, randomized Phase 3 study to evaluate the efficacy and safety of Elrexfio versus standard-of-care daratumumab plus oral pomalidomide and dexamethasone in patients with RRMM.”

According to Pfizer, “the study enrolled 497 patients across 26 countries who have received at least one line of previous treatment, including lenalidomide and a proteasome inhibitor (PI). Participants received subcutaneous Elrexfio as two step-up priming doses followed by a weekly 76 mg injection, with frequency adjusted to every two weeks after 24 weeks if a partial response was achieved for more than two months, and again to every four weeks for all patients after 48 weeks on treatment. The primary endpoint is progression-free survival (PFS), as assessed by blinded independent central review (BICR). A key secondary endpoint is overall survival.”

Elrexfio: Prescribing Information and Boxed Warning 

Elrexfio is available only through the FDA’s Risk Evaluation and Mitigation Strategy (REMS) Program due to the risk of CRS and neurologic problems.

The Risk Evaluation and Mitigation Strategies (REMS) is “a drug safety program a drug safety program that the U.S. Food and Drug Administration (FDA) can require for certain medications with serious safety concerns to help ensure the benefits of the medication outweigh its risks. REMS are designed to reinforce medication use behaviors and actions that support the safe use of that medication. While all medications have labeling that informs health care stakeholders about medication risks, only a few medications require a REMS.”

“REMS are not designed to mitigate all the adverse events of a medication, these are communicated to health care providers in the medication’s prescribing information. Rather, REMS focus on preventing, monitoring and/or managing a specific serious risk by informing, educating and/or reinforcing actions to reduce the frequency and/or severity of the event,” according to the FDA.

For U.S. Important Safety Information and Indication on Elrexfio (elranatamab), read the full press release or view Elrexfio’s prescribing information and boxed warning.

References:

• Pfizer’s ELREXFIO Significantly Improves Progression-Free Survival for Double-Class Exposed Patients with Relapsed or Refractory Multiple Myeloma. Pfizer press release. April 29, 2026.
• FDA grants accelerated approval to elranatamab-bcmm for multiple myeloma. U.S. Food and Drug Administration. August 14, 2023.
• Elrexfio (elranatamab). European Medicines Agency. December 7, 2023.
• Risk Evaluation and Mitigation Strategies | REMS. U.S. Food and Drug Administration. Current as of May 20, 2025.
• Elrexfio-elranatamab-bcmm injection, solution. Pfizer Laboratories Div Pfizer Inc.