Nearly three years after the FDA approved Pfizer's bispecific antibody Elrexfio as a late-line treatment for patients with relapsed or refractory multiple myeloma (RRMM), the drug has yet to gain meaningful commercial momentum and remains low on the pharma giant's sales charts. Now, with a new positive trial readout, the company is aiming to reach a broader set of patients.
In the phase 3 MagnetisMM-5 study, Elrexfio as a monotherapy demonstrated a statistically significant and clinically meaningful improvement in progression‑free survival (PFS) versus standard-of-care daratumumab, pomalidomide and dexamethasone (DPd), Pfizer said in a Wednesday press release. The open-label trial enrolled 497 patients with RRMM who had received at least one prior line of treatment, including lenalidomide and a proteasome inhibitor (PI).
The positive result on the trial's primary endpoint represents a win for "double-class exposed" patients who have relapsed or are refractory. The term describes those who have already received two major types of therapies and are in need of a new treatment.
"The MagnetisMM-5 results reinforce our confidence in Elrexfio's potential to benefit patients earlier in their treatment journey and support our comprehensive strategy to evaluate Elrexfio both as monotherapy and as part of combination approaches across multiple lines of therapy," Pfizer's chief oncology officer, Jeff Legos, said in a statement.
As it stands, the drug is approved for adults with RRMM who've received at least four prior lines of therapy, including a PI, an immunomodulatory agent and an anti-CD38 monoclonal antibody.
The overall survival analysis was not yet mature at the time of the interim analysis, Pfizer said. The trial remains ongoing to obtain results in this secondary endpoint.
Pfizer said it plans to discuss the data with health regulators and submit the findings for presentation at a future medical congress.
In the MagnetisMM-5 study, Elrexfio's safety and tolerability was consistent with its known profile, Pfizer said.
First approved in 2023, Pfizer's Elrexfio generated $74 million in global sales last year, a 30% increase from 2024. The drug is going up against in-class rival Tecvayli from J&J, which pulled down $670 million in 2025. Also in the ring is Regeneron's Lynozyfic, following its approval in the summer of 2025.