USFDA grants priority review to Pfizer Elranatamab for relapsed or refractory multiple myeloma

"Today, multiple myeloma is a fatal hematologic malignancy, with a median survival of just over five years. As an off-the-shelf treatment, BCMA bispecific antibodies are heralding a new treatment paradigm that can greatly impact the lives of people with this disease.” said Chris Boshoff, M.D., Ph.D., Chief Development Officer, Oncology and Rare Disease, Pfizer Global Product Development. “We believe that elranatamab, if approved, has the potential to become the next standard of care for multiple myeloma given its favorable clinical results and convenient subcutaneous route of administration. We look forward to working with the FDA and EMA to bring this new innovative medicine to patients globally.”

Elranatamab is designed to bind to BCMA, which is highly expressed on the surface of multiple myeloma (MM) cells, and CD3 receptors found on the surface of T-cells, bridging them together and activating the T-cells to kill the myeloma cells. The BLA and MAA for elranatamab are primarily based on data from cohort A (BCMA-naïve - n=123) of MagnetisMM-3 (NCT04649359), an ongoing, open-label, multicenter, single-arm, Phase 2 study designed to evaluate the safety and efficacy of elranatamab monotherapy in patients with RRMM. Enrolled patients represent a heavily pretreated population, who previously received at least three classes of therapies, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody.

With a median follow up of 10.4 months, patients who received elranatamab as their first BCMA-targeted therapy achieved a high objective response rate of 61% (55% had a very good partial response rate or better), with an 84% probability of maintaining the response at nine months. The MagnetisMM-3 results also suggest elranatamab has a manageable safety profile. The two-step-up priming dose regimen (12/32 mg) helped mitigate the rate and severity of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) among the 119 patients in cohort A who were treated with this priming regimen. All cases of CRS were Grade 1 or 2 and the majority occurred after the first (43% of patients) or second (24% of patients) dose, with only 6% of patients experiencing CRS after dose 3 and fewer than 1% experiencing CRS after dose 4. Observed cases of ICANS (3%) were neither common nor severe (Grade 1/2 only were reported). No fatal neurotoxicity events were observed. These data were presented at the 64th American Society of Hematology Annual Meeting and Exposition in December 2022.

This study is part of the MagnetisMM clinical research program that expands to additional patient populations over time, with ongoing registrational-intent trials that explore elranatamab both as monotherapy and in combination with standard or novel therapies, spanning multiple patient populations, from newly diagnosed MM to RRMM. This includes MagnetisMM-5 (NCT05020236) in the double class exposed setting, MagnetisMM-6 (NCT05623020) in transplant ineligible newly diagnosed patients, and MagnetisMM-7 (NCT05317416) as maintenance treatment in newly diagnosed patients after transplant, all of which are currently enrolling.

In November 2022, Pfizer announced that elranatamab was granted Breakthrough Therapy Designation by the FDA. In addition, elranatamab has been granted Orphan Drug Designation by the FDA and the EMA for the treatment of MM. The FDA and EMA have also granted elranatamab Fast Track Designation and the PRIME scheme, respectively, for the treatment of patients with RRMM. The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has granted elranatamab Innovative Medicine Designation and the Innovation Passport for the treatment of MM. The FDA has accepted elranatamab for Project ORBIS, which is a framework for the concurrent submission and review of oncology products to potentially expedite approvals in certain countries outside of the US; currently 5 countries (Switzerland, Brazil, Canada, Australia, and Singapore) have accepted to participate.