Pfizer Inc. (NYSE:PFE) announced today that the U.S. Food and Drug Administration (FDA) has granted Priority Review for the company's Biologics License Application (BLA) for elranatamab, an investigational B-cell maturation antigen (BCMA) CD3-targeted bispecific antibody (BsAb), for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). Priority Review is intended to direct attention and resources from regulatory authorities toward drugs that, if approved, could offer significant improvements over existing options for serious conditions in order to make these drugs available to patients faster. The FDA's decision on the application is expected in 2023. The European Medicines Agency (EMA) has also accepted elranatamab's marketing authorization application (MAA). The company is working closely with the EMA to facilitate their review and will provide updates on timing as appropriate.
"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.
About Elranatamab
Elranatamab is an investigational, off-the-shelf, humanized BCMA CD3-targeted BsAb. BsAbs are a novel form of cancer immunotherapy that bind to and engage two different targets at once. One arm binds directly to specific antigens on cancer cells and the other arm binds to T-cells, bringing both cell types together. The binding affinity of elranatamab for BCMA and CD3 has been engineered to elicit potent T-cell-mediated anti-myeloma activity. Elranatamab is administered subcutaneously, which offers more convenience over intravenous administration.
About MagnetisMM-3
MagnetisMM-3 (NCT04649359) is an ongoing, open-label, multicenter, single-arm, Phase 2 study designed to evaluate the safety and efficacy of elranatamab monotherapy in patients with RRMM. Patients received subcutaneous (SC) elranatamab 76 mg weekly (QW) on a 28-day cycle with a step-up priming dose regimen, wherein 12 mg and 32 mg are administered on Day 1 and Day 4, respectively, during Cycle 1. For patients receiving 6 or more cycles and achieving a partial response or better for at least 2 months, the dosing interval was once every two weeks (Q2W).
About Multiple Myeloma
MM is a blood cancer that affects plasma cells made in the bone marrow. Healthy plasma cells make antibodies that help the body fight infection. There are over 34,000 new cases of MM diagnosed annually in the U.S. and 176,000 globally.1,2 Despite treatment advances, there is currently no cure. The median survival is just over five years, and most patients receive four or more lines of therapy.3
About Pfizer in Hematology
At Pfizer, we have an industry-leading portfolio of 24 approved innovative cancer medicines and biosimilars, including seven therapies to treat hematologic malignancies. We have taken bold new approaches over the past decade to translate scientific research into transformative medicines for people living with blood cancer. For the millions living with blood cancer today and for those diagnosed tomorrow, we work tirelessly to deliver on our mission: Breakthroughs that change patients' lives.
