Elrexfio now approved in Canada as recurring myeloma treatment
Approval conditional on more studies in patients already treated 3 times
Health Canada has granted conditional approval to Pfizer’s Elrexfio (elranatamab-bcmm), expanding the list of countries where the medication can be used for adults with multiple myeloma whose cancer has returned and who have not responded to previous treatment.
The conditional approval, officially a Notice of Compliance, will require Pfizer to undertake additional studies to verify the clinical benefit of Elrexfio in patients. Those studies must involve people with myeloma who have received at least three prior lines of therapy — a proteasome inhibitor, an immunomodulatory agent, and a CD38 inhibitor — and whose disease progressed during the latest treatment.
While Pfizer “will continue its clinical development program investigating Elrexfio’s use across the entire spectrum of myeloma progression,” per a press release, the company said it’s eager to get the therapy to patients.
“We are immensely proud that we can offer a new treatment option for patients living with multiple myeloma in Canada,” said Cynthia Di Lullo, oncology business lead at Pfizer Canada.
Multiple myeloma is a cancer of the plasma cells, which are white blood cells in the body that produce protective antibodies. When plasma cells become cancerous and grow out of control, they no longer help protect the body, but instead produce abnormal proteins that cause symptoms including weakness, shortness of breath, and kidney and neurological issues.
‘Unmet need’ for myeloma treatment for those who relapse
While there are many medications available to treat myeloma, new therapies continue to be developed for people with the disease who have already been heavily treated and whose cancer has returned or is refractory, meaning it doesn’t respond to treatment.
“Multiple myeloma is a disease of high unmet need as patients relapse and become refractory to successive and limited therapies,” said Richard LeBlanc, MD, a hematologist and medical oncologist at Hôpital Maisonneuve-Rosemont, in Montreal.
Martine Elias, the executive director of Myeloma Canada, a non-profit dedicated to people in the country who are living with multiple myeloma, said each new treatment is important for patients.
“When it comes to treating myeloma, each case must be assessed individually,” Elia said.
“What works for one patient may not work for another. This is why it’s so important that people living with the disease have access to many and new options, even more so when they have relapsed,” Elias said.
When it comes to treating myeloma, each case must be assessed individually. … What works for one patient may not work for another. This is why it’s so important that people living with the disease have access to many and new options, even more so when they have relapsed.
Elrexfio contains an injectable antibody that targets both B-cell maturation antigen (BCMA), a protein on the surface of plasma cells, and CD3, which is found on immune T-cells. Bringing T-cells close to plasma cells allows plasma cells to be removed from the body.
Over 60% of trial participants responded to therapy
The decision to conditionally approve Elrexfio was based on data from MagnetisMM-3 (NCT04649359), an open-label Phase 2 clinical trial in adults that launched in 2021. Treatment with Elrexfio resulted in clinically meaningful, long-lasting responses in some of the study’s 187 participants, all of whom had relapsed and refractory multiple myeloma.
After two priming doses, each patient received a weekly subcutaneous or under-the-skin injection of 76 mg of Elrexfio for about six months. Those who achieved a partial response or better could switch to every other week dosing.
Some 61% of study participants who had never received a BCMA-directed therapy had a partial or complete response to Elrexfio, with 71.5% projected to live for 15 months without their cancer worsening. Among those who switched to dosing every other week, most (80%) maintained or improved their response for at least six months.
Common side effects included cytokine release syndrome, a heightened inflammatory response that causes fever, and anemia, in which individuals have a low red blood cell or hemoglobin count. Low neutrophil counts and fatigue were among other common side effects.
“The approval of Elrexfio is good news for patients and their healthcare teams, as it offers a new treatment possibility for those living with the disease,” said LeBlanc, who also is the Myeloma Canada chair on multiple myeloma.
The data were reviewed under Project Orbis, an international initiative that allows the concurrent submission of anticancer medications in participating countries. Elrexfio has already been approved in the U.S., Switzerland, and Brazil, as well as the European Union, Iceland, Liechtenstein, and Norway.
In line with the conditional marketing authorization for Elrexfio, Pfizer will continue its clinical development program, testing how well the medication may work across the spectrum from newly diagnosed to relapsed and refractory multiple myeloma patients.