Pfizer celebrates accelerated approval for potential multiple myeloma blockbuster

Pfizer has secured an accelerated approval for Elrexfio, a potential multiple myeloma blockbuster that Pfizer expects could become a “multibillion-dollar franchise.”

Elrexfio, also known as elranatamab, will be available for relapsed or refractory multiple myeloma patients who’ve had at least four prior therapies, including a proteasome inhibitor, an immunomodulatory agent and an anti-CD38 monoclonal antibody, Pfizer announced Monday. The drug targets BCMA on myeloma cells and CD3 on T cells, prompting the T cells to attack the myeloma cells.

The average monthly list price will be $41,500, according to a Pfizer spokesperson, and a treatment course could total $330,000 based on the duration seen in a clinical trial. However, the monthly price could lower after six months as the administration schedule shifts to biweekly doses. It will be available in the weeks following approval.

The drug comes with a boxed warning for an aggressive immune response called cytokine release syndrome (CRS) and neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS), as well as warnings around infections, neutropenia and other toxicities.

The approval was based on data from a single-arm Phase II study dubbed MagnetisMM-3, which showed an overall response rate of 58% among a group of 97 patients who received four or more prior treatments. Researchers estimate that 82% maintained their response for at least nine months, Pfizer said.

Because it was approved via the FDA’s accelerated pathway, the OK hinges upon a confirmatory study. Pfizer kicked off a Phase III confirmatory study last year, enrolling 854 patients, pitting Elrexfio alone and in combination with the anti-CD38 antibody daratumumab against a combination of daratumumab, anti-cancer drug pomalidomide and the steroid dexamethasone.

Pfizer touted Elrexfio’s dosing schedule, which calls for administration once every other week after 24 weeks of weekly administration, meaning “less time at the clinic and potentially greater long-term treatment tolerability,” the company said in a news release. More than 35,000 patients are diagnosed each year in the US, and relapse is “nearly inevitable.”

The news comes as Johnson & Johnson celebrates a win for its bispecific antibody targeting CD3 and GPRC5D on myeloma cells. Talvey was approved on Thursday in the fifth line or higher and is priced at $45,000 per month or a range of $270,000 to $360,000, depending on treatment duration.

Talvey’s label also includes a boxed warning for CRS and neurologic toxicity and warnings against other toxicities.

“With significant responses in a patient population with highly refractory disease, we believe Elrexfio is poised to potentially become the new standard of care for multiple myeloma, as we plan to build upon this indication with continued development across the expansive MagnetisMM program,” Pfizer’s chief commercial officer and president of the global biopharmaceuticals business Angela Hwang said in the release.

Mikael Dolsten

Pfizer is focused on extending Elrexfio into earlier lines of treatment as a monotherapy and in combinations. In the company’s most recent quarterly earnings call, CSO and president of R&D Mikael Dolsten said elranatamab “is expected to be the anchor of an anticipated multibillion-dollar franchise.”

“Given factors currently limiting the availability of novel therapies in the triple-class exposed setting, elranatamab has the potential to reach a broad and greater number of patients as an off-the-shelf option with reduced dosing frequency that is administered subcutaneously, offering more convenience than intravenous administration,” he said on the company’s Q4 2022 investor call.

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