Arcellx’s Gilead-partnered multiple myeloma cell therapy is in the clear, as the FDA has removed the partial clinical hold it placed on the CAR-T candidate in June following a patient death.
The California drugmaker said Monday that the patient who died was “managed in a manner that conflicted with the trial protocol.” The patient was treated with the therapy even though they were ineligible for it under the protocol, Arcellx added.
The biotech has since retrained the study’s clinical trial sites and shook hands with the FDA on adjusting methods for preventing and managing potential adverse events. Arcellx’s pen-label iMMagine-1 study is being run at 17 sites and is testing patients’ overall response to one dose per a federal database.
More bridging therapy options are now allowed under the FDA’s lift “to better align its protocol with current clinical practice,” Arcellx said.
Arcellx’s stock price $ACLX was up about 7% before Tuesday’s opening bell.
“Such rapid resolution is encouraging and meets the best-case scenario assumed by many investors,” Leerink Partners analyst Daina Graybosch wrote in a note. “The FDA’s action validates Arcellx and Gilead management’s explanation for the hold and mitigation plans.” Arcellx said it expects to have preliminary data from the potentially pivotal Phase II study in the second half of next year, a milestone originally targeted for the first half, Graybosch noted.
“Importantly, during the partial clinical hold, FDA approved dosing of all 17 patients who had been enrolled but not yet dosed prior to the hold, minimizing treatment disruption for patients and clinicians,” Arcellx chair and CEO Rami Elghandour said in a press release. “We and our partners at Kite remain confident in CART-ddBCMA’s potential as a best-in-class therapy for the treatment of patients with rrMM [relapsed or refractory multiple myeloma] given the totality of data to date across our studies.”
Arcellx anticipates launching the CART-ddBCMA cell therapy in 2026, pending trial results and BLA approval. With $506.5 million at the end of June, Arcellx has enough money to make it into launch year, it said in a quarterly update Monday.
While a few cell therapies have already been greenlit for multiple myeloma, patients and doctors still seek more treatment options. FDA added two bispecific antibodies to the arsenal this month, with accelerated nods for Johnson & Johnson’s Talvey and Pfizer’s Elrexfio.
One of those approved cell therapy makers, Gilead and its unit Kite, doled out $225 million to pair up on the autologous cell therapy around the time of initial data at last year’s annual American Society of Hematology confab. The partners will jointly commercialize the cell therapy in the US and Kite will run it elsewhere.
Arcellx said it’s working with Kite to resume screening and enrollment in the study, in which patients must have tried at least three prior treatment regimens. Once the trial is completely enrolled, it will start another study, aptly dubbed iMMagine-2, to test the cell therapy in earlier lines.
