- The Food and Drug Administration is allowing biotechnology company Arcellx to resume a clinical trial of a Gilead-partnered cell therapy for multiple myeloma, eight weeks after the agency called for a pause due to a patient death, the company announced Monday.
- To aid the trial’s resumption, Arcellx said it has retrained site clinicians on prevention and management of severe side effects, and the FDA will allow more types of “bridging therapies” to help keep patients’ disease at bay while they await the personalized CAR-T therapy. The patient who died developed an aggressive form of multiple myeloma while undergoing bridging therapy.
- The pause will delay results from the trial by up to six months, to the second half of 2024. If approved, Arcellx’s drug, code-named CART-ddBCMA, would compete with established CAR-T therapies Abecma and Carvykti.
CAR-T therapies are engineered from patients’ own T cells to attack cancer. The process requires the cells to be withdrawn from patients’ bodies and manufactured into the treatment, a time lag that makes recipients vulnerable to disease progression in the interim.
Chemotherapy, radiation and immunotherapy can keep cancer at bay. However, under the trial protocol the FDA approved for CART-ddBCMA, trial clinicians could only use treatments patients were previously exposed to and had progressed on. That may make bridging therapy less effective and put patients at risk of progression, according to a handbook on CAR-T treatment.
The patient who died progressed to plasma cell leukemia while awaiting an infusion of CART-ddBCMA but was given the treatment anyway.
While the trial was paused, 17 patients who had been enrolled and were awaiting treatment underwent an infusion.
The trial’s resumption “meets the best-case scenario assumed by many investors,” Leerink Partners analyst Daina Graybosch wrote in a note to clients. “The FDA's action validates Arcellx and Gilead management's explanation for the hold and mitigation plans.”
Arcellx shares were up by mid-single digits Tuesday morning, to roughly the same level they traded at the day before the company announced the hold.
Gilead paid $225 million in cash and made a $100 million investment in Arcellx for rights to CART-ddBCMA, which if approved would join lymphoma treatment Yescarta and leukemia and lymphoma treatment Tecartus in its commercial armory.
The multiple myeloma CAR-T targets a protein on diseased cells called BCMA, similar to Abecma and Carvykti as well as newer antibody drugs.
Abecma, from Bristol Myers Squibb and 2Seventy Bio, gained approval in 2021, while Johnson & Johnson and Legend Biotech won approval for Carvykti in 2022. Bristol Myers reported $279 million in Abecma sales through the first six months of 2023, while J&J said Carvykti had sales of $189 million.