FDA Places Hold on Arcellx Phase 2 Clinical Program in Multiple Myeloma after Patient Death

Rare Daily Staff

Arcellx said the U.S. Food and Drug Administration has placed a clinical hold on its experimental cell therapy for the treatment of patients with relapsed or refractory multiple myeloma.

The clinical hold, received on June 16, follows a recent patient death. The company believes limitations on bridging therapy are a contributing factor and is working with FDA to amend the protocol to expand options for patients that are consistent with current clinical practice. The FDA has provided clearance to Arcellx to continue to dose patients who have undergone lymphodepletion.

Multiple myeloma is a type of hematological cancer in which diseased plasma cells proliferate and accumulate in the bone marrow, crowding out healthy blood cells and causing bone lesions, loss of bone density, and bone fractures. These abnormal plasma cells also produce excessive quantities of an abnormal immunoglobulin fragment, called a myeloma protein, causing kidney damage and impairing the patient’s immune function. Multiple myeloma is the third most common hematological malignancy in the United States and Europe, representing approximately 10 percent of all hematological cancer cases and 20 percent of deaths due to hematological malignancies. Because the condition tends to afflict patients at an advanced stage of life, patients often have multiple co-morbidities and toxicities that can quickly escalate and become life-endangering.

CART-ddBCMA is Arcellx’s BCMA-specific CAR-modified T-cell therapy utilizing the company’s novel BCMA-targeting binding domain for the treatment of patients with relapsed or refractory multiple myeloma. CART-ddBCMA is currently in a phase 2 study. Arcellx’s proprietary binding domains are novel synthetic proteins designed to bind specific therapeutic targets. The FDA has granted CART-ddBCMA Fast Track, Orphan Drug, and Regenerative Medicine Advanced Therapy designations.

“In coordination with our investigators, data safety monitoring board, and our partners at Kite Pharma, we are working with FDA to address the clinical hold. The expansion of bridging therapy regimens is consistent with what’s currently available in clinical practice and is in the best interest of patients,” said Rami Elghandour, Arcellx’s chairman and CEO. “Additionally, we continue to evaluate other potential improvements to the study. We remain confident that CART-ddBCMA is a potential best-in-class therapy for the treatment of patients with [relapsed and remitting multiple myeloma] based on the clinical profile observed in the patients dosed to date across our studies.”