Kite, a Gilead Company, has agreed to co-develop and co-commercialize Arcellx’s lead candidate CART-ddBCMA as a treatment for relapsed or refractory multiple myeloma, through a collaboration that could generate more than $4 billion for Arcellx.
The collaboration comes less than a month after Arcellx launched the Phase II pivotal iMMagine-1 trial (NCT05396885), an open-label study with an estimated 110 participants. At the time, Arcellx said it planned to dose patients in the study with CART-ddBCMA by year’s end. Arcellx also said it had begun to scale trial operations by initiating clinical sites, enrolling patients, and overseeing the manufacturing of cells with Oxford vector through Lonza.
CART-ddBCMA generated positive results from a Phase I expansion trial (NCT04155749) in patients with relapsed or refractory multiple myeloma, which the company announced Friday in addition to news of the Kite partnership.
According to Arcellx, CART-ddBCMA achieved a 100% overall response rate (ORR) in all 38 evaluable patients with a median follow-up of 15 months as of the October 31, 2022, cutoff date, per International Myeloma Working Group criteria. Thirty-four of 38 patients (89%) achieved at least a very good partial response (VGPR) or higher (including seven VGPR patients), while 27 of the 38 (71%) achieved a complete response (CR) or a stringent complete response
The CR rate was comparable to the 67% to 68% 12-month CR rates shown by Legend Biotech and Johnson & Johnson’s Janssen Pharmaceutical Cos. for Carvykti in 57 patients evaluated in the LEGEND-2 trial (NCT03090659) and 97 in the CARTITUDE-1 trial (NCT03548207), both Phase I/II studies, noted Jefferies analyst Michael Yee. The FDA approved Carvykti in February to treat adults with relapsed or refractory multiple myeloma after four or more prior lines of therapy.
Daina M. Graybosch, Ph.D., senior managing director, immuno-oncology and a senior research analyst with SVB Securities, wrote in a research note Friday that CART-ddBCMA “is more valuable now that Kite/Gilead will co-develop and co-commercialize the program with Arcellx and applaud this deal.”
Arcellx investors appeared to agree with Graybosch, responding to news of the collaboration with a buying surge that sent the company’s shares soaring 29% on Friday, from $21.68 to $29.04. However, shares of Gilead dipped nearly 2%, from $89.47 to $87.97.
“Kite is the best possible partner for Arcellx, given Kite’s experience developing class-leading CD19 CAR-T products,” Graybosch added. She cited Kite’s success in developing and commercializing two cell therapies: Tecartus, approved in 2021 for adults with relapsed or refractory mantle cell lymphoma (MCL), or with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL); and Yescarta approved by the FDA in 2017 as the second CAR-T therapy with oncology indications, namely several forms of lymphoma.
Yescarta’s indications include relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL).