Cellectis has given up on its multiple myeloma CAR-T candidate UCARTCS1. With the phase 1 clinical trial two years behind schedule, and heavy investment needed to accelerate enrollment, the off-the-shelf cell therapy specialist is stopping the study and focusing its resources on three other candidates.
Transatlantic biotech Cellectis advanced the anti-CS1 candidate into the clinic in 2019, making it the first allogeneic CAR-T cell therapy to begin tests in multiple myeloma patients. However, the study suffered a setback the following year when the FDA imposed a clinical hold after learning that a patient died from a cardiac arrest.
Cellectis resolved the hold by the end of 2020 but struggled to gain momentum, leading it to push back the targeted completion date in August 2022 and again in March 2023. Now, the slow pace of progress has become intolerable to the biotech.
“The company decided to stop enrollment and treatment of patients with UCARTCS1,” Cellectis CEO André Choulika, Ph.D., said in a statement to disclose first-quarter results. “Indeed, to accelerate the speed of enrollment of patients in the MELANI-01 study, evaluating UCARTCS1, the company would have had to invest [a] meaningful amount of resources.”
Cellectis’ chances of delivering a return on any additional investment in UCARTCS1 have been hurt by the evolution of the multiple myeloma market since the candidate entered the clinic in 2019. Talking to investors on a quarterly results conference call in March, Mark Frattini, M.D., Ph.D., chief medical officer at Cellectis, set out how he saw UCARTCS1 fitting into a treatment pathway that is being reshaped by other drugs.
“Obviously, there are a great number of BCMA-directed [programs], both cellular therapy and antibody/ antibody-drug conjugate trials, and the recent approval of teclistamab,” Frattini said. “So, we feel that CS1 is obviously going to fit in currently after a BCMA-directed therapy, and the question would be if it’s after one or two BCMA-directed therapies.”
Cellectis ended March with $88 million in the bank. The biotech expects its cash to fund operations into the third quarter of next year.