Gilead Sciences Inc.'s chimeric antigen receptor T cell therapy Tecartus received accelerated approval from the U.S. Food and Drug Administration for the treating a type of blood cancer in adults.

Santa Monica, Calif.-based Kite Pharma Inc., a unit of Gilead, designed Tecartus, or brexucabtagene autoleucel, as a one-time therapy for mantle cell lymphoma, or MCL, in adult patients whose disease has returned or stopped responding to other treatments.

MCL is a rare form of non-Hodgkin lymphoma, a type of cancer that develops from white blood cells called B cells that become abnormal and no longer able to fight infection.

The approval comes after the FDA had granted a priority review and breakthrough-therapy designation to Tecartus, formerly known as KTE-X19.

Accelerated approval is granted by the regulator to enable earlier approval of treatments for serious conditions that fill an unmet medical need based on the drugs' anticipated clinical benefit. Pharmaceutical companies are required to conduct further studies to confirm such anticipated clinical benefit, in order to obtain traditional approval from the FDA.

Findings from a study called Zuma-2 form the basis for the Tecartus approval. The study showed that 87% of previously treated patients with relapsed or refractory MCL have experienced a disappearance of signs of cancer after taking a single infusion of the CAR-T cell therapy, with 62% of them having no detectable cancer.

Tecartus' product label has a boxed warning citing the risks of cytokine release syndrome — which occurs when the immune system overreacts to an infection — and neurologic side effects associated with the therapy.

The regulator has approved a risk evaluation and mitigation strategy, or REMS, for Tecartus and combined it with the REMS program for Kite's other lymphoma treatment, Yescarta, or axicabtagene ciloleucel. The REMS program is aimed at informing and educating medical professionals about such risks. Centers offering Tecartus are required to undergo training and obtain certification on the REMS program to be authorized to provide the therapy.