One of the primary advantages of CAR T-cell therapy is that the patient does not have to be in remission to receive it; thus, this treatment can be administered to patients with MCL who have active disease, which broadens eligibility compared with autologous stem cell transplantation. This is a significant advantage, as achieving remission in patients with relapsed/refractory high-risk MCL is challenging. In addition, advanced age does not automatically disqualify someone for CAR T-cell therapy. I have seen reports of patients over the age of 80 years with diffuse large B-cell lymphoma who were treated with CAR T-cell therapy, patients who may not have been considered candidates for autologous stem cell transplantation.

Regarding the side effects and tolerability of CAR T-cell therapy, the disease burden correlates with the risk of side effects such as cytokine release syndrome and immune effector cell–associated neurologic syndrome. One needs to be relatively fit to tolerate cytokine release syndrome and the neurologic toxicities associated with CAR T cells. We are cautious about steroid use in patients with immune effector cell–associated neurologic syndrome due to the possibility of impairing the effectiveness of the CAR T cells, although we understand that steroids can be used at certain points, including when the patient starts experiencing toxic effects. The toxicities of the more recent CAR T-cell products appear to be less significant than the earlier products, possibly because we have learned how to better manage the toxicities.

A candidate also needs to have access to a center that administers CAR T cells, something that is generally not available in community practice. For high-risk patients with MCL, including those with primary refractory MCL, blastoid morphology, TP53 alterations, and other high-risk features, I would consider CAR T-cell therapy earlier in the disease course. For a patient with high-risk MCL who underwent induction therapy, achieved remission, received autologous stem cells, and then relapsed very quickly, I would consider CAR T cells as well, based on the clinical course and regardless of the disease biology.