Treatment of older patients with mantle cell lymphoma in the era of novel agents

Mantle cell lymphoma (MCL) is a rare, B-cell non-Hodgkin's lymphoma with a highly heterogeneous presentation that ranges from an indolent disease to an extremely aggressive one. Several clinical and biological prognostic markers can assist in determining the aggressiveness of the disease. Such as MIPI, Ki-67, and TP53, NOTCH1, and CDKN2A mutations. While aggressive chemoimmunotherapy regimens combining rituximab and cytarabine, followed by autologous stem-cell transplantation yield the most promising results, this treatment is too toxic for older patients. Several lower-intensity regimens have shown efficacy in older patients with reduced toxicity profiles. However, older relapsed/refractory patients have an extremely poor outcome. In the last several years, there is a major trend toward chemotherapy-free regimens, targeted therapies such as BTK, BCL-2 and PI3K inhibitors, and immunotherapies such as lenalidomide and CAR-T, which can provide a promising strategy for older patients. Herein we review the current therapies for older MCL patients, chemotherapy regimens, targeted therapies, and immunotherapies.

CAR T-cell therapy for follicular lymphoma and mantle cell lymphoma

Patients with relapsed and/or refractory (R/R) follicular lymphoma (FL) and mantle cell lymphoma (MCL) have a poor prognosis with anticipated short progression-free and overall survivals. Two CD19-directed chimeric antigen receptor T-cell (CAR T) therapies are approved in the United States for R/R FL, namely, axicabtagene ciloleucel (axi-cel) and tisagenlecleucel. The results of ZUMA-5 and ELARA studies led to the approval of axi-cel and tisagenlecleucel, respectively, after demonstrating high overall (ORR) and complete response (CR) rates in this high-risk population of FL patients who had received a median of 3 (range = 2-4) and 4 (range = 2-13) prior lines of therapies, respectively. For instance, the ORR for ZUMA-5 was 94% (CR = 79%), and for ELARA, it was 86% (CR = 69.1%). Pertaining to MCL, brexucabtagene autoleucel is approved for R/R MCL based on results of the ZUMA-2 study. In the latter study, despite the fact that all R/R MCL patients had been exposed to prior Bruton's tyrosine kinase inhibitors, the reported ORR was 91%, with 68% achieving a CR. These results undoubtedly demonstrate a strong efficacy of CAR T therapy in both R/R FL and MCL; yet, one must acknowledge the relatively short follow-up time of all aforementioned studies. Thus, longer follow-up showing durability of responses and long-term safety is definitely needed.