Evolving patterns of transplant strategies for mantle cell lymphoma in the era of BTK inhibitors and CAR-T therapy.

Abstract

e19012 Background: Mantle cell lymphoma is an aggressive lymphoma with poor survival after chemotherapy alone. Both autologous (auto) and allogeneic (allo) transplants have improved outcomes over the years, but transplant strategies most beneficial for MCL are not clearly defined. Recently, BTK inhibitors and chimeric antigen therapies (CAR T) therapy approach has changed the landscape of Mantle cell Lymphoma. Methods: Patient Population:A total of 71 patients underwent transplant for diagnosis of MCL at Penn State Cancer Institute, between March 1993 and March 2023. Median follow up was 3.1 years (32 days-9883 days) after transplant. Patient Characteristics: A total of 71 patients (62 M: 9 F) underwent transplants, including autologous (n=30), allogeneic (n=32), and CAR T (n=9). Since 2020, 19 transplants were performed: CAR T (n=9) auto transplants (n=9) and allogeneic transplants (n=1). Relapsed and refractory MCL (n=4) patients received CAR T whereas patients achieving CR 1 (n=8) and PR1 (n=1) received auto transplants. Most patients were Caucasian (n= 68), with few Hispanic (1), African American (1), or Asian (1). Results: Median age at the time of transplant was 61 (37-70) years for autologous, 56 (33-67) years for allogenic and 63 (55 -75) years for CAR T respectively. Disease status at transplant was CR 52.1% (n=37), primary induction failure or relapsed/refractory 36.6% (n=26), PR 11.3% (n=8). High LDH was seen at the time of transplant in 16.9% (n=12) patients and normal in 83.1%(n=59) patients. Blastoid morphology was seen in only 13.8% (n=4) autologous, 37.9% (n=11) allogenic and 33.3% (n=3) CAR T patients. Outcomes: Overall survival (OS) at 1 year and 3 years was 93.3% and 85.9% for autologous (auto) transplants, 62.5% and 52.9% for Allogeneic (allo) transplants, 88.9% and 76.2% for CAR-T therapy respectively (P = 0.007). Progression free survival at 1 year and 3 years was 86.3% and 75.0% for auto transplants; 50.0% and 43.3% for allo Transplants; 66.7% and 66.7% for CART Therapy (P = 0.03). Primary cause of death was Treatment Related Mortality (TRM) (n= 9) (GVHD=4; Pulmonary=3; MOF=2) and disease progression (n=10); unknown (n=4); other (n=1). Primary cause of death for CAR T therapy was grade IV ICANS and disease progression. Conclusions: Recently CAR T therapies have changed the landscape of MCL treatment algorithm in both Blastoid and non-Blastoid histology MCL patients. But in the era of CAR T therapy and BTK inhibitors for MCL, achieving CR at the time of transplant predicts improved long-term outcomes. Randomized studies or larger retrospective CIBMTR data analysis may be important to answer best transplant strategy for MCL patients. [Table: see text]