Compared with chimeric antigen receptor (CAR) T-cell therapy, autologous hematopoietic cell transplantation (AHCT) led to a lower incidence of relapse and superior overall survival (OS) in patients with diffuse large B-cell lymphoma (DLBCL) in partial remission (PR) after salvage chemotherapy. This is according to research recently published in Blood.
To determine the relative efficacy of AHCT versus CAR T-cell therapy in this population, Mazyar Shadman, MD, of the University of Washington, and colleagues compared the clinical outcomes of 411 adult patients who received either AHCT (n=266) or CAR T-cell therapy (n=145) while in PR per international working group criteria confirmed by CT or PET scan. The analysis included patients with DLBCL, high-grade B-cell lymphoma with MYC and BCL2 or BCL6 rearrangements, or primary mediastinal large B-cell lymphoma. Data was obtained from the Center for International Blood and Marrow Transplant Research registry.
Between the two groups, no significant differences were found in age (median 58 vs. 60 years; p=0.07), performance status (Karnofsky Performance Status ≥90: 51% vs. 39%, p=0.09), or the proportion of patients who had a PET scan prior to treatment (83% vs. 87%; p=0.36). Patients who received AHCT had undergone fewer median prior lines of therapy (median 2 vs. 3; p<0.001).
In the AHCT group, the cumulative incidence of relapse/progression was lower at one year compared to the CAR T-cell therapy cohort (34% [95% CI 28-40] vs. 45% [95% CI 37-54]; p=0.03) and at two years (40% [95% CI 33-46] vs. 52% [95% CI 41-63]; p=0.05). Two-year OS was higher for patients who received AHCT than for those in the CAR T-cell therapy group (69% [95% CI 63-74] vs. 47% [95% CI 33-60]; p=0.004).
Progression-free survival (PFS) was similar across both groups. For patients in the AHCT group, the two-year PFS was 52% (95% CI 46-58), compared with 42% (95% CI 30-53) in the CAR T-cell therapy group.
During the follow-up period, 143 patients died: 91 from the AHCT cohort (34%) and 52 who received CAR T-cell therapy (36%). In both groups, the most common cause of mortality was primary disease, accounting for 74% and 75% of deaths in the AHCT and CAR T-cell therapy groups, respectively. Other common causes of death included infections (6%) and organ failure (4%) among patients who received AHCT, as well as infections (4%), cytokine release syndrome (4%), organ failure (4%), and malignancies (4%) in the CAR T-cell therapy group.
“These data support the role of AHCT as standard-of-care in transplant-eligible patients with relapsed DLBCL that achieve at least a PR as the best response to salvage therapy but more data are needed to answer this question in patients with fewer lines of salvage therapy,” the authors concluded.
Limitations of this analysis include those inherent in a retrospective study and the subjectivity of the definition of PR, especially in the non-clinical trial setting.
Study authors report no relevant conflicts of interest.
Shadman M, Pasquini M, Woo Ahn K, et al. Autologous transplant versus chimeric antigen receptor T-cell therapy for relapsed DLBCL in partial remission [published online ahead of print, 2021 Sep 27]. Blood. doi: 10.1182/blood.2021013289.