A single-institution study of allograft outcomes for chronic lymphocytic leukaemia over 20 years.

Abstract

Background: Allogeneic stem cell transplantation (alloSCT) is an established potentially curative therapy for patients with high-risk chronic lymphocytic leukaemia (CLL). Future availability of chimeric antigen receptor T-cell therapies and bispecific antibodies may further reduce utilisation of alloSCT.

Aim: This retrospective analysis sought to describe institutional outcomes for alloSCT for CLL, to which future outcomes following immunotherapies may be compared locally.

Methods: Patients with CLL in the institutional alloSCT database were identified. Kaplan-Meier estimates were used to assess survival outcomes, and Gray's competing incidence analyses were used for cumulative incidence of relapse (CIR) and non-relapse mortality (NRM).

Results: Sixty-two patients with CLL of median age 54 years (range 25-75), including 17 with prior Richter transformation, underwent alloSCT between 2000 and 2022. A total of 39% and 35.4% of tested patients harboured complex karyotype and del(17p) respectively. Median follow-up for survivors was 9.2 years. Two-year progression-free survival (PFS), overall survival (OS), CIR and NRM rates were 57.7%, 74%, 16.3% and 18.2% respectively. Ten-year PFS and OS were 38.2% and 50.8% respectively. Twenty-nine deaths occurred during follow-up, including 14 without prior CLL relapse. Del(17p) abnormality was associated with inferior PFS, and age ≥54 years at alloSCT was associated with inferior OS.

Conclusions: Survival outcomes from this study align with prospective and retrospective data published from the chemoimmunotherapy era of CLL treatment. Although more recent data suggest improved post-alloSCT survival outcomes, data assessing the impact of novel agents distinct from improved alloSCT care are lacking. Our recommendations for the current role of alloSCT in CLL therapy are summarised.