Outcomes of haploidentical stem cell transplantation for chronic lymphocytic leukemia: a retrospective study on behalf of the chronic malignancies working party of the EBMT

Abstract

Allogeneic hematopoietic stem cell transplantation (HCT) may result in long-term disease control in high-risk chronic lymphocytic leukemia (CLL). Recently, haploidentical HCT is gaining interest because of better outcomes with post-transplantation cyclophosphamide (PTCY). We analyzed patients with CLL who received an allogeneic HCT with a haploidentical donor and whose data were available in the EBMT registry. In total 117 patients (74% males) were included; 38% received PTCY as GVHD prophylaxis. For the whole study cohort OS at 2 and 5 yrs was 48 and 38%, respectively. PFS at 2 and 5 yrs was 38 and 31%, respectively. Cumulative incidence (CI) of NRM in the whole group at 2 and 5 years were 40 and 44%, respectively. CI of relapse at 2 and 5 yrs were 22 and 26%, respectively. All outcomes were not statistically different in patients who received PTCY compared to other types of GVHD prophylaxis. In conclusion, results of haploidentical HCT in CLL seem almost identical to those with HLA-matched donors. Thereby, haploidentical HCT is an appropriate alternative in high risk CLL patients with a transplant indication but no available HLA-matched donor. Despite the use of PTCY, the CI of relapse seems not higher than observed after HLA-matched HCT.

Allogeneic Haploidentical Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide in Chronic Lymphocytic Leukemia

“…Our findings suggest that haploidentical allo-BMT with PTCy in patients with <20% CLL marrow involvement produces outcomes similar to those previously reported with HLAmatched allo-BMT [14,16,18]. As seen in other diseases using PTCy after haploidentical allo-BMT [27][28][29][30], we found a low incidence of GVHD, with a 1-year CuI of grade II-IV aGVHD of 27% (95% CI, 15% to 38%) and a 2-year CuI of cGVHD of 17% (95% CI, 7% to 26%)].…”

“…Subsequently, the Dana-Farber group reported a superior 5-year OS of 63% associated with a reduced-intensity conditioning regimen, compared with 49% with myeloablative conditioning regimens [17]. The sole report of haploidentical allo-BMT for CLL published Biology of Blood and Marrow Transplantation journal homepage : www.bbmt.org to date with a 5-year OS of 38% and PFS of 31% in 117 patients with CLL [18]. Although the outcomes seem to be significantly worse with haploidentical allo-BMT compared with HLA matched allo-BMT, only 38% of the haploidentical allo-BMT recipients received PTCy GVHD prophylaxis; therefore, the outcomes of haploidentical transplantation with PTCy in CLL remain unclear.…”

Anti-T-lymphocyte globulin (ATLG) compared to post-transplant cyclophosphamide as GvHD prophylaxis in ALL patients undergoing allogeneic stem cell transplantation

“…In recent years, in addition to a well-established GvHD prophylaxis regimen with ATG/ATLG, which is widely used in Europe, PTCy-based strategies have become part of conditioning regimens [19][20][21][22][39][40][41][42][43][44][45][46][47][48][49][50]. Bailen et al observed no significant differences in OS, EFS, CIR, NRM and GRFS with PTCy or ATG based GvHD prophylaxis in a retrospective study with 132 heterogenous patients (AML, MDS, ALL, NHL, CLL and others) undergoing a matched or 9/10 mismatched unrelated donor SCT.…”

The role of allogeneic hematopoietic cell transplantation for chronic lymphocytic leukemia: A review

“…In CLL, the Baltimore group reported 4-year OS 52% and progression-free survival (PFS) 37% among 64 patients undergoing NMA haploidentical HCT with PTCy prophylaxis, with grade II-IV acute GVHD incidence of 27% and chronic GVHD incidence of 17% ( 57 ). An EBMT study of 117 patients who underwent haploidentical HCT for CLL (of whom only 38% received PTCy) reported 2-year OS 48% and PFS 38%, with grade II-IV acute GVHD 32% and chronic GVHD not reported ( 58 ).…”