Outcome after allogeneic stem cell transplantation with haploidentical versus HLA-matched donors in patients with higher-risk MDS

HLA-Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide versus HLA-Matched Unrelated Donor Transplantation for Myelodysplastic Syndrome

Allogeneic hematopoietic cell transplantation (allo-HCT) is the sole curative therapy for myelodysplastic syndrome (MDS). In the absence of an HLA-matched sibling donor, an HLA-matched unrelated donor (MUD) is considered the leading candidate. However, in recent decades, the alternative donor pool has been extended to HLA-haploidentical donors, especially with the development of graft-versus-host disease (GVHD) prophylaxis using post-transplantation cyclophosphamide (PTCy). Comparative data for haploidentical and MUD allo-HCT in patients with MDS are scarce. We retrospectively analyzed 697 adult patients with MDS who underwent HLA-haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) with PTCy (n = 136), MUD bone marrow transplantation (MUD-BMT) (n = 465), or MUD peripheral blood stem cell transplantation (MUD-PBSCT) (n = 96) as their first allo-HCT between 2014 and 2020 using Japanese registry data. Multivariable analyses demonstrated faster neutrophil engraftment (hazard ratio [HR], 2.19; 95% confidence interval [CI], 1.65 to 2.90; P < .001) and platelet engraftment (HR, 2.31; 95% CI, 1.72 to 3.10; P < 0001) in the MUD-PBSCT cohort compared with the haplo-PBSCT cohort. MUD-BMT was associated with a higher incidence of grade II-IV acute GVHD than haplo-PBSCT (HR, 1.52; 95% CI, 1.00 to 2.29; P = .048). Among patients without in vivo T cell depletion using antithymocyte globulin (ATG) (haplo-PBSCT, n = 136; MUD-BMT, n = 446; MUD-PBSCT, n = 65), MUD-PBSCT recipients experienced faster hematopoietic recovery, MUD-BMT recipients (HR, 1.54; 95% CI, 1.02 to 2.32; P = .042) or MUD-PBSCT recipients (HR, 1.83; 95% CI, 1.06 to 3.18; P = .03) had a higher incidence of grade II-IV acute GVHD, and MUD-PBSCT recipients developed chronic GVHD more frequently than haplo-PBSCT recipients (HR, 1.74; 95% CI, 1.04 to 2.89; P = .034). There were no significant differences in overall survival, disease-free survival, GVHD-free relapse-free survival, relapse, or nonrelapse mortality in the haplo-PBSCT cohort versus the MUD-BMT or MUD-PBSCT cohorts. In conclusion, despite differences in the incidences of hematopoietic engraftment and GVHD depending on graft type and ATG use in MUD transplant recipients, major transplantation outcomes were comparable between recipients of haplo-PBSCT using PTCy and recipients of MUD-BMT or MUD-PBSCT.

Phase I study of zoledronic acid combined with escalated doses of interleukine-2 for early in vivo generation of Vγ9Vδ2 T-cells after haploidentical stem cell transplant with posttransplant cyclophosphamide

The presence of donor Vγ9Vδ2 T-cells after haploidentical hematopoietic stem cell transplant (h-HSCT) has been associated with improved disease-free survival. These cells kill tumor cells in a non-MHC restricted manner, do not induce graft-versus-host disease (GVHD), and can be generated by stimulation with zoledronic acid (ZA) in combination with interleukin-2 (IL-2). This monocentric phase I, open-label, dose-escalating study (ClinicalTrials.gov: NCT03862833) aimed at evaluating the safety and possibility to generate Vγ9Vδ2 T-cells early after h-HSCT. It applied a standard 3 + 3 protocol to determine the maximum tolerated dose (MTD) of increasing low-doses of IL-2 (5 days [d] per week, 4 weeks) in combination with a single dose of ZA, starting both the first Monday after d + 15 posttransplant. Vγ9Vδ2 T-cell monitoring was performed by multiparameter flow cytometry on blood samples and compared with a control cohort of h-HSCT recipients. Twenty-six patients were included between April 2019 and September 2022, 16 of whom being ultimately treated and seven being controls who received h-HSCT only. At the three dose levels tested, 1, 0, and 1 dose-limiting toxicities were observed. MTD was not reached. A significantly higher number of Vγ9Vδ2 T-cells was observed during IL-2 treatment compared with controls. In conclusion, early in vivo generation of Vγ9Vδ2 T-cells is feasible after h-HSCT by using a combination of ZA and repeated IL-2 infusions. This study paves the way to a future phase 2 study, with the hope to document lesser posttransplant relapse with this particular adaptive immunotherapy.

Allogeneic hematopoietic stem cell transplantation: A single-center experience, 2017 to 2021

INTRODUCTION

Hematopoietic stem cell transplantation (HSCT) remains a critical treatment for advanced or high-risk hematological malignancies, posing challenges such as finding suitable donors and managing of graft-versus-host disease (GvHD). This study estimates 3-year overall survival in patients who underwent HSCT at our referral service in the state of Minas Gerais, Brazil.

MATERIAL AND METHODS

This retrospective observational cohort study involved 41 patients who received HSCT between 2017 and 2021 at the Felício Rocho Hospital. Recipients received HSCT from either haploidentical donor (Haplo), matched unrelated donor (MUD), or HLA-matched sibling donor (MSD). The study evaluated parameters that included 3-year overall survival (OS), treatment-related mortality (TRM), GvHD incidence, post-transplant relapse rate, and engraftment. ANOVA, Kruskal-Wallis, and chi-square tests were used for statistical analysis. Survival curves were calculated using the Kaplan-Meier method and the Log-rank test compared the curves.

RESULTS

Our study found that the engraftment time differed among groups: Haplo recipients engrafted earlier within a median of 16 days (ranging between 10 and 20 days) than MSD recipients with 18 days (ranging between 11 and 28 days), and MUD recipients with 19 days (ranging between 11 and 24 days; p = 0.019). Mild acute GvHD (grade I-II) was observed in 13 patients, progressing to chronic GvHD in 5 patients. Three-year OS rates were as follows: MSD group - 67.7%, Haplo group - 42.2%, and MUD group - 44.4% (MSD vs Haplo, p = 0.039). Three-year cumulative treatment-related mortality (TRM) rates were 17.8% for MSD group, 22.9% for Haplo group, and 22.1% for MUD group (pairwise comparisons p > 0.05). Infection-related mortality was reported in eight patients, while relapse rates at 3 years were similar across MSD, Haplo, and MUD groups (p = 0.891). Donor age influenced OS rates, showing better outcomes with donors under 45 years old, and significant differences were found in pairwise comparisons (p = 0.015).

CONCLUSION

Donor type and donor age significantly impacted HSCT outcomes in our analysis, thus emphasizing the importance of rigorous donor selection in risk stratification and suggesting potential benefits for younger donors.

The prognosis and risk factors for patients with complex karyotype myelodysplastic syndrome undergoing allogeneic haematopoietic stem cell transplantation

Allogeneic haematopoietic stem cell transplantation (HCT) is the curative treatment for myelodysplastic syndrome with a complex karyotype (CK-MDS). However, only a few studies have been limited to patients with CK-MDS undergoing allogeneic HCT. This study aimed to identify the risk factors for patients with CK-MDS undergoing allogeneic HCT. We included 691 patients with CK-MDS who received their first allogeneic HCT. The overall survival (OS) was the primary end-point, estimated using the Kaplan-Meier method. Prognostic factors were identified using a Cox proportional hazards model. The 3-year OS was 29.8% (95% confidence interval [CI]: 26.3-33.3). In the multivariable analysis, older age (hazard ratio [HR]: 1.44, 95% CI: 1.11-1.88), male sex (HR: 1.38, 95% CI: 1.11-1.71), poor haematopoietic cell transplant comorbidity index (HR: 1.47, 95% CI: 1.20-1.81), red blood cell transfusion requirement (HR: 1.58, 95% CI: 1.13-2.20), platelet transfusion requirement (HR: 1.85, 95% CI: 1.46-2.35), not-complete remission (HR: 1.55, 95% CI: 1.16-2.06), a high number of karyotype abnormality (HR: 1.63, 95% CI: 1.18-2.25) and monosomal karyotype (HR: 1.49, 95% CI: 1.05-2.12) were significantly associated with OS. Thus, the 3-year OS of allogeneic HCT was 29.8% in patients with CK-MDS, and we identified risk factors associated with poor OS.