Salvaged single-unit cord blood transplantation for 26 patients with hematologic malignancies not in remission

Decitabine prior to salvaged cord blood transplantation for acute myeloid leukaemia/myelodysplastic syndrome not in remission

WHAT IS KNOWN AND OBJECTIVE

Many refractory/relapsed haematological malignancies, in non-remission state, still have poor prognosis even after allogeneic haematopoietic stem cell transplantation. Recently, decitabine or umbilical cord blood transplantation (UCBT) seemed to be effective in these patients. However, few studies have added decitabine to myeloablative conditioning regimens for UCBT in patients with haematological malignancies not in remission. Therefore, the objective was to evaluate the clinical outcomes of patients with refractory/relapsed acute myeloid leukaemia (AML) or myelodysplastic syndrome (MDS) using decitabine as part of a myeloablative conditioning regimen prior to salvaged unrelated UCBT at our centre.

METHODS

We enrolled 20 consecutive patients with refractory/relapsed AML/MDS between 2013 and 2018. All patients were in non-remission state before transplantation. All transplants were performed with decitabine as part of the myeloablative conditioning regimen, which was decitabine + fludarabine/busulfan/cyclophosphamide.

RESULTS AND DISCUSSION

All patients achieved neutrophil and platelet engraftment. Incidence of grade III/IV acute graft-vs-host disease (GVHD) was 20.0%, which was also decreased compared to non-decitabine group (P = .025). The median follow-up time after UCBT was 29 months (range 14-64 months). The 2-year probability of GVHD-free relapse-free survival (GRFS) was higher in the decitabine group. Univariate showed that the decitabine group was associated with a higher GRFS than the non-decitabine group. The estimated probability of overall survival and relapse was 55% and 20.0%, respectively.

WHAT IS NEW AND CONCLUSIONS

Our results suggest that addition of decitabine as part of the myeloablative conditioning regimen prior to UCBT for refractory/relapsed AML/MDS in patients who are not in remission is safe and might be an effective treatment option.

Single cord blood transplantation in Japan; expanding the possibilities of CBT

Cord blood (CB) has been an alternative stem cell source for patients with a wide variety of hematological diseases. Cord blood confers the advantages of rapid availability and higher tolerance to two HLA antigen mismatches compared with unrelated donors, and this has increased opportunities for patients who do not have suitable donors or require urgent transplantation. Although the higher rate of engraftment failure remains a serious concern after cord blood transplantation (CBT), the mechanisms underlying this risk have gradually been clarified, which has helped to improve engraftment. Recent studies of CBT and other alternatives have reported comparable outcomes. Moreover, CBT shows promise even when patients are in a non-remission status, which may reflect the potent graft-versus-leukemia effect of CB. Here we compare the most recent outcomes of CBT with those of other stem cell sources and discuss the potential of CB and several outstanding issues that require resolution.

Decitabine prior to salvaged unrelated cord blood transplantation for refractory or relapsed childhood acute leukemia

No clinical studies have investigated the role of decitabine as a part of the myeloablative conditioning regimen prior to UCBT for refractory or relapsed childhood AL in patients in NR status. The aim of this study was to identify the potential benefits of decitabine as a prior therapy before salvaged unrelated UCBT for refractory or relapsed childhood AL. Eight consecutive patients with childhood refractory/relapsed AL were enrolled in our study between 2013 and 2014. All patients were in NR status before the time of transplant and had features associated with poor outcomes, such as CNSL, MDS-AML, high WBC count at diagnosis, and hypodiploid status (FLT3+/ITD+). Additionally, all patients had one of the following disease statuses: PIF, multiple relapse, or early relapse. All transplants were performed with decitabine as part of the myeloablative conditioning regimen, which was decitabine+Flu/Bu/CY±BCNU or decitabine+Ara-c/BU/CY2±BCNU. A total of seven patients (7 of 8) achieved neutrophil engraftment and platelet engraftment, and one patient experienced primary graft failure. All eight patients (100%) developed PES at a median of 7 days. Three patients developed stage II-IV acute GVHD at a median of 18 days. Additionally, three patients developed chronic GVHD, but it was not extensive in any of those three patients. The median follow-up time after CBT was 19.9 months (range, 9.2-30.7 months). The estimated probability of OS was 75%. Two patients (2 of 8) experienced a testis relapse, and two patients (2 of 8) died. Our experience suggests that the additional application of decitabine as part of the myeloablative conditioning regimen prior to UCBT for refractory or relapsed childhood AL among patients who are not in remission is safe and might be an effective treatment option.