Allogeneic peripheral blood stem cell transplantation from two- or three-loci-mismatched related donors in adult Japanese patients with high-risk hematologic malignancies

Comparative study of the efficacy of allogeneic hematopoietic stem cell transplantation from human leukocyte antigen-haploidentical related and unrelated donors in the treatment of leukemia

AIMS

To compare the efficacy of hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA)-haploidentical related donors (RD) and unrelated donors (URD) in the treatment of leukemia.

METHODS

Ninety-three leukemia patients underwent allogeneic HSCT were divided into two groups: 51 cases of RD-HSCT and 42 cases of URD-HSCT. In the RD-HSCT group, a preconditioning regimen with fludarabine (Flu) + busulfan (Bu) + cytosine arabinoside (Ara-C) was used in 42 patients and total body irradiation (TBI) + Flu + Ara-C was used in the remaining 9.

RESULTS

In the URD-HSCT group, a modified preconditioning regimen with Bu + cyclophosphamide was used in 35 patients, while the other 7 patients underwent treatment with TBI + Flu. After transplantation, the occurrence rate of grade II-IV acute graft-versus-host disease (GVHD) was 46.0 and 51.2% in the two groups. Likewise, the rate of chronic GVHD was 46.0 and 63.4%, respectively. No significant differences in the occurrence of acute and chronic GVHD were detected between the two groups. The differences in early-stage infection rate after transplantation, recurrence rate, 3-year survival rate, and disease-free survival rate between the two groups were not significant.

CONCLUSION

HLA-haploidentical RD-HSCT with enhanced preconditioning and administration of immunosuppressants showed a clinical efficacy similar to that of URD-HSCT against leukemia, without the risk of increased infection and GVHD.

Unmanipulated HLA-mismatched/haploidentical peripheral blood stem cell transplantation for high-risk hematologic malignancies

BACKGROUND

Haploidentical hematopoietic stem cell transplantation (HSCT) has been increasingly applied in high-risk hematologic patients due to the absence of HLA-matched donors. The aim of this study was to investigate the efficacy and safety of unmanipulated haploidentical allogeneic peripheral blood stem cells transplantation (PBSCT) for hematologic malignancies.

STUDY DESIGN AND METHODS

Patients who underwent unmanipulated HLA-mismatched/haploidentical PBSCT from July 2007 to March 2010 with high-risk hematologic malignancies were enrolled for retrospective analysis.

RESULTS

Twenty-one patients with high-risk hematologic malignancies underwent unmanipulated HLA-mismatched/haploidentical PBSCT with myeloablative conditioning. The numbers of CD34+ cells infused at transplantation were 4.81 (range, 2.61-11.47)×10(6)/kg. Patients achieved myeloid and platelet engraftment at a median of 16.5 and 20 days, respectively. The cumulative incidence of acute graft-versus-host disease (GVHD) on Day 100 was 52.7±10.7%, and the 2-year cumulative incidence of chronic GVHD was 39.5±10.6%. The cumulative incidences of cytomegalovirus antigenemia and hemorrhagic cystitis within 100 days after PBSCT were 59.5±16.7 and 34.8±13.3%, respectively. One hundred-day transplantation-related mortality (TRM) rate and the 2-year cumulative TRM rate were 14.3 and 20.5±7.8%, respectively. The 2-year cumulative overall survival was 62.1±11.4% and the probability of disease-free survival at 2 years was 55.6±10.7% with a 16-month median follow-up.

CONCLUSION

Unmanipulated PBSCT is a promising protocol in HLA-mismatched/haploidentical transplant settings.

Hematopoietic SCT from partially HLA-mismatched (HLA-haploidentical) related donors

Hematopoietic SCT from a partially HLA-mismatched (HLA-haploidentical) first-degree relative offers the benefits of rapid and near universal donor availability but also the risks that result from traversing the HLA barrier; namely, graft failure, severe GVHD and prolonged immunodeficiency. Improvements over the last 10 years in conditioning regimens, graft engineering and pharmacological immunoprophylaxis of GVHD have substantially reduced the morbidity and mortality of HLA-haploidentical SCT. Highly immunosuppressive but nonmyeloablative conditioning extends the availability of HLA-haploidentical SCT to elderly hematologic malignancy patients lacking HLA-matched donors and permits recovery of autologous hematopoiesis in the event of graft failure. Current regimens for HLA-haploidentical SCT are associated with a 2-year non-relapse mortality of 20+/-5%, relapse of 35+/-15% and overall survival of 50+/-20%. Major developmental areas include harnessing natural killer cell alloreactivity to reduce the risk of disease relapse and improving immune reconstitution by delayed infusions of lymphocytes selectively depleted of alloreactive cells. Hematologic malignancy patients who lack suitably matched related or unrelated donors can now be treated with HLA-haploidentical related donor or unrelated umbilical cord blood SCT. Future clinical trials will assess the relative risks and benefits of these two graft sources.

Long-term follow-up of peripheral blood stem cell transplantation from mismatched related and unrelated donors

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) (''alternative donors'') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.

Partially Matched, Nonmyeloablative Allogeneic Transplantation: Clinical Outcomes and Immune Reconstitution

Purpose

Allogeneic transplantation is typically limited to younger patients having a matched donor. To allow a donor to be found for nearly all patients, we have used a nonmyeloablative conditioning regimen in conjunction with stem cells from a related donor with one fully mismatched HLA haplotype.

Patients and Methods

Fludarabine, cyclophosphamide, and alemtuzumab were used as the preparatory regimen. Additional graft-versus-host disease (GVHD) prophylaxis included mycophenolate with or without cyclosporine. Patients with persistence of disease had a donor lymphocyte boost planned. Toxicities, engraftment, response, survival, and immune recovery are reported.

Results

Forty-nine patients with hematologic malignancies or marrow failure and no other available donors were enrolled. Ninety-four percent of patients had successful engraftment, and 8% had secondary graft failure. The treatment-related mortality rate was 10.2%, and 8% of patients had severe GVHD. Encouraging evidence of quantitative lymphocyte recovery through expansion of transplanted T cells was noted by 3 to 6 months. Seventy-five percent of patients attained a complete remission, and 1-year survival rate was 31% (95% CI, 18% to 44%). A standard-risk group of 19 patients with aplasia or in remission at transplantation demonstrated a 63% 1-year survival rate (95% CI, 38% to 80%) and 2.9-year median overall survival time (95% CI, 6.2 to 48 months).

Conclusion

Nonmyeloablative therapy using haploidentical family member donors is feasible because the main obstacles of GVHD and graft rejection are manageable, allowing readily available stem-cell donors to be found for nearly all patients. Further qualitative and quantitative improvement in immune recovery is needed to address the high rate of relapse and risk of severe infections.

In Vivo Alemtuzumab Enables Haploidentical Human Leukocyte Antigen-Mismatched Hematopoietic Stem-Cell Transplantation Without Ex Vivo Graft Manipulation

BACKGROUND

Alemtuzumab, a humanized monoclonal antibody directed against human CD52, has a strong lympholytic effect. This study evaluates the safety of unmanipulated peripheral blood stem-cell transplantation from two or three loci-mismatched related donors using alemtuzumab in vivo.

METHODS

A total body irradiation-based regimen was used in young patients, whereas those 50 years or older received fludarabine-based conditioning. Alemtuzumab was added to these regimens by intravenous infusion at 0.2 mg/kg per day for 6 days (days -8 to -3).

RESULTS

We treated 12 patients with a median age of 49.5 years. Eight patients demonstrated active disease, and four patients demonstrated acute leukemia in high-risk remission. All achieved neutrophil engraftment a median of 17.5 days after transplantation with complete donor-type chimerism. The cumulative incidence of grades III to IV acute graft-versus-host disease was only 9%. Infection-related deaths were not observed. CD3+/CD4+ and CD3+/CD8+ T cells were strongly suppressed within 2 months after transplantation, but recovered on day 90. Relapse was observed in five of eight patients who underwent transplantation for active disease, whereas none of the three patients who underwent transplantation in first remission had a relapse.

CONCLUSIONS

We conclude that in vivo alemtuzumab enables haploidentical hematopoietic stem-cell transplantation without ex vivo graft manipulation.

Conditioning regimen of melphalan, fludarabine and total body irradiation in unmanipulated HLA haploidentical stem cell transplantation based on feto-maternal tolerance

Unmanipulated hematopoietic stem cell transplantation from haploidentical family donors is frequently associated with graft failure and severe graft-versus-host disease (GVHD). We employed a myeloablative conditioning regimen consisting of 125 mg/m2 of fludarabine, 140 mg/m2 of melphalan and TBI of 10 to 12 Gy for three patients. The donor in each case was a haploidentical two-loci HLA mismatch mother or son. Engraftment failure was observed in one patient. In the other two patients, engraftment was confirmed within 15 days after transplantation. Acute and chronic GVHD was observed, but was controllable in both cases. HLA mismatched transplantation based on feto-maternal tolerance may provide an alternative option for patients who do not have HLA-matched donors.