Post-transplant сyclophosphamide after matched donor hematopoietic stem cell transplantation in children with acute leukemia

INTRODUCTION

The data on post-transplant cyclophosphamide (PTCy) in pediatric acute leukemia after matched allo-HSCT are limited to case series. The present study aimed to assess the results of PTCy-based GVHD prophylaxis in a large cohort of children with acute leukemia after matched allo-HSCT.

METHODS

A retrospective analysis of 190 pediatric patients with acute leukemia who had a first allograft between 2008 and 2020 from a matched sibling donor (MSD) or matched unrelated donor (MUD) was carried out. In the MSD setting, GVHD prophylaxis consisted of PTCy alone (n = 28) for the study group, and calcineurin inhibitor (CNI) ± antimetabolite (n = 30) for the control group. In MUD setting, most patients in the study group received GVHD prophylaxis with PTCy+CNI+mycophenolate mofetil (n = 42, 66.7%) or PTCy+CNI+sirolimus (n = 12, 19%). All patients (n = 69) in the control group received ATG+CNI+antimetabolite.

RESULTS

After MUD allo-HSCT, the incidences of acute GVHD grade III-IV and moderate/severe chronic GVHD were significantly lower in the PTCy group compared to control (6.6% vs. 35.0% and 12.7% vs. 47.1%, respectively, p < .0001). Five-year GVHD-free, relapse-free survival (GRFS) after MUD allo-HSCT was higher in the PTCy group compared to control (35.1% vs. 7.3%, p < .0001). At the same time, there was no significant difference between both groups after MSD allo-HSCT.

CONCLUSIONS

In pediatric acute leukemia, PTCy-based GVHD prophylaxis for MUD allo-HSCT is a feasible and effective option that results in a low incidence of GVHD. Compared to the ATG-based approach, PTCy provides better control of GVHD in children. In pediatric allo-HSCT from MSD, PTCy demonstrates comparable effectiveness to conventional GVHD prophylaxis.

Trends in Outcome of Hematopoietic Stem Cell Transplantation: 5000 Transplantations and 30 Years of Single-Center Experience

In this single-center analysis, we evaluated the trends in 5185 hematopoietic cell transplantations performed between 1990 and 2022. The study group comprised 3237 allogeneic (alloHCT) and 1948 autologous (autoHCT) hematopoietic cell transplantations. In the multivariate analysis, there was an improvement in event-free-survival (EFS) after autoHCT (HR 0.6, 95% CI 0.4-0.7, p < 0.0001) due to reduced cumulative incidence of relapse in the last five years (56% in 2010-2014 vs. 38% in 2015-2022). An improvement in EFS after alloHCT over time was observed (HR 0.33, 95% CI 0.23-0.48, p < 0.0001), which was due to reduced non-relapse mortality. No difference in cumulative relapse incidence was observed over the last decade for allografted patients. Survival after autoHCT improved in Hodgkin's disease (HR 0.1, 95% CI 0.1-0.3), multiple myeloma (HR 0.4, 95% CI 0.2-0.7) and solid tumors (HR 0.2, 95% CI 0.2-0.4), while after alloHCT, improvement was observed in acute myeloid leukemia (HR 0.3, 95% CI 0.1-0.5), acute lymphoblastic leukemia (HR 0.2, 95% CI 0.1-0.5), Hodgkin's disease (HR 0.1, 95% CI 0.0-0.4), non-Hodgkin's lymphomas and chronic lymphocytic leukemia (HR 0.2, 95% CI 0.0-0.6), inborn diseases (HR 0.2, 95% CI 0.2-0.4) and acquired aplastic anemia with matched related donors and matched unrelated donors (HR 0.3, 95% CI 0.2-0.8).

[The use of allogeneic bone marrow transplantation and immunosuppressive therapy in the treatment of patients with acquired aplastic anemia]

AIM

To evaluate the efficiency of related and unrelated allogeneic bone marrow transplantation (alloBMT) versus immunosuppressive therapy (IST) in patients with aplastic anemia (AA) having no HLA-compatible bone marrow donor.

SUBJECTS AND METHODS

The study covered 61 patients (34 men and 27 women) diagnosed as having acquired AA. Of them, 51 patients were diagnosed as having severe AA, 5 had supersevere AA, and 5 had non-severe AA. Combined IST (antithymocyte globulin (ATG) + cyclosporin A (CsA)) was used in 43 patients; allo-BMT was performed in 18. The basic types of ATG (ATGAM (Pfizer), thymoglobulin (Genzim), ATG (Fresenius), and goat antilymphocyte globulin (ALG) (Research Institute of Gerontology, Ministry of Health of the Russian Federation) were administered. CsA was given in a dose of 5 mg/kg/day. The standard conditioning regimen (ATGAM + cyclophosphanum) and fludarabine-containing (fludarabine + cyclophosphanum + ATG; busulfan + fludarabine + ATG) programs were used in the allo-BMT group. A combination of CsA and metothrexate was given to prevent a graft-versus-host reaction.

RESULTS

Among the IST-receiving patients, overall survival (OS) was 71%. After the first course of IST by follow-up month 6, the response rate was 74%. The second course of IST was performed in 7 patients unresponsive after the first-line IST and in 8 patients with recurrent AA. After the second course of IST, the response rate was 46.7%. Four patients who failed to achieve remission after 2 courses of IST received its third course. A complete response was obtained in 3 patients. In 18 patients following allo-BMT (related and unrelated), OS was 86%; event-free survival was 65. In 12 patients after related allo-BMT, OS was 91.7%.

CONCLUSION

Related allo-BMT is the method of choice if there is a HLA-compatible sibling. If there are contraindications to it or no related donor, IST with ATG + CsA is indicated. Ineffective IST is an indication for unrelated allo-BMT that may be recommended as life-saving therapy for young patients under 40 years of age.

[The experience in non-relative allogenic transplantation of stem hemopoietic cells in the Clinic of Bone Marrow Transplantation at I.P. Pavlov St-Petersburg Medical Academy]

AIM

To evaluate efficacy of allogenic transplantation of hemopoietic stem cells (allo-THSC) from non-relative donor in patients with hematological diseases in the Clinic of Bone Marrow Transplantation at L.P. Pavlov St-Petersburg Medical Academy for the period 2000-2006.

MATERIAL AND METHODS

A total of 84 allo-THSC from non-relative donor to patients aged from 10 months to 65 years (median 18 months, 44 years) was carried out.

RESULTS

Six-year overall survival (OS) in all the patients was 51.4%, in remission of AML--66.7%, ALL--33%, depending on the presence or absence of acute reaction graft versus host reaction (GVHR)--54 and 50.9%, chronic FVHR--75.6 and 58.2%, blood group compatibility or incompatibility in donor/recipient pairs--58.4 and 47.9%, by gender--61.4 and 40.6%, in use of HSC of the bone marrow--58.3%, peripheral blood--26.7%. OS in the dose of transplanted CD 34+ cells per 1 kg body mass < 5.0 x 10(6)/kg--173%, in the dose 5.0--8.0 x 10(6)/kg--38.8%, > 8.0 x 10(6)/kg--35.5%. Acute GVHR developed in 56% patients, chronic--in 20%, hemorrhagic cystitis--in 27.7%, bacterial, cytomegalovirus and fungal infection--in 10, 70 and 30%, respectively. The causes of death were acute GVHR (20%), infection 99%), polyorganic failure (4%), transplant rejection (5.3%), recurrence (18.7%).

CONCLUSION

Bone marrow transplantation clinics in the Russian Federation must develop all kinds of allo-THSC--relative, non-relative and haploidentical using bone marrow, peripheral blood, umbilical blood as the source of HSC. It is necessary to create a national register of non-relative donors.

[Mobilization of peripheral blood cells for auto- and allogenic transplantations of hemopoietic cells]

AIM

To study mobilisation of peripheral blood stem cells (PBSC) via single and split subcutaneous injection of granulocytic colony-stimulating factor (G-CSF) and isolation of PBSC concentrates for their transplantation with leukapheresis (LA) and large volume leukapheresis (LVL) in patients with solid tumors and hematological diseases as well as in the group of relative donors.

MATERIAL AND METHODS

LA procedures were made on cell blood fractionator COBE Spectra. In groups 1 and 2 LVL was made with apparatus perfusion of circulating blood of the patient or donor (15-33 l) vs 7-12 l in LA by standard technique in group 3. To reduce the volume of sodium citrate solution used in LVL, to prevent citrate intoxication and hypervolemia, a sharp rise of anticoagulant/blood ration was applied.

RESULTS

PBSC-mobilisation with split doses of G-CSF and large volume leukapheresis in 23 patients and 11 relative donors vs mobilisation in 26 patients with single-daily dose of G-CSF and leukapheresis of 3 TBV has revealed that split administration of G-CSF increased the number of leukocytes and CD34+ cells more considerably.

CONCLUSION

LVL provides PBSC dose sufficient for transplantation during one procedure in the majority of donors and relative donors. This makes the method more comfortable and cost-effective.