Donor's age influences outcome in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide - a single center experience.

Haploidentical stem cell transplantation (haplo-SCT) using post-transplantation cyclophosphamide (post-Cy) is considered a reasonable therapeutic option for patients who lack matched donor or who urgently need transplant procedure due to high risk disease. We analyzed the results of haplo-SCT performed in years 2018-2023. Eighty one patients (46 males) at median age of 52 years underwent haplo-SCT using peripheral blood as a stem cell source in most cases. Indications included hematological malignancies (acute leukemias in 88% of cases). In 25 cases (31%) transplantation was performed in relapsed/refractory disease. Majority of patients (61%) presented with very high and high disease risk index (DRI). Conditioning regimens were as follows: nonmyeloablative - 46 cases (57%), myeloablative - in 18 (22%) and reduced intensity - 17(20%). 90% of patients engrafted. All patients received unified immunosuppressive treatment (post-Cy/TAC/MMF). Median follow-up time was 12 months The cumulative incidence of acute and chronic GVHD was 37.5% and 37.6%, respectively. Estimated 2-year overall survival (OS) was 43.1% and donor's age was the only factor influencing survival. The 2-year progression-free survival (PFS) was 42.5%, whereas relapse incidence (RI) - 35%. The cumulative incidence of non-relapse mortality (NRM) was 44% and was mostly due to infections. Haplo-SCT is a feasible treatment option for hematological patients. Younger donor improves post-transplant survival. Strategies to reduce infection-related mortality and relapse rate remain a challenge.

Real-Life Data on the Efficacy and Safety of Letermovir for Primary Prophylaxis of Cytomegalovirus in Allogeneic Hematopoietic Stem Cell Recipients: A Single-Center Analysis

Objective: Cytomegalovirus (CMV) reactivation is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). Introduction of letermovir (LMV) seems to improve post-transplant outcomes, but delayed-onset CMV reactivation still remains a challenge. In this study, we report on our first experience with LMV prophylaxis in 93 CMV-seropositive adult patients receiving HSCT in our center. Materials and Methods: We retrospectively analyzed the data of 93 adult CMV-seropositive recipients receiving LMV as CMV prophylaxis after HSCT for hematological malignancies between 2019 and 2023. The starting LMV dose was 480 mg daily, reduced to 240 mg daily for those receiving cyclosporin A co-administration. CMV DNA in the blood was measured by real-time polymerase chain reaction weekly for the first 2 months after transplantation, then every other week until the end of immunosuppressive treatment. LMV was continued to day +100 or to CMV reactivation. Results: The median recipient age at the time of transplant was 51 (range: 20-71) years. All patients received grafts from peripheral blood, mostly for acute myeloid leukemia (60%). The median time from transplantation to LMV initiation was 3 (range: 0-24) days. While 55% of patients were transplanted from matched related donors, 32% had unrelated donors and 13% underwent haploidentical HSCT. Four patients (4%) had CMV "blips" while on LMV, but the drug was continued and repeated assays were negative. Only 2 patients (2%) experienced CMV reactivation while on LMV, on days 48 and 34 after HSCT, respectively. Seven patients (7%) developed late-onset CMV reactivation after a median of 124 days after HSCT (range: 118-152 days) and they were successfully treated with ganciclovir. CMV disease was not observed. Grade III-IV acute graft-versus-host disease occurred in 6 patients (6%) during LMV treatment. LMV treatment was free of side effects. Conclusion: LMV prophylaxis was effective in preventing CMV reactivation with a favorable safety profile. CMV reactivation occurred mostly after LMV discontinuation; thus, extending the duration of prophylaxis beyond 100 days could be beneficial.

Allogeneic hematopoietic stem cell transplantation for acquired severe aplastic anemia: a summary of a 20-year experience.

INTRODUCTION: Severe aplastic anemia (SAA) is a rare but potentially fatal disorder characterized by hypocellular bone marrow and resulting in pancytopenia. It can be cured with allogeneic hematopoietic stem cell transplantation (allo­HSCT), especially in young individuals. OBJECTIVES: The main objective of the study was to assess the safety of the procedure and to identify the factors influencing long­term post­transplant outcome. PATIENTS AND METHODS: Using our institutional database, we performed a retrospective analysis of the patients with SAA allotransplanted in the years 2001-2021. RESULTS: Seventy patients (49 men) at a median age of 25 years at transplantation underwent allo­HSCT. Thirty-eight patients received immunosuppressive treatment (IST) before transplantation. Twenty-one patients received grafts from human leukocyte antigen-matched sibling, 44 from unrelated donors, and 5 from haploidentical related donors. Peripheral blood remained the source of stem cells in the majority of patients. Primary graft failure was observed in 2 cases. The incidence of acute graft­versus­host disease (GVHD) was 44%, whereas chronic GVHD was observed only in 4 patients. Median follow­up was 3 years (interquartile range, 0.45-11.5). Post­transplant outcome was comparable between patients with upfront allo­HSCT and those who relapsed after IST. In the univariable analysis, only a higher Eastern Cooperative Oncology Group (ECOG) score at transplantation and infections in the post­transplant period were found to be associated with unfavorable outcome. Fifty­three patients were alive at last contact. Most transplanted patients died due to infectious complications. A 2­year overall survival was 73%. CONCLUSIONS: The results of allo­HSCT in SAA are satisfactory and offer long­term survival and good quality of life. Higher ECOG score and the presence of infections are associated with poor post­transplant outcome.