Unconventional T Cells Influence Clinical Outcome After Allogeneic Hematopoietic Cell Transplantation.

We evaluated the impact of early recovery of mucosal-associated invariant T cells (MAIT) and gamma-delta (γδ) T cells, especially Vδ2+ T cells, on the clinical outcomes of 76 patients who underwent allogeneic hematopoietic cell transplantation (allo-HCT). MAIT cells were identified at day 20-30 post-transplant using flow cytometry and defined as CD3+ TCRVα7.2+CD161+. Two subsets of Vδ2+ T cells were analyzed according to the expression of CD26. The cytotoxicity profile of MAIT and Vδ2+ T cells was analyzed according to the intracellular expression of perforin and granzyme B, and intracellular IFN-γ was evaluated after in vitro activation. CD26+Vδ2+ T cells displayed higher intracellular levels of IFN-γ, whereas CD26- Vδ2+ T were found to be more cytotoxic. Moreover, MAIT cell frequency was correlated with the frequency of Vδ2+ T cells with a better correlation observed with Vδ2+CD26+ than with the Vδ2+CD26- T cell subset. By using the composite endpoint graft-versus-host disease (GvHD)-free, relapse-free survival (GRFS) as the primary endpoint, we found that patients with a higher MAIT cell frequency at day 20-30 after allo-HCT had a significantly increased GRFS and a better overall survival (OS) and disease-free survival (DFS). Moreover, patients with a low CD69 expression by MAIT cells had an increased cumulative incidence of grade 2-4 acute GvHD (aGvHD). These results suggest that MAIT cell reconstitution may provide mitigating effects early after allo-HCT depending on their activation markers and functional status. Patients with a high frequency of Vδ2+CD26+ T cells had a significantly higher GRFS, OS and DFS, but there was no impact on cumulative incidence of grade 2-4 aGVHD, non-relapse mortality and relapse. These results revealed that the impact of Vδ2+ T cells on the success of allo-HCT may vary according to the frequency of the CD26+ subset.

Photobiomodulation: a promising innovative approach for preventing oral mucositis in patients undergoing hematopoietic stem cell transplantation.

PURPOSE: This single-center retrospective study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, for both preventing oral mucositis (OM) and reducing its severity in the setting of hematopoietic stem cell transplantation (HCT). METHODS: Patients who underwent autologous HCT for hematological malignancies between November 2020 and October 2021 could be included. Prophylactic photobiomodulation (PBM) was used daily from day 1 of conditioning until the day of neutrophil recovery at a dose of 3 J/cm2. Curative PBM was started at a dose of 6 J/cm2 when at least one grade 1 OM had occurred. For each OM case, time of onset, National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0 grade for OM, analgesic dose, and time to resolution were reported. RESULTS: Twenty-five consecutive patients were included. The median age was 58 years (range, 39-74) and 14 (56%) were male. Twenty-one patients (84%) received a high-dose melphalan conditioning regimen for multiple myeloma, and 4 (16%) patients received BEAM conditioning for aggressive lymphoma. A total of 178 CareMin650 sessions were performed, with a median of 7 days of application (range, 4-12), with no device-related adverse events (AEs). According to the NCI-CTCAE v5.0 scale, 76% (19 of 25) of patients presented grade 0 or 1 mucositis (no ulcers), five patients (20%) developed small ulcers (grade 2), and only one patient developed grade 4 mucositis. Satisfaction rates were high among patients and users. CONCLUSION: Photobiomodulation provides excellent safety and tolerance, as well as promising efficacy, both as a preventive and curative strategy, in patients undergoing autologous HCT.

Defibrotide for Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease Prophylaxis in High-Risk Adult Patients: A Single-Center Experience Study.

Sinusoidal obstruction syndrome (SOS), also known as hepatic veno-occlusive disease (VOD), is a serious complication after hematopoietic stem cell transplantation (HSCT). SOS/VOD usually occurs within 3 weeks of HSCT, but the 2016 European Society for Blood and Marrow Transplantation diagnosis criteria have been revised to include late forms. Prophylactic use of defibrotide is recommended in the pediatric setting, but its value remains uncertain in the adult population. We report here a single-center series of 63 adult patients considered at high risk for SOS/VOD who received defibrotide prophylaxis in combination with ursodeoxycholic acid between May 2012 and August 2016. The median duration of defibrotide therapy was 23 days. Bleeding occurred in 14 patients (21.5%). Defibrotide prophylaxis was discontinued in 7 patients (10.8%): 4 cases (6.3%) due to bleeding and 3 cases (4.6%) because of the need for antithrombotic therapy. Overall, SOS/VOD occurred in 4 cases (6.3%) within 21 days after HSCT (days 13 and 14) in 2 cases and late-onset SOS/VOD (days 57 and 58) in the other 2 cases. SOS/VOD was moderate in 1 case, very severe in 3 cases, with 2 deaths related to SOS/VOD. Cumulative incidence of grades II to IV acute graft-versus-host disease and transplant-associated thrombotic microangiopathy were 22.2% and 3.2%, respectively. With a median follow-up of 31 months (range, 10.7 to 60.3), the rates of 2-year overall survival, progression-free survival, incidence of relapse, and nonrelapse mortality were 56.5%, 49%, 28.7%, and 22.3%, respectively. In our experience defibrotide prophylaxis is associated with a low incidence of SOS/VOD after allogeneic HSCT in a high-risk adult population with an acceptable safety profile.

[Mobilization and conditioning protocols actualization for autologous stem cell transplantation for autoimmune diseases: Guidelines from MATHEC-SFGM-TC]. / Actualisation des protocoles de mobilisation et conditionnement pour la pratique des autogreffes de cellules souches hématopoïétiques chez les patients atteints de maladies auto-immunes : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (MATHEC-SFGM-TC).

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 13th workshop on hematopoietic stem cell transplantation clinical practices harmonization procedures in September 2022 in Lille, France. The aim of this workshop is to update the mobilization and conditioning protocols for autologous hematopoietic stem cell transplantation for autoimmune diseases, and to specify contraindications for transplant, conditioning regimen selection, immunosuppressive treatment discontinuation before mobilization and disease-specific surveillance.

Human herpesvirus type 6 reactivation after haploidentical hematopoietic cell transplantation with post-transplant cyclophosphamide and antithymocyte globulin: risk factors and clinical impact.

Human herpesvirus type 6 (HHV6) reactivation after haploidentical hematopoietic cell transplantation (HCT) with post-transplant cyclophosphamide (PT-Cy) has been scarcely studied, especially when antithymocyte globulin (ATG) is added to the graft-versus-host disease (GvHD) prophylaxis. We conducted a retrospective cohort study in 100 consecutive patients receiving haploidentical HCT with PT-Cy. We systematically monitored HHV6 DNA loads in blood samples on a weekly basis using quantitative PCR until day +100. The 100-day cumulative incidence of HHV6 reactivation was 54%. Clinically significant HHV6 infections were rare (7%), associated with higher HHV6 DNA loads, and had favorable outcomes after antiviral therapy. The main risk factor for HHV6 reactivation was a low absolute lymphocyte count (ALC) \< 290/µL on day +30 (68% versus 40%, p = 0.003). Adding ATG to PT-Cy did not increase the incidence of HHV6 reactivation (52% with ATG versus 79% without ATG, p = 0.12). Patients experiencing HHV6 reactivation demonstrated delayed platelet recovery (HR 1.81, 95% CI 1.07-3.05, p = 0.026), higher risk of acute grade II-IV GvHD (39% versus 9%, p \< 0.001) but similar overall survival and non-relapse mortality to the other patients. In conclusion, our findings endorse the safety of combining ATG and PT-Cy in terms of the risk of HHV6 reactivation and infection in patients undergoing haploidentical HCT. Patients with a low ALC on day +30 face a higher risk of HHV6 reactivation and may require careful monitoring.

Thiotepa, busulfan and fludarabine conditioning-regimen is a promising approach for older adult patients with acute lymphoblastic leukemia treated with allogeneic stem cell transplantation.

For acute lymphoblastic leukemia (ALL) patients, total body irradiation (TBI)- based conditioning regimens are the first choice specially in young population. However, several studies have shown an equivalence in clinical outcomes with thiotepa-based conditioning regimen. We performed a retrospective study to evaluate the outcome of adult ALL patients who received allogeneic hematopoietic stem cell transplantation (allo-HCT) with a thiotepa-busulfan-fludarabine (TBF) myeloablative conditioning regimen with reduced toxicity. Fifty-five patients received a TBF regimen. The median age of the patients was 51 years (range, 17 to 72.4). Most patients had a diagnosis of B-ALL (93%) with 7% having T-ALL. Two - and 5-year overall survival was 73.2% and 64%, respectively. At 2 years, leukemia-free survival and GVHD-free, relapse-free survival were 59.5% and 57.6%, and at 5 years, 53.4% and 51.8%, respectively. The 5-year non-relapse mortality was 15%. The day 180 cumulative incidence (CI) of grade II-IV acute GVHD and grade III-IV acute GVHD were 38.2% and 5.5%, respectively. At 2 years, the CI of chronic GVHD and extensive chronic GVHD was 16.9% and 1.9%, respectively. Our study results do suggest that using TBF as the conditioning regimen in adult ALL patients is a promising option with acceptable toxicity.

Implementation and operational management of marketed chimeric antigen receptor T cell (CAR-T Cell) therapy-a guidance by the GoCART Coalition Pharmacist Working Group.

Chimeric Antigen Receptor T cells (CAR-T cells) are a type of Advanced Therapy Medicinal Product (ATMP) classified as ex-vivo (cell-based) gene therapy. CAR-T cells constitute an immunotherapy that works by enabling T cells to specifically recognise cancer cells and destroy them [1]. CAR-T cells are currently licensed to treat certain blood cancers including relapsed or refractory lymphomas, B-cell acute lymphoblastic leukaemia or multiple myeloma [2]. The indications for their use are expanding and are expected to encompass other therapeutic areas. CAR-T cells are used both in children and adults [2]. CAR-T cells are biologic drugs and are therefore more complex than traditional medicinal products. T cells collected from the patient (or donor) are sent to a Good manufacturing Practice (GMP) manufacturing facility where they are genetically modified to contain a chimeric antigen receptor (CAR). This receptor is designed to recognise and target a specific protein on cancer cells. Once manufactured, they are delivered to the hospital where they are administered to the designated patient. Hospital pharmacies are central in the process of ensuring appropriate organisational governance, operational handling, clinical suitability, and pharmacovigilance [1, 3]. The GoCART Coalition Pharmacist working group's mission was to develop standards of care to advance the field of cellular therapies in Europe. The purpose of this document is to provide practical guidance on the implementation and safe operational use of marketed CAR-T cell products within hospital pharmacies primarily throughout Europe. This document outlines the key areas where pharmaceutical expertise should focus and the key considerations for the hospital pharmacy. Countries may have different requirements and there may be variation in practice between hospitals. This document is intended as a guide and the recommendations should be adapted to meet local requirements. This document does not provide clinical information relating to the use of CAR-T cell products. The Summary of medicinal Product Characteristics (SmPC) [4, 5], and national and international clinical guidelines (where in place) should be followed for the most up-to-date clinical management of CAR-T cell patients. An example is the UK "institutional readiness documents" for pharmacy which includes detailed checklists for each stage of the pathway [6]. Spain developed the Plan of Advanced Therapies in the National Health System: CAR medicines published in November 2018 [7], the CAR-T Medicines Management Procedure of the Spanish Society of Hospital Pharmacy [8] or the Hospital pharmacist's roles and responsibilities with CAR-T medicines article published also by the Spanish Oncology group of the Spanish Society of Pharmacy [9]. This guide has been designed to support the implementation of marketed CAR-T products; however, the principles may also be applicable to clinical trials. For CAR-T cell products being used in clinical trials, additional trial regulation and clinical trial protocols must be followed. This document is divided into two sections. Section 1 outlines considerations for hospital pharmacies during the implementation of a CAR-T cell service. Section 2 outlines the key operational considerations for hospital pharmacies in the patient and product pathway.

Reduced post-transplant cyclophosphamide dose with antithymocyte globulin in peripheral blood stem cell haploidentical transplantation.

Post-transplant cyclophosphamide (PT-Cy) is effective for graft-versus-host disease (GVHD) prophylaxis, but it may cause dose-dependent toxicities, particularly in frail patients. Therefore, we compared the outcomes with a reduced PT-Cy total dose (70 mg/kg) to those with the standard PT-Cy dose (100 mg/kg) in haploidentical hematopoietic cell transplantation (HCT) patients aged ≥ 65 years and those with cardiac comorbidities. All consecutive patients with a hematological malignancy receiving peripheral blood stem cells (PBSCs) after a thiotepa-based conditioning with low-dose antithymocyte globulin were included. Thirty-three patients received PT-Cy at 70 mg/kg and 25 at 100 mg/kg. PT-Cy dose reduction did not increase the risk of GVHD and was associated with faster neutrophil and platelet recovery, and lower cumulative incidences of bacteremia (38% versus 72%, p = 0.004) and cardiac complications (12% versus 44%, p = 0.028). At 2 years, GVHD-free, relapse-free survival (GRFS) was higher with the reduced dose compared to the standard dose (60% versus 33%, p = 0.04). In conclusion, reducing PT-Cy total dose to 70 mg/kg is a safe and valid approach for elderly patients and those with cardiac comorbidities underdoing haploidentical HCT with PBSCs and low-dose antithymocyte globulin. The reduced PT-Cy dose was associated with improved hematological count recovery, lower incidence of toxicities, and higher GRFS.

Thiotepa-busulfan-fludarabine as a conditioning regimen for patients with myelofibrosis undergoing allogeneic hematopoietic transplantation: a single center experience.

We assessed the outcomes associated with thiotepa, busulfan and fludarabine (TBF) conditioning regimen in a cohort of 29 consecutive patients allografted for myelofibrosis (MF). The median age was 56 (range 42-70) years. According to the refined Dynamic International Prognostic Scoring System (DIPSS-plus), 15 (52%) patients were classified as high risk. Graft source was peripheral blood stem cells in 27 patients. Donor type was HLA-matched related (n = 5), matched unrelated (n = 16), mismatched unrelated (n = 1), and haploidentical (n = 7). All but 2 patients engrafted. The cumulative incidence (CI) of grade II-IV acute graft-versus-host disease (GVHD) was 21% (95% CI, 10-42) at day 100. The CI of chronic GVHD was 39% (95% CI, 23-65) at 3 years. The median follow-up period was 39 (range 14-60) months. Overall survival was 69% (95% CI, 50-83) at 3 years. No relapse was observed. TBF is a valid conditioning strategy in patients with MF.

Early Cardiac Toxicity Associated With Post-Transplant Cyclophosphamide in Allogeneic Stem Cell Transplantation.

BACKGROUND: Post-transplant cyclophosphamide (PT-Cy) has become a standard of care in haploidentical hematopoietic stem cell transplantation (HSCT) to reduce the risk of graft-versus-host disease. However, data on cardiac events associated with PT-Cy are scarce. OBJECTIVES: This study sought to assess the incidence and clinical features of cardiac events associated with PT-Cy. METHODS: The study compared clinical outcomes between patients who received PT-Cy (n = 136) and patients who did not (n = 195), with a focus on early cardiac events (ECE) occurring within the first 100 days after HSCT. All patients had the same systematic cardiac monitoring. RESULTS: The cumulative incidence of ECE was 19% in the PT-Cy group and 6% in the no-PT-Cy group (p < 0.001). The main ECE occurring after PT-Cy were left ventricular systolic dysfunction (13%), acute pulmonary edema (7%), pericarditis (4%), arrhythmia (3%), and acute coronary syndrome (2%). Cardiovascular risk factors were not associated with ECE. In multivariable analysis, the use of PT-Cy was associated with ECE (hazard ratio: 2.7; 95% confidence interval: 1.4 to 4.9; p = 0.002]. Older age, sequential conditioning regimen, and Cy exposure before HSCT were also associated with a higher incidence of ECE. Finally, a history of cardiac events before HSCT and ECE had a detrimental impact on overall survival. CONCLUSIONS: PT-Cy is associated with a higher incidence of ECE occurring within the first 100 days after HSCT. Patients who have a cardiac event after HSCT have lower overall survival. These results may help to improve the selection of patients who are eligible to undergo HSCT with PT-Cy, especially older adult patients and patients with previous exposure to Cy.

[Antiviral prophylaxis for CMV, HSV/VZV and HBV in allogeneic hematopoietic cell transplantation in adult patients: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Prophylaxie antivirale pour le CMV, l'HSV/VZV et le VHB après allogreffe de cellules souches hématopoïétiques chez l'adulte : recommandations de la Société francophone de greffe de mœlle et de thérapie cellulaire (SFGM-TC).

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here, we report our recommendations regarding the prophylaxis of cytomegalovirus (CMV), herpes simplex virus (HSV), varicella zoster virus (VZV) and hepatitis B virus infection after allogeneic hematopoietic cell transplantation in adult patients.

[Multidrug-resistant bacteria detection in patients undergoing allogeneic hematopoietic cell transplantation: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Dépistage des bactéries multirésistantes (BMR) et hautement résistantes émergentes (BHRe) aux antibiotiques en allogreffe de cellules souches hématopoïétiques : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organizes annual workshops in the attempt to harmonize clinical practices among different francophone transplantation centers. Here we report our recommendations regarding detection of the multidrug-resistant bacteria in hematology.

Pre-emptive rituximab treatment for Epstein-Barr virus reactivation after allogeneic hematopoietic stem cell transplantation is a worthwhile strategy in high-risk recipients: a comparative study for immune recovery and clinical outcomes.

This retrospective study evaluated the impact of a pre-emptive rituximab (RTX) strategy for Epstein-Barr virus (EBV) reactivation on immune recovery and outcomes of 219 high-risk recipients undergoing allogeneic stem cell transplantation (allo-SCT) for hematological malignancies or bone marrow failure. One-hundred and seven patients received pre-emptive RTX for EBV reactivation (RTX group) and 112 did not (control group). The median onset time of EBV reactivation was 49 days (range, 14-561), including five patients who developed post-transplant lymphoproliferative disorder (EBV-PTLD). RTX and control groups were pair-matched to assess the impact of RTX on all endpoints. In RTX patients, CD19 + B cells were significantly decreased until 1-year post-transplant, so were immunoglobulin levels. Twenty-one patients (17%) developed RTX-related neutropenia. There was, in the RTX group, a trend towards a lower cumulative incidence of chronic GvHD (P = 0.059). Overall survival, progression-free survival, non-relapse mortality, relapse incidence, and incidence of overall infections at 2 years following allo-SCT were comparable in the two groups. We conclude that pre-emptive RTX, despite inducing a delayed B-cell reconstitution and a high risk of RTX-related neutropenia, may be considered as a worthwhile treatment, given the absence of negative impact on post allo-SCT outcomes and a low incidence of EBV-PTLD.

Gemtuzumab Ozogamicin Combined With Intensive Chemotherapy in Patients With Acute Myeloid Leukemia Relapsing After Allogenic Stem Cell Transplantation.

BACKGROUND: More than one-third of patients with acute myeloid leukemia (AML) will relapse after allogenic hematopoietic cell transplant (allo-HCT). The main challenge is to overcome disease resistance to achieve a new complete remission while avoiding excessive toxicity. Gemtuzumab ozogamicin (GO), a conjugate of calicheamicin linked to the humanized monoclonal anti-CD33 antibody, has been used for refractory or relapsed AML with promising response rates, but liver toxicity of GO has long been considered a limiting factor. PATIENTS AND METHODS: We included 18 consecutive patients with AML relapsing after a first allo-HCT and treated with fractioned GO (fGO) and intensive chemotherapy. The median age was 40 years (range, 18-65). RESULTS: The overall response rate was 72% (13/18), including 7 complete remissions. No death was attributed to treatment toxicity. The main liver toxicity was transient and consisted of transaminase level elevation and hyperbilirubinemia. No cases of veno-occlusive disease were observed after the GO treatment. From the time of salvage treatment initiation, 1- and 2-year OS rates were 54% (95% confidence interval, 28%-74%) and 42% (95% confidence interval, 19%-63%), respectively. CONCLUSIONS: Our study suggests the feasibility, efficacy, and safety of an fGO-based salvage regimen combined with intensive chemotherapy in patients with CD33+ AML in the case of early relapse after an allo-HCT.

[Quality assessment of CAR T-cell activity: Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Mutualisation des outils de qualité pour les cellules CAR-T : recommandations de la Société francophone de greffe de moelle et thérapie cellulaire (SFGM-TC).

CAR T-cells are anti-cancer immunocellular therapy drugs that involve reprogramming the patient's T-cells using a transgene encoding a chimeric antigen receptor (CAR). Although CAR T-cells are cellular therapies, the organization for manufacturing and delivering these medicinal products is in many ways different from the one for hematopoietic cell grafts or donor lymphocyte infusions. The implementation of this innovative therapy is recent and requires close coordination between clinical teams, the therapeutic apheresis unit, the cell therapy unit, the pharmaceutical laboratory, and pharmacy. Apart from the regulatory texts, which are regularly modified, and the specific requirements of each pharmaceutical laboratory, there is currently no guide to help the centers initiating their activity and there is no specific indicator to assess the quality of the CAR T-cell activity in each center. The purpose of the current harmonization workshop is to clarify the regulatory prerequisites warranted for a center to have a CAR T-cell activity and to propose recommendations for implementing quality tools, in particular indicators, and allowing their sharing.

Fractionated gemtuzumab ozogamicin in association with high dose chemotherapy: a bridge to allogeneic stem cell transplantation in refractory and relapsed acute myeloid leukemia.

Optimization of the salvage regimen is required to improve prognosis in primary refractory or relapsed acute myeloid leukemia (AML). In fit patients, a bridge to allogeneic transplant is the primary purpose of salvage. We tested the combination of fractionated gemtuzumab ozogamicin with cytarabine and mitoxantrone (MYLODAM schema) with primary endpoint of efficacy and safety. We also attempted to define predictive factors for survival and response after salvage. We included 58 patients with a median age at salvage of 56 years. The overall response rate was 67%. Leukemia-free survival (LFS) and overall survival (OS) at 2 years was 36% (95% CI: 23-49) and 54% (95% CI: 39-68), respectively. Treatment-related mortality was 7%. Three veno-occlusive diseases (SOS/VOD) occurred during salvage. In the allogeneic group of 28 patients (48%), LFS and OS at 2 years was 57 % (95% CI: 36.3-77.5) and 69 % (95% CI: 49.3-88.7), respectively. Incidences of nonrelapse mortality, grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD were 16%, 40%, and 45%, respectively. A GO-based intensive regimen is a viable option for salvage therapy and a feasible schedule as a bridge to allogeneic transplant.

Thiotepa and antithymocyte globulin-based conditioning prior to haploidentical transplantation with posttransplant cyclophosphamide in high-risk hematological malignancies.

We report results of a thiotepa-based conditioning in haploidentical stem cell transplantation (haplo-SCT) with posttransplant cyclophosphamide (PT-CY) and antithymocyte globulin (ATG), for unmanipulated peripheral blood stem cell (PBSC) transplants, in 80 patients with hematological malignancies. Patients in complete remission (CR) received a thiotepa-busulfan-fludarabine (TBF) regimen, while patients with relapsed/refractory (R/R) malignancies received a sequential regimen consisting of thiotepa-etoposide-cyclophosphamide (TEC) and reduced-intensity conditioning (RIC). The median age was 52 (range, 17-72) years, 44% patients had R/R disease at transplant, and the median follow-up was 417 (range, 180-1595) days. The median days to neutrophil engraftment was 17 (range, 12-34). The cumulative incidences (CI) of acute graft-versus-host disease (GVHD) grade III to IV, severe chronic GVHD, nonrelapse mortality (NRM), and relapse were 16%, 16%, 26, and 26%, respectively. The 2-year overall survival (OS) and disease-free survival (DFS) were 53% and 47%, respectively. There were no significant differences between the patients in CR and R/R patients in terms of engraftment, GVHD, NRM, relapse, OS, or DFS. We conclude that thiotepa-based regimen with PT-CY can be modified with PBSC and ATG, still providing low toxicity, protection against GVHD, and low relapse incidence. Particularly encouraging are the results with the modification to sequential regimen in R/R patients.

Tolerability and Efficacy of Treatment With Azacytidine as Prophylactic or Preemptive Therapy for Myeloid Neoplasms After Allogeneic Stem Cell Transplantation.

INTRODUCTION/BACKGROUND: Azacytidine (AZA) has been used as a promising treatment for relapse after allogeneic transplantation. A clear benefit has been demonstrated when treating patients with a reduced disease burden, thus a prophylactic and preemptive approach to these patients has emerged. MATERIALS AND METHODS: We retrospectively analyzed patients with myeloid malignancies treated with azacytidine in the posttransplantation setting between September 2013 and April 2018 in a single tertiary care hospital. Of 32 patients analyzed, 21 were treated for prophylactic use and 11 preemptively, with a median follow-up of 20 months. Prophylactic treatment consisted of AZA at 32 mg/m2 for 5 days every 28 days, and preemptive treatment of AZA 75 mg/m2 for 5 or 7 days per cycle. In addition, 10 patients received one or more donor lymphocyte infusions (DLIs). Two patients presented with infectious complications demanding hospitalization, and 13 patients (10 in the prophylactic group and 3 in the preemptive group) presented graft-versus-host disease (GvHD). Of patients who had GvHD, 3 needed treatment discontinuation. Overall, 12 patients suspended treatment, 8 for disease progression and 1 due to patient request. RESULTS: In the prophylactic group, all patients are alive at 1 year with an event-free survival (EFS) of 95%, as only 1 patient relapsed. In the preemptive group, 1-year EFS was 54% and 1-year overall survival was 82%. CONCLUSION: Low-dose AZA in posttransplantation patients with myeloid neoplasms is a well-tolerated therapy with the potential to prevent relapse and maintain stable remissions. Randomized prospective trials are needed to determine patient selection and dosage, timing, and duration of treatment.