Patients with secondary acute myeloid leukemia undergoing allogeneic stem-cell transplant have inferior outcomes than de novo acute myeloid leukemia regardless minimal residual disease level by flow cytometry.

Secondary acute myeloid leukemia (s-AML) patients have a poor prognosis and currently the only curative therapy is allogeneic stem-cell transplant (HSCT). However, we do not yet know whether transplantation is sufficient to reverse the poor prognosis compared to de novo AML patients. We analyzed survival after HSCT comparing a cohort of 58 patients with s-AML versus 52 de novo patients who were transplanted between 2012 and 2020. Patients with s-AML had worse event-free survival (EFS) (p = 0.001) and overall survival (OS) (p < 0.001) compared to de novo AML due to an increased risk of relapse (p = 0.06) and non-relapse mortality (p = 0.03). The main difference in survival was observed in patients who achieved complete remission (CR) before HSCT (EFS p = 0.002 OS and <0.001), regardless minimal residual disease (MRD) by |multiparametric flow cytometry cohorts. In patients transplanted with active disease (AD), the prognosis was adverse in both s-AML and de novo AML groups (EFS p = 0.869 and OS p = 0.930). After excluding patients with AD, we stratified the cohort according to conditioning intensity, noticing that s-AML who received MAC had comparable outcomes to de novo AML, but the survival differences remained among reduce intensity conditioning group. In conclusion, transplanted s-AML patients have worse survival among patients in CR before HSCT, regardless of MRD level by flow cytometry compared to de novo AML. MAC patients had similar outcomes irrespective of leukemia ontogeny.

Survival after allogeneic transplantation according to pretransplant minimal residual disease and conditioning intensity in patients with acute myeloid leukemia.

Background: The measurement of minimal residual disease (MRD) by multiparametric flow cytometry (MFC) before hematopoietic stem cell transplantation (HSCT) in patients with acute myeloid leukemia (AML) is a powerful prognostic factor. The interaction of pretransplant MRD and the conditioning intensity has not yet been clarified. Objective: The aim of this study is to analyze the transplant outcomes of patients with AML who underwent HSCT in complete remission (CR), comparing patients with positive MRD (MRD+) and negative MRD (MRD-) before HSCT, and the interaction between conditioning intensity and pre-HSCT MRD. Study design: We retrospectively analyzed the transplant outcomes of 118 patients with AML who underwent HSCT in CR in a single institution, comparing patients with MRD+ and MRD- before HSCT using a cutoff of 0.1% on MFC, and the interaction between conditioning intensity and pre-HSCT MRD. Results: Patients with MRD+ before HSCT had a significantly worse 2-year (2y) event-free survival (EFS) (56.5% vs. 32.0%, p = 0.018) than MRD- patients, due to a higher cumulative incidence of relapse (CIR) at 2 years (49.0% vs. 18.0%, p = 0.002), with no differences in transplant-related mortality (TRM) (2y-TRM, 19.0% and 25.0%, respectively, p = 0.588). In the analysis stratified by conditioning intensity, in patients who received MAC, those with MRD- before HSCT had better EFS (p = 0.009) and overall survival (OS) (p = 0.070) due to lower CIR (p = 0.004) than MRD+ patients. On the other hand, the survival was similar in reduced intensity conditioning (RIC) patients regardless of the MRD status. Conclusions: Patients with MRD+ before HSCT have worse outcomes than MRD- patients. In patients who received MAC, MRD- patients have better EFS and OS due to lower CIR than MRD+ patients, probably because they represent a more chemo-sensitive group. However, among RIC patients, results were similar regardless of the MRD status.

Use of Eltrombopag to Improve Thrombocytopenia and Tranfusion Requirement in Anti-CD19 CAR-T Cell-Treated Patients.

Background/Objectives: Immune effector cell-associated hematotoxicity (ICAHT) is a frequent adverse event after chimeric antigen receptor (CAR)-T cell therapy. Grade ≥ 3 thrombocytopenia occurs in around one-third of patients, and many of them become platelet transfusion-dependent. Eltrombopag is a thrombopoietin receptor agonist (TPO-RA) able to accelerate megakaryopoiesis, which has been used successfully in patients with bone marrow failure and immune thrombocytopenia (ITP). Its role in managing thrombocytopenia and other cytopenias in CAR-T cell-treated patients has been scarcely addressed. Our aim was to report the safety and efficacy of this approach in patients included in the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC) registry. Methods: This is a retrospective, multicenter, observational study. Patients who developed platelet transfusion dependence subsequently to CAR-T cells and received eltrombopag to improve platelet counts were recruited in 10 Spanish hospitals. Results: Thirty-eight patients were enrolled and followed up for a median (interquartile range [IQR]) of 175 (99, 489) days since CAR-T cell infusion. At the moment eltrombopag was indicated, 18 patients had thrombocytopenia and another severe cytopenia, while 8 patients had severe pancytopenia. After 32 (14, 38) days on eltrombopag, 29 (76.3%) patients recovered platelet transfusion independence. The number of platelet units transfused correlated with the time needed to restore platelet counts higher than 20 × 109/L (Rho = 0.639, p < 0.001). Non-responders to eltrombopag required more platelet units (58 [29, 69] vs. 12 [6, 26] in responders, p = 0.002). Nineteen out of twenty-three (82.6%) patients recovered from severe neutropenia after 22 (11, 31) days on eltrombopag. Twenty-nine out of thirty-five (82.9%) patients recovered red blood cell (RBC) transfusion independence after 29 (17, 44) days. Seven patients recovered all cell lineages while on treatment. No thromboembolic events were reported. Only two transient toxicities (cholestasis, hyperbilirubinemia) were reported during eltrombopag treatment, none of which compelled permanent drug withdrawal. Conclusions: Eltrombopag could be safely used to manage thrombocytopenia and accelerate transfusion independence in CAR-T cell-treated patients.

Cost-effectiveness analysis of defibrotide in the treatment of patients with severe veno-occlusive disease/sinusoidal obstructive syndrome with multiorgan dysfunction following hematopoietic cell transplantation in Spain.

AIMS: This study evaluated cost-effectiveness of defibrotide vs best supportive care (BSC) for the treatment of hepatic veno-occlusive disease/sinusoidal obstructive syndrome (VOD/SOS) with multiorgan dysfunction (MOD) post-hematopoietic cell transplantation (HCT) in Spain. MATERIALS AND METHODS: A two-phase Markov model, comprising a 1-year acute phase with daily cycles and a lifetime long-term phase with annual cycles, was adapted to the Spanish setting. The model included a cohort of patients with severe VOD/SOS (defined as VOD/SOS with MOD) post-HCT. For the acute phase, efficacy and VOD/SOS-related length of stay were obtained from a phase 3 defibrotide study (NCT00358501). VOD/SOS-related hospital stays were 7.5 and 23.2 days in defibrotide-treated and BSC patients, respectively. Defibrotide-treated patients spent 30% of their stay in the intensive care unit vs 60% in BSC patients. Assumptions for the long-term phase and utility values were obtained from the literature. Costs were from the Spanish Health System perspective (€2019). Defibrotide cost was based on 25 mg/kg/day over 17.5 days, using local expert opinion. Life-years (LYs), quality-adjusted LYs (QALYs), and costs were estimated over a lifetime horizon, applying a 3% discount rate for costs and outcomes. Sensitivity analyses assessed the robustness of the results. RESULTS: Defibrotide produced an additional 1.214 QALYs and 1.348 LYs vs BSC, with a total cost of €33,708 more than BSC alone. However, defibrotide resulted in savings up to €16,644/patient for cost of hospital stay. Difference between costs and effective measures led to ratios of €27,757/QALY and €25,007/LY gained. Additional hospital stays had the greatest influence on base-case results. Probabilistic analysis confirmed the robustness of the deterministic results. LIMITATIONS: Limitations include use of historical controls and assumptions extrapolated from the literature. CONCLUSIONS: This cost-effectiveness model, adapted to the Spanish setting, showed that defibrotide is a cost-effective alternative to BSC alone in patients with severe VOD/SOS post-HCT.