Allo-hematopoietic Stem Cell Transplantation Research Articles

Analysis of the characteristics of primary acute myeloid leukemia with 11q23/KMT2A rearrangements in ninety patients

To investigate the clinical and prognostic characteristics of primary acute myeloid leukemia (AML) with 11q23/KMT2A rearrangements. Clinical data of 90 patients with primary AML and 11q23/KMT2A rearrangements were analyzed retrospectively. By karyotyping analysis, 80 of the 90 patients had translocations involving 11q23/KMT2A, with t(9;11)(p22;q23), t(6;11)(q27;q23), t(10;11)(p12;q23) and t(11;19)(q23;p13) being the most common ones, while 10 cases were found to have non-translocation abnormalities. The overall complete remission (CR) rate was 75.6%, and patients with t(6;11) had lower CR rate compared with non-t(6;11) patients (47.1% vs. 82.2%, P = 0.005). After a median follow-up of 24.5 months, the patients receiving allo-hematopoietic stem cell transplantation (allo-HSCT) had significantly higher 3-year overall survival (OS) (80.3% vs. 16.6%, P < 0.001) and 3-year event-free survival (EFS) (73.5% vs. 16.3%, P < 0.001) compared with non-transplant patients. Patients with t(6;11) had the lowest 3-year OS (11.8% vs. 56.0%, P < 0.001) and 3-year EFS (5.9% vs. 53.8%, P < 0.001) compared with other type of abnormalities. No significant difference was noted in the survival between patients with t(9;11) and non-t(9;11) regardless whether they had received HSCT. The clinical characteristics of primary AML with 11q23/KMT2A rearrangements are heterogeneous. Patients did not receive HSCT had poorer survival, particularly with the presence of t(6;11). Allo-HSCT could significantly improve the survival of such patients.

Toxic complications of high doses of treîsulfan in children: experience of the N.N. Blokhin National Medical Research Centre of Oncology, Ministry of Health of Russia

Hematopoietic stem cell transplantation (HSCT) is a treatment method for a number of severe malignant and non-tumor diseases. Autologous (auto) and allogeneic (allo) HSCT improves outcomes in patients with solid and hematological malignancies. The toxicity of conditioning regimens before HSCT is often a limiting factor for successful transplant outcomes. The most common manifestations of visceral and tissue toxicity are epithelial (dermatological and mucosal) toxicity, hepatotoxicity, and neurotoxicity. Reducing the incidence of toxic complications of preparative regimens preceding HSCT is the optimization of accompanying therapy, and and individualized selection of doses of chemotherapy. In our study, among 119 HSCT cases performed in 2021–2022, treosulfan-containing preparative regimens were used. Dermatological toxicity was diagnosed in 80.0 %, mucositis – in 100 %, hepatotoxicity – in 18.5 % of observations, no neurological toxicity was recorded.

Glycolysis-Driven IFN-γ Expression in T-Cell Via Histone Lactylation Promotes Acute Graft-Versus-Host Disease

Background Cell metabolism is a highly regulated process essential for sustaining life and driving evolution. Cellular metabolites and metabolic flux intricately govern post-translational modifications of proteins. In the context of acute graft-versus-host disease (aGVHD), T cells undergo enhanced glycolysis, resulting in increased lactate production. Consequently, lactate may act as a substrate for lysine lactylation (Kla), influencing gene expression by modulating histone biology. This study aims to assess T cell glucose metabolism during aGVHD, investigate the role of histone lactylation, and explore its impact on T cell functionality. Methods We conducted a comparative analysis of histone lactylation between aGVHD patients and individuals undergoing allo hematopoietic stem cell transplantation (control). Subsequently, we established a murine bone marrow transplant model and isolated T cells for analysis. Glucose metabolism status was assessed using extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) assays, along with the 2-NBDG glucose uptake assay. To comprehensively investigate histone lactylation in T cells, we employed the cleavage under targets and tagmentation (CUT&amp;Tag) technique to explore its regulatory effects on gene expression. To investigate the impact of lactatylation on aGVHD pathology, we constructed an aGVHD model by applying T cells with a specific deletion of LDHA. Results By analyzing the serum lactate at the onset of aGVHD, we found that patients with grade III-IV aGVHD had significantly higher lactate levels compared to those with grade I-II aGVHD ( Figure 1A). In light of this finding, we further examined the histone lactylation levels in T cells from aGVHD patients. The results demonstrated an enhanced histone lactylation in these T cells compared to controls ( Figure 1B). In the aGVHD mice, the ECAR of T cells exhibited a significant increase ( Figure 1C). Intriguingly, the OCR were also significantly higher in the aGVHD mice compared to the bone marrow T cell-depleted (BM-TCD) mice ( Figure 1D). Additionally, the 2-NBDG revealed a significantly higher fluorescence intensity in aGVHD mice ( Figure 1E). Through analysis of T cell RNA-seq data, we discovered upregulation of most glycolytic enzymes in aGVHD mice similar to human data ( Figure 1F). Notably, LDHA, glucose transporter 1 ( Slc2a1), and monocarboxylate transporter 4 ( Slc16a3) were highly upregulated ( Figure 1G). The upregulation of LDHA in T cells from aGVHD mice prompted us to investigate the presence of histone lactylation. The results revealed that histone in T cells from aGVHD mice exhibited a higher level of lactylation ( Figure 1H). Because lactylation was particularly prominent at the H4K12 site, we conducted CUT&amp;Tag experiments. We found promoters of key regulatory genes of the Th1 subset, such as Tbx21 and Ifng, along with several genes associated with IFN-γ production, including Stim2, Crtam, Il18rap, Fasl, and Phf11a, Cxcr3 were all lactylated ( Figure 1I). Specifically, the Call Peak analysis confirmed the elevated H4K12la levels on the promoters Tbx21 and Ifng ( Figure 1J). The expression of IFN-γ and CXCR3 in CD4 + and CD8 + T cells of aGVHD mice was significantly higher than in BM-TCD mice ( Figure 1K). To confirm the role of histone lactylation in IFN-γ generation, we intervened with T cells using the p300 lactylation writer inhibitor (A485). The results demonstrated a significant reduction in histone lactylation upon A485 treatment, which was effectively restored by the addition of neutral lactate sodium (Nala) ( Figure 1L). Notably, A485 treatment led to a decrease in IFN-γ + T cells, while Nala administration resulted in a substantial recovery of IFN-γ expression ( Figure 1M). Additionally, the infusion of Cd4creLdhafl/fl T cells into recipient mice improved the survival of aGVHD mice ( Figure 1N). Conclusion This study represents the first global investigation of T cell histone lactylation in aGVHD. Importantly, we have uncovered a novel link between histone lactylation and the regulation of IFN-γ-related gene expression in the context of aGVHD. Considering the heightened glycolysis and the pivotal role of IFN-γ in aGVHD pathology, it is plausible to postulate that T cell-produced lactate induces histone lactylation, thereby promoting the transcription of IFN-γ-related genes and contributing to the development of aGVHD.

Successful Incorporation of Electronic Patient Reported Outcomes Using Promis-29 into Standard of Care after Hematopoietic Stem Cell Transplant and Chimeric Antigen Receptor T Cell Therapy

Background: Cellular therapies including hematopoietic stem cell transplant (HCT) and CAR T are mainstays of treatment for hematologic malignancies, but can have significant and prolonged side effects. Patient reported outcome (PRO) measures are instruments which allow a patient to self-report symptoms to their care team and have been shown to be more comprehensive and reliable than provider assessment. Using our center's electronic platform, we aimed to integrate PRO collection into standard of care to improve the clinical experience after HCT and CAR T. Methods: Patients received the PROMIS-29 survey through the patient portal. Baseline surveys were automatically generated by a chemotherapy order, and follow-up surveys on Day 0 (infusion), weekly for the first month, monthly for the first year, and every 3 months for the second year were generated off the cell infusion order. Patients were manually censored from further surveys at time of relapse or progression of disease. Survey responses in pre-identified severe ranges prompted instructions to call the clinician's office and for the clinical team to call the patient. Results: From May 2019 to December 2022, 1025 patients underwent a cell therapy at MSK (323 allo HCT, 450 allo HCT, 228 commercial CAR T, 24 with both HCT and CAR T) with overall median age of 63 (range 20 -85), 44% female. HCT patients had leukemia (22%), myelodysplastic syndrome (10%), myeloproliferative neoplasm (3%), non-Hodgkin lymphoma (NHL, 18%), Hodgkin lymphoma (5%), plasma cell disorders (40%), or other diseases (1%); while CAR T cell patients had NHL (85%), multiple myeloma (12%), or leukemia (3%). Seventy-eight percent answered at least one survey over the two years, with response rates at baseline, Day 0, week 1, week 2, week 3, and week 4 of 51%, 27%, 26%, 26%, 29% and 29%, respectively (Figure 1). PROMIS-29 physical health summary scores at at baseline, Day 0, week 1, week 2, week 3, and week 4 were 49 [21 - 59], 45 [22 - 59], 43 [21 - 59], 41 [21 - 59], and 42 [21 - 59], respectively (Figure 2). Mental health summary scores were 51 [30 - 64], 49 [29 - 64], 48 [29 - 64], 47 [26 - 64], 48 [24-64] and 49 [30 - 64], respectively. Conclusions: We demonstrate the feasibility of incorporating patient reported outcomes into standard of care practice after HCT and CAR T cell therapy. Missing surveys were more common while inpatient, which may be due to toxicity or less use of the patient portal while admitted. Additional work is ongoing to improve the response rates at all time points. Importantly, the electronic system allowed us to capture later timepoints when patients have less frequent visits and may be followed locally. Full survey results will be presented.

Efficacy and Safety of Recombinant Thrombopoietin Combined with Immunosuppressive Therapy for Primary Treatment of Severe Aplastic Anemia: A Single-Center, Open-Label, Randomized, Clinical Trial

Standard immunosuppressive therapy (IST) combined with eltrombopag is the first-line treatment regimen for severe aplastic anemia patients who are ineligible for allo-hematopoietic stem cell transplantation (allo-HSCT). However, there was no second-generation TPO receptor agonist available in China before 2019, and only a first-generation TPO preparation was available for clinical treatment. Although rhTPO and eltrombopag act on different receptor binding sites, the differentiation pathways are similar, so rhTPO can theoretically also stimulate hematopoietic stem cells and promote hematopoietic recovery in AA. In 2015, we used rhTPO combined with IST as the first-line treatment for SAA. The results showed that the OR and quality of response in the rhTPO group were significantly higher than those in the control group. Multivariate analysis showed that the application of rhTPO was an independent prognostic factor affecting the efficacy of IST. Based on these results, we performed a single-center, randomized, open-label, parallel-controlled clinical trial to assess the hematologic response rate and long-term safety 3, 6, and 12 months after treatment. The study was conducted between 2015 and 2019 with 188 patients with primary SAA who were randomly assigned to the control or rhTPO group (95 with IST alone and 93 with rhTPO). For rhTPO, 15000 IU was administered subcutaneously starting on day 14 after p-ATG administration and then once every other day for a total of 14 injections. The median age of the 93 patients in the rhTPO group was 33 years (range 16-67). These included 58 patients with SAA and 35 patients with very severe aplastic anemia (VSAA), which were comparable to the control group. There were no significant differences in baseline clinical parameters between groups. No significant differences were observed in the overall hematologic response rates at 3, 6, and 12 months between the rhTPO and control groups (3 months: 40.9% vs 41.1%, P = 0.979; 6 months: 52.7% vs 52.6%, P = 0.994; 12 months: 65.6% vs 63.2%, P = 0.782, respectively). The median time of platelet transfusion independent was 49 (0-376) days in the rh-TPO group and 47 (0-195) days in the control group, which was not different between the two groups ( P = 0.757). The median time of RBC transfusion independence was 47 (5-404) days and 49 (0-295) days, respectively ( P = 0.592). The median follow-up time was 64 (1.3-86.2) months. The 5-year overall survival was 86.4% (95% confidence interval [CI], 77.2-92.0%) in the rh-TPO group and 84.1% (95% CI, 74.5-90.3%, P = 0.898) in the control group. The 5-year event-free survival was 51.7% (95% CI, 41.0-61.5%) and 54.1% (95% CI, 43.5-63.6%, P = 0.947) in the two groups, respectively. No significant differences were observed in the relapse rate and clonal evolution rate between the two groups (11.5% vs. 11.7%, 4.3% vs.3.2%, repectively). Subcutaneous rhTPO injection was well tolerated by patients, with no significant adverse effects other than mild localized pain at the injection site. The patients in the rhTPO group did not have concomitant thrombotic or embolic complications; moreover, reticulo-fibrillary or collagen fibrillary hyperplasia in bone marrow was not detected in any patients at three and six months after IST. Ten patients had anti-TPO antibodies at the end of TPO treatment, with no positive anti-TPO antibodies. In conclusion, our study is the only prospective randomized controlled clinical trial in China of rhTPO combined with IST for the treatment of SAA, with no difference in the hematologic response rate of the 28-day rhTPO combination regimen compared to standard IST; however, we did confirm the safety of rhTPO at this dose. Further clinical studies are required to determine the most effective dosage and duration of rhTPO treatment.

Chemotherapy Combined with Venetoclax Followed by Allo-Hematopoietic Stem Cell Transplantation for Treatment of Blastic Plasmacytoid Dendritic Cell Neoplasm

To investigate the efficacy and safety of chemotherapy combined with venetoclax followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN). The clinical data of 3 patients with BPDCN undergoing allo-HSCT in Department of Hematology, Wuhan First Hospital from July 2017 to November 2021 were collected and retrospectively analyzed. Among the 3 patients, there were 1 male and 2 females, aged 27-52 years old. Skin lesions were observed during initial diagnosis, and it could also be characterized by acute leukemia. Characteristic molecular markers of tumor cells, such as CD4, CD56, CD123, and CD303 were positive. In addition, the expression detection of Bcl-2 in 3 patients were positive. Chemotherapy combined with venetoclax in the initial induction of chemotherapy (1 case) or disease recurrence and progress (2 cases) was performed. There were 2 cases evaluated as complete remission (CR) and 1 case as partial remission (PR) before allo-HSCT. The patients all received a nonmyeloablative conditioning without total body irradiation (TBI). The prevention programme of graft-versus-host disease (GVHD) was antithymocyte globulin + mycophenolate mofetil + cyclosporin A/FK506 ± methotrexate. The number of mononuclear cell (MNC) count was (16.73-18.35)×108/kg, and CD34+ cell count was (3.57-4.65)×106/kg. The 3 patients were evaluated as CR after allo-HSCT (+21 to +28 d), the donor-recipient chimerism rate was 100%, and Ⅲ-Ⅳ GVHD was not observed. One patient died at +50 d after transplantation, two patients were followed up for 28 months and 15 months, respectively, and achieved disease-free survival (DFS). BPDCN is a highly aggressive malignant tumor with poor prognosis. Chemotherapy combined with venetoclax followed by allo-HSCT may lead to long-term DFS or even cure. Post-transplant maintenance is still unclear.

Metachromatic leukodystrophy: To screen or not to screen?

Metachromatic leukodystrophy (MLD) is a neurodegenerative lysosomal storage disorder caused by biallelic pathogenic variants in the gene encoding arylsulfatase A. Disease onset is variable (with late infantile, early and late juvenile, and adult forms) and treatment options depend on age and disease symptoms at onset. In the past, allo-hematopoietic stem cell transplantation (allo-HSCT) has been the best treatment option, following strict selection criteria. The outcome however is variable and morbidity remains high. This paved the way to the development of new treatment options, some of them aiming to be curative. In the light of this changing therapeutic field, newborn screening is becoming a valuable option. This narrative review aims to describe the outcome of allo-HSCT in the different MLD disease forms, and, in addition, reviews new treatment options. Finally, the shift of the field towards newborn screening for MLD is discussed.

Economic analysis of allogeneic hematopoietic stem cell transplantation in the Bone Marrow Transplant Center of Tunisia

ABSTRACT Introduction: New procedures and diagnostic tests in hematopoietic stem cell transplantation (HSCT) are associated with a significant increase in costs. The last cost estimate of allogeneic HSCT done in Tunisia was in 1996 and concerned only direct medical costs. Therefore, an updated cost analysis is needed. Objective: Analysis of direct costs during the first-year post-allogeneic HSCT in two groups of patients: Bone Marrow Transplant (Allo-BMT) and Peripheral Blood Stem Cell Transplant (Allo-PBSCT) and identification of factors leading to interindividual variations in costs in order to compare these costs with the budget allocated by the payer (CNAM). Methods: Pharmacoeconomic retrospective study, concerning patients who underwent allogeneic HSCT in 2013. Clinical and unit cost data were obtained from medical and administration records. Results:This study showed that the average direct cost of allogeneic HSCT in the population during the first year reached 56 638€. The average cost of Allo-BMT was 63 612€, and Allo-PBSCT was 45 966€ (p > 0.05). The initial hospitalization counted for 88% of total direct cost with an average cost of 41 441€ in Allo-BMT and 24 672€ in Allo-PBSCT (p < 0.05). Direct medical costs represented more than 70% of total direct costs, drugs, and laboratory tests occupied the largest share. Antifungals, antitumors, and antiviral drugs were the most expensive pharmaceutical classes with a mean cost, respectively, of 4 526€; 3 737€ and 3 268€. Some clinical criteria were significantly related to total direct costs like length of aplasia (p < 0.01) and GVHD (p < 0.05). However, the type of blood disease, its risk, length of mucositis, and the treatment protocol have no effect on the costs for all allogeneic patients. Conclusion: Our results showed that the costs of Allo HSCT have exceeded by far the budget allocated by the CNAM to the center, since the 90s to this day. That’s why the total reimbursement mechanism should be revised.

Non-osteopenic Bone Pathology After Allo-hematopoietic Stem Cell Transplantation in Patients with Inborn Errors of Immunity

PurposeThere is a lack of data on post-HSCT non-osteopenic bone pathology specifically for children with inborn errors of immunity (IEI). We collected data on non-osteopenic bone pathology in children with IEI post-HSCT over two decades in a large tertiary pediatric immunology center.MethodsDescriptive study with data analysis of bone pathology in allo-HSCT for IEI was performed between 1/1/2000 to 31/12/2018 including patients alive at follow-up to July 2022. Records were analyzed for bone pathology and risk factors. Exclusion criteria included isolated reduced bone density, fractures, and skeletal anomalies due to underlying IEI and short stature without other bone pathology. Bone pathologies were divided into 5 categories: bone tumors; skeletal dysplasia; avascular necrosis; evolving bone deformities; slipped upper femoral epiphysis.ResultsA total of 429 children received HSCT between 2000 and 2018; 340 are alive at last assessment. Non-osteopenic bone pathology was observed post-HSCT in 9.4% of patients (32/340, mean 7.8 years post-HSCT). Eleven patients (34%) had > 1 category of bone pathology. Seventeen patients (17/32; 53%) presented with bilateral bone pathology. The majority of patients received treosulfan-based conditioning (26/32; 81.2%). Totally, 65.6% (21/32) of patients had a history of prolonged steroid use (> 6 months). Pain was the presenting symptom in 66% of patients, and surgical intervention was required in 43.7%. The highest incidence of bone pathologies was seen in Wiskott-Aldrich syndrome (WAS) (n = 8/34; 23.5%) followed by hemophagocytic lymphohistiocytosis patients (n = 3/16; 18.8%).ConclusionNon-osteopenic bone pathology in long-term survivors of allo-HSCT for IEI is not rare. Most patients did not present with complaints until at least 5 years post-HSCT highlighting the need for ongoing bone health assessment for patients with IEI. Children presenting with stunted growth and bone pathology post-HSCT should undergo skeletal survey to rule out development of post-HSCT skeletal dysplasia. Increased rates and complexity of bone pathology were seen amongst patients with Wiskott-Aldrich syndrome.

Human herpesvirus-6 in hematopoietic stem cell transplant recipients: a prospective cohort study in Egypt

BackgroundImmunocompromised patients face reactivation of latent viruses that increase the risk of morbidity.AimThe study aimed to detect human herpes virus 6 (HHV-6) reactivation among allogeneic (allo) and autologous (auto) hematopoietic stem cell transplant (HSCT) recipients and to correlate potentially attributed clinical manifestations to HHV-6 DNA plasma level.MethodsA prospective study included all (forty) patients undergoing allo and auto-HSCT from Jan 2020 till June 2022. Plasma samples were collected for HHV-6 serology, and for HHV-6 quantitative PCR at post-transplantation weeks 2, 4, 6. Demographic and clinical data were recorded.ResultsOut of 40 peripheral blood stem cell transplant (PBSCT) recipients, 34 (85%) were HHV-6 IgG positive pre-HSCT. Of which, fourteen patients (14/34, 41.2%) showed positive HHV-6 DNaemia. HHV-6 DNAemia (15/40, 37.5%) was significantly higher among allo (8/12, 66.7%) versus auto (7/28, 25%) HSCT recipients (p = 0.030). Patients with HHV-6 DNAemia developed fever, delayed engraftment and bone marrow suppression in 6/15, 40%, thrombocytopenia (5/15, 33.3%), rash and pneumonitis (2/15, 13.3%), acute GVHD (aGVHD) (1/15, 6.7%). HHV-6 DNAemia ranged from 101 to 102,000 copies/mL. Univariate analysis identified conditioning with busulfan–cyclophosphamide as a significant risk (p = 0.043), while receiving BEAM protocol was a protective factor (p = 0.045). In multivariate analysis, receiving BEAM protocol retained significance (p = 0.040).ConclusionFrequent HHV-6 reactivation was detected after HSCT, especially in allo-HSCT recipients with clinical manifestations which could not be otherwise explained. To our best knowledge this is the first study of HHV6 reactivation in HSCT recipients from Egypt. Raising awareness for HHV-6 reactivation manifestations and screening in HSCT recipients could be lifesaving.

Pulmonary Veno-occlusive Disease that Developed Following Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia: A Case Report.

We herein report a case of pulmonary veno-occlusive disease (PVOD) induced by allo-hematopoietic stem cell transplantation (HSCT) in a 48-year-old man who was diagnosed with acute myeloid leukemia. Five months after transplantation, he developed dyspnea and was diagnosed with pulmonary hypertension based on right heart catheterization. Although he received treatment with pulmonary vasodilators, diuretics, and corticosteroids, his pulmonary artery pressure did not decrease, and his pulmonary edema worsened. Based on the clinical course, hypoxemia, diffusion impairment, and computed tomography findings, the patient was diagnosed with HSCT-related PVOD. Critical attention should be paid to dyspnea after HSCT for the early diagnosis of PVOD.

1464. Real-World (RW) Utilization Pattern of Letermovir in Adult Cytomegalovirus Seropositive Allogeneic Hematopoietic Stem Cell Transplant (HCT) Recipients: A Multicenter Retrospective Cohort Study from the European Society for Blood and Marrow Transplantation (EBMT) Registry

Abstract Background Letermovir (LET) prophylaxis in CMV seropositive (R+) allogeneic (allo) HCT recipients was approved in 2017 based on a Phase 3 randomized clinical trial (RCT) demonstrating lower rates of CMV infection, disease, and all-cause mortality among LET treated participants. While RCTs demonstrate causal effects between treatments and outcomes, RW data answer practical aspects of utilization such as time to initiation of LET and duration of use. The objective of this study was to assess LET RW utilization pattern in adult CMV R+ recipients of allo-HCT in a large cohort of multiple centers in Europe participating in the EBMT registry. Methods A retrospective observational cohort design was used to examine the RW utilization patterns of LET among CMV R+ of an allo-HCT in France, Germany &amp; Italy. Inclusion criteria were CMV R+ recipients &amp;gt;18 years who received LET for any reason between Jan 1 2018- Dec 31, 2020 and had data available for at least until 100 days post-HCT. Results In this interim analysis, 138 allo-HCT recipients (52% male) with median age 55 years (range 19-72) received LET as primary prophylaxis. Donor/recipient CMV serostatus was D+/R+ 64% D-/R+ 36%. Donor type was 65% unrelated, 20% mismatched relative, 15% sibling. Standard conditioning was used in 56% and reduced-intensity in 44%. Peripheral blood stem cells were the source in 89%. T-cell depletion was performed in 48%. All centers followed WHO standardization guidelines for CMV viral load assay by PCR. Viral load was determined at time of LET initiation in 86% patients. Oral (PO) only LET formulation was used in 98% of patients (median 2 days post HCT; LET was initiated prior to HCT in 3% of the recipients). Centers indicated that intravenous (IV) formulation was administered only if patients could not tolerate PO. The median duration of PO use was 98 days. LET dose was 240 mg (86%) mostly in patients receiving cyclosporine, 480 mg (9%) or sequentially 240/480 mg (5%). Conclusion Some differences were observed in this interim RW LET analysis compared to the phase 3 RCT. Notably, patients began LET at a median of D+2 post HCT (compared to D+9 in the trial), and 98% received only PO LET (as compared to 26.5% receiving IV LET in the trial). Further studies are needed to determine drivers of LET utilization in RW settings. Disclosures Jan Styczynski, MD, PhD, MSD: Honoraria Amit D. Raval, PhD, Merck and Co., Inc.: Employee of Merck|Merck and Co., Inc.: Stocks/Bonds Sanjay Merchant, PhD, Merck &amp; Co., Inc.: Stocks/Bonds Rafael de la Camara, MD, MSD: Honoraria.

ALL-REZ BFM 2002 Is Associated with Improved Outcome as Compared to ALL-R3 Strategy in Children with Standard Risk Isolated CNS Relapse of Acute Lymphoblastic Leukemia, while Maintaining Comparable Efficacy in Patients with Bone Marrow Relapse. Results of the Multi-National, Multi-Center Trial IntReALL SR 2010

Background: Around 15% of children with acute lymphoblastic leukemia (ALL) experience disease relapse. The prognosis of these patients largely depends on the site of recurrence, time to relapse and leukemia immunophenotype. The ALL-REZ BFM 2002 and the ALL R3 trials have proved to be effective in previous trials. The IntReALL SR 2010 trial, conducted under the umbrella of the I-BFM SG, aimed at investigating feasibility, toxicity and efficacy of both treatment strategies in a large multi-national, multi-center prospective randomized trial. Methods: Patients with a first standard-risk (SR) ALL relapse aged 1 - 17 years were recruited to the trial from 23/Oct/2014 to 31/Jul/2020 in 17 countries (210 centers). SR relapse criteria were: late (≥ 6 months after end of initial therapy) isolated bone marrow (BM) relapse, late or early (< 6 months after end of initial therapy and ≥ 18 months after initial diagnosis) combined BCP-ALL BM relapse, any late/early isolated extramedullary (IEM) relapse. They were randomized at a 1:1 rate to receive either arm A (ALL-REZ BFM 2002) or B (ALL R3). During consolidation, patients were randomized to receive the CD22-directed monoclonal antibody epratuzumab in addition to backbone chemotherapy. Results of this 2nd randomization will be communicated separately. Patients with late BM relapse were allocated to consolidation and maintenance chemotherapy or to allogeneic hematopoietic stem-cell transplantation (HSCT), depending on their minimal residual disease (MRD, cut-off arm A 10e-3 and arm B 10e-4) assessed after induction therapy. Patients with early either combined BM or IEM relapse were allocated to receive allogeneic HSCT. Results: Overall, 620 patients were randomized to receive arm A (n=304) or Arm B (n=316). Patient's characteristics were equally distributed among both groups (table 1). Induction death, 2nd remission rate, death in remission (5-years cumulative incidence (CI) 4.1 vs 7.4%, p=0.10), and subsequent relapse rates by arm A and B (CI 23.8 vs 22.8, p=0.80) did not differ between both groups. The MRD response rate with < 10e-4 post induction was significantly higher in Arm B (p=0.015), but not significantly different based on the arm specific cut-off, leading to comparable rates of allogeneic HSCT. The probability of 5-years event-free survival (pEFS) with arm A versus arm B was 70.2±3.1 SE versus 68.5±3.1 (p=0.61, figure 1) and that of overall survival (pOS) was 86.7±2.3 versus 87.1±2.0 (p=0.8). Subgroup analyses revealed a significantly higher pEFS in patients with isolated CNS relapse when treated with arm A (81.6±6.3, n=40) compared to arm B (43.3±8.3, n=45, p=0.001), whereas in patients with BM involvement or those with non-CNS IEM relapse, no significant difference was found (p=0.41). However, patients with isolated BM relapse experienced a higher CI of subsequent relapse with arm A (12.5±2.1, n=146) as compared to arm B (6.5±1.6, n=153, p=0.008). Patients with late BM relapse and MRD poor response after induction had comparable pDFS (arm A 65.8±6.4, n=74; arm B 68.8±6.2, n=75; p=0.71), which also did not differ from that of patients with MRD good response (arm A 67.7±5.6, n=100; arm B 68.9±5.6, n=113; p=0.77). Patients with late IEM relapse achieved a pEFS of 86.7±4.6 whereas those with early relapse and HSCT indication achieved a pEFS 61.8±5.4 (p=0.0004). Rates of reported severe adverse events (SAEs) per treatment phase did not differ between arms except nervous system disorders occurring more frequently in arm A (p=0.03, table 1). Conclusion: Both arm A and B were effective in this large multi-national trial. EFS and OS probabilities compare favorably to results recently published by other cooperative groups. In particular, the outcome of patients with early IEM relapse or with late BM relapse and MRD poor response is encouraging confirming the benefit of allo HSCT in these subgroups. Due to superior outcome of isolated CNS relapse with arm A, patients without BM involvement will receive that arm as backbone in future trials. Since arm B showed a better MRD response rate after induction and a lower relapse rate in patients with BM relapse, it will be implemented as backbone for future trials in patients with BM involvement. Toxicity (TRM and SAE rates) is substantial in both arms demonstrating the urgent medical need of replacing toxic chemotherapy elements with equally effective, but less toxic targeted immunotherapy strategies in future trials. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical characteristics and prognostic analysis of acute myeloid leukemia patients with PTPN11 mutations

ABSTRACT Objectives Little is known about the clinical impact of germline/somatic mutations of PTPN11 in acute leukemia. The aim of this study was to investigate the clinical characteristics and prognostic impact of PTPN11 mutations in patients with acute myeloid leukemia (AML). Methods: Seventy-four patients with PTPN11 mutation-positive AML treated at our institution were enrolled in this study. The prevalence of PTPN11 mutations was examined using targeted next-generation sequencing technology, and patients with AML and PTPN11 mutations were screened. Clinical characteristics, prognostic impact, and association between PTPN11 mutations and other mutations were analyzed retrospectively. Results: PTPN11 mutations co-occurred more commonly with DNMT3A, NPM1, and FLT3 internal tandem duplication mutations. Compared with PTPN11 wild-type (WT) patients, PTPN11 mutation-positive AML patients presented with higher white blood cell (WBC) and platelet (PLT) counts. In 74 PTPN11 positive AML patients, PTPN11 mutations had an adverse effect on overall survival (OS) (62.5%) and a negative prognostic effect on event-free survival (EFS) (50%). Allo-hematopoietic stem cell transplantation (HSCT) abrogated the negative effect of mutations in PTPN11; the OS and EFS of AML patients with PTPN11 mutations who received transplantation were longer than those of AML patients with PTPN11 mutations who did not undergo allo-HSCT (P = 0.001, EFS; P < 0.001, OS). Discussion: Newly diagnosed PTPN11 mutation-positive AML patients with high WBC and PLT counts or presenting no remission after first induction chemotherapy suffer from high mortality rates. Conclusion: Given the lack of targeted therapies for PTPN11 mutations, timely HSCT is necessary for patients.

Risk factors and survival of refractory cytomegalovirus reactivation after allogeneic peripheral blood stem cell transplantation

Refractory cytomegalovirus reactivation (RCR) after allo-hematopoietic stem cell transplantation (HSCT) is associated with poor outcomes. Current studies for the risk factors and survival of patients with post-transplantation RCR remain limited. 163 patients with Cytomegalovirus (CMV) reactivation undergoing allo-HSCT in Jiangsu Province hospital from Jan 2013 to Dec 2020 were analyzed retrospectively. Multivariate analysis revealed that highest CMV viremia>1×104copies/mL (hazard ratio [HR] 16.895, 95% confidence interval [CI] 3.394-84.109, P=0.001) and platelet count at Day 90 of more than 87.3×109/L (HR 0.381, 95% CI 0.154-0.945, P=0.037) were independent risk factors affecting RCR. As for prognosis of patients with CMV reactivation, results showed that patients with RCR had higher risk of non-relapse mortality (NRM) (39.5% vs. 22.5%, P=0.045), and RCR was an independent risk factor for NRM (HR 2.216, 95% CI 1.137-4.317, P=0.019). There was no significance between patients with or without RCR in terms of overall survival (OS) (50.7% vs. 55.6%, P=0.281) and relapse-free survival (RFS) (43.6% vs. 52.0%, P=0.179). The landmark analysis showed that patients with RCR had higher NRM (P=0.01), worse OS (P=0.02), and RFS (P =0.01) within 100 days after transplantation. Patients with hemorrhagic cystitis (40.9% vs. 64.5%, P =0.028) and who developed viremia>1×105copies/mL (43.4% vs. 58.4%, P=0.033) were associated with worse OS. Factors such as higher viral load, thrombocytopenia, and ATG used in conditioning therapy increased the incidence of RCR. Patients with RCR had worse NRM, OS, and RFS within 100 days after transplantation.

The Clinical Observation with Ruxolitinib as Graft-Versus-Host Disease Prophylaxis for Children with Thalassemia after Unrelated or Haploidentical Allo-Hematopoietic Stem Cell Transplantation

To retrospectively analyze the efficacy and safety of ruxolitinib therapy for children with thalassemia after unrelated or haploidentical stem cell transplantation. From March 2020 to March 2021, 22 patients received successfully allogeneic hematopoietic stem cell transplantation in the Zhongshan Hospital of Xiamen University, from +30 to 100 days,those patients received ruxolitinib therapy (2.5 mg, twice daily) and all adverse reactions were observed, include aGVHD, cGVHD, CMV and EBV infection. 22 patients underwent allogeneic stem cell transplantation, 5 patients were diagnosed as aGVHD, 3 patients had grade I－II skin GVHD and 2 patients had grade II intestinal GVHD, those patients were cured. All patients were followed up for more than 21 weeks, 4 cases developed cGVHD, including 3 cases of localized liver GVHD and 1 case of pulmonary GVHD, those were relieved after active treatment. 8 patients had elevated EBV copies (>3×103/ml), and 3 patients had increased CMV copies, the patients recovered after immunosuppressant and antiviral treatment. There was no CMV infection and EBV related post-transplantant lymphoproliferative disorders(PTLD), and no transplant related deaths. Ruxolitinib can effectively reduce the incidence and severity of GVHD without affecting the hematopoietic recovery, and improve the survival status of thalassemia children after transplantation.

Tear Film Immunological Profile in Patients with Ocular Graft versus Host Disease

ABSTRACT Purpose To analyze and compare the tear immunological profile in ocular GVHD (oGVHD) patients with that in non-oGVHD patients and to correlate them with ocular surface parameters based on the International Chronic Ocular GVHD Consensus Group (ICCGVHD) diagnostic criteria. Methods Tear samples from 20 individuals who underwent allo-hematopoietic stem cell transplantation and were grouped according the presence or absence of oGVHD were analyzed using Bio-Plex assay. Results IL-8 and MIP-1α levels were significantly higher in tears from oGVHD patients compared with those in tears from non-oGVHD patients (p<0.001 and p=0.001, respectively). Tear IL-8 levels correlated significantly with OSDI criteria (ρ=0.5159, p=0.001), ocular hyperemia (ρ=0.469, p=0.002), and corneal staining (ρ=0.339, p=0.032), whereas tear Mip-1α levels correlated with OSDI score (ρ=0.358, p=0.023). Conclusion We demonstrated higher tear levels of IL-8 and MIP-1α in oGVHD patients and significant correlations between theses cytokines and ocular surface parameters based on the ICCGVHDCG criteria.

Prognostic significance of IKZF1 gene deletions in patients with B-cell acute lymphoblastic leukemia

目的分析IKZF1基因缺失在急性B淋巴细胞白血病（B-ALL）患者中的预后意义。方法回顾性分析2016年3月至2019年9月南方医科大学附属南方医院收治的142例接受儿童样化疗方案的B-ALL患者的临床资料，分析IKZF1缺失患者的临床特征。无事件生存（EFS）和总生存（OS）的多因素分析使用Cox回归模型。将患者分为IKZF1缺失/单纯化疗组（A组）、IKZF1缺失/移植组（B组）、IKZF1非缺失/单纯化疗（C组）、IKZF1非缺失/移植（D组）四组比较患者生存。结果142例患者，50例（35.2％）检出IKZF1基因缺失，其中4～7号外显子缺失占44.0％；与非缺失型比较，IKZF1缺失组B-ALL患者初诊时白细胞计数升高比例更高（52.0％对28.3％，P＝0.005）、诱导治疗第14天微小残留病转阴率更低（MRD1，40.0％对70.7％，P<0.001）以及Ph染色体阳性比例更高（52.0％对21.7％，P<0.001）。单因素分析显示，IKZF1缺失组3年EFS率、OS率明显低于IKZF1非缺失组［（37.1±7.3）％对（54.7±5.4）％，P＝0.025；（51.8±7.9）％对（73.9±4.7）％，P＝0.013］；多因素分析显示IKZF1缺失是影响B-ALL患者EFS（HR＝1.744，95％CI 1.082～2.812，P＝0.022）、OS（HR＝2.036，95％CI 1.119～3.705，P＝0.020）的独立危险因素。其中，A组的3年EFS、OS、无病生存率（DFS）均明显低于其他亚组。在IKZF1缺失患者中，接受异基因造血干细胞移植（allo-HSCT）组3年OS率为（67.9±10.4）％，3年EFS率为（46.6±10.5）％，均明显高于非移植组的（31.9±11.0）％和（26.7±9.7）％（P值分别为0.005、0.026）。结论IKZF1基因缺失的B-ALL患者整体预后差，儿童样化疗方案不能完全纠正IZKF1缺失对预后的不良影响；儿童样方案联合allo-HSCT可显著改善IKZF1缺失B-ALL的整体预后。

Hematopoietic Stem Cell Transplantation in Nepal: International Partnership, Implementation Steps, and Clinical Outcomes

Blood and marrow transplantation (BMT) is rarely available in many low- to middle-income countries (LMICs). In 2012, Civil Service Hospital, a government hospital in Kathmandu, partnered with the University of Illinois at Chicago to consult on the establishment of BMT in their hospital, train staff, and promote educational activities. The implementation of BMT occurred in 3 phases over 4 years and included regular onsite visits, training of personnel in Chicago, continuous remote communication, and co-organization of educational events in Kathmandu. The Nepalese government funded the construction of a state-of-the art BMT unit and stem cell laboratory inside Civil Hospital. Autologous (auto) hematopoietic stem cell transplantation (HSCT) was started in 2016, and allogeneic (allo) HSCT from matched related donors (MRDs) or haploidentical (haplo) donors was initiated in 2017. The cost of transplantation was $5200 for auto-HSCT, $10,000 for MRD HSCT, and $13,300 for haplo HSCT. The major socioeconomic determinants reported by Nepalese BMT providers were the cost of transplantation, loss of revenue of the patient and/or caregiver, and cost of transportation. All patients (n=66) received peripheral blood stem cell grafts, and all allo-HSCT recipients were given post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis. Among recipients of auto-HSCT (n=30), with a median follow-up of 1029 days (range, 130 to 1653 days), 87% were alive, and transplantation-related mortality (TRM) was 10%. Among allo-HSCT recipients (n=36), all patients engrafted, and at a median follow-up of 204 days (range, 12 to 1131 days), 75% of them were alive (MRD, 71%; haplo, 83%), with a TRM of 19%. Only 3 of 36 patients developed acute GVHD grade II-IV. The median overall survival in auto-HSCT recipients was 1610 days and was not reached in allo-HSCT recipients. The long-lasting partnership with University of Illinois at Chicago helped build capacity and allowed the Civil Service Hospital team to establish a BMT program in Nepal that has high quality standards at an affordable cost for the majority of patients.

A Phase 1b Study of Blinatumomab Including Subcutaneous Administration in Relapsed / Refractory (R/R) Indolent Non Hodgkin's Lymphoma (NHL)

A Phase 1b Study of Blinatumomab Including Subcutaneous Administration in Relapsed / Refractory (R/R) Indolent Non Hodgkin's Lymphoma (NHL)