Ablation of Wnt signaling in bone marrow stromal cells overcomes microenvironment-mediated drug resistance in acute myeloid leukemia.

The survival of leukemic cells is significantly influenced by the bone marrow microenvironment, where stromal cells play a crucial role. While there has been substantial progress in understanding the mechanisms and pathways involved in this crosstalk, limited data exist regarding the impact of leukemic cells on bone marrow stromal cells and their potential role in drug resistance. In this study, we identify that leukemic cells prime bone marrow stromal cells towards osteoblast lineage and promote drug resistance. This biased differentiation of stroma is accompanied by dysregulation of the canonical Wnt signaling pathway. Inhibition of Wnt signaling in stroma reversed the drug resistance in leukemic cells, which was further validated in leukemic mice models. This study evaluates the critical role of leukemic cells in establishing a drug-resistant niche by influencing the bone marrow stromal cells. Additionally, it highlights the potential of targeting Wnt signaling in the stroma by repurposing an anthelmintic drug to overcome the microenvironment-mediated drug resistance.

Immortalised chronic myeloid leukemia (CML) derived mesenchymal stromal cells (MSCs) line retains the immunomodulatory and chemoprotective properties of CML patient-derived MSCs.

Despite the success of Tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML), leukemic stem cells (LSCs) persist, contributing to relapse and resistance. CML Mesenchymal Stromal Cells (MSCs) help in LSC maintenance and protection from TKIs. However, the limited passage and self-differentiation abilities of primary CML MSCs hinder extensive research. To overcome this, we generated and characterized an immortalised CML patient-derived MSC (iCML MSC) line and assessed its role in LSC maintenance. We also compared the immunophenotype and differentiation potential between primary CML MSCs at diagnosis, post-treatment, and with normal bone marrow MSCs. Notably, CML MSCs exhibited enhanced chondrogenic differentiation potential compared to normal MSCs. The iCML MSC line retained the trilineage differentiation potential and was genetically stable, enabling long-term investigations. Functional studies demonstrated that iCML MSCs protected CML CD34+ cells from imatinib-induced apoptosis, recapitulating the bone marrow microenvironment-mediated resistance observed in patients. iCML MSC-conditioned media enabled CML CD34+ and AML blast cells to proliferate rapidly, with no impact on healthy donor CD34+ cells. Gene expression profiling revealed dysregulated genes associated with calcium metabolism in CML CD34+ cells cocultured with iCML MSCs, providing insights into potential therapeutic targets. Further, cytokine profiling revealed that the primary CML MSC lines abundantly secreted 25 cytokines involved in immune regulation, supporting the hypothesis that CML MSCs create an immune modulatory microenvironment that promotes growth and protects against TKIs. Our study establishes the utility of iCML MSCs as a valuable model to investigate leukemic-stromal interactions and study candidate genes involved in mediating TKI resistance in CML LSCs.

Comparison of telomere length in patients with bone marrow failure syndromes and healthy controls.

INTRODUCTION: During normal aging, telomeric DNA is gradually lost in dividing somatic cells, and critically short telomeres lead to replicative senescence, apoptosis, or chromosomal instability. We studied telomere length in bone marrow failure syndromes (BMFS) compared to normal healthy population. METHODS: Peripheral blood was collected from the participants, and genomic DNA was extracted. Relative telomere length was measured using a quantitative polymerase chain reaction. Statistical analysis was performed using SPSS and GraphPad Prism 8.2 software. RESULTS: The median age of normal Indian population was 31 (0-60) years. As expected, telomere length (TL) showed a decline with age and no difference in TL between males and females. The median age of 650 patients with aplastic anemia (AA) was 30 (1-60) years. TL was significantly shorter in patients with AA compared to healthy controls (p < .001). In FA and MDS patients, TL was significantly shorter than age-matched healthy controls (p = .028; p < .001), respectively. There was no difference between the median TL in age-matched AA and FA patients (p = .727). However, patients with MDS had shorter TL than age-matched AA (p = .031). CONCLUSION: TL in BMF syndrome patients was significantly shorter than age-matched healthy controls.

Non-surgical correction of knee flexion deformity in persons with haemophilia: A staged multidisciplinary approach.

INTRODUCTION: Flexion deformity of the knee is a common complication following recurrent haemarthrosis in persons with haemophilia (PWH) on episodic factor replacement therapy, restricting independent mobility. There is limited literature on the comprehensive management of this condition. This report provides the outcome of a staged multidisciplinary approach for the correction of knee flexion deformity (KFD) even in limited resource settings. PATIENTS AND METHODS: The data of 49 consecutive PWH who were treated for KFD were analysed. The approach included graded physical therapy (PT), followed by serial casting and/or mobilisation under anaesthesia (MUA). MUA was done in carefully selected knees. Surgical correction was opted when non-surgical methods failed. RESULTS: Of the 49 patients (55 knees), with a median KFD of 40 degrees (range: 10-90), 26/55 (47%) were corrected by graded PT. With serial casting, 9/19 (47%) knees had their KFD corrected. MUA was done for 11 knees of which five achieved correction (45%). Surgical correction was required for only seven knees (12.7%). Following this approach, KFD improved from 40 degrees (range: 10-90) to 15 degrees (range: 0-40), with only minor loss of flexion from 105 (range: 60-155) to 90 degrees (range: 30-150). Out of 55 KFD, 46 (83.6%) KFD were corrected; non-surgical, 39 (70.9%) and surgery, seven (12.7%). The remaining patients (nine KFD; 16.4%) were able to achieve their functional goal despite not meeting the correction criteria. CONCLUSION: This study shows that in PWH, functionally significant KFD correction can be achieved in about 71%, through non-surgical methods, even without prophylactic factor replacement.

Relapse and transformation to myelodysplastic syndrome and acute myeloid leukemia following immunosuppressive therapy for aplastic anemia is more common as compared to allogeneic stem cell transplantation with a negative impact on survival.

We studied the incidence of relapse, transformation to myelodysplastic syndrome/acute myeloid leukemia, and survival in patients with aplastic anemia (AA) surviving more than 1 year after ATG/ALG-based immunosuppressive therapy (IST) between 1985 and 2020. Four-hundred seventy patients (413 adults and 57 children) were studied, and data were compared with 223 patients who underwent matched sibling donor transplant (MSD HSCT). Median follow-up is 50 months (12-359). Relapse occurred in 21.9% at a median time of 33.5 months (5-228) post IST. Twenty-six (5.5%) patients progressed to PNH, while 20 (4.3%) evolved to MDS/AML. Ten-year estimated overall survival (OS) is 80.9 ± 3% and was significantly better in patients without an event (85.1 ± 4%) compared to relapse (74.6% ± 6.2%) or clonal evolution (12.8% ± 11.8%) (p = 0.024). While the severity of AA (p = 0.011) and type of ATG (p = 0.028) used predicted relapse, only age at IST administration influenced clonal evolution (p = 0.018). Among HSCT recipients, relapse rates were 4.9% with no clonal evolution, and the 10-year OS was 94.5 ± 2%. In patients who survived 1 year following IST, outcomes were good except with clonal evolution to MDS/AML. These outcomes, however, were still inferior compared to matched sibling donor HSCT.

Early detection, reactivation of cytomegalovirus DNA & immediate early (IE)-mRNA expression in hematopoietic stem cell-transplant patients.

BACKGROUND: Human cytomegalovirus (HCMV) reactivation is a major cause of morbidity and mortality among stem cell transplant recipients post-transplantation. AIM: HCMV immediate-early messenger RNA (IE-mRNA) was evaluated as marker of post-transplant HCMV reactivation in bone marrow transplant recipients. METHOD: ology: An in-house real-time reverse transcriptase PCR targeting IE-mRNA was developed to estimate HCMV mRNA levels post-transplantation. Blood samples collected in K2-EDTA tubes from patients (n = 162) admitted with Department of Clinical Hematology were transported in cold condition for routine HCMV DNA screening. For HCMV IE-mRNA quantification, peripheral blood mononuclear cells (PBMCs) were separated from whole blood and stored in RNA later at -70 °C until testing. Samples were collected weekly once for first 3 weeks post-transplantation and thereafter from week 4-12, samples were collected twice weekly. A total of 2467 samples were collected from 162 study participants. RESULTS: Thirty five patients (21.6 %) had post-transplant HCMV reactivation. Twenty five patients with complete follow-up were selected for monitoring HCMV DNA. HCMV IE-mRNA PCR was performed for 15 patients and 7(46.6 %) patients had detectable mRNA levels. HCMV IE-mRNA was detected in all patients with increasing HCMV DNA levels except for one patient in whom IE-mRNA appeared 3 days before HCMV DNA was detected. One patient had detectable HCMV IE-mRNA during declining HCMV DNA level. However the patient showed an increased HCMV DNA one week later, indicating the importance of HCMV mRNA in predicting HCMV replication. CONCLUSION: Quantification of HCMV IE-mRNA may be a valuable tool to predict progression of HCMV infection post-transplantation, with further prospective studies needed for validation.

Treosulfan Exposure Predicts Thalassemia-Free Survival in Patients with Beta Thalassemia Major Undergoing Allogeneic Hematopoietic Cell Transplantation.

A toxicity-reduced conditioning regimen with treosulfan, fludarabine, and thiotepa in patients with high-risk ß-thalassemia major has significantly improved hematopoietic stem cell transplantation (HCT) outcomes. However, complications resulting from regimen-related toxicities (RRTs), mixed chimerism, and graft rejection remain a challenge. We evaluated the dose-exposure-response relationship of treosulfan and its active metabolite S, S-EBDM, in a uniform cohort of patients with ß-thalassemia major to identify whether therapeutic drug monitoring (TDM) and dose adjustment of treosulfan is feasible. Plasma treosulfan/S, S-EBDM levels were measured in 77 patients using a validated liquid chromatography with tandem mass spectrometry method, and the pharmacokinetic parameters were estimated using nlmixr2. The influence of treosulfan and S, S-EBDM exposure, and GSTA1/NQO1 polymorphisms on graft rejection, RRTs, chimerism status, and 1-year overall survival (OS), and thalassemia-free survival (TFS) were assessed. We observed that treosulfan exposure was lower in patients with graft rejection than those without (1,655 vs. 2,037 mg•h/L, P = 0.07). Pharmacodynamic modeling analysis to identify therapeutic cutoff revealed that treosulfan exposure ≥1,660 mg•hour/L was significantly associated with better 1-year TFS (97% vs. 81%, P = 0.02) and a trend to better 1-year OS (90% vs. 69%, P = 0.07). Further, multivariate analysis adjusting for known pre-HCT risk factors also revealed treosulfan exposure <1,660 mg•h/L (hazard ratio (HR) = 3.23; 95% confidence interval (CI) = 1.12-9.34; P = 0.03) and GSTA1*B variant genotype (HR = 3.75; 95% CI = 1.04-13.47; P = 0.04) to be independent predictors for inferior 1-year TFS. We conclude that lower treosulfan exposure increases the risk of graft rejection and early transplant-related mortality affecting TFS. As no RRTs were observed with increasing treosulfan exposure, TDM-based dose adjustment could be feasible and beneficial.

Speckle tracking echocardiography-derived left ventricular global longitudinal strain in ex-thalassaemics.

AIMS: Long term survivors of haematopoietic stem cell transplantation (HSCT) for ß-thalassemia major are designated "ex-thalassaemics". Whether ex-thalassaemics continue to harbour residual myocardial dysfunction and thereby stand the risk of heart failure-related morbidity and mortality is unknown. The aim of this study was to assess the prevalence and predictors of subclinical left ventricular (LV) dysfunction in an apparently normal ex-thalassaemic population. METHODS: We conducted a single centre cross-sectional study among 62 ex-thalassaemic patients, who had undergone HSCT for ß-thalassaemia major at our centre. The primary outcome variable was LV systolic dysfunction, as assessed by 1) LV global longitudinal strain (GLS) derived by 2D speckle tracking echocardiography and 2) LV ejection fraction (EF) derived by 2D Simpsons Biplane method. RESULTS: Among the 62 patients included in the study, 7 [11.3%] were found to have LV systolic dysfunction, all of which were subclinical. Of these, 4 [6.5%] had abnormal GLS and LVEF, 2 [3.2%] had abnormal GLS with normal LVEF, and 1 [1.6%] had abnormal LVEF with low normal mean GLS. There were no statistically significant predictors of LV dysfunction in this cohort. CONCLUSION: There was a high prevalence of subclinical myocardial dysfunction in the ex-thalassaemic population reiterating the need for close follow up of these patients. 2D Speckle tracking echocardiography-derived LV global longitudinal strain is an effective tool in detecting subclinical myocardial dysfunction in this cohort.

Haploidentical Natural Killer Cell Therapy as an Adjunct to Stem Cell Transplantation for Treatment of Refractory Acute Myeloid Leukemia.

Refractory acute myeloid leukemia (AML), defined as failure of two cycles of induction therapy at diagnosis or of one cycle at relapse, represents a subgroup with poor outcomes. Haploidentical natural killer cell (NK) therapy is a strategy that is being explored in refractory malignancies. Historically, at our center, patients with refractory AML have been treated with cytoreductive therapy (fludarabine + cytosine + granulocyte colony-stimulating factor ± idarubicin or mitoxantrone + etoposide) followed by 1-week rest and then reduced-intensity transplant with fludarabine + melphalan. We used the same backbone for this trial (CTRI/2019/02/017505) with the addition of CD56-positive cells from a family donor infused 1 day after the completion of chemotherapy. CD56-positive selection was done using a CliniMACS Prodigy system (Miltenyi Biotec, Bergisch Gladbach, Germany) followed by overnight incubation in autologous plasma with 2 micromolar arsenic trioxide and 500 U/mL of interleukin-2. From February 2019, 14 patients with a median age of 29 years (interquartile range [IQR]: 16.5-38.5) were enrolled in this trial. Six were females. Six had primary refractory AML while eight had relapsed refractory AML. The median CD56-cell dose infused was 46.16 × 106/kg (IQR: 25.06-70.36). One patient withdrew consent after NK cell infusion. Of the 13 patients who proceeded to transplant, five died of immediate post-transplant complications while two did not engraft but were in morphologic leukemia-free state (both subsequently died of infective complications after the second transplant). Of the remaining six patients who engrafted and survived beyond 1 month of the transplant, two developed disease relapse and died. The remaining four patients are alive and relapse free at the last follow-up (mean follow-up duration of surviving patients is 24 months). The 2-year estimated overall survival for the cohort was 28.6% ± 12.1% while the treatment-related mortality (TRM) with this approach was 38.5% ± 13.5%. Haploidentical NK cell therapy as an adjunct to transplant is safe and needs further exploration in patients with AML. For refractory AML, post-transplant NK infusion and strategies to reduce TRM while using pre-transplant NK infusion merit exploration.

Cytogenetic profile of 1791 adult acute myeloid leukemia in India.

BACKGROUND: Cytogenetic analysis continues to have an important role in the management of acute myeloid leukemia (AML) because it is essential for prognostication. It is also necessary to diagnose specific categories of AML and to determine the most effective form of treatment. Reports from South Asia are few because the availability of cytogenetic services is relatively limited. METHODS: We performed a retrospective analysis of the cytogenetic findings in adults with AML seen consecutively in a single centre in India. The results were categorised according to the 2022 World Health Organisation (WHO), International Consensus Classification (ICC) and European LeukemiaNet (ELN) classifications. RESULTS: There were 1791 patients aged 18-85 years (median age 42, 1086 males). Normal karyotypes were seen in 646 (36%) patients. The 1145 (64%) abnormal karyotypes comprised 585 (32.7%) with recurrent genetic abnormalities (RGA), 403 (22.5%) with myelodysplasia-related cytogenetic abnormalities (MRC), and 157 (8.8%) with other abnormalities. There were 567 (31.7%) patients with solitary abnormalities and 299 (16.7%) with two abnormalities. Among the 279 (15.6%) patients with ≥ 3 abnormalities, 200 (11.2%) had complex karyotypes (CK) as per the WHO/ICC and 184 (10.3%), as per the ELN definition. There were 158 (8.8%) monosomal karyotypes (MK). Patients with normal karyotypes had a higher median age (45 years) than those with abnormal karyotypes (40 years, p < 0.001), and those with ≥ 3 abnormalities (43 years), than those with fewer abnormalities (39 years, p = 0.005). Patients with CK (WHO/ICC) and monosomal karyotypes had a median age of 48 years. Those with RGA had a lower median age (35 years, p < 0.001) than MRC (46 years) or other abnormalities (44 years). The t(15;17) was the most common abnormality (16.7%),followed by trisomy 8 (11.6%), monosomy 7/del 7q (9.3%), t(8;21) (7.2%), monosomy 5/del 5q (6.7%) and monosomy 17/del 17p (5.2%). CONCLUSION: Our findings confirm the lower age profile of AML in India and show similarities and differences with respect to the frequencies of individual abnormalities compared to the literature. The frequencies of the t(15;17), trisomy 8 and the high-risk abnormalities monosomy 7 and monosomy 5/del 5q were higher, and that of the inv(16), lower than in most reports.

Clinical significance of end of induction measurable residual disease monitoring in B-cell acute lymphoblastic leukemia: A single center experience.

The assessment of measurable residual disease (MRD) has emerged as a powerful prognostic tool for both pediatric and adult acute lymphoblastic leukemia (ALL). This retrospective study aimed to evaluate the prognostic relevance of the end of induction MRD in B-cell acute lymphoblastic leukemia (B ALL) patients. The study included 481 patients who underwent treatment for B ALL between August 2012 and March 2019 and had their MRD at the end of induction assessed by flow cytometry. Baseline demographic characteristics were collected from the patient's clinical records. Event free survival (EFS) and relapse free survival (RFS) were calculated using Kaplan-Meier analysis and survival estimates were compared using the log-rank test. End of induction MRD and baseline karyotype were the strongest predictors of EFS and RFS on multivariate analysis. The EFS was inversely related to the MRD value and the outcomes were similar in patients without morphological remission at the end of induction and patients in remission with MRD ≥1.0%. Even within the subgroups of ALL based on age, karyotype, BCR::ABL1 translocation and the treatment protocol, end of induction MRD positive patients had poor outcomes compared to patients who were MRD negative. The study outcome would help draft end of induction MRD-based treatment guidelines for the management of B ALL patients.

Phase 3 Trial of Concizumab in Hemophilia with Inhibitors.

BACKGROUND: Concizumab is an anti-tissue factor pathway inhibitor monoclonal antibody designed to achieve hemostasis in all hemophilia types, with subcutaneous administration. A previous trial of concizumab (explorer4) established proof of concept in patients with hemophilia A or B with inhibitors. METHODS: We conducted the explorer7 trial to assess the safety and efficacy of concizumab in patients with hemophilia A or B with inhibitors. Patients were randomly assigned in a 1:2 ratio to receive no prophylaxis for at least 24 weeks (group 1) or concizumab prophylaxis for at least 32 weeks (group 2) or were nonrandomly assigned to receive concizumab prophylaxis for at least 24 weeks (groups 3 and 4). After a treatment pause due to nonfatal thromboembolic events in three patients receiving concizumab, including one from the explorer7 trial, concizumab therapy was restarted with a loading dose of 1.0 mg per kilogram of body weight, followed by 0.2 mg per kilogram daily (potentially adjusted on the basis of concizumab plasma concentration as measured at week 4). The primary end-point analysis compared treated spontaneous and traumatic bleeding episodes in group 1 and group 2. Safety, patient-reported outcomes, and pharmacokinetics and pharmacodynamics were also assessed. RESULTS: Of 133 enrolled patients, 19 were randomly assigned to group 1 and 33 to group 2; the remaining 81 were assigned to groups 3 and 4. The estimated mean annualized bleeding rate in group 1 was 11.8 episodes (95% confidence interval [CI], 7.0 to 19.9), as compared with 1.7 episodes (95% CI, 1.0 to 2.9) in group 2 (rate ratio, 0.14 [95% CI, 0.07 to 0.29]; P<0.001). The overall median annualized bleeding rate for patients receiving concizumab (groups 2, 3, and 4) was 0 episodes. No thromboembolic events were reported after concizumab therapy was restarted. The plasma concentrations of concizumab remained stable over time. CONCLUSIONS: Among patients with hemophilia A or B with inhibitors, the annualized bleeding rate was lower with concizumab prophylaxis than with no prophylaxis. (Funded by Novo Nordisk; explorer7 ClinicalTrials.gov number, NCT04083781.).

Fludarabine-Based Low-Intensity Conditioning for Fanconi Anemia is Associated with Good Outcomes in Aplastic Anemia but not in MDS - a Single-Center Experience.

Background: Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with Fanconi Anemia (FA) with hematological abnormalities. Materials and Methods: This is a retrospective analysis of patients with FA who underwent a matched-related donor HSCT. Results: Sixty patients underwent 65 transplants between 1999-2021 using a fludarabine-based low-intensity conditioning regimen. The median age at transplant was 11 years (range: 3-37). Aplastic anemia (AA) was the underlying diagnosis in 55 (84.6%), while 8 (12.4%) had myelodysplastic syndrome (MDS) and 2 (3%) had acute myeloid leukemia (AML). The conditioning regimen used was Fludarabine with low-dose Cyclophosphamide for aplastic anemia and Fludarabine with low-dose Busulfan for MDS/AML. Graft versus host disease (GVHD) prophylaxis consisted of Cyclosporine and methotrexate. Peripheral blood was the predominant stem cell graft source (86.2%). Engraftment occurred in all but one patient. The median time to neutrophil and platelet engraftment was 13 days (range: 9-29) & 13 days (range: 5-31), respectively. Day 28 chimerism analysis showed complete chimerism in 75.4 % and mixed chimerism in 18.5%. Secondary graft failure was encountered in 7.7%. Grade II-IV acute GVHD occurred in 29.2%, while Grade III-IV acute GVHD occurred in 9.2%. Chronic GVHD was seen in 58.5% and was limited in most patients. The median follow-up is 55 months (range: 2-144) & the 5-year estimated overall survival (OS) is 80.2 ± 5.1%. Secondary malignancies were noted in 4 patients. The 5-year OS was significantly higher in patients undergoing HSCT for AA (86.6 + 4.7%) as compared to MDS/AML (45.7+16.6%) (p= 0.001). Conclusion: SCT using a fully matched donor provides good outcomes with low-intensity conditioning regimens in patients with FA who have aplastic marrow.

Simoctocog alfa (Nuwiq®) in previously untreated patients with severe haemophilia A-Final efficacy and safety results from the NuProtect study.

INTRODUCTION: Simoctocog alfa (Nuwiq®) is a 4th generation recombinant FVIII with proven efficacy for the prevention and treatment of bleeding episodes (BEs) in previously treated patients with severe haemophilia A. The NuProtect study assessed the immunogenicity, efficacy and safety of simoctocog alfa in 108 previously untreated patients (PUPs). The incidence of high-titre inhibitors was 16.2% and no patients with non-null F8 mutations developed inhibitors. AIM: To report the efficacy and safety results from the NuProtect study. METHODS: PUPs received simoctocog alfa for prophylaxis, treatment of BEs, or as surgical prophylaxis. The efficacy of prophylaxis (during inhibitor-free periods) was assessed using annualised bleeding rates (ABRs). The efficacy in treating BEs and in surgical prophylaxis was assessed using a 4-point scale. Adverse events were recorded throughout the study. RESULTS: Of 108 PUPs treated with simoctocog alfa, 103 received at least one prophylactic dose and 50 received continuous prophylaxis for at least 24 weeks. In patients on continuous prophylaxis, the median ABR was 0 (mean 0.5) for spontaneous BEs and 2.5 (mean 3.6) for all BEs. In 85 patients who had BEs, efficacy of BE treatment was excellent or good for 92.9% (747/804) of rated BEs; 92.3% of BEs were treated with 1 or 2 infusions. The efficacy of surgical prophylaxis was excellent or good for 94.7% (18/19) of rated procedures. There were no safety concerns and no thromboembolic events. CONCLUSION: Simoctocog alfa was efficacious and well tolerated as prophylaxis, surgical prophylaxis and for the treatment of BEs in PUPs with severe haemophilia A.

Long-term immunogenicity, efficacy and tolerability of simoctocog alfa in patients with severe haemophilia A who had completed the NuProtect study in previously untreated patients.

BACKGROUND: The NuProtect study reported data on the immunogenicity, efficacy and tolerability of simoctocog alfa (Nuwiq® ) in 108 previously untreated patients with severe haemophilia A planned to be treated for ≥100 exposure days or up to 5 years. The NuProtect-Extension study collected long-term prophylaxis data in children with severe haemophilia A. METHODS: Patients who completed the NuProtect study according to the protocol were eligible for the NuProtect-Extension study, a prospective, multinational, non-controlled, Phase 3b study. RESULTS: Of 48 patients who entered the extension study, 47 (median age 2.8 years) received prophylaxis with simoctocog alfa for a median of 24 months, with 82%-88% on a twice-weekly or less regimen. No patient developed FVIII inhibitors during the extension study. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 0 (0-0.5) for spontaneous bleeding episodes (BEs) and 1.00 (0-1.95) for all BEs. ABRs estimated using a negative binomial model were .28 (95% CI: .15, .53) for spontaneous and 1.62 (95% CI: 1.09, 2.42) for all BEs. During the median follow-up of 24 months, 34 (72%) patients had zero spontaneous BEs and 46 (98%) had zero spontaneous joint BEs. Efficacy in treating BEs was excellent or good for 78.2% of rated BEs, and efficacy of surgical prophylaxis was excellent for two rated surgeries. No treatment-related adverse events were reported. CONCLUSION: No FVIII inhibitors developed during long-term prophylaxis in the NuProtect-Extension study. Prophylaxis with simoctocog alfa was efficacious and well-tolerated, and is therefore an attractive long-term option for children with severe haemophilia A.

Profile and Predictors of Infection Following Anti-thymocyte Globulin or Anti-lymphocyte Globulin with Cyclosporine in Aplastic Anemia.

Immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG) and Cyclosporine (CSA) in aplastic anaemia (AA) results in improvement of blood counts between 3 and 6 months for the majority of patients. Infection is the most lethal complication in aplastic anemia and may arise due to several factors. We performed this study to determine the prevalence and predictors of specific infection types before and after IST. Six hundred and seventy-seven (546 adults; 434 males) transplant ineligible patients received ATG and CSA between 1995 and 2017. All patients who were transplant ineligible and received IST in this period were included. Infections before IST was seen in 209 (30.9%) and in 430 (63.5%) patients post IST. There were 700 infective episodes in the six months post-IST, including 216 bacterial, 78 fungal, 33 viral, and 373 culture-negative febrile episodes. Infections were highest (98, 77.8%) in very severe aplastic anaemia as compared to Severe AA (SAA) and Non-Severe AA (NSAA) (p < 0.001). Infections were also significantly higher in those who did not respond to ATG (71.1% vs. 56.8%, p = 0.003). At six months post-IST were 545 (80.5%) alive, and there were 54 (7.9%) deaths due to infection. Significant predictors of mortality were paediatric AA, very severe aplastic anaemia, pre or post ATG infections, and lack of response to ATG. Mortality was highest in those with combined bacterial and fungal infections post IST (p < 0.001). We conclude that infections are a common complication (63.5%) of IST. Mortality was highest when both bacterial and fungal infections were present. Routine use of growth factors and prophylactic antifungal and antibacterial agents was not part of our protocol, despite which 80.5% of the cohort was alive at the end of six months.

Modulating retinoid-X-receptor alpha (RXRA) expression sensitizes chronic myeloid leukemia cells to imatinib in vitro and reduces disease burden in vivo.

Introduction: The ligand-activated transcription factors, nuclear hormone receptors (NHRs), remain unexplored in hematological malignancies except for retinoic acid receptor alpha (RARA). Methods: Here we profiled the expression of various NHRs and their coregulators in Chronic myeloid leukemia (CML) cell lines and identified a significant differential expression pattern between inherently imatinib mesylate (IM)-sensitive and resistant cell lines. Results: Retinoid-X-receptor alpha (RXRA) was downregulated in CML cell lines inherently resistant to IM and in primary CML CD34+ cells. Pre-treatment with clinically relevant RXRA ligands improved sensitivity to IM in-vitro in both CML cell lines and primary CML cells. This combination effectively reduced the viability and colony-forming capacity of CML CD34+ cells in-vitro. In-vivo, this combination reduced leukemic burden and prolonged survival. Overexpression (OE) of RXRA inhibited proliferation and improved sensitivity to IM in-vitro. In-vivo, RXRA OE cells showed reduced engraftment of cells in the bone marrow, improved sensitivity to IM, and prolonged survival. Both RXRA OE and ligand treatment markedly reduced BCR::ABL1 downstream kinase activation, activating apoptotic cascades and improving sensitivity to IM. Importantly, RXRA OE also led to the disruption of the oxidative capacity of these cells. Conclusion: Combining IM with clinically available RXRA ligands could form an alternative treatment strategy in CML patients with suboptimal response to IM.