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Hemophilia A is a bleeding disorder resulting from deficient factor VIII (FVIII), which normally functions as a cofactor to activated factor IX (FIXa) that facilitates activation of factor X (FX). To mimic this property in a bispecific antibody format, a screening was conducted to identify functional pairs of anti-FIXa and anti-FX antibodies, followed by optimization of functional and biophysical properties. The resulting bispecific antibody (Mim8) assembled efficiently with FIXa and FX on membranes, and supported activation with an apparent equilibrium dissociation constant of 16 nM. Binding affinity with FIXa and FX in solution was much lower, with equilibrium dissociation constant values for FIXa and FX of 2.3 and 1.5 µM, respectively. In addition, the activity of Mim8 was dependent on stimulatory activity contributed by the anti-FIXa arm, which enhanced the proteolytic activity of FIXa by 4 orders of magnitude. In hemophilia A plasma and whole blood, Mim8 normalized thrombin generation and clot formation, with potencies 13 and 18 times higher than a sequence-identical analogue of emicizumab. A similar potency difference was observed in a tail vein transection model in hemophilia A mice, whereas reduction of bleeding in a severe tail-clip model was observed only for Mim8. Furthermore, the pharmacokinetic parameters of Mim8 were investigated and a half-life of 14 days shown in cynomolgus monkeys. In conclusion, Mim8 is an activated FVIII mimetic with a potent and efficacious hemostatic effect based on preclinical data.

Hemophilia A is a bleeding disorder resulting from deficient factor VIII (FVIII), which normally functions as a cofactor to activated factor IX (FIXa) that facilitates activation of factor X (FX). To mimic this property in a bispecific antibody format, a screening was conducted to identify functional pairs of anti-FIXa and anti-FX antibodies, followed by optimization of functional and biophysical properties. The resulting bispecific antibody (Mim8) assembled efficiently with FIXa and FX on membranes, and supported activation with an apparent equilibrium dissociation constant of 16 nM. Binding affinity with FIXa and FX in solution was much lower, with equilibrium dissociation constant values for FIXa and FX of 2.3 and 1.5 µM, respectively. In addition, the activity of Mim8 was dependent on stimulatory activity contributed by the anti-FIXa arm, which enhanced the proteolytic activity of FIXa by 4 orders of magnitude. In hemophilia A plasma and whole blood, Mim8 normalized thrombin generation and clot formation, with potencies 13 and 18 times higher than a sequence-identical analogue of emicizumab. A similar potency difference was observed in a tail vein transection model in hemophilia A mice, whereas reduction of bleeding in a severe tail-clip model was observed only for Mim8. Furthermore, the pharmacokinetic parameters of Mim8 were investigated and a half-life of 14 days shown in cynomolgus monkeys. In conclusion, Mim8 is an activated FVIII mimetic with a potent and efficacious hemostatic effect based on preclinical data.

Novel therapies for the treatment of acute myeloid leukemia (AML) are urgently needed, because current treatments do not cure most patients with AML. We report a domain-focused, kinome-wide CRISPR-Cas9 screening that identified protein kinase targets for the treatment of AML, which led to the identification of Rio-kinase 2 (RIOK2) as a potential novel target. Loss of RIOK2 led to a decrease in protein synthesis and to ribosomal instability followed by apoptosis in leukemic cells, but not in fibroblasts. Moreover, the ATPase function of RIOK2 was necessary for cell survival. When a small-molecule inhibitor was used, pharmacological inhibition of RIOK2 similarly led to loss of protein synthesis and apoptosis and affected leukemic cell growth in vivo. Our results provide proof of concept for targeting RIOK2 as a potential treatment of patients with AML.

Novel therapies for the treatment of acute myeloid leukemia (AML) are urgently needed, because current treatments do not cure most patients with AML. We report a domain-focused, kinome-wide CRISPR-Cas9 screening that identified protein kinase targets for the treatment of AML, which led to the identification of Rio-kinase 2 (RIOK2) as a potential novel target. Loss of RIOK2 led to a decrease in protein synthesis and to ribosomal instability followed by apoptosis in leukemic cells, but not in fibroblasts. Moreover, the ATPase function of RIOK2 was necessary for cell survival. When a small-molecule inhibitor was used, pharmacological inhibition of RIOK2 similarly led to loss of protein synthesis and apoptosis and affected leukemic cell growth in vivo. Our results provide proof of concept for targeting RIOK2 as a potential treatment of patients with AML.

Truncation of asparaginase treatment due to asparaginase-related toxicities or silent inactivation (SI) is common and may increase relapse risk in acute lymphoblastic leukemia (ALL). We investigated relapse risk following suboptimal asparaginase exposure among 1401 children aged 1 to 17 years, diagnosed with ALL between July 2008 and February 2016, treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol (including extended asparaginase exposure [1000 IU/m2 intramuscularly weeks 5-33]). Patients were included with delayed entry at their last administered asparaginase treatment, or detection of SI, and followed until relapse, death, secondary malignancy, or end of follow-up (median, 5.71 years; interquartile range, 4.02-7.64). In a multiple Cox model comparing patients with (n = 358) and without (n = 1043) truncated asparaginase treatment due to clinical toxicity, the adjusted relapse-specific hazard ratio (HR; aHR) was 1.33 (95% confidence interval [CI], 0.86-2.06; P = .20). In a substudy including only patients with information on enzyme activity (n = 1115), the 7-year cumulative incidence of relapse for the 301 patients with truncation of asparaginase treatment or SI (157 hypersensitivity, 53 pancreatitis, 14 thrombosis, 31 other, 46 SI) was 11.1% (95% CI, 6.9-15.4) vs 6.7% (95% CI, 4.7-8.6) for the 814 remaining patients. The relapse-specific aHR was 1.69 (95% CI, 1.05-2.74, P=.03). The unadjusted bone marrow relapse-specific HR was 1.83 (95% CI, 1.07-3.14, P=.03) and 1.86 (95% CI, 0.90- 3.87, P=.095) for any central nervous system relapse. These results emphasize the importance of therapeutic drug monitoring and appropriate adjustment of asparaginase therapy when feasible. This trial was registered at www.clinicaltrials.gov as #NCT03987542.

Truncation of asparaginase treatment due to asparaginase-related toxicities or silent inactivation (SI) is common and may increase relapse risk in acute lymphoblastic leukemia (ALL). We investigated relapse risk following suboptimal asparaginase exposure among 1401 children aged 1 to 17 years, diagnosed with ALL between July 2008 and February 2016, treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol (including extended asparaginase exposure [1000 IU/m2intramuscularly weeks 5-33]). Patients were included with delayed entry at their last administered asparaginase treatment, or detection of SI, and followed until relapse, death, secondary malignancy, or end of follow-up (median, 5.71 years; interquartile range, 4.02-7.64). In a multiple Cox model comparing patients with (n = 358) and without (n = 1043) truncated asparaginase treatment due to clinical toxicity, the adjusted relapse-specific hazard ratio (HR; aHR) was 1.33 (95% confidence interval [CI], 0.86-2.06; P= .20). In a substudy including only patients with information on enzyme activity (n = 1115), the 7-year cumulative incidence of relapse for the 301 patients with truncation of asparaginase treatment or SI (157 hypersensitivity, 53 pancreatitis, 14 thrombosis, 31 other, 46 SI) was 11.1% (95% CI, 6.9-15.4) vs 6.7% (95% CI, 4.7-8.6) for the 814 remaining patients. The relapse-specific aHR was 1.69 (95% CI, 1.05-2.74, P=.03). The unadjusted bone marrow relapse-specific HR was 1.83 (95% CI, 1.07-3.14, P=.03) and 1.86 (95% CI, 0.90- 3.87, P=.095) for any central nervous system relapse. These results emphasize the importance of therapeutic drug monitoring and appropriate adjustment of asparaginase therapy when feasible. This trial was registered at www.clinicaltrials.govas #NCT03987542.

Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P= 1.1 × 10−8) related to suppression of enhancer activity, whereas rs35789560 in FPGS(p.R466C, P= 5.6 × 10−9) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGSvariant was linked with increased relapse risk (P= .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.

Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P = 1.1 × 10−8) related to suppression of enhancer activity, whereas rs35789560 in FPGS (p.R466C, P = 5.6 × 10−9) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGS variant was linked with increased relapse risk (P = .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.

Adrenoleukodystrophy (ALD) is caused by mutations within the X-linked ABCD1 gene, resulting in the inability to transport acylated very long chain fatty acids (VLCFAs) into the peroxisome for degradation. VLCFAs subsequently accumulate in tissues, including the central nervous system. Up to 40% of boys develop a severe progressive demyelinating form of ALD, cerebral ALD, resulting in regions of demyelination observed on brain magnetic resonance imaging that are associated with a “garland ring” of gadolinium contrast enhancement. Gadolinium enhancement indicates blood-brain barrier (BBB) disruption and an active inflammatory disease process. Only hematopoietic cell transplant (HCT) has been shown to halt neurologic progression, although the mechanism of disease arrest is unknown. We evaluated imaging- and transplant-related biomarkers in 66 males who underwent HCT. In 77% of patients, gadolinium contrast resolved by 60 days post-HCT. We determined that time to neutrophil recovery and extent of donor chimerism correlated significantly with time to contrast resolution post-HCT. Graft failure was associated with a significantly slower rate of contrast resolution (P < .0001). Time to neutrophil recovery remained significant in multivariate analysis with other biomarkers (P = .03). Our data suggest that robust donor myeloid recovery is necessary for timely repair of the BBB.

Adrenoleukodystrophy (ALD) is caused by mutations within the X-linked ABCD1gene, resulting in the inability to transport acylated very long chain fatty acids (VLCFAs) into the peroxisome for degradation. VLCFAs subsequently accumulate in tissues, including the central nervous system. Up to 40% of boys develop a severe progressive demyelinating form of ALD, cerebral ALD, resulting in regions of demyelination observed on brain magnetic resonance imaging that are associated with a “garland ring” of gadolinium contrast enhancement. Gadolinium enhancement indicates blood-brain barrier (BBB) disruption and an active inflammatory disease process. Only hematopoietic cell transplant (HCT) has been shown to halt neurologic progression, although the mechanism of disease arrest is unknown. We evaluated imaging- and transplant-related biomarkers in 66 males who underwent HCT. In 77% of patients, gadolinium contrast resolved by 60 days post-HCT. We determined that time to neutrophil recovery and extent of donor chimerism correlated significantly with time to contrast resolution post-HCT. Graft failure was associated with a significantly slower rate of contrast resolution (P< .0001). Time to neutrophil recovery remained significant in multivariate analysis with other biomarkers (P= .03). Our data suggest that robust donor myeloid recovery is necessary for timely repair of the BBB.

Multiple myeloma (MM) patients have highly variable overallsurvival (OS) ranging from few weeks to more than ten years. Discovering an early biosignature to stratify short-term from long-term survivors offers the prospect of treating at-risk patients. Machine learning (ML) algorithms are currently being tested to discover biosignatures, but they consist of several features that make their implementation in healthcare an arduous task.

Background

Background: Genomically-targeted Diffuse Large B-cell (DLBCL) treatments for refractory or relapsing patients remain a clinical need alongside the growing success of Chimeric Antigen T-cells (CAR-T), which have ushered in durable responses in 40-70% of patients. However, recent studies have identified factors indicative of an inferior CAR-T response. Recent tumor Ecotype studies from Kotlov and Steen reveal that a Depleted or Cold tumor microenvironment (TME) is associated with poor CAR-T response. Notable features of these environments include a decreased presence of native T-cells alongside oncogenic alterations associated with their exhaustion, namely MYC and XPO1. Few precision treatments exist given the difficulty targeting MYC, but two avenues have shown recent success: inhibition of the downstream oncogene CDK9 via AZD4573 and upstream inhibition of a MYC propagator, the nuclear exportin XPO1 via Selinexor. Herein, we report the first observations of synergy between AZD4573 and Selinexor within DLBCL cell lines and data supporting that these genes may serve as accessible markers for inferior tumor immune microenvironments.

Background:Hydroxyurea (HU) is the most commonly used first-line cytoreductive treatment option for patients with myeloproliferative neoplasms (MPN) worldwide. However, increasing evidence on the efficacy and safety of pegylated interferon-alpha2 (IFNα) is emerging, and optimal first-line treatment is to be established.

Multiple Myeloma (MM) progresses from monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering MM (SMM). Despite similar primary genetic events as MM, MGUS and SMM PCs are non- or low-proliferative. Since oncogene activation and DNA damage drive senescence growth arrest to promote immune clearance of potentially malignant cells, we hypothesized that MGUS and SMM pre-malignant PCs exhibit senescence features.

Background

INTRODUCTION

Introduction

We report the international experience in outcomes after related and unrelated hematopoietic transplantation for infantile osteopetrosis in 193 patients. Thirty-four percent of transplants used grafts from HLA-matched siblings, 13% from HLA-mismatched relatives, 12% from HLA-matched, and 41% from HLA-mismatched unrelated donors. The median age at transplantation was 12 months. Busulfan and cyclophosphamide was the most common conditioning regimen. Long-term survival was higher after HLA-matched sibling compared to alternative donor transplantation. There were no differences in survival after HLA-mismatched related, HLA-matched unrelated, or mismatched unrelated donor transplantation. The 5- and 10-year probabilities of survival were 62% and 62% after HLA-matched sibling and 42% and 39% after alternative donor transplantation (P= .01 and P= .002, respectively). Graft failure was the most common cause of death, accounting for 50% of deaths after HLA-matched sibling and 43% of deaths after alternative donor transplantation. The day-28 incidence of neutrophil recovery was 66% after HLA-matched sibling and 61% after alternative donor transplantation (P= .49). The median age of surviving patients is 7 years. Of evaluable surviving patients, 70% are visually impaired; 10% have impaired hearing and gross motor delay. Nevertheless, 65% reported performance scores of 90 or 100, and in 17%, a score of 80 at last contact. Most survivors >5 years are attending mainstream or specialized schools. Rates of veno-occlusive disease and interstitial pneumonitis were high at 20%. Though allogeneic transplantation results in long-term survival with acceptable social function, strategies to lower graft failure and hepatic and pulmonary toxicity are urgently needed.

We report the international experience in outcomes after related and unrelated hematopoietic transplantation for infantile osteopetrosis in 193 patients. Thirty-four percent of transplants used grafts from HLA-matched siblings, 13% from HLA-mismatched relatives, 12% from HLA-matched, and 41% from HLA-mismatched unrelated donors. The median age at transplantation was 12 months. Busulfan and cyclophosphamide was the most common conditioning regimen. Long-term survival was higher after HLA-matched sibling compared to alternative donor transplantation. There were no differences in survival after HLA-mismatched related, HLA-matched unrelated, or mismatched unrelated donor transplantation. The 5- and 10-year probabilities of survival were 62% and 62% after HLA-matched sibling and 42% and 39% after alternative donor transplantation (P = .01 and P = .002, respectively). Graft failure was the most common cause of death, accounting for 50% of deaths after HLA-matched sibling and 43% of deaths after alternative donor transplantation. The day-28 incidence of neutrophil recovery was 66% after HLA-matched sibling and 61% after alternative donor transplantation (P = .49). The median age of surviving patients is 7 years. Of evaluable surviving patients, 70% are visually impaired; 10% have impaired hearing and gross motor delay. Nevertheless, 65% reported performance scores of 90 or 100, and in 17%, a score of 80 at last contact. Most survivors >5 years are attending mainstream or specialized schools. Rates of veno-occlusive disease and interstitial pneumonitis were high at 20%. Though allogeneic transplantation results in long-term survival with acceptable social function, strategies to lower graft failure and hepatic and pulmonary toxicity are urgently needed.

The PR-domain (PRDM) family of genes encodes transcriptional regulators, several of which are deregulated in cancer. By using a functional screening approach, we sought to identify novel tumor suppressors among the PRDMs. Here we demonstrate oncogenic collaboration between depletion of the previously uncharacterized PR-domain family member Prdm11 and overexpression of MYC. Overexpression of PRDM11 inhibits proliferation and induces apoptosis. Prdm11 knockout mice are viable, and loss of Prdm11 accelerates MYC-driven lymphomagenesis in the Eµ-Myc mouse model. Moreover, we show that patients with PRDM11-deficient diffuse large B-cell lymphomas (DLBCLs) have poorer overall survival and belong to the nongerminal center B-cell–like subtype. Mechanistically, genome-wide mapping of PRDM11 binding sites coupled with transcriptome sequencing in human DLBCL cells evidenced that PRDM11 associates with transcriptional start sites of target genes and regulates important oncogenes such as FOS and JUN. Hence, we characterize PRDM11 as a putative novel tumor suppressor that controls the expression of key oncogenes, and we add new mechanistic insight into B-cell lymphomagenesis.

The PR-domain (PRDM) family of genes encodes transcriptional regulators, several of which are deregulated in cancer. By using a functional screening approach, we sought to identify novel tumor suppressors among the PRDMs. Here we demonstrate oncogenic collaboration between depletion of the previously uncharacterized PR-domain family member Prdm11and overexpression of MYC. Overexpression of PRDM11 inhibits proliferation and induces apoptosis. Prdm11knockout mice are viable, and loss of Prdm11accelerates MYC-driven lymphomagenesis in the Eµ-Mycmouse model. Moreover, we show that patients with PRDM11-deficient diffuse large B-cell lymphomas (DLBCLs) have poorer overall survival and belong to the nongerminal center B-cell–like subtype. Mechanistically, genome-wide mapping of PRDM11 binding sites coupled with transcriptome sequencing in human DLBCL cells evidenced that PRDM11 associates with transcriptional start sites of target genes and regulates important oncogenes such as FOSand JUN.Hence, we characterize PRDM11 as a putative novel tumor suppressor that controls the expression of key oncogenes, and we add new mechanistic insight into B-cell lymphomagenesis.