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•Caplacizumab with immunosuppression, but without additional TPE, is an effective and safe treatment strategy for acute iTTP.

Neutrophils are key players during host defense and sterile inflammation. Neutrophil dysfunction is a characteristic feature of the acquired immunodeficiency during kidney disease. We speculated that the impaired renal clearance of the intrinsic purine metabolite soluble uric acid (sUA) may account for neutrophil dysfunction. Indeed, hyperuricemia (HU, serum UA of 9-12 mg/dL) related or unrelated to kidney dysfunction significantly diminished neutrophil adhesion and extravasation in mice with crystal- and coronavirus-related sterile inflammation using intravital microscopy and an air pouch model. This impaired neutrophil recruitment was partially reversible by depleting UA with rasburicase. We validated these findings in vitro using either neutrophils or serum from patients with kidney dysfunction–related HU with or without UA depletion, which partially normalized the defective migration of neutrophils. Mechanistically, sUA impaired β2 integrin activity and internalization/recycling by regulating intracellular pH and cytoskeletal dynamics, physiological processes that are known to alter the migratory and phagocytic capability of neutrophils. This effect was fully reversible by blocking intracellular uptake of sUA via urate transporters. In contrast, sUA had no effect on neutrophil extracellular trap formation in neutrophils from healthy subjects or patients with kidney dysfunction. Our results identify an unexpected immunoregulatory role of the intrinsic purine metabolite sUA, which contrasts the well-known immunostimulatory effects of crystalline UA. Specifically targeting UA may help to overcome certain forms of immunodeficiency, for example in kidney dysfunction, but may enhance sterile forms of inflammation.

Biallelic mutations of the CEBPA gene (CEBPAbi) define a distinct entity associated with favorable prognosis; however, the role of monoallelic mutations (CEBPAsm) is poorly understood. We retrospectively analyzed 4708 adults with acute myeloid leukemia (AML) who had been recruited into the Study Alliance Leukemia trials, to investigate the prognostic impact of CEBPAsm. CEBPA mutations were identified in 240 patients (5.1%): 131 CEBPAbi and 109 CEBPAsm (60 affecting the N-terminal transactivation domains [CEBPAsmTAD] and 49 the C-terminal DNA-binding or basic leucine zipper region [CEBPAsmbZIP]). Interestingly, patients carrying CEBPAbi or CEBPAsmbZIP shared several clinical factors: they were significantly younger (median, 46 and 50 years, respectively) and had higher white blood cell (WBC) counts at diagnosis (median, 23.7 × 109/L and 35.7 × 109/L) than patients with CEBPAsmTAD (median age, 63 years, median WBC 13.1 × 109/L; P < .001). Co-mutations were similar in both groups: GATA2 mutations (35.1% CEBPAbi; 36.7% CEBPAsmbZIP vs 6.7% CEBPAsmTAD; P < .001) or NPM1 mutations (3.1% CEBPAbi; 8.2% CEBPAsmbZIP vs 38.3% CEBPAsmTAD; P < .001). CEBPAbi and CEBPAsmbZIP, but not CEBPAsmTAD were associated with significantly improved overall (OS; median 103 and 63 vs 13 months) and event-free survival (EFS; median, 20.7 and 17.1 months vs 5.7 months), in univariate and multivariable analyses. Additional analyses revealed that the clinical and molecular features as well as the favorable survival were confined to patients with in-frame mutations in bZIP (CEBPAbZIP-inf). When patients were classified according to CEBPAbZIP-inf and CEBPAother (including CEBPAsmTAD and non-CEBPAbZIP-inf), only patients bearing CEBPAbZIP-inf showed superior complete remission rates and the longest median OS and EFS, arguing for a previously undefined prognostic role of this type of mutation.

Biallelic mutations of the CEBPAgene (CEBPAbi) define a distinct entity associated with favorable prognosis; however, the role of monoallelic mutations (CEBPAsm) is poorly understood. We retrospectively analyzed 4708 adults with acute myeloid leukemia (AML) who had been recruited into the Study Alliance Leukemia trials, to investigate the prognostic impact of CEBPAsm. CEBPAmutations were identified in 240 patients (5.1%): 131 CEBPAbiand 109 CEBPAsm(60 affecting the N-terminal transactivation domains [CEBPAsmTAD] and 49 the C-terminal DNA-binding or basic leucine zipper region [CEBPAsmbZIP]). Interestingly, patients carrying CEBPAbior CEBPAsmbZIPshared several clinical factors: they were significantly younger (median, 46 and 50 years, respectively) and had higher white blood cell (WBC) counts at diagnosis (median, 23.7 × 109/L and 35.7 × 109/L) than patients with CEBPAsmTAD(median age, 63 years, median WBC 13.1 × 109/L; P< .001). Co-mutations were similar in both groups: GATA2mutations (35.1% CEBPAbi; 36.7% CEBPAsmbZIPvs 6.7% CEBPAsmTAD; P< .001) or NPM1mutations (3.1% CEBPAbi; 8.2% CEBPAsmbZIPvs 38.3% CEBPAsmTAD; P< .001). CEBPAbiand CEBPAsmbZIP, but not CEBPAsmTADwere associated with significantly improved overall (OS; median 103 and 63 vs 13 months) and event-free survival (EFS; median, 20.7 and 17.1 months vs 5.7 months), in univariate and multivariable analyses. Additional analyses revealed that the clinical and molecular features as well as the favorable survival were confined to patients with in-frame mutations in bZIP (CEBPAbZIP-inf). When patients were classified according to CEBPAbZIP-infand CEBPAother(including CEBPAsmTADand non-CEBPAbZIP-inf), only patients bearing CEBPAbZIP-infshowed superior complete remission rates and the longest median OS and EFS, arguing for a previously undefined prognostic role of this type of mutation.

Chronic lymphocytic leukemia (CLL) remains incurable despite B-cell receptor–targeted inhibitors revolutionizing treatment. This suggests that other signaling molecules are involved in disease escape mechanisms and resistance. Toll-like receptor 9 (TLR9) is a promising candidate that is activated by unmethylated cytosine guanine dinucleotide–DNA. Here, we show that plasma from patients with CLL contains significantly more unmethylated DNA than plasma from healthy control subjects (P < .0001) and that cell-free DNA levels correlate with the prognostic markers CD38, β2-microglobulin, and lymphocyte doubling time. Furthermore, elevated cell-free DNA was associated with shorter time to first treatment (hazard ratio, 4.0; P = .003). We also show that TLR9 expression was associated with in vitro CLL cell migration (P < .001), and intracellular endosomal TLR9 strongly correlated with aberrant surface expression (sTLR9; r = 0.9). In addition, lymph node–derived CLL cells exhibited increased sTLR9 (P = .016), and RNA-sequencing of paired sTLR9hi and sTLR9lo CLL cells revealed differential transcription of genes involved in TLR signaling, adhesion, motility, and inflammation in sTLR9hi cells. Mechanistically, a TLR9 agonist, ODN2006, promoted CLL cell migration (P < .001) that was mediated by p65 NF-κB and STAT3 transcription factor activation. Importantly, autologous plasma induced the same effects, which were reversed by a TLR9 antagonist. Furthermore, high TLR9 expression promoted engraftment and rapid disease progression in a NOD/Shi-scid/IL-2Rγnull mouse xenograft model. Finally, we showed that dual targeting of TLR9 and Bruton’s tyrosine kinase (BTK) was strongly synergistic (median combination index, 0.2 at half maximal effective dose), which highlights the distinct role for TLR9 signaling in CLL and the potential for combined targeting of TLR9 and BTK as a more effective treatment strategy in this incurable disease.

Wiskott-Aldrich syndrome (WAS) is an X-linked disease caused by mutations in the WAS gene, leading to thrombocytopenia, eczema, recurrent infections, autoimmune disease, and malignancy. Hematopoietic cell transplantation (HCT) is the primary curative approach, with the goal of correcting the underlying immunodeficiency and thrombocytopenia. HCT outcomes have improved over time, particularly for patients with HLA-matched sibling and unrelated donors. We report the outcomes of 129 patients with WAS who underwent HCT at 29 Primary Immune Deficiency Treatment Consortium centers from 2005 through 2015. Median age at HCT was 1.2 years. Most patients (65%) received myeloablative busulfan-based conditioning. With a median follow-up of 4.5 years, the 5-year overall survival (OS) was 91%. Superior 5-year OS was observed in patients <5 vs ≥5 years of age at the time of HCT (94% vs 66%; overall P = .0008). OS was excellent regardless of donor type, even in cord blood recipients (90%). Conditioning intensity did not affect OS, but was associated with donor T-cell and myeloid engraftment after HCT. Specifically, patients who received fludarabine/melphalan-based reduced-intensity regimens were more likely to have donor myeloid chimerism <50% early after HCT. In addition, higher platelet counts were observed among recipients who achieved full (>95%) vs low-level (5%-49%) donor myeloid engraftment. In summary, HCT outcomes for WAS have improved since 2005, compared with prior reports. HCT at a younger age continues to be associated with superior outcomes supporting the recommendation for early HCT. High-level donor myeloid engraftment is important for platelet reconstitution after either myeloablative or busulfan-containing reduced intensity conditioning. (This trial was registered at www.clinicaltrials.gov as #NCT02064933.)

We examined the impact of total body irradiation (TBI) dose and fractionation on risk of subsequent malignant neoplasms (SMNs) in the era of reduced-intensity and nonmyeloablative conditioning regimens for hematopoietic cell transplantation (HCT). Among 4905 1-year survivors of allogeneic HCT for hematologic malignancies (N = 4500) or nonmalignant disorders (N = 405) who received transplants between 1969 and 2014, we identified 581 SMNs (excluding squamous and basal cell of skin) in 499 individuals. With a median length of follow-up of 12.5 years, the cumulative incidence of SMNs by 30 years after HCT was 22.0%. Compared with age-, sex-, and calendar year–matched Surveillance, Epidemiology, and End Results (SEER) population rates, the standardized incidence ratio (SIR) of SMNs was increased 2.8-fold. The highest SIRs were for SMNs of bones (SIR, 28.8), oral cavity (SIR, 13.8), skin (SIR, 7.3), central nervous system (SIR, 6.0), and endocrine organs (SIR, 4.9). The highest excess absolute risks (EARs) were seen with breast cancer (EAR, 2.2) and cancers of the oral cavity (EAR, 1.5) and skin (EAR, 1.5) per 1000 person-years. The highest incidence of SMNs was in survivors exposed to unfractionated (600-1000 cGy) or high-dose fractionated (1440-1750 cGy) TBI. For patients receiving low-dose TBI, the incidence was comparable to myeloablative chemotherapy alone, although still twofold higher than in the general population. These data demonstrate a strong effect of TBI dose, dose fractionation, and risk of SMNs after HCT. The cumulative incidence of SMNs increases with follow-up time; thus, HCT survivors require lifetime monitoring for early detection and effective therapy of SMNs.

Conditional knockout (KO) mouse models are invaluable for elucidating the physiological roles of platelets. The Platelet factor 4-Cre recombinase (Pf4-Cre) transgenic mouse is the current model of choice for generating megakaryocyte/platelet-specific KO mice. Platelets and leukocytes work closely together in a wide range of disease settings, yet the specific contribution of platelets to these processes remains unclear. This is partially a result of the Pf4-Cre transgene being expressed in a variety of leukocyte populations. To overcome this issue, we developed a Gp1ba-Cre transgenic mouse strain in which Cre expression is driven by the endogenous Gp1ba locus. By crossing Gp1ba-Cre and Pf4-Cre mice to the mT/mG dual-fluorescence reporter mouse and performing a head-to-head comparison, we demonstrate more stringent megakaryocyte lineage-specific expression of the Gp1ba-Cre transgene. Broader tissue expression was observed with the Pf4-Cre transgene, leading to recombination in many hematopoietic lineages, including monocytes, macrophages, granulocytes, and dendritic and B and T cells. Direct comparison of phenotypes of Csk, Shp1, or CD148 conditional KO mice generated using either the Gp1ba-Cre or Pf4-Cre strains revealed similar platelet phenotypes. However, additional inflammatory and immunological anomalies were observed in Pf4-Cre-generated KO mice as a result of nonspecific deletion in other hematopoietic lineages. By excluding leukocyte contributions to phenotypes, the Gp1ba-Cre mouse will advance our understanding of the role of platelets in inflammation and other pathophysiological processes in which platelet-leukocyte interactions are involved.

Conditional knockout (KO) mouse models are invaluable for elucidating the physiological roles of platelets. The Platelet factor 4-Cre recombinase(Pf4-Cre) transgenic mouse is the current model of choice for generating megakaryocyte/platelet-specific KO mice. Platelets and leukocytes work closely together in a wide range of disease settings, yet the specific contribution of platelets to these processes remains unclear. This is partially a result of the Pf4-Cretransgene being expressed in a variety of leukocyte populations. To overcome this issue, we developed a Gp1ba-Cretransgenic mouse strain in which Creexpression is driven by the endogenous Gp1balocus. By crossing Gp1ba-Creand Pf4-Cremice to the mT/mGdual-fluorescence reporter mouse and performing a head-to-head comparison, we demonstrate more stringent megakaryocyte lineage-specific expression of the Gp1ba-Cretransgene. Broader tissue expression was observed with the Pf4-Cretransgene, leading to recombination in many hematopoietic lineages, including monocytes, macrophages, granulocytes, and dendritic and B and T cells. Direct comparison of phenotypes of Csk, Shp1, or CD148conditional KO mice generated using either the Gp1ba-Creor Pf4-Crestrains revealed similar platelet phenotypes. However, additional inflammatory and immunological anomalies were observed in Pf4-Cre-generated KO mice as a result of nonspecific deletion in other hematopoietic lineages. By excluding leukocyte contributions to phenotypes, the Gp1ba-Cremouse will advance our understanding of the role of platelets in inflammation and other pathophysiological processes in which platelet-leukocyte interactions are involved.

In ENDEAVOR, carfilzomib (56 mg/m2) and dexamethasone (Kd56) demonstrated longer progression-free survival (PFS) over bortezomib and dexamethasone (Vd) in patients with relapsed/refractory multiple myeloma (RRMM). Here we evaluated Kd56 vs Vd by baseline renal function in a post hoc exploratory subgroup analysis. The intent-to-treat population included 929 patients (creatinine clearance [CrCL] ≥15 to <50 mL/min, n = 85 and n = 99; CrCL 50 to <80 mL/min, n = 186 and n = 177; and CrCL ≥80 mL/min, n = 193 and n = 189 for Kd56 and Vd arms, respectively). In these respective subgroups, median PFS was 14.9 vs 6.5 months (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.320-0.757), 18.6 vs 9.4 months (HR, 0.48; 95% CI, 0.351-0.652), and not reached (NR) vs 12.2 months (HR, 0.60; 95% CI, 0.434-0.827) for those receiving Kd56 vs Vd, respectively; median overall survival (OS) was 42.1 vs 23.7 months (HR, 0.66; 95% CI, 0.443-0.989), 42.5 vs 32.8 months (HR, 0.83; 95% CI, 0.626-1.104), and NR vs 42.3 months (HR, 0.75; 95% CI, 0.554-1.009). Complete renal response (ie, CrCL improvement to ≥60 mL/min in any 2 consecutive visits if baseline CrCL <50 mL/min) rates were 15.3% (95% CI, 8.4-24.7) and 14.1% (95% CI, 8.0-22.6) for those receiving Kd56 vs Vd, respectively. In a combined Kd56 and Vd analysis, complete renal responders had longer median PFS (14.1 vs 9.4 months; HR, 0.805; 95% CI, 0.438-1.481) and OS (35.3 vs 29.7 months; HR, 0.91; 95% CI, 0.524-1.577) vs nonresponders. Grade ≥3 adverse event rates in the respective subgroups were 87.1% vs 79.4%, 84.4% vs 71.8%, and 77.1% vs 65.9% for those receiving Kd56 vs Vd, respectively. Thus, Kd56 demonstrated PFS and OS improvements over Vd in RRMM patients regardless of their baseline renal function. The ENDEAVOR trial was registered at www.clinicaltrials.gov as #NCT01568866.

The CD33-targeting bispecific T-cell engager (BiTE) AMG 330 proved to be highly efficient in mediating cytolysis of acute myeloid leukemia (AML) cells in vitro and in mouse models. Yet, T-cell activation is correlated with upregulation of programmed cell death-ligand 1 (PD-L1) and other inhibitory checkpoints on AML cells that confer adaptive immune resistance. PD-1 and PD-L1 blocking agents may counteract T-cell dysfunction, however, at the expense of broadly distributed immune-related adverse events (irAEs). We developed a bifunctional checkpoint inhibitory T cell–engaging (CiTE) antibody that combines T-cell redirection to CD33 on AML cells with locally restricted immune checkpoint blockade. This is accomplished by fusing the extracellular domain of PD-1 (PD-1ex), which naturally holds a low affinity to PD-L1, to an αCD3.αCD33 BiTE-like scaffold. By a synergistic effect of checkpoint blockade and avidity-dependent binding, the PD-1ex attachment increases T-cell activation (3.3-fold elevation of interferon-γ) and leads to efficient and highly selective cytotoxicity against CD33+PD-L1+ cell lines (50% effective concentration = 2.3-26.9 pM) as well as patient-derived AML cells (n = 8). In a murine xenograft model, the CiTE induces complete AML eradication without initial signs of irAEs as measured by body weight loss. We conclude that our molecule preferentially targets AML cells, whereas high-affinity blockers, such as clinically approved anticancer agents, also address PD-L1+ non-AML cells. By combining the high efficacy of T-cell engagers with immune checkpoint blockade in a single molecule, we expect to minimize irAEs associated with the systemic application of immune checkpoint inhibitors and suggest high therapeutic potential, particularly for patients with relapsed/ refractory AML.

We investigated the role of copy number alterations to refine risk stratification in adult Philadelphia chromosome positive (Ph)+ acute lymphoblastic leukemia (ALL) treated with tyrosine kinase inhibitors (TKIs) and allogeneic stem cell transplantation (aSCT). Ninety-seven Ph+ ALL patients (median age 41 years; range 18-64 years) within the prospective multicenter German Multicenter ALL Study Group studies 06/99 (n = 8) and 07/2003 (n = 89) were analyzed. All patients received TKI and aSCT in first complete remission (CR1). Copy number analysis was performed with single nucleotide polymorphism arrays and validated by multiplex ligation-dependent probe amplification. The frequencies of recurrently deleted genes were: IKZF1, 76%; CDKN2A/2B, 45%; PAX5, 43%; BTG1, 18%; EBF1, 13%; ETV6, 5%; RB, 14%. In univariate analyses, the presence of CDKN2A/2B deletions had a negative impact on all endpoints: overall survival (P = .023), disease-free survival (P = .012), and remission duration (P = .036). The negative predictive value of CDKN2A/2B deletions was retained in multivariable analysis along with other factors such as timing of TKI therapy, intensity of conditioning, achieving remission after induction phase 1 and BTG1 deletions. We therefore conclude that acquired genomic CDKN2A/2B deletions identify a subgroup of Ph+ ALL patients, who have an inferior prognosis despite aSCT in CR1. Their poor outcome was attributable primarily to a high relapse rate after aSCT.

We investigated the role of copy number alterations to refine risk stratification in adult Philadelphia chromosome positive (Ph)+acute lymphoblastic leukemia (ALL) treated with tyrosine kinase inhibitors (TKIs) and allogeneic stem cell transplantation (aSCT). Ninety-seven Ph+ALL patients (median age 41 years; range 18-64 years) within the prospective multicenter German Multicenter ALL Study Group studies 06/99 (n = 8) and 07/2003 (n = 89) were analyzed. All patients received TKI and aSCT in first complete remission (CR1). Copy number analysis was performed with single nucleotide polymorphism arrays and validated by multiplex ligation-dependent probe amplification. The frequencies of recurrently deleted genes were: IKZF1, 76%; CDKN2A/2B, 45%; PAX5, 43%; BTG1, 18%; EBF1, 13%; ETV6, 5%; RB, 14%. In univariate analyses, the presence of CDKN2A/2B deletions had a negative impact on all endpoints: overall survival (P= .023), disease-free survival (P= .012), and remission duration (P= .036). The negative predictive value of CDKN2A/2B deletions was retained in multivariable analysis along with other factors such as timing of TKI therapy, intensity of conditioning, achieving remission after induction phase 1 and BTG1 deletions. We therefore conclude that acquired genomic CDKN2A/2B deletions identify a subgroup of Ph+ALL patients, who have an inferior prognosis despite aSCT in CR1. Their poor outcome was attributable primarily to a high relapse rate after aSCT.

Background

Introduction

Background

Introduction

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the field of immune therapy in treating relapsed and refractory B cell malignancies. Despite remarkable progress, CD19 CAR-T cell therapy is associated with major side effects, most significantly are cytokine-release syndrome and neurotoxicity. Of note, 40-60% of patients receiving CD19 CAR-T cells suffer from severe neurotoxicity termed immune cell-associated-neurotoxicity-syndrome (ICANS), which remains a major obstacle limiting their therapeutic efficacy. Several pre-clinical reports using xenograft mouse models have been published to address ICANS, however, they do not fully recapitulate the clinical scenario. Identifying and targeting the molecular mediators of neurotoxicity could help ameliorate ICANS induced by CD19 CAR-T cells.

Background:

Background:Social determinants of health (SDoH) may impact outcomes in sickle cell disease (SCD), and recent literature reports that particular SDoH, such as food insecurity and housing insecurity, may impact diet choices for individuals with SCD. Notably, health outcomes in SCD are linked to diet choices through increased protein and caloric needs, and through nutrients, such as polyphenols, omega fatty acids and micronutrients, which are involved in SCD pathophysiology. The connection between SDoH and diet quality may occur through multiple pathways including access to food, affordability, chronic pain and psychosocial factors at the individual and family level. Importantly, the impact of this connection may relate to outcomes such as pain frequency, hospitalizations, and SCD pathophysiologic biomarkers, such as inflammation.

Background

Background and Significance

Introduction

Introduction

Background:Patient engagement is becoming increasingly important for all facets of healthcare, from drug development and approval, to ensuring equitable access and the delivery of care. It is imperative to bring the voice of those impacted by the actual disease into these processes: this is particularly true for rare diseases, such as hereditary hemolytic anemias (HHAs), where the disease burden is often high and coupled with a poor quality of life and complex treatment requirements. The Red Cell Revolution™ (RCR) advisory council arose organically as part of an Agios Pharmaceuticals-sponsored discovery process, during which a range of stakeholders including healthcare providers (HCPs), advocates, patients, and company leaders offered perspectives on how to optimize engagement with the disease communities. Insights uncovered as part of this process demonstrated that there are unifying health concerns and needs among those impacted by pyruvate kinase (PK) deficiency, sickle cell disease (SCD), and thalassemia, and that there is an opportunity to explore new patient-advocacy research, supported by the creation of a unique multi-stakeholder council.

Background:Patient perspectives have shifted towards greater expectations of autonomy and personalized care, leading to growing demands for partnerships between patients, healthcare providers (HCPs), and industry. Such collaborations provide a mechanism to understand the unique needs of patient communities, which is particularly important for rare diseases, such as hereditary hemolytic anemias (HHAs). The Patient Vision Project (initiated and sponsored by Agios Pharmaceuticals) was launched in November 2021, aiming to establish a set of principles for defining industry standards in engagement with multiple stakeholders, including (but not limited to) HCPs, caregivers and patients with HHA.

Mutations in the core RNA splicing factor SF3B1 are common across MDS, CLL, and clonal hematopoiesis. Prior studies have elucidated that mutations in SF3B1 result in neomorphic widespread changes in splicing due to usage of aberrant intronic branchpoint nucleotides. However, the molecular basis by which mutant SF3B1 induces mis-splicing is not established and therapeutic means to correct mis-splicing due to mutant SF3B1 do not exist.

Background: Myelodysplastic syndromes (MDS) are a group of rare, clonal bone marrow malignancies characterized by ineffective erythropoiesis. Erythropoiesis-stimulating agents (ESAs) are a treatment option for anemia in patients with lower-risk MDS (LR-MDS); however as only one in three patients respond to ESAs, there is a need for additional treatment options. In April 2020, luspatercept was approved for the treatment of anemia in adult patients with LR-MDS who failed to respond to ESAs. The aim of this study was to investigate real-world treatment patterns and early clinical outcomes in adult patients in the United States with LR-MDS receiving luspatercept.