Biologic and Clinical Efficacy of LentiGlobin for Sickle Cell Disease.

BACKGROUND: Sickle cell disease is characterized by the painful recurrence of vaso-occlusive events. Gene therapy with the use of LentiGlobin for sickle cell disease (bb1111; lovotibeglogene autotemcel) consists of autologous transplantation of hematopoietic stem and progenitor cells transduced with the BB305 lentiviral vector encoding a modified ß-globin gene, which produces an antisickling hemoglobin, HbAT87Q. METHODS: In this ongoing phase 1-2 study, we optimized the treatment process in the initial 7 patients in Group A and 2 patients in Group B with sickle cell disease. Group C was established for the pivotal evaluation of LentiGlobin for sickle cell disease, and we adopted a more stringent inclusion criterion that required a minimum of four severe vaso-occlusive events in the 24 months before enrollment. In this unprespecified interim analysis, we evaluated the safety and efficacy of LentiGlobin in 35 patients enrolled in Group C. Included in this analysis was the number of severe vaso-occlusive events after LentiGlobin infusion among patients with at least four vaso-occlusive events in the 24 months before enrollment and with at least 6 months of follow-up. RESULTS: As of February 2021, cell collection had been initiated in 43 patients in Group C; 35 received a LentiGlobin infusion, with a median follow-up of 17.3 months (range, 3.7 to 37.6). Engraftment occurred in all 35 patients. The median total hemoglobin level increased from 8.5 g per deciliter at baseline to 11 g or more per deciliter from 6 months through 36 months after infusion. HbAT87Q contributed at least 40% of total hemoglobin and was distributed across a mean (±SD) of 85±8% of red cells. Hemolysis markers were reduced. Among the 25 patients who could be evaluated, all had resolution of severe vaso-occlusive events, as compared with a median of 3.5 events per year (range, 2.0 to 13.5) in the 24 months before enrollment. Three patients had a nonserious adverse event related or possibly related to LentiGlobin that resolved within 1 week after onset. No cases of hematologic cancer were observed during up to 37.6 months of follow-up. CONCLUSIONS: One-time treatment with LentiGlobin resulted in sustained production of HbAT87Q in most red cells, leading to reduced hemolysis and complete resolution of severe vaso-occlusive events. (Funded by Bluebird Bio; HGB-206 ClinicalTrials.gov number, NCT02140554.).

Betibeglogene Autotemcel Gene Therapy for Non-ß0/ß0 Genotype ß-Thalassemia.

BACKGROUND: Betibeglogene autotemcel (beti-cel) gene therapy for transfusion-dependent ß-thalassemia contains autologous CD34+ hematopoietic stem cells and progenitor cells transduced with the BB305 lentiviral vector encoding the ß-globin (ßA-T87Q) gene. METHODS: In this open-label, phase 3 study, we evaluated the efficacy and safety of beti-cel in adult and pediatric patients with transfusion-dependent ß-thalassemia and a non-ß0/ß0 genotype. Patients underwent myeloablation with busulfan (with doses adjusted on the basis of pharmacokinetic analysis) and received beti-cel intravenously. The primary end point was transfusion independence (i.e., a weighted average hemoglobin level of ≥9 g per deciliter without red-cell transfusions for ≥12 months). RESULTS: A total of 23 patients were enrolled and received treatment, with a median follow-up of 29.5 months (range, 13.0 to 48.2). Transfusion independence occurred in 20 of 22 patients who could be evaluated (91%), including 6 of 7 patients (86%) who were younger than 12 years of age. The average hemoglobin level during transfusion independence was 11.7 g per deciliter (range, 9.5 to 12.8). Twelve months after beti-cel infusion, the median level of gene therapy-derived adult hemoglobin (HbA) with a T87Q amino acid substitution (HbAT87Q) was 8.7 g per deciliter (range, 5.2 to 10.6) in patients who had transfusion independence. The safety profile of beti-cel was consistent with that of busulfan-based myeloablation. Four patients had at least one adverse event that was considered by the investigators to be related or possibly related to beti-cel; all events were nonserious except for thrombocytopenia (in 1 patient). No cases of cancer were observed. CONCLUSIONS: Treatment with beti-cel resulted in a sustained HbAT87Q level and a total hemoglobin level that was high enough to enable transfusion independence in most patients with a non-ß0/ß0 genotype, including those younger than 12 years of age. (Funded by Bluebird Bio; HGB-207 ClinicalTrials.gov number, NCT02906202.).

Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024.

We report highly pathogenic avian influenza A(H5N1) virus in dairy cattle and cats in Kansas and Texas, United States, which reflects the continued spread of clade 2.3.4.4b viruses that entered the country in late 2021. Infected cattle experienced nonspecific illness, reduced feed intake and rumination, and an abrupt drop in milk production, but fatal systemic influenza infection developed in domestic cats fed raw (unpasteurized) colostrum and milk from affected cows. Cow-to-cow transmission appears to have occurred because infections were observed in cattle on Michigan, Idaho, and Ohio farms where avian influenza virus-infected cows were transported. Although the US Food and Drug Administration has indicated the commercial milk supply remains safe, the detection of influenza virus in unpasteurized bovine milk is a concern because of potential cross-species transmission. Continued surveillance of highly pathogenic avian influenza viruses in domestic production animals is needed to prevent cross-species and mammal-to-mammal transmission.

Real-world evidence: Long-term safety of deferiprone in a large cohort of patients with sickle cell disease enrolled in a registry for up to 10 years.

Patients with sickle cell disease (SCD) and other anemias who receive blood transfusions are at risk of organ damage due to transfusional iron overload. Deferiprone is an iron chelator with a well-established safety and efficacy profile that is indicated for the treatment of transfusional iron overload. Here, we report safety data from the large-scale, retrospective Ferriprox® Total Care Registry, which involved all patients with SCD taking deferiprone following the 2011 approval of deferiprone in the United States through August 2020. A total of 634 patients who had initiated deferiprone treatment were included. The mean (SD) duration of deferiprone exposure in the registry was 1.6 (1.6) years (range 0 to 9.7 years). In the overall patient population (N = 634), 64.7% (n = 410) of patients reported a total of 1885 adverse events (AEs). In subgroup analyses, 54.6% (n = 71) of pediatric patients and 67.3% (n = 339) of adult patients reported AEs. The most common AEs reported in patients receiving deferiprone were sickle cell crisis (22.7%), nausea (12.1%), vomiting (8.7%), abdominal discomfort (5.4%), and fatigue (5.4%). Neutropenia was reported in four (0.6%) patients and severe neutropenia/agranulocytosis (defined as absolute neutrophil count <0.5 × 109/L) was reported in two (0.3%) patients. Of patients with evaluable data, all cases of neutropenia and severe neutropenia/agranulocytosis resolved with deferiprone discontinuation. Results from the nearly 10 years of real-world data collected in the Ferriprox® Total Care Registry demonstrate that deferiprone is safe and well tolerated in patients with SCD or other anemias who have transfusional iron overload.

Attitudes, Beliefs, and Intention to Receive a COVID-19 Vaccine for Pediatric Patients With Sickle Cell Disease.

Sickle cell disease (SCD), which occurs primarily in individuals of African descent, has been identified as a preexisting health condition for COVID-19 with higher rates of hospitalization, intensive care unit admissions, and death. National data indicate Black individuals have higher rates of vaccine hesitancy and lower COVID-19 vaccination rates. Understanding the key predictors of intention to receive a COVID-19 vaccine is essential as intention is strongly associated with vaccination behavior. This multisite study examined attitudes, beliefs, intentions to receive COVID-19 vaccines, and educational preferences among adolescents, young adults, and caregivers of children living with SCD. Participants completed an online survey between July 2021 and March 2022. Multivariate logistic regression was used to examine the association between participant age and COVID-19 vaccine attitudes, beliefs, and vaccine intentions. Of the 200 participants, 65.1% of adolescents, 62.5% of young adults, and 48.4% of caregivers intended to receive a COVID-19 vaccine for themselves or their child. Perception that the vaccine was safe was statistically significant and associated with patient and caregiver intention to receive the COVID-19 vaccine for themselves or their child. Participant age was also statistically significant and associated with the intent to get a booster for patients. Study findings highlight key concerns and influencers identified by patients with SCD and their caregivers that are essential for framing COVID-19 vaccine education during clinical encounters. Study results can also inform the design of messaging campaigns for the broader pediatric SCD population and targeted interventions for SCD subpopulations (eg, adolescents, caregivers).

Safety of Ultrasound Contrast Agents in Pediatric Patients With Sickle Cell Disease and Trait.

Ultrasound contrast agent (UCA) use is increasing. Recent isolated reports observed a rise in pain-related adverse events with the intravenous administration of the UCA Definity in adults with sickle cell disease. To date, no studies have investigated the incidence of similar adverse events with UCA Lumason or Optison. We describe our experience regarding the safety of Lumason and Optison in children with sickle cell disease and trait who underwent contrast-enhanced ultrasound exams in our department with intravenous, intravesical, and other intracavitary routes. No pain-related or other adverse events were observed in this pediatric population with any route of UCA administration.

A Phase 3 Trial of Luspatercept in Patients with Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Patients with transfusion-dependent ß-thalassemia need regular red-cell transfusions. Luspatercept, a recombinant fusion protein that binds to select transforming growth factor ß superfamily ligands, may enhance erythroid maturation and reduce the transfusion burden (the total number of red-cell units transfused) in such patients. METHODS: In this randomized, double-blind, phase 3 trial, we assigned, in a 2:1 ratio, adults with transfusion-dependent ß-thalassemia to receive best supportive care plus luspatercept (at a dose of 1.00 to 1.25 mg per kilogram of body weight) or placebo for at least 48 weeks. The primary end point was the percentage of patients who had a reduction in the transfusion burden of at least 33% from baseline during weeks 13 through 24 plus a reduction of at least 2 red-cell units over this 12-week interval. Other efficacy end points included reductions in the transfusion burden during any 12-week interval and results of iron studies. RESULTS: A total of 224 patients were assigned to the luspatercept group and 112 to the placebo group. Luspatercept or placebo was administered for a median of approximately 64 weeks in both groups. The percentage of patients who had a reduction in the transfusion burden of at least 33% from baseline during weeks 13 through 24 plus a reduction of at least 2 red-cell units over this 12-week interval was significantly greater in the luspatercept group than in the placebo group (21.4% vs. 4.5%, P<0.001). During any 12-week interval, the percentage of patients who had a reduction in transfusion burden of at least 33% was greater in the luspatercept group than in the placebo group (70.5% vs. 29.5%), as was the percentage of those who had a reduction of at least 50% (40.2% vs. 6.3%). The least-squares mean difference between the groups in serum ferritin levels at week 48 was -348 µg per liter (95% confidence interval, -517 to -179) in favor of luspatercept. Adverse events of transient bone pain, arthralgia, dizziness, hypertension, and hyperuricemia were more common with luspatercept than placebo. CONCLUSIONS: The percentage of patients with transfusion-dependent ß-thalassemia who had a reduction in transfusion burden was significantly greater in the luspatercept group than in the placebo group, and few adverse events led to the discontinuation of treatment. (Funded by Celgene and Acceleron Pharma; BELIEVE ClinicalTrials.gov number, NCT02604433; EudraCT number, 2015-003224-31.).

Health-related quality of life in patients with ß-thalassemia: Data from the phase 3 BELIEVE trial of luspatercept.

BACKGROUND: Patients with transfusion-dependent (TD) ß-thalassemia require long-term red blood cell transfusions (RBCTs) that lead to iron overload, impacting health-related quality of life (HRQoL). METHODS: The impact of luspatercept, a first-in-class erythroid maturation agent, versus placebo on HRQoL of patients with TD ß-thalassemia was evaluated in the phase 3 BELIEVE trial. HRQoL was assessed at baseline and every 12 weeks using the 36-item Short Form Health Survey (SF-36) and Transfusion-dependent Quality of Life questionnaire (TranQol). Mean change in HRQoL was evaluated from baseline to week 48 for patients receiving luspatercept + best supportive care (BSC) and placebo + BSC and between luspatercept responders and non-responders. RESULTS: Through week 48, for both groups, mean scores on SF-36 and TranQol domains were stable over time and did not have a clinically meaningful change. At week 48, more patients who achieved clinical response (≥50% reduction in RBCT burden over 24 weeks) in the luspatercept + BSC group had improvement in SF-36 Physical Function compared with placebo + BSC (27.1% vs. 11.5%; p = .019). CONCLUSIONS: Luspatercept + BSC reduced transfusion burden while maintaining patients' HRQoL. HRQoL domain improvements from baseline through 48 weeks were also enhanced for luspatercept responders.

Lovo-cel gene therapy for sickle cell disease: Treatment process evolution and outcomes in the initial groups of the HGB-206 study.

lovo-cel (bb1111; LentiGlobin for sickle cell disease [SCD]) gene therapy (GT) comprises autologous transplantation of hematopoietic stem and progenitor cells transduced with the BB305 lentiviral vector encoding a modified ß-globin gene (ßA-T87Q ) to produce anti-sickling hemoglobin (HbAT87Q ). The efficacy and safety of lovo-cel for SCD are being evaluated in the ongoing phase 1/2 HGB-206 study (ClinicalTrials.gov: NCT02140554). The treatment process evolved over time, using learnings from outcomes in the initial patients to optimize lovo-cel's benefit-risk profile. Following modest expression of HbAT87Q in the initial patients (Group A, n = 7), alterations were made to the treatment process for patients subsequently enrolled in Group B (n = 2, patients B1 and B2), including improvements to cell collection and lovo-cel manufacturing. After 6 months, median Group A peripheral blood vector copy number (≥0.08 c/dg) and HbAT87Q levels (≥0.46 g/dL) were inadequate for substantial clinical effect but stable and sustained over 5.5 years; both markedly improved in Group B (patient B1: ≥0.53 c/dg and ≥2.69 g/dL; patient B2: ≥2.14 c/dg and ≥6.40 g/dL, respectively) and generated improved biologic and clinical efficacy in Group B, including higher total hemoglobin and decreased hemolysis. The safety of the lovo-cel for SCD treatment regimen largely reflected the known side effects of HSPC collection, busulfan conditioning regimen, and underlying SCD; acute myeloid leukemia was observed in two patients in Group A and deemed unlikely related to insertional oncogenesis. Changes made during development of the lovo-cel treatment process were associated with improved outcomes and provide lessons for future SCD GT studies.

Return visit rates after an emergency department discharge for children with sickle cell pain episodes.

BACKGROUND: High return visit rates after hospitalization for people with sickle cell disease (SCD) have been previously established. Due to a lack of multicenter emergency department (ED) return visit rate data, the return visit rate following ED discharge for pediatric SCD pain treatment is currently unknown. PROCEDURE: A seven-site retrospective cohort study of discharged ED visits for pain by children with SCD was conducted using the Pediatric Emergency Care Applied Research Network Registry. Visits between January 2017 and November 2021 were identified using previously validated criteria. The primary outcome was the 14-day return visit rate, with 3- and 7-day rates also calculated. Modified Poisson regression was used to analyze associations for age, sex, initial hospitalization rate, and a visit during the COVID-19 pandemic with return visit rates. RESULTS: Of 2548 eligible ED visits, approximately 52% were patients less than 12 years old, 50% were female, and over 95% were non-Hispanic Black. The overall 14-day return visit rate was 29.1% (95% confidence interval [CI]: 27.4%-30.9%; site range 22.7%-31.7%); the 7- and 3-day return visit rates were 23.0% (95% CI: 21.3%-24.6%) and 16.7% (95% CI: 15.3%-18.2%), respectively. Younger children had slightly lower 14-day return visit rates (27.3% vs. 31.1%); there were no associations for site hospitalization rate, sex, and a visit occurring during the pandemic with 14-day returns. CONCLUSION: Nearly 30% of ED discharged visits after SCD pain treatment had a return visit within 14 days. Increased efforts are needed to identify causes for high ED return visit rates and ensure optimal ED and post-ED care.

The effect of an aiming device on the accuracy of humeral transcondylar screw placement.

OBJECTIVES: (1) To evaluate the accuracy of an aiming device on placement of humeral transcondylar screws compared to fluoroscopic methods. (2) To compare experience level on outcome. STUDY DESIGN: Randomized, match pair, prospective ex-vivo study. SAMPLE POPULATION: A total of 68 dogs. METHODS: Canine cadaveric forelimbs were randomly assigned to either aiming device or fluoroscopic-guided groups, and to diplomate or resident. Digital radiography was used to evaluate screw trajectory deviation and eccentricity on the humeral condyle. Procedure time, outcome based on experience, and complications were recorded. RESULTS: The aiming device screw trajectory angle was decreased in the right limb (1.9 ± 1.1°) compared with the left (3.6 ± 1.1°, p = .0178), and compared to fluoroscopy (3.4 ± 1.1° p = .0128). There was no difference between leg laterality with fluoroscopy (p = .9979). Trajectory angle was increased with resident versus diplomate (3.4 ± 1.1° and 2.5 ± 1.1° respectively, p = .0366). Eccentricity deviation was decreased using fluoroscopy versus aiming device (3.1 ± 0.36 mm, 4.2 ± 0.36 mm, respectively, p = .0017). The risk of joint involvement was 8 times greater in aiming device groups, though not significant (p = .0575). Significant complications included increased drill attempts in fluoroscopic groups (p = .0237). CONCLUSION: The aiming device provided accurate placement of transcondylar screws, in terms of both position on the condyle and trajectory angle. Results were similar to fluoroscopic-guided method. CLINICAL SIGNIFICANCE: An aiming device is an acceptable means of placing humeral transcondylar screws. The use of the aiming device had an eight times increased risk of joint involvement compared to fluoroscopy.

An update on the US adult thalassaemia population: a report from the CDC thalassaemia treatment centres.

Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.

Superhydrophobic 3D-Assembled Metallic Nanoparticles for Trace Chemical Enrichment in SERS Sensing.

The performance of surface-enhanced Raman spectroscopy (SERS) is determined by the interaction between highly diluted analytes and boosted localized electromagnetic fields in nanovolumes. Although superhydrophobic surfaces are developed for analyte enrichment, i.e., to concentrate and transfer analytes toward a specific position, it is still challenging to realize reproducible, uniform, and sensitive superhydrophobic SERS substrates over large scales, representing a major barrier for practical sensing applications. To overcome this challenge, a superhydrophobic SERS chip that combines 3D-assembled gold nanoparticles on nanoporous substrates is proposed, for a strong localized field, with superhydrophobic surface treatment for analyte enrichment. Intriguingly, by concentrating droplets in the volume of 40 µL, the sensitivity of 1 nm is demonstrated using 1,2-bis(4-pyridyl)-ethylene molecules. In addition, this unique chip demonstrates a relative standard deviation (RSD) of 2.2% in chip-to-chip reproducibility for detection of fentanyl at 1 µg mL-1 concentration, revealing its potential for quantitative sensing of chemicals and drugs. Furthermore, the trace analysis of fentanyl and fentanyl-heroin mixture in human saliva is realized after a simple pretreatment process. This superhydrophobic chip paves the way toward on-site and real-time drug sensing to tackle many societal issues like drug abuse and the opioid crisis.

Use of nCounter mRNA profiling to identify at-arrival gene expression patterns for predicting bovine respiratory disease in beef cattle.

BACKGROUND: Transcriptomics has identified at-arrival differentially expressed genes associated with bovine respiratory disease (BRD) development; however, their use as prediction molecules necessitates further evaluation. Therefore, we aimed to selectively analyze and corroborate at-arrival mRNA expression from multiple independent populations of beef cattle. In a nested case-control study, we evaluated the expression of 56 mRNA molecules from at-arrival blood samples of 234 cattle across seven populations via NanoString nCounter gene expression profiling. Analysis of mRNA was performed with nSolver Advanced Analysis software (p < 0.05), comparing cattle groups based on the diagnosis of clinical BRD within 28 days of facility arrival (n = 115 Healthy; n = 119 BRD); BRD was further stratified for severity based on frequency of treatment and/or mortality (Treated_1, n = 89; Treated_2+, n = 30). Gene expression homogeneity of variance, receiver operator characteristic (ROC) curve, and decision tree analyses were performed between severity cohorts. RESULTS: Increased expression of mRNAs involved in specialized pro-resolving mediator synthesis (ALOX15, HPGD), leukocyte differentiation (LOC100297044, GCSAML, KLF17), and antimicrobial peptide production (CATHL3, GZMB, LTF) were identified in Healthy cattle. BRD cattle possessed increased expression of CFB, and mRNA related to granulocytic processes (DSG1, LRG1, MCF2L) and type-I interferon activity (HERC6, IFI6, ISG15, MX1). Healthy and Treated_1 cattle were similar in terms of gene expression, while Treated_2+ cattle were the most distinct. ROC cutoffs were used to generate an at-arrival treatment decision tree, which classified 90% of Treated_2+ individuals. CONCLUSIONS: Increased expression of complement factor B, pro-inflammatory, and type I interferon-associated mRNA hallmark the at-arrival expression patterns of cattle that develop severe clinical BRD. Here, we corroborate at-arrival mRNA markers identified in previous transcriptome studies and generate a prediction model to be evaluated in future studies. Further research is necessary to evaluate these expression patterns in a prospective manner.

Pediatric Transport-Specific Illness Severity Scores Predict Clinical Deterioration of Transported Patients.

OBJECTIVE: The Transport Risk Assessment in Pediatrics (TRAP) and Transport Pediatric Early Warning Scores (T-PEWS) are transport-specific pediatric illness severity scores that are adjunct assessment tools for determining disposition of transported patients. We hypothesized that these scores would predict the risk of clinical deterioration in transported patients admitted to general pediatric wards. METHODS: Activation of a rapid response team (RRT) in the first 24 hours of admission was used as a marker of deterioration. All pediatric transports between March 2017 and February 2020 admitted via critical care transport were included. Transports to the emergency department (ED) were excluded. This retrospective chart review evaluated TRAP and T-PEWS scores at 3 points: (1) arrival of transport team at referring hospital, (2) admission to the children's hospital, and (3) RRT activation, if occurring within 24 hours of admission. RESULTS: There were 1137 team transports during this period. Three hundred ninety-nine patients transported to the ED were excluded, leaving 738 included patients; 405 (55%) admitted to the general wards and 333 (45%) admitted to the pediatric intensive care unit. Twenty-five patients admitted to the wards (6%) had an RRT activation within 24 hours of admission. Statistical analysis used 2-sample t tests. There was a statistically significant difference in scores for ward admissions between those who had RRT activation and those who did not. CONCLUSIONS: Both TRAP and T-PEWS can be used to predict the risk of clinical deterioration in transported patients admitted to general wards. These scores may assist in assessing which patients admitted to the wards need closer observation.

Time to rethink haemoglobin threshold guidelines in sickle cell disease.

Alleviating anaemia in patients with sickle cell disease (SCD) is crucial in managing acute complications, mitigating end-organ damage and preventing early mortality. Some disease-modifying and curative therapies have increased haemoglobin (Hb) levels to exceed 100 g/l, a threshold above which complications from red blood cell (RBC) transfusions have occurred, raising concern about whole-blood viscosity-related complications with these therapies. Here we discuss the rationale behind this limit, the effect of viscosity on blood flow and the applicability of this Hb threshold to therapies for SCD beyond RBC transfusions.

The pyruvate kinase (PK) to hexokinase enzyme activity ratio and erythrocyte PK protein level in the diagnosis and phenotype of PK deficiency.

Diagnosis of pyruvate kinase deficiency (PKD), the most common cause of hereditary non-spherocytic haemolytic anaemia, remains challenging in routine practice and no biomarkers for clinical severity have been characterised. This prospective study enrolled 41 patients with molecularly confirmed PKD from nine North American centres to evaluate the diagnostic sensitivity of pyruvate kinase (PK) enzyme activity and PK:hexokinase (HK) enzyme activity ratio, and evaluate the erythrocyte PK (PK-R) protein level and erythrocyte metabolites as biomarkers for clinical severity. In this population not transfused for ≥90 days before sampling, the diagnostic sensitivity of the PK enzyme assay was 90% [95% confidence interval (CI) 77-97%], whereas the PK:HK ratio sensitivity was 98% (95% CI 87-100%). There was no correlation between PK enzyme activity and clinical severity. Transfusion requirements correlated with normalised erythrocyte ATP levels (r = 0·527, P = 0·0016) and PK-R protein levels (r = -0·527, P = 0·0028). PK-R protein levels were significantly higher in the never transfused [median (range) 40·1 (9·8-73·9)%] versus ever transfused [median (range) 7·7 (0·4-15·1)%] patients (P = 0·0014). The PK:HK ratio had excellent sensitivity for PK diagnosis, superior to PKLR exon sequencing. Given that the number of PKLR variants and genotype combinations limits prognostication based on molecular findings, PK-R protein level may be a useful prognostic biomarker of disease severity and merits further study.

Gene Therapy in Patients with Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Donor availability and transplantation-related risks limit the broad use of allogeneic hematopoietic-cell transplantation in patients with transfusion-dependent ß-thalassemia. After previously establishing that lentiviral transfer of a marked ß-globin (ßA-T87Q) gene could substitute for long-term red-cell transfusions in a patient with ß-thalassemia, we wanted to evaluate the safety and efficacy of such gene therapy in patients with transfusion-dependent ß-thalassemia. METHODS: In two phase 1-2 studies, we obtained mobilized autologous CD34+ cells from 22 patients (12 to 35 years of age) with transfusion-dependent ß-thalassemia and transduced the cells ex vivo with LentiGlobin BB305 vector, which encodes adult hemoglobin (HbA) with a T87Q amino acid substitution (HbAT87Q). The cells were then reinfused after the patients had undergone myeloablative busulfan conditioning. We subsequently monitored adverse events, vector integration, and levels of replication-competent lentivirus. Efficacy assessments included levels of total hemoglobin and HbAT87Q, transfusion requirements, and average vector copy number. RESULTS: At a median of 26 months (range, 15 to 42) after infusion of the gene-modified cells, all but 1 of the 13 patients who had a non-ß0/ß0 genotype had stopped receiving red-cell transfusions; the levels of HbAT87Q ranged from 3.4 to 10.0 g per deciliter, and the levels of total hemoglobin ranged from 8.2 to 13.7 g per deciliter. Correction of biologic markers of dyserythropoiesis was achieved in evaluated patients with hemoglobin levels near normal ranges. In 9 patients with a ß0/ß0 genotype or two copies of the IVS1-110 mutation, the median annualized transfusion volume was decreased by 73%, and red-cell transfusions were discontinued in 3 patients. Treatment-related adverse events were typical of those associated with autologous stem-cell transplantation. No clonal dominance related to vector integration was observed. CONCLUSIONS: Gene therapy with autologous CD34+ cells transduced with the BB305 vector reduced or eliminated the need for long-term red-cell transfusions in 22 patients with severe ß-thalassemia without serious adverse events related to the drug product. (Funded by Bluebird Bio and others; HGB-204 and HGB-205 ClinicalTrials.gov numbers, NCT01745120 and NCT02151526 .).

Effect of Poloxamer 188 vs Placebo on Painful Vaso-Occlusive Episodes in Children and Adults With Sickle Cell Disease: A Randomized Clinical Trial.

Importance: Although effective agents are available to prevent painful vaso-occlusive episodes of sickle cell disease (SCD), there are no disease-modifying therapies for ongoing painful vaso-occlusive episodes; treatment remains supportive. A previous phase 3 trial of poloxamer 188 reported shortened duration of painful vaso-occlusive episodes in SCD, particularly in children and participants treated with hydroxyurea. Objective: To reassess the efficacy of poloxamer 188 for vaso-occlusive episodes. Design, Setting, and Participants: Phase 3, randomized, double-blind, placebo-controlled, multicenter, international trial conducted from May 2013 to February 2016 that included 66 hospitals in 12 countries and 60 cities; 388 individuals with SCD (hemoglobin SS, SC, S-ß0 thalassemia, or S-ß+ thalassemia disease) aged 4 to 65 years with acute moderate to severe pain typical of painful vaso-occlusive episodes requiring hospitalization were included. Interventions: A 1-hour 100-mg/kg loading dose of poloxamer 188 intravenously followed by a 12-hour to 48-hour 30-mg/kg/h continuous infusion (n = 194) or placebo (n = 194). Main Outcomes and Measures: Time in hours from randomization to the last dose of parenteral opioids among all participants and among those younger than 16 years as a separate subgroup. Results: Of 437 participants assessed for eligibility, 388 were randomized (mean age, 15.2 years; 176 [45.4%] female), the primary outcome was available for 384 (99.0%), 15-day follow-up contacts were available for 357 (92.0%), and 30-day follow-up contacts were available for 368 (94.8%). There was no significant difference between the groups for the mean time to last dose of parenteral opioids (81.8 h for the poloxamer 188 group vs 77.8 h for the placebo group; difference, 4.0 h [95% CI, -7.8 to 15.7]; geometric mean ratio, 1.2 [95% CI, 1.0-1.5]; P = .09). Based on a significant interaction of age and treatment (P = .01), there was a treatment difference in time from randomization to last administration of parenteral opioids for participants younger than 16 years (88.7 h in the poloxamer 188 group vs 71.9 h in the placebo group; difference, 16.8 h [95% CI, 1.7-32.0]; geometric mean ratio, 1.4 [95% CI, 1.1-1.8]; P = .008). Adverse events that were more common in the poloxamer 188 group than the placebo group included hyperbilirubinemia (12.7% vs 5.2%); those more common in the placebo group included hypoxia (12.0% vs 5.3%). Conclusions and Relevance: Among children and adults with SCD, poloxamer 188 did not significantly shorten time to last dose of parenteral opioids during vaso-occlusive episodes. These findings do not support the use of poloxamer 188 for vaso-occlusive episodes. Trial Registration: ClinicalTrials.gov Identifier: NCT01737814.