Immunogenicity, efficacy and safety of Nuwiq® (human-cl rhFVIII) in previously untreated patients with severe haemophilia A-Interim results from the NuProtect Study.

INTRODUCTION: Nuwiq® (Human-cl rhFVIII) is a fourth generation recombinant FVIII, produced in a human cell line, without chemical modification or protein fusion. No inhibitors developed in studies with Nuwiq® in 201 previously treated patients with haemophilia A (HA). The immunogenicity, efficacy and safety of Nuwiq® in previously untreated patients (PUPs) with severe HA are being assessed in the ongoing NuProtect study. METHODS: The study, conducted across 38 centres worldwide, is evaluating 110 true PUPs of all ages and ethnicities enrolled for study up to 100 exposure days (EDs) or 5 years maximum. The primary objective is to assess the immunogenicity of Nuwiq® (inhibitor activity ≥0.6 BU) using the Nijmegen-modified Bethesda assay at a central laboratory. RESULTS: Data for 66 PUPs with ≥20 EDs from a preplanned interim analysis were analysed. High-titre (HT) inhibitors developed in 8 of 66 patients after a median of 11.5 EDs (range 6-24). Five patients developed low-titre inhibitors (4 transient). The cumulative incidence (95% confidence interval) was 12.8% (4.5%, 21.2%) for HT inhibitors and 20.8% (10.7%, 31.0%) for all inhibitors. During inhibitor-free periods, median annualized bleeding rates during prophylaxis were 0 for spontaneous bleeds and 2.40 for all bleeds. Efficacy was rated as "excellent" or "good" in treating 91.8% of bleeds. Efficacy of surgical prophylaxis was "excellent" or "good" for 8 (89%) procedures and "moderate" for 1 (11%). No tolerability concerns were evident. CONCLUSION: These interim data show a cumulative incidence of 12.8% for HT inhibitors and convincing efficacy and tolerability in PUPs treated with Nuwiq® .

Perioperative management of haemophilia B: A critical appraisal of the evidence and current practices.

BACKGROUND: While there is substantial literature addressing the principles of general management of haemophilia, literature on perioperative management of haemostasis is scarce. OBJECTIVE: The aim of this study was to better understand perioperative management among congenital haemophilia B patients (without inhibitors) and to gain insights into real-world surgical practices. METHOD: A systematic literature review, with an emphasis on haemophilia B, was conducted using EMBASE® , Medline® and the Cochrane Library. Studies from 1974 to June 2015 were accessed, and 132 studies were eligible for the full-study review. An international expert panel with five haematologists and one surgeon reviewed the resulting literature and provided further insights. RESULTS: The literature review revealed that documented experience in the perioperative management of bleeding risk in haemophilia B patients is relatively scarce. Therefore, the review was amended to provide a comprehensive overview of the perioperative management for haemophilia A and B patients; the expert panel applied a particular focus to haemophilia B. Several gaps were identified in the literature including the lack of consensus on defining surgery in terms of bleeding risk, optimal factor levels during surgery and lack of robust evidence on surgical outcomes. The ensuing discussions with the expert panel provided validation of some of the results from the systematic literature review and proposed future directions for perioperative management. Suggestions included collaboration with haemophilia treatment centres (HTCs) to collect real-world data on perioperative management, establishing the need for optimal factor level monitoring practice, and the appropriate adoption of extended half-life products in clinical settings.

Recombinant porcine factor VIII for high-risk surgery in paediatric congenital haemophilia A with high-titre inhibitor.

INTRODUCTION: High-titre factor VIII (FVIII) inhibitors complicate peri-operative haemostasis. Recombinant porcine FVIII (r-pFVIII) may provide an alternative haemostatic agent for high-risk procedures and allow FVIII activity monitoring. AIM: Devise an effective haemostatic plan for repair of a progressively symptomatic aortic coarctation in a 5-year-old male with immune tolerance induction (ITI) refractory high-titre FVIII inhibitors. METHODS: Preprocedure human FVIII inhibitor titre was 58 Bethesda Units mL-1 (BU) and cross-reacted to neutralize porcine FVIII at 30 BU. Daily ITI with plasma-derived FVIII concentrate was supplemented with anti-B-cell and anti-plasma cell immunotherapy to reduce FVIII inhibitor titres. Potential haemostatic agents were evaluated in comparative ex vivo thrombin generation assays (TGA). RESULTS: Four weeks after immunosuppression, human and porcine inhibitor titres declined to 16 and 2 BU respectively. TGA with r-pFVIII was less robust than with activated prothrombin complex concentrate (aPCC); however, r-pFVIII was selected for cardiac surgery to secure the ability to assay FVIII levels throughout this high-bleeding risk procedure. Haemostasis with r-pFVIII was excellent; initial trough FVIII activity levels ranged from 0.81-1.17 IU mL-1 . On postoperative day 3, peak and trough levels markedly declined suggesting a rising porcine inhibitor titre. Postprocedure prophylaxis was transitioned to aPCC, informed by TGA. CONCLUSIONS: R-pFVIII provided effective peri-procedural haemostasis with no adverse events. Rapid neutralization of r-pFVIII after the first 60 hours, despite intensive immune suppression, accentuates the importance of careful monitoring. Use of TGA can support bypassing agent selection for convalescence. The comparative cost of r-pFVIII may limit its use to high morbidity clinical scenarios.

Recognizing the need for personalization of haemophilia patient-reported outcomes in the prophylaxis era.

The safety and efficacy of treatment options for patients with haemophilia have significantly improved over the last two decades, particularly with greater utilization of prophylactic approaches. Consequently, it is becoming increasingly difficult to differentiate the treatment benefits of available choices based on standard endpoints such as annualized bleeding rates and joint health scores. Patient-reported outcomes (PROs) have shown limited ability to discriminate between treatment outcomes, in part because of their comprehensive nature; i.e. differences in specific outcomes meaningful to individual patients are masked by a global scoring system based on a fixed set of items, many of which may be unimportant for any given patient. There is a clear need for new outcome measures. Initiatives to develop patient-centric outcomes that capture clinically meaningful change are ongoing. One such approach, goal attainment scaling (GAS), allows patients, in collaboration with a trained clinician, to select goals from a medical condition-specific menu of options and subsequently facilitates quantitative assessment of goal realization. Thus, it is fully personalized and sensitive to small, often idiosyncratic, treatment benefits, such as improvements in functional capacity. In this paper, we present the underlying rationale for GAS and one other novel approach to PRO personalization, and discuss their potential to augment current outcome measures by reliably detecting and quantifying treatment effects in individuals with haemophilia on prophylaxis.

CSF 5-Methyltetrahydrofolate Serial Monitoring to Guide Treatment of Congenital Folate Malabsorption Due to Proton-Coupled Folate Transporter (PCFT) Deficiency.

Hereditary folate malabsorption is characterized by folate deficiency with impaired folate transport into the central nervous system (CNS). This disease is characterized by megaloblastic anemia of early appearance, combined immunodeficiency, seizures, and cognitive impairment. The anemia and immunologic disease are responsive but neurological signs are refractory to folic-acid treatment. We report a 7-year-old girl who has congenital folate deficiency and SLC46A1 gene mutation who is unable to transport folate from her gut to the circulatory system and consequently from the blood to the cerebrospinal fluid (CSF). As a result she developed undetectable 5-methyltetrahydrofolate levels in her plasma and CSF and became immunocompromised and quite ill. Intramuscular treatment with 5-formyltetrahydrofolate (folinic acid) was therapeutic at her presentation and has been successful preventing other signs and symptoms of hereditary folate malabsorption even at relatively low CSF levels. Although difficult, early detection and diagnosis of cerebral folate deficiency are important because folinic acid at a pharmacologic dose may normalize outcome in PCFT gene defects, as well as bypass autoantibody-blocked folate receptors and enter the cerebrospinal fluid by way of the reduced folate carrier. This route elevates the 5-methyltetrahydrofolate level within the central nervous system and can prevent the neuropsychiatric disorder. CSF levels of 5-methyltetrahydrofolate between 18 and 46 nmol/L may be sufficient to eradicate CNS disease.

Correlation between dispensed and prescribed doses of factor products for bleeding disorders: can a small, centre-based pharmacy hit the mark?

The prescribing and dispensing of factor replacement products have come under scrutiny in recent years. Some payers are shunting patients away from local 340B pharmacies anticipating larger pharmacies will be better able to match dispensed antihaemophilic factor vials to the prescribed dose. Our aims were to assess our baseline ability to achieve an aggregate and per patient dispensed to prescribed factor ratio (D:P ratio) of 1 and to evaluate obstacles to achieving unity. We conducted a retrospective review of the factor products dispensed from our 340B pharmacy and the corresponding prescriptions over the 6-month period prior to instituting routine D:P ratio assessment. The mean D:P ratio for all 65 patients was 1.00 (SD = 0.07). The mean paediatric D:P ratio differed from unity (P = 0.017) and from the mean adult D:P ratio (P = 0.003) in favour of a higher dispensed dose. A correlation between lighter patients and a higher dispensed dose was observed. Also, paediatric patients receiving 2 vials per dose had a mean D:P ratio greater than unity (P = 0.002). Pharmacy size does not dictate the ability to achieve a D:P ratio of unity. Ongoing monitoring of D:P ratios and dose ranges prescribed should be performed by all pharmacies to ensure acceptable allocation and cost of factor replacement for each patient. To further improve the D:P ratio metric in the paediatric population manufacturers should strongly consider adding more nominal dose increments within their lower range of vial sizes.

Rituximab for treatment of inhibitors in haemophilia A. A Phase II study.

The development of antibodies against infused factor VIII (FVIII) in patients with haemophilia A is a serious complication leading to poorly controlled bleeding and increased morbidity. No treatment has been proven to reduce high titre antibodies in patients who fail immune tolerance induction or are not candidates for it. The Rituximab for the Treatment of Inhibitors in Congenital Hemophilia A (RICH) study was a phase II trial to assess whether rituximab can reduce anamnestic FVIII antibody (inhibitor) titres. Male subjects with severe congenital haemophilia A and an inhibitor titre ≥5 Bethesda Units/ml (BU) following a FVIII challenge infusion received rituximab 375 mg/m² weekly for weeks 1 through 4. Post-rituximab inhibitor titres were measured monthly from week 6 through week 22 to assess treatment response. Of 16 subjects who received at least one dose of rituximab, three (18.8%) met the criteria for a major response, defined as a fall in inhibitor titre to <5 BU, persisting after FVIII re-challenge. One subject had a minor response, defined as a fall in inhibitor titre to <5 BU, increasing to 5-10 BU after FVIII re-challenge, but <50% of the original peak inhibitor titre. Rituximab is useful in lowering inhibitor levels in patients, but its effect as a solo treatment strategy is modest. Future studies are indicated to determine the role of rituximab as an adjunctive therapy in immune tolerisation strategies.

Safety of recombinant activated factor VII (rFVIIa) in patients with congenital haemophilia with inhibitors: overall rFVIIa exposure and intervals following high (>240 µg kg⁻¹) rFVIIa doses across clinical trials and registries.

Recombinant activated factor VII (rFVIIa) is indicated for treatment of bleeding in congenital haemophilia with inhibitors (CHwI) using 90 µg kg(-1) every 2-3 h (EU and US) or a single 270 µg kg(-1) dose (EU only) with ~90% efficacy reported for both regimens. Dosing of rFVIIa varies, and home treatment makes assessment of frequency of doses >90 µg kg(-1), the intervals before additional treatment, and the risk for thromboembolic events (TEs) more difficult. This post hoc analysis assessed the safety and distribution of rFVIIa dosing in CHwI and the impact of >240 µg kg(-1) dosing on subsequent bypassing agent (BPA) dosing interval and frequency. Data regarding on-demand or prophylactic rFVIIa dosing, TE incidence and subsequent BPA dosing after high rFVIIa doses were compiled from multiple sources incorporating safety surveillance. A total of 61 734 rFVIIa doses were reported in 481 patients treated for 3947 bleeds and for 43 135 prophylaxis days. Over half (52%) exceeded 120 µg kg(-1), 37% exceeded 160 µg kg(-1) and 15% exceeded 240 µg kg(-1). Subsequent doses of BPA(s) were administered after 38% of initial and 49% of any rFVIIa dose >240 µg kg(-1), and were most frequently administered ≥24 h after initial (40%) or any (53%) doses >240 µg kg(-1). No TEs were reported. The findings of this analysis show that rFVIIa doses >90 µg kg(-1) are utilized for 'real-world' treatment of children and adults. When additional BPA was administered following an rFVIIa dose >240 µg kg(-1), reported intervals were prolonged, often ≥24 h. No safety issues were identified in the 61,734 doses analysed.

Assessment of individual dose utilization vs. physician prescribing recommendations for recombinant activated factor VII (rFVIIa) in paediatric and adult patients with congenital haemophilia and alloantibody inhibitors (CHwI): the Dosing Observational Study in Hemophilia (DOSE).

Recent data from the Dosing Observational Study in Hemophilia diary study has described home treatment with recombinant activated factor VII (rFVIIa) in congenital haemophilia with inhibitors (CHwI). The current analysis compares prescribed and patient/caregiver-reported rFVIIa administration in paediatric and adult CHwI patients in this study. Patients with ≥ 4 bleeding episodes within a 3-month period prescribed rFVIIa as first-line therapy for bleeding episodes were eligible. Patients/caregivers completed a diary for ≥ 90 days or until the patient experienced four bleeds. Initial, total and mean rFVIIa doses reported for each bleeding episode were calculated and compared with the physician-prescribed doses. Of 52 enrolled patients (25 children; 27 adults), 39 (75%) completed the study. Children and adults had similar mean durations of bleeding episodes. Both patient groups were administered higher initial rFVIIa doses for joint bleeds than prescribed: median (range) 215.2 (74.1-400.0) mcg kg(-1) vs. 200.0 (61.0-270.0) mcg kg(-1) for children, and 231.3 (59.3-379.7) mcg kg(-1) vs. 123.0 (81.0-289.0) mcg kg(-1) for adults. The median infused dose for joint bleeds was higher in adults than children (175.2 vs. 148.0 mcg kg(-1) ), but children received significantly more doses per joint bleed than adults (median 6.5 vs. 3.0). The median total dose per joint bleed was higher in children than adults (1248.7 vs. 441.6). For children and adults, both initial and additional doses administered for bleeds were higher than prescribed. Children received higher total doses per bleed due to an increased number of infusions per bleed.

The use of a single von Willebrand factor-containing, plasma-derived FVIII product in hemophilia A immune tolerance induction: the US experience.

BACKGROUND: Inhibitors are a serious complication for patients with severe hemophilia A. Immune tolerance induction (ITI) is the primary method for eradicating these inhibitors. The role of type of concentrate and in particular the use of von Willebrand factor-containing, plasma-derived factor VIII (VWF/pd-FVIII) concentrate in primary or rescue ITI remains unclear. OBJECTIVES: To report retrospective collection of data on the use of a single VWF/pd-FVIII concentrate in primary and rescue ITI. METHODS: Retrospective chart review of hemophilia A inhibitor patients at 11 US institutions who received VWF/pd-FVIII concentrate in primary or rescue ITI. RESULTS: Primary ITI was carried out in eight inhibitor patients with a 75% complete and partial success. Secondary ITI was carried out in 25 inhibitor patients, with 52% attaining complete or partial success. CONCLUSIONS: This report represents the largest group of primarily pediatric, high-titer inhibitor patients treated with a single VWF/pd-FVIII concentrate. It adds retrospective data to the use of VWF-containing plasma-derived factor VIII concentrate in primary and rescue ITI, particularly in those patients with characteristics of poor response to ITI.

Exposure and safety of higher doses of recombinant factor VIIa ≥250 µg kg(-1) in individuals with congenital haemophilia complicated by alloantibody inhibitors: the Haemophilia and Thrombosis Research Society Registry experience (2004-2008).

Recombinant factor VIIa (rFVIIa) is a well-established treatment for managing bleeding episodes in individuals with congenital haemophilia complicated by alloantibody inhibitors (CHwI). The safety and efficacy of standard dosing (90-120 µg kg(-1) every 2-3 h) are well-established; however, the desire to optimize therapy with one or more higher doses instead of multiple lower doses has created a need for evidence of the safety and efficacy of such regimens. Analysis of data from the Haemophilia and Thrombosis Research Society (HTRS) Registry was performed on episodes where doses of ≥250 µg kg(-1) were reported. From 2041 rFVIIa-treated bleeds, 172 bleeding episodes were identified in 25 individuals with CHwI who were treated with ≥1 higher doses (≥250 µg kg(-1) , ≥270 µg kg(-1) or ≥300 µg kg(-1) ) of rFVIIa between January 2004 and November 2008. Bleeds occurred in individuals ranging in age from 0.4 to 41.7 years who were predominantly non-Hispanic and white (40%) with haemophilia A (88%). Bleed types most frequently treated with higher doses of rFVIIa were spontaneous (62-65%) or traumatic (27-32%). Bleed locations most frequently treated with higher doses of rFVIIa were joint (60-68%) or muscle (20-25%). A total of 1521 rFVIIa doses were administered (median, three doses per bleed); 26% were 250 µg kg(-1) or higher (initial dose, 82%). Bleeding stopped in 93% (160/172) of bleeds treated with rFVIIa 250 µg kg(-1) or higher. No serious adverse drug-related events or thrombotic complications were reported. This data analysis from the HTRS Registry provides evidence of the safe and effective use of higher doses of rFVIIa (≥250 µg kg(-1) ) in US practice.

Quality of life in thalassemia: a comparison of SF-36 results from the thalassemia longitudinal cohort to reported literature and the US norms.

Thalassemia is a chronic, inherited blood disorder, which, in its most severe form, causes life-threatening anemia. Advances in treatment have led to increased life expectancy however the need for chronic blood transfusions and chelation therapy remains a significant burden for patients. Our study compared health related quality of life (HRQOL) from the Thalassemia Clinical Research Network's (TCRNs) Thalassemia Longitudinal Cohort (TLC) study to US norms and assessed association with clinical variables. There were 264 patients over age 14 who completed the Medical Outcomes Study 36-Item Short Form Health Survey version 2 (SF36v2) baseline assessment. When compared to US norms, TLC patients had statistically significant (P < 0.05) worse HRQOL on five of the eight subscales (physical functioning, role-physical, general health, social functioning, and role-emotional) and on both summary scales (physical component summary and mental component summary). Women, older patients, and those with more disease complications and side effects from chelation reported lower HRQOL. In general, adolescents and adults with thalassemia report worse HRQOL than the US population, despite contemporary therapy. The SF-36 should become a standard instrument for assessing HRQOL in thalassemia to determine predictors of low HRQOL which may be better addressed by a multidisciplinary team.

Direct-to-consumer advertising for bleeding disorders: a content analysis and expert evaluation of advertising claims.

OBJECTIVE: In the United States, the Food and Drug Administration (FDA) requires that all direct-to-consumer advertising (DTCA) contain both an accurate statement of a medication's effects ('truth') and an even-handed discussion of its benefits and risks/adverse effects ('fair balance'). DTCA for medications to treat rare diseases such as bleeding disorders is unlikely to be given high priority for FDA review. METHODS: We reviewed all DTCA for bleeding disorder products appearing in the patient-directed magazine HemeAware from January 2004 to June 2006. We categorized the information presented in each advertisement as benefit, risk/adverse effect, or neither, and assessed the amount of text and type size devoted to each. We also assessed the readability of each type of text using the Flesch Reading Ease Score (FRES, where a score of >or=65 is considered of average readability), and assessed the accuracy of the advertising claims utilizing a panel of five bleeding disorder experts. RESULTS: A total of 39 unique advertisements for 12 products were found. On average, approximately twice the amount of text was devoted to benefits as compared with risks/adverse effects, and the latter was more difficult to read [FRES of 32.0 for benefits vs. 20.5 for risks/adverse effects, a difference of 11.5 (95% CI: 4.5-18.5)]. Only about two-thirds of the advertising claims were considered by a majority of the experts to be based on at least low-quality evidence. CONCLUSION: As measured by our methods, print DTCA for bleeding disorders may not reach the FDA's standards of truth and fair balance.

Rituximab for adolescents with haemophilia and high titre inhibitors.

Neutralizing alloantibodies (inhibitors) to factor VIII or factor IX develop in approximately 25% of patients with haemophilia A and <3% of patients with haemophilia B treated with factor concentrate. Patients with high titre inhibitors, in whom immune tolerance therapy fails, have few treatment options. Targeted anti-B-cell therapy with rituximab (chimeric anti-CD20) has been useful in several antibody-mediated autoimmune states. Case reports of rituximab treatment in small numbers of haemophilia patients with inhibitors have been inconclusive. We describe three adolescent patients with severe haemophilia and inhibitors treated with four weekly doses of rituximab, 375 mg m(-2). Treatment with rituximab was effective in reducing the inhibitor titre in two of three patients. Rituximab may be beneficial for patients with severe haemophilia and inhibitors in whom standard therapies have failed, but larger prospective studies are required to determine safety, efficacy and predictors of success.

Deletion of SLC19A2, the high affinity thiamine transporter, causes selective inner hair cell loss and an auditory neuropathy phenotype.

Mutations in the gene coding for the high-affinity thiamine transporter Slc19a2 underlie the clinical syndrome known as thiamine-responsive megaloblastic anemia (TRMA) characterized by anemia, diabetes, and sensorineural hearing loss. To create a mouse model of this disease, a mutant line was created with targeted disruption of the gene. Cochlear function is normal in these mutants when maintained on a high-thiamine diet. When challenged with a low-thiamine diet, Slc19a2-null mice showed 40-60 dB threshold elevations by auditory brainstem response (ABR), but only 10-20 dB elevation by otoacoustic emission (OAE) measures. Wild-type mice retain normal hearing on either diet. Cochlear histological analysis showed a pattern uncommon for sensorineural hearing loss: selective loss of inner hair cells after 1-2 weeks on low thiamine and significantly greater inner than outer hair cell loss after longer low-thiamine challenges. Such a pattern is consistent with the observed discrepancy between ABR and OAE threshold shifts. The possible role of thiamine transport in other reported cases of selective inner hair cell loss is considered.