Turoctocog Research Articles

Foreword.

With improved healthcare strategies and more effective treatments, patients with haemophilia now have a greater life expectancy and better quality of life than ever before. Despite many advances, remaining challenges in haemophilia care include achieving parity of treatment, increasing treatment options, optimising patient outcomes (including musculoskeletal care) and improving the management of patients with inhibitors. As in other chronic diseases, psychosocial issues have a profound impact on the well-being of people living with haemophilia and also need to be considered alongside treatment for prevention and management of bleeding episodes. The 12th Novo Nordisk Symposium on Haemostasis Management, held in Vienna, Austria, in June 2014, brought together an international faculty of haemophilia experts and healthcare professional delegates to consider how these challenges can be addressed, focusing on medical, psychological and social issues associated with rare bleeding disorders, with an emphasis on haemophilia and its management. The Symposium consisted of an introductory session with the keynote lecture ‘Improving care and treatment options for women and girls with rare bleeding disorders’, followed by a presentation outlining the work of the Novo Nordisk Haemophilia Foundation. Five main sessions comprised the Symposium, the first of which, ‘Research in the spotlight’, included a summary of recent scientific research that may influence future clinical practice. The second session, ‘New opportunities and insights for factor VIII (FVIII)’, explored the rationale behind the use of recombinant replacement therapies and described the clinical development and pivotal trial results of the recombinant FVIII product, turoctocog alfa, for the treatment of haemophilia A. The third session comprised four specialised workshops led by faculty who shared their wealth of knowledge and experiences of everyday clinical practice on the topics ‘Optimising musculoskeletal health: implications for clinical practice’, ‘Challenges in transition: case studies’, ‘Pathways to surgery: utilising multidisciplinary care for optimal outcomes’ and ‘Acquired haemophilia: integrating technology for improved diagnosis and outcomes in acquired haemophilia’. The fourth session, ‘Continuing the journey of inhibitor management’, provided an overview of efficacy and safety data derived from 18 years’ experience of using recombinant activated factor FVIIa in patients with haemophilia and inhibitors. The final session, ‘Rare bleeding disorders in focus’, summarised evidence to guide the management of acquired haemophilia and Glanzmann's thrombasthenia. To facilitate knowledge acquisition, and thus inform best practice in haemostasis management, five topics were selected from the varied Symposium programme for presentation in this supplement: ‘Improving care and treatment options for women and girls with bleeding disorders’; ‘Optimising musculoskeletal care for patients with haemophilia’; ‘Updates from guardian™: a comprehensive registration programme’; ‘Challenges in transition’; and ‘Acquired haemophilia: an overview for clinical practice’. Editorial assistance was provided by Tracey Spurway of Bioscript Medical Ltd (Macclesfield, UK) and funded by Novo Nordisk Health Care AG (Zurich, Switzerland). DL was involved in the drafting, and approval for submission, of this manuscript. None to declare. Please always refer to local prescribing information. UK prescribing information for Novo Nordisk treatment options discussed during the Symposium can be found at the end of this Supplement.

Turoctocog alfa in the treatment of individuals with hemophilia A: review of quality of life data collected in Phase III trials

Hemophilia A is an X-linked recessive hereditary bleeding disorder resulting from a deficiency in coagulation factor VIII. Difficulties due to hemophilia and its management present challenges for patient's quality of life. Turoctocog alfa, a recombinant, B-domain truncated factor VIII, is a recent US FDA- and EMA-approved replacement therapy shown to be an effective and safe option for the treatment of individuals with hemophilia A. Data collected throughout two Phase 3, multinational, open-label, non-randomized, non-comparative trials demonstrated that individuals with hemophilia A, particularly young adults experienced improvements in health-related quality of life when switched from an on-demand to a prophylactic regimen of turoctocog alfa.

PSY17 - Budget impact analysis of factor replacement Therapy with Turoctocog Alfa in the treatment of Hemophilia A

PSY17 - Budget impact analysis of factor replacement Therapy with Turoctocog Alfa in the treatment of Hemophilia A

Turoctocog alfa: an evidence-based review of its potential in the treatment of hemophilia A.

Turoctocog alfa is the first B-domain-truncated third generation recombinant coagulation factor VIII (FVIII) product. Nonclinical in vitro and animal model studies have demonstrated that turoctocog alfa has similar functional potency and hemostatic efficacy as comparator FVIII products. With respect to discrepancies in the level of FVIII concentrate in plasma of current FVIII products on comparing measurement results between one-stage clot and chromogenic assays, there was no difference in the in vitro turoctocog alfa study; however, measured FVIII concentrate in field study was higher with the chromogenic assay (1.08 IU/mL) than with one-stage assay (0.83 IU/mL). Two published clinical studies on previously treated patients (PTPs) and clinical pharmacokinetics have described that the pharmacokinetic parameters are similar, and the safety and efficacy for prevention and treatment for bleeding are also similar to those of standard half-life FVIII products. Three clinical trials are ongoing to assess the long-term safety and efficacy of turoctocog alfa for PTPs and previously untreated patients. Those data will be published in the near future, and it will be possible to use turoctocog alfa for all hemophilia patients. However, studies will be needed to confirm the turoctocog alfa profile, such as the stability of dissolved turoctocog alfa over 24 hours at room temperature and post-marketing clinical research aimed at meeting Europe Medicines Agency post-marketing safety and efficacy requirements in PTPs. It is recommended to wait before using turoctocog alfa for previously untreated patients and major surgery until further data have been collected and published.

The pharmacokinetics of a B‐domain truncated recombinant factor VIII, turoctocog alfa (NovoEight®), in patients with hemophilia A

Turoctocog alfa (NovoEight(®)) is a human recombinant coagulation factor VIII (rFVIII) for the treatment of patients with hemophilia A. To evaluate the pharmacokinetics of turoctocog alfa in all age groups across clinical trials. Data from previously treated patients with severe hemophilia A (FVIII activity level of ≤ 1%) with no history of FVIII inhibitors, in a non-bleeding state, were included. The pharmacokinetics were assessed following a wash-out period and a subsequent single intravenous 50 IU kg(-1) dose of turoctocog alfa. Blood was sampled during a 48-h period postdose. Standard pharmacokinetic (PK) parameters were estimated on the basis of plasma FVIII activity vs. time (PK profiles) with non-compartmental methods. Furthermore, a population PK analysis was conducted. Data from 76 patients (aged 1-60 years) enrolled globally across six clinical trials were included, totaling 105 turoctocog alfa PK profiles. Single-dose PK results 3-6 months after the first dose of turoctocog alfa were comparable with the results obtained after the first dose. Similar PK characteristics were shown for different lots and strengths of the drug product. Overall, area under the plasma concentration (activity) curve from administration to infinity (AUC) and t1(/2) tended to increase with increasing age, with lower AUC and shorter t(1/2) being seen in children than in adolescents and adults. The PK profiles of turoctocog alfa and other commercially available plasma-derived FVIII and rFVIII products were similar in all age groups. The PK characteristics of turoctocog alfa have been thoroughly studied, and shown to be consistent over time, reproducible between different lots and strengths of drug product, and similar to those observed for other FVIII products.

Turoctocog alfa (recombinant factor VIII)

Turoctocog alfa (NovoEight®) is a new recombinant factor VIII (rFVIII) with a truncated B domain and a high degree of tyrosine sulphation, similar to plasma-derived FVIII products. The manufacturing process includes double nanofiltration with a 20-nm pore size and immunoaffinity chromatography with monoclonal F25 anti-FVIII antibodies. Treatment with turoctocog alfa can be monitored with both one-stage and chromogenic substrate assays without a product-specific laboratory standard. In total, 213 previously-treated patients with severe haemophilia A participated in the pivotal part of the clinical trial programme guardianTM. The median annualised bleeding rate during turoctocog alfa prophylaxis was 3.7 and 3.0 in adolescents/adults and children, respectively, with marked differences between participating countries. The success rate for the treatment of breakthrough bleeds was 85% (adults/adolescents) and 94% (children). A total of 41 surgical procedures (15 major, 26 minor) were performed in 33 patients, with a successful haemostatic response reported in all cases. No patient developed confirmed inhibitors in any of the trials.

Changes in Annualized Bleeding Rate over Time and Relationship with Dosing of Turoctocog Alfa during the guardian™ Program

▪Introduction: The guardian™ program is a large, multinational trial program designed to support the registration of turoctocog alfa (NovoEight®), a new B-domain–truncated recombinant Factor VIII (FVIII) molecule. A total of 214 patients with severe hemophilia A without inhibitors were enrolled in the guardian™ program as of 1 Sept 2012. Two open-label, non-controlled, phase 3a trials assessing the efficacy, safety, and pharmacokinetics of turoctocog alfa in previously treated patients (PTPs) ≥12 years old (guardian™1) or PTPs <12 years old (guardian™3) were conducted; upon completion, participants could enter an extension trial (guardian™2) that is ongoing. Patients received turoctocog alfa as prophylaxis and to treat bleeds. The primary endpoint was incidence of FVIII inhibitors (≥0.6 Bethesda Units) and a key efficacy endpoint was the annualized bleeding rate (ABR).Methods: For inclusion in this post-hoc analysis, PTPs must have participated in guardian™2 and either guardian™1 or 3, had ≤1 week of surgery treatment in guardian™1/guardian™3 (initial period), and had ≥3 months of exposure to turoctocog alfa prophylaxis during a selected time period (1 January 2012 – 30 June 2013) in guardian™2. This guardian™2 time period was selected to obtain a group of patients who had participated in the trial for an adequate duration to enable comparison over time. Starting dose of turoctocog alfa was 20 IU/kg in guardian™1 and was determined by the investigator in guardian™3; doses were adjusted based upon clinical criteria, at the discretion of the physician.This analysis investigated the relationship between change in ABR from guardian™1/guardian™3 to guardian™2 and average ABR during these periods. Change in ABR was defined as the change in number of bleeds per year and average ABR was defined as (ABR [guardian™1/guardian™3] + ABR [guardian™2]) /2 for each patient. Change in ABR versus the ratio of mean weekly preventive dose was also investigated, with ratio defined as (mean weekly dose [guardian™ 2] / [mean weekly dose [guardian™1/guardian™3]) for each patient. Analyses were descriptive; statistical analyses were not conducted.Results: A total of 166 patients met inclusion criteria for this analysis (111 from guardian™1 [21 adolescents 12–17 years old and 90 adults ≥18 years old] and 55 from guardian™3 [27 children ≤5 years old and 28 children 6–11 years old]). For this subgroup of patients with prolonged extension study exposure, overall median ABR in guardian™1 was 4.0 bleeds/patient/year (range: 0.0–38.4), and in guardian™3 was 3.8 bleeds/patient/year (range: 0.0–34.7); overall median ABR during guardian™2 was 1.6 bleeds/patient/year (range: 0.0-18.8). ABR by age is shown in table 1.Table 1: Median annualized bleeding rate and reduction over time Abstract 2850. Tableguardian™1/ guardian™3guardian™2% reduction during extensionAdults4.21.369%Adolescents4.01.563%Children 6–11 years3.62.336%Children ≤5 years3.82.047%The majority of patients had a reduction in ABR during the trials (Fig. 1). The patients with the highest ABR during the initial period were those with the largest reduction in ABR. When the change in ABR was examined by age, older patients tended to have a larger reduction in ABR than younger patients. For some patients, ABR in guardian™2 was higher than in the initial period. There was no clear correlation between dose and ABR (figure not shown in abstract). Within age groups, weekly doses were highly variable. The majority of patients showed an increase in dose over the analyzed period, most by approximately 20% compared with the initial dose (figure not shown). [Display omitted] Conclusions: For PTPs on long-term prophylaxis with turoctocog alfa, change in ABR over time may be correlated with initial ABR levels. Patients who initiated with high ABR levels (and therefore likely poor joint status) tended to have the most pronounced reduction in ABR while, for others, low ABR was maintained. Older patients likewise tended to have a larger reduction in ABR than younger patients. No clear correlation was found between dose and ABR, indicating that dose changes may occur due to considerations other than bleeding frequency. Slight increases in dose over time likely represent individualized dose adjustments by physicians aimed to optimize treatment outcomes. DisclosuresOzelo:Novo Nordisk, Baxter and Bayer: Consultancy, Speakers Bureau; Bayer, CSL Behring and Novo Nordisk: Research Funding. Janic:Novo Nordisk, Baxter, Bayer, Pfizer and Octafarma: Honoraria; Novo Nordisk, Baxter and Bayer: Speakers Bureau; Novo Nordisk, Baxter, Bayer and Pfizer: Research Funding. Matytsina:Novo Nordisk A/S: Employment. Landorph:Novo Nordisk A/S: Employment. Zeuthan:Novo Nordisk A/S: Employment. Santagostino:Pfizer: Research Funding; Bayer, Pfizer, Baxter, CSL Behring, Novo Nordisk and Grifols: Consultancy; Biotest, Kedrion and Octapharma: Speakers Bureau.

Distribution of F8 Gene Mutations in 81 Inhibitor-Free, Severe Hemophilia a Patients with Full Exposure to FVIII

Introduction: Factor (F) VIII genotype has been shown to be a risk factor for inhibitor development, where different mutation types are associated with different degrees of risk (Oldenburg J, et al.Haemophilia 2006;12 Suppl 6:15–22). However, it is not clear why some patients with a specific mutation develop inhibitors while others with the same mutation do not, including those with high-risk defects such as null mutations. Patients with severe hemophilia A (HA) with low-risk mutations are thought to produce some functional or non-functional FVIII that is sufficient to induce immune tolerance (Oldenburg J, et al.Haemophilia 2002;8 Suppl 2:23–29). In the present study, the distribution of F8 gene mutations in 81 patients fully exposed to FVIII with severe HA and no inhibitors is compared to data on mutation distribution among severe HA patients with/without inhibitors.Materials & Methods: Turoctocog alfa (NovoEight®) is a new recombinant FVIII product with a truncated B-domain. Previously treated patients (PTPs) with severe HA participated in the pivotal trials guardian™1 (n=150; 12–65 yrs) or guardian™3 (n=63; <12 yrs), in which they received turoctocog alfa as prophylaxis and to treat bleeds. The majority continued in an ongoing extension trial, guardian™2. All patients ≥12 yrs had a history of ≥150 exposure days (EDs) to FVIII products and patients <12 yrs had ≥50 EDs. No patients had inhibitors prior to or after turoctocog alfa treatment. Distribution of mutation types has previously been reported in populations with HA that consisted of or included patients with inhibitors (Salviato R, et al. Haemophilia 2007;13:361–372; Gouw SC, et al.Blood 2012;119:2922–2934). Here we report mutation distribution in a sample of guardian™ patients with severe HA who had long been previously treated with FVIII protein and remained inhibitor free, and compared this distribution with that from 2 published studies (Oldenburg J, et al. 2006; Salviato R, et al. 2007).Results: Eighty-one patients enrolled in the guardian™ trials had F8 gene mutation analyzed. For 52 patients <12 yrs old, genotype was analyzed during guardian™3. For 29 patients ≥12 yrs old, genotype analysis was done prior to enrollment and obtained from medical records. In 77/81 patients, the F8 gene defect was identifiable. Distribution of gene mutations in guardian™, in a population with severe HA with inhibitors, and in a population with severe HA with/without inhibitors are compared in table 1. It is interesting that the overall distribution of mutations among the populations appears quite similar, pointing toward the multifactorial nature of inhibitor development.Null mutations (inversions, nonsense mutations, and large deletions) were present in 66% and 75% of patients with severe HA and severe HA with inhibitors, respectively (table 1). In guardian™, 57% (46/81) of patients had null mutations despite never having developed an inhibitor. The difference in distribution of null mutations in the 3 populations is mainly accounted for by large deletions and nonsense mutations, while distribution of inversions was similar. It should be noted that in guardian™, 10/11 patients with missense mutations had these located outside the C1/C2 domain, which reportedly has a lower frequency of inhibitors compared with missense mutations at the C1/C2 domain (Oldenburg J, et al. 2006).Conclusions: Eighty-one patients in the guardian™ trial with severe hemophilia A had their genotype analyzed and all of them were inhibitor-free over their lifetime. Interestingly, the prevalence of high-risk mutation types does not seem to differ markedly from previously published data in patients with inhibitors, probably indicating the relevance of other factors in inhibitor development.Table 1Distribution of F8 gene mutation typesguardian™Additional studiesguardian™ patients (N)Distribution (%) in guardian™ patients (severe HA without inhibitors)Distribution (%) in patients with severe HA and inhibitors (Salviato R, et al. 2007)*Distribution (%) in patients with severe HA with/without inhibitors (Oldenburg J, et al. 2006)Total, N818176753Intron 22 inversion3340.744.745.0Intron 1 inversion33.71.32.5Nonsense89.918.413.5Large deletion22.510.55.0Missense1113.65.214.5Small del/ins/dupl1619.810.516.0Splice site44.95.23.5Unidentified/ not enough information44.93.90.0Total81100.0100.0100.0*Only patients with severe HA included. DisclosuresMatytsina:Novo Nordisk A/S: Employment. Arai:Novo Nordisk Pharma, Ltd: Employment. Oldenburg:Baxter, Bayer, Biogen Idec, Biotest, CSL-Behring, Grifols, Novo Nordisk, Octapharma, Swedish Orphan Biovitrum and Pfizer: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.

Factor VIII Dosing and Preventive Efficacy in Obese Patients with Hemophilia (BMI ≥30 kg/m2) – a Post-Hoc Sub-Analysis of the guardian™ Trials

Introduction & Objectives: Given the longer life expectancy for people with hemophilia today, an increase in diseases such as obesity (defined as body mass index [BMI] ≥30 kg/m2) (Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults – The Evidence Report. National Institutes of Health. Obes Res 1998;6 Suppl 2:51S–209S), diabetes, and cardiovascular disease poses an increasing challenge to their care. Obesity may be of special relevance in hemophilia, both in terms of dosing as well as in impact on general health, yet little is known and published on this topic. Factor (F) VIII dosing is based on body weight (BW) and it has been shown that in vivo recovery increases with BMI due to a decrease in volume of distribution (Blanchette VS, et al. J Thromb Haemost 2008;6:1319–1326). Consequently, dosing based on ideal BW instead of actual BW has been suggested (Hanley MJ, et al. Clin Pharmacokinet 2010;49:71–87; Henrard S, et al. Haematologica 2013;98:1481–1486). In addition to negative effects on general health, obesity can also affect joint health. Intuitively, an increased BMI can have a deleterious effect on joints and aggravate arthropathy, which could theoretically be reflected in higher annualized bleeding rates (ABRs). However, published data are scarce, and conflicting or inconclusive. We performed a post hoc analysis of prevalence, dosing, and outcomes recorded in obese patients in clinical trials of turoctocog alfa (NovoEight®), a new B-domain–truncated recombinant FVIII product.Materials & Methods: Previously treated patients with severe hemophilia A without FVIII inhibitors participated in the phase 3a guardian™1 trial (Lentz SR, et al. Haemophilia 2013;19:691–697), and most continued in the extension trial, guardian™2, which is currently ongoing. Adult patients with BW >120 kg were not eligible (in guardian™1), but there were otherwise no restrictions regarding BMI. Prophylactic treatment with turoctocog alfa was given every other day or 3 times weekly. All patients started with an actual body–weight based dose of 20 IU/kg, which could be increased at the investigator’s discretion. Dosing based on ideal BW was not used. Patients who participated in either guardian™1 or guardian™2 and who were ≥18 years old at entry to the latest of the 2 studies (i.e., at entry to guardian™2 unless the patient only participated in guardian™1) were included in this analysis. Data were included up to 30 June 2013.Results: Mean age at the time of enrollment in the guardian™2 trial was 32 years for obese and 31 years for non-obese patients. Mean duration of observation was 2.23 years per patient for obese and 2.16 years for non-obese patients. Twenty-two of 137 patients (16.1%) had a BMI of ≥30 kg/m2 at some point during the observation period. Of these, 13 patients were from the US (comprising 46% of the total adult US patient cohort), which is approximately double the percentage reported in data compiled by the Centers for Disease Control and Prevention in 2005 (Report on the Universal Data Collection Program. 2005;7[1]:30–39).Mean turoctocog alfa dose/kg BW used for prevention per administration was 25.9 IU/kg in obese and 28.3 IU/kg in non-obese patients (p=0.20). The mean annualized consumption of turoctocog alfa was 4154 IU/kg/year in obese and 4393 IU/kg/year in non-obese patients (p=0.39). The estimated mean ABR was 3.28 and 3.85 bleeds/patient/year in the obese and non-obese patients, respectively (p=0.57).Conclusions: In the guardian™ clinical trial population examined in this analysis, 16.1% of the total and 46% of US patients were obese, thus highlighting the importance of this co-morbidity in modern hemophilia care. Dosing was similar for both non-obese and obese patients, which was expected given the setting of relatively rigid (and body-weight based) dosing in these trials. Importantly, no statistically significant difference in ABR between obese and non-obese patients was found in the guardian™ trials. These findings could be related to the small subgroup population size and exclusion of patients with BW >120 kg. Given the high prevalence of obesity and its potential effect on pharmacokinetic parameters, joint health, and overall health status, more research is needed on this topic. DisclosuresRecht:Novo Nordisk: Research Funding. Lentz:Novo Nordisk: Consultancy; Novo Nordisk: Research Funding. Matytsina:Novo Nordisk A/S: Employment. Landorph:Novo Nordisk A/S: Employment. Saugstrup:Novo Nordisk A/S: Employment.

A new recombinant factor VIII: from genetics to clinical use.

Advances in recombinant technology and knowledge about coagulation factor VIII (FVIII) are building a platform for new therapeutic options in patients with hemophilia A. The development of turoctocog alfa, a novel, high-purity, third-generation, B-domain truncated recombinant FVIII, has been produced and formulated without the use of animal-derived or human serum-derived components, in the wake of understanding of the new biochemical characteristics of FVIII, namely its protein structure, and glycosylation and sulfating patterns. Culture conditions and a five-step purification process have been developed to optimize the safety of turoctocog alfa. The results of two pilot clinical trials using turoctocog alfa confirmed high safety levels, with no patient developing inhibitors during the period of observation. The purpose of this review is to describe briefly the molecular and biological properties of turoctocog alfa, together with details of its clinical development, with emphasis on the needs of patients with hemophilia A.

Safety and efficacy of turoctocog alfa (NovoEight®) during surgery in patients with haemophilia A: results from the multinational guardian™ clinical trials.

Recombinant factor VIII (rFVIII) products provide a safe and efficacious replacement therapy for prevention and treatment of bleeding episodes in patients with haemophilia A. The present investigations from the multinational, open-label guardian™ clinical trials assessed the haemostatic response of turoctocog alfa (NovoEight®), a rFVIII product, in patients with severe haemophilia A (FVIII ≤ 1%) undergoing surgery. All patients had a minimum of 50 exposure days to any FVIII product prior to surgery and no history of inhibitors. A total of 41 procedures (13 orthopaedic, 19 dental and 9 general) were performed in 33 patients aged 4–59 years. Of the 41 procedures, 15 were major surgeries in 13 patients and 26 were minor surgeries in 21 patients. The success rate for haemostatic response was 100% (success was defined as ‘excellent’ or ‘good’ haemostatic outcome). Turoctocog alfa consumption on the day of surgery ranged from 27 to 153 IU kg−1. The mean daily dose declined over time, while retaining adequate FVIII coverage as measured by trough levels. Overall, no safety issues were identified. No thrombotic events were observed and none of the patients developed FVIII inhibitors. In conclusion, the present results show that turoctocog alfa was effective in controlling blood loss by obtaining a sufficient haemostatic response in patients with severe haemophilia A undergoing surgery.

Turoctocog alfa for the treatment of hemophilia a.

Hemophilia A (HA) represents one of the most common genetic bleeding disorders worldwide and results from a deficiency in factor VIII (FVIII). The mainstay of treatment for HA is repletion of FVIII. Numerous plasma-derived and recombinant factor concentrates are available, each with clinical advantages and disadvantages. Nonfactor products including desmopressin and antifibrinolytic agents can also be used, depending on the clinical situation and severity of FVIII deficiency. Turoctocog alfa is the most recent addition to recombinant FVIII concentrates available for the treatment of HA. Pharmacokinetic trials in animals and humans have demonstrated characteristics similar to those of other recombinant FVIII concentrates. Clinical trials have supported efficacy and safety in the management of HA in treatment-experienced patients; study results of turoctocog alfa in treatment-naïve patients are pending. A smaller study in hemophilic patients undergoing surgery has demonstrated positive results. Although turoctocog alfa was approved by the U.S. Food and Drug Administration in 2013, it will not be available on the market until 2015. Turoctocog alfa appears to be a safe and effective alternative to currently available recombinant FVIII concentrates; however, its place in therapy among these products has yet to be elucidated.

Turoctocog alfa (NovoEight®)--from design to clinical proof of concept.

Turoctocog alfa (NovoEight®) is a recombinant factor VIII (rFVIII) with a truncated B-domain made from the sequence coding for 10 amino acids from the N-terminus and 11 amino acids from the C-terminus of the naturally occurring B-domain. Turoctocog alfa is produced in Chinese hamster ovary (CHO) cells without addition of any human- or animal-derived materials. During secretion, some rFVIII molecules are cleaved at the C-terminal of the heavy chain (HC) at amino acid 720, and a monoclonal antibody binding C-terminal to this position is used in the purification process allowing isolation of the intact rFVIII. Viral inactivation is ensured by a detergent inactivation step as well as a 20-nm nano-filtration step. Characterisation of the purified protein demonstrated that turoctocog alfa was fully sulphated at Tyr346 and Tyr1664, which is required for optimal proteolytic activation by thrombin. Kinetic assessments confirmed that turoctocog alfa was activated by thrombin at a similar rate as seen for other rFVIII products fully sulphated at these positions. Tyr1680 was also fully sulphated in turoctocog alfa resulting in strong affinity (low nm Kd) for binding to von Willebrand factor (VWF). Half-lives of 7.2 ± 0.9 h in F8-KO mice and 8.9 ± 1.8 h haemophilia A dogs supported that turoctocog alfa bound to VWF after infusion. Functional studies including thromboelastography analysis of human haemophilia A whole blood with added turoctocog alfa and effect studies in mice bleeding models demonstrated a dose-dependent effect of turoctocog alfa. The non-clinical data thus confirm the haemostatic effect of turoctocog alfa and, together with the comprehensive clinical evaluation, support the use as FVIII replacement therapy in patients with haemophilia A.

Innovative approach for improved rFVIII concentrate

The development of a new recombinant factor VIII was designed and implemented to answer a number of unmet needs of patients affected by hemophilia A. Turoctocog alfa is bioengineered in a specific Chinese hamster ovary clone to present translational and posttranslational characteristics (sulphation, glycosylation) biosimilar to natural circulating forms of FVIII, with the aim to devoid any minimal change which may impact immunogenicity and antigenicity of recombinant protein. Both producer cell line and media are maintained free of any animal or human plasma derivative. Downstream processes of purification are performed by five steps (immunoaffinity chromatography, ion‐exchange chromatography, virus inactivation by means of solvent‐detergent treatment and nanofiltration, and to end with gel filtration), to provide the best possible margin of safety from known and unknown infectious agents. Large clinical trials seem to confirm the expectations placed in Turoctocog alfa in terms of high quality and safety of recombinant FVIII toward the goal of overcoming actual and future challenges of hemophilia therapy.

Turoctocog alfa for the treatment of hemophilia A

Patients with hemophilia A lack functional coagulation factor VIII (FVIII), causing excessive spontaneous bleeding episodes and bleeding during trauma or surgery. Plasma-derived or synthetic recombinant FVIII is used to control bleeding, but currently available treatments are limited because of patient development of FVIII inhibitors and cross-contamination of human and animal-derived infectious agents. Turoctocog alfa is a recombinant FVIII produced in Chinese hamster ovary cells that has demonstrated good efficacy in thrombin generation and clot formation in preclinical evaluations in murine and canine models of hemophilia A and in patient-derived whole blood. Evaluation in clinical trials in pediatric and adult patients with hemophilia A have demonstrated that the drug has good pharmacokinetic parameters, excellent efficacy in improving annualized bleeding rates, few adverse events and no induction of FVIII inhibitors. The drug is FDA approved as a prophylactic agent and for on-demand treatment to control bleeding including during operative procedures.

The Pharmacokinetics Of Turoctocog Alfa Are Consistent Over Different Concentrations and Production Lots

Introduction Turoctocog alfa is a B domain truncated human recombinant FVIII for treatment of patients with hemophilia A. The production yields a highly homogenous product with the same tyrosine sulphation as human FVIII. In order to confirm the consistency of turoctocog alfa pharmacokinetics (PK) over different production lots and vial strengths, a clinical trial was performed in 15 patients with severe hemophilia A. Aim To compare the PK of 3 lots of 2000 IU/vial and 1 lot of 3000 IU/vial of turoctocog alfa after i.v. administration of 50 IU/kg in patients with severe haemophilia A. Methods This was a multi-centre, open-label trial investigating the PK of 4 lots of turoctocog alfa (3 lots of 2000 IU/vial; Lots A, B and C, and 1 lot of 3000 IU/vial; Lot D) in patients with severe hemophilia A (FVIII&lt;1%). The trial was performed as a two-period, incomplete block, cross-over trial, in which each patient was allocated at random to a predefined sequence of 2 different lots of turoctocog alfa. The FVIII activity was assessed using both the one-stage clot and chromogenic assays. Both the primary endpoint, normalized AUC (AUC*(planned dose/actual dose)), and the secondary PK endpoints were analyzed by ANCOVA on the log transformed values, with lot, visit and patient as fixed effects. Each of the three 2000 IU/vial lots was compared and tested against the 2 other 2000 IU/vial lots. If not significantly different on a 5% level, the 3 lots were pooled together and tested against the 3000 IU/vial lot. Results Fifteen patients with a mean age of 38.6 years (ranging from 21 to 60 years) were included from 3 hemophilia centres in 3 different countries. Three adverse events (AEs) were reported in the trial by 2 separate patients; all AEs were judged to be unlikely related to the trial product. There was no development of inhibitors. There was no pharmacokinetic difference observed between Lots A, B, C (2000 IU/vials) and there was no pharmacokinetic difference observed between the pooled data from lot A, B and C (2000 IU/vial) and lot D (3000 IU/vial) based on normalized AUC, half-life, incremental recovery and clearance. The estimated mean values (with 90% CI) for the PK parameters based on the chromogenic assay are presented in Table 1. The results were similar for the one-stage clot assay and the chromogenic assay. Conclusions No pharmacokinetic differences were observed between the three 2000 IU/vial lots (Lot A, Lot B and Lot C), nor were there pharmacokinetic differences between Lot D (3000 IU/vial) and pooled data from Lots A, B and C, based on normalized AUC, half-life, incremental recovery and clearance. There were no safety concerns and no inhibitor development in the trial. Disclosures: Jiménez-Yuste: Novo Nordisk: Consultancy, Research Funding, Speakers Bureau. Klamroth:Novo Nordisk, CSL Behring, Bayer, Baxter, Pfizer: Honoraria, Research Funding. Saugstrup:Novo Nordisk: Employment. Moss:Novo Nordisk: Employment.

Prolonged effect of a new O-glycoPEGylated FVIII (N8-GP) in a murine saphenous vein bleeding model

Prophylaxis in severe haemophilia significantly increases health-related quality of life for patients, but the dosing frequency still constitutes a challenge. Thus, there is a need for new treatment options, utilizing compounds with longer duration of action, while still maintaining potency. The objective of this study was to evaluate the acute and prolonged effects of a new glycoPEGylated recombinant factor VIII (rFVIII) (N8-GP) in a venous bleeding model in haemophilia A mice and to compare the efficacy and potency to turoctocog alfa (rFVIII). Following intravenous administration of turoctocog alfa or N8-GP to normal and FVIII-deficient mice, bleeding time and blood loss from a saphenous vein incision were evaluated in an acute dose-response study and a duration of action study. In the acute setting, N8-GP dose dependently reduced the number and duration of bleeding episodes as well as blood loss compared to FVIII-deficient mice, reaching statistical significance at doses as low as 5-10 U kg(-1) . In the duration of action study, a significantly prolonged and maintained effect of N8-GP was found for up to 48 h after dosing, whereas the effect of rFVIII was no longer present for any end-points 24 h after dosing. Seventy-two hours after dosing, no significant effect of either compound was found. This study shows a prolonged haemostatic effect of N8-GP compared to rFVIII supporting other recent studies that N8-GP may hold a potential to increase the quality of life for patients with haemophilia A by reducing dosing frequency.

Results from a large multinational clinical trial (guardian™3) using prophylactic treatment with turoctocog alfa in paediatric patients with severe haemophilia A: safety, efficacy and pharmacokinetics

Recombinant factor VIII (rFVIII) products provide a safe and efficacious replacement therapy for prophylaxis and treatment of bleeding episodes in patients with severe haemophilia A. This multinational, open-label, non-controlled trial investigated the safety, efficacy and pharmacokinetics (PK) of turoctocog alfa, a new rFVIII product, in a paediatric population. The primary objective was to evaluate safety. A total of 31 younger children (0-5 years) and 32 older children (6-11 years), with ≥ 50 exposure days to any factor VIII (FVIII) product and no history of inhibitors, received prophylaxis with turoctocog alfa (25-50 IU kg(-1) every second day or 25-60 IU kg(-1) three times weekly). PK assessments of turoctocog alfa and the patients' previous FVIII product were performed in 28 patients. Mean exposure to turoctocog alfa was 60 exposure days per patient. This corresponds to approximately 4.5 months in the trial. None of the patients developed inhibitors (≥ 0.6 BU) and no safety concerns were raised. A total of 120 bleeding episodes (95%) were controlled with 1-2 infusions of turoctocog alfa. Based on patient reports, the success rate (defined as 'excellent' or 'good' haemostatic response) for treatment of bleeding episodes was 92%. Overall, the median annualized bleeding rate was 3.0 (interquartile range: 8.5) bleeds patient(-1) year(-1) . PK parameters were comparable between the two age groups. In conclusion, the present large global clinical trial showed that turoctocog alfa was safe, effective in treatment of bleeding episodes and had a prophylactic effect in paediatric patients.

Results from a large multinational clinical trial (guardian™1) using prophylactic treatment with turoctocog alfa in adolescent and adult patients with severe haemophilia A: safety and efficacy

Recombinant factor VIII (rFVIII) products provide a safe and efficacious replacement therapy for prophylaxis and treatment of bleeding episodes in patients with severe haemophilia A. This multinational, open-label, non-controlled trial investigated the safety and efficacy of turoctocog alfa, a new rFVIII product. The primary objective was to evaluate safety. A total of 150 patients (24 adolescents and 126 adults) with severe haemophilia A (FVIII activity ≤ 1%), with at least 150 exposure days (EDs) to any FVIII product and no history of inhibitors were enrolled, and 146 patients (97%) completed the trial. All patients received prophylaxis with turoctocog alfa for approximately 6 months and had a mean of 85 EDs during the trial. None of the patients developed FVIII inhibitors, there were no indications of early FVIII inhibitor development and no safety concerns were identified. A total of 225 adverse events were reported in 100 (67%) patients, with the most common being events associated with dosing procedures, headaches, and nasopharyngitis. A total of 499 bleeding episodes were reported during the trial, the majority (89%) were controlled with 1-2 infusions of turoctocog alfa. Based on patient reports, the success rate (defined as 'excellent' or 'good' haemostatic response) for treatment of bleeding episodes was 81%. The overall median annualized bleeding rate was 3.7 (interquartile range: 8.7) bleeds/patient/year. In conclusion, turoctocog alfa provides a new, safe and effective alternative for prophylaxis and treatment of bleeding episodes in patients with haemophilia A.

Evaluation of the metal binding sites in a recombinant coagulation factor VIII identifies two sites with unique metal binding properties

Coagulation factor VIII is a glycosylated, non-covalent heterodimer consisting of a heavy chain (A1-A2-B domains) and a light chain (A3-C1-C2 domains). The association of the chains, and the stability and function of the dimer depend on the presence of metal ions. We applied X-ray fluorescence, X-ray crystallographic structure determination with anomalous signals at different wavelengths, and colorimetric measurements to evaluate the metal binding sites in a recombinant factor VIII molecule, turoctocog alfa. We identified a metal binding site in domain A3 dominated by Cu(+) binding and a site in domain A1 dominated by Zn(2+) binding.