Recombinant Coagulation Factor Research Articles

Effect of the intraoperative infusion of recombinant activated coagulation factor VII on short-term prognosis and thoracic complications after acute aortic coarctation

Purpose: To investigate the impact of intraoperative infusion of recombinant human-activated coagulation factor VII (rFVIIa) on postoperative outcomes in patients with acute aortic dissection (AAD). Methods: This study involved 120 individuals who underwent aortic coarctation surgery between January 1, 2020, and December 31, 2022 in the First Affiliated Hospital of Xinjiang Medical University, Xinjiang, China. The participants were divided into control (receiving only conventional treatment) and study (receiving rFVIIa infusion in addition to conventional treatment) groups. Various parameters, including patient status, postoperative measures, and complications were evaluated. Results: There was no significant difference in age, gender distribution, duration of myocardial block, onset time, or surgery duration (p > 0.05) between both groups. However, the study group exhibited longer extracorporeal circulation duration (p < 0.05). The study group also demonstrated lower levels of chest drainage compared to the control group 12 and 24 h after surgery (p < 0.05). Moreover, fewer concentrated red blood cells and fresh frozen plasma transfusions were administered to study group (p < 0.05). Despite having longer stays in the ICU (p < 0.05), the study group required less postoperative mechanical ventilation (p < 0.05). There was a significant difference in the incidence of postoperative thrombosis cases, positive gram-negative bacilli sputum culture results, and deaths within the study group (p < 0.05). Conclusion: Intraoperative rFVIIа infusion in AAD patients enhances short-term prognosis, with elevated risk of chest complications. However, further studies with larger sample sizes is essential to comprehensively assess clinical advantages and drawbacks.

Design and construction of a phage-displayed Camelid nanobody library using a simple bioinformatics method

BackgroundRational design of synthetic phage-displayed libraries requires the identification of the most appropriate positions for randomization using defined amino acid sets to recapitulate the natural occurrence. The present study uses position-specific scoring matrixes (PSSMs) for identifying and randomizing Camelidae nanobody (VHH) CDR3. The functionality of a synthetic VHH repertoire designed by this method was tested for discovering new VHH binders to recombinant coagulation factor VII (rfVII). MethodsBased on PSSM analysis, the CDR3 of cAbBCII10 VHH framework was identified, and a set of amino acids for the substitution of each PSSM-CDR3 position was defined. Using the Rosetta design SwiftLib tool, the final repertoire was back-translated to a degenerate nucleotide sequence. A synthetic phage-displayed library was constructed based on this repertoire and screened for anti-rfVII binders. ResultsA synthetic phage-displayed VHH library with 1 × 108 variants was constructed. Three VHH binders to rfVII were isolated from this library with estimated dissociation constants (KD) of 1 × 10−8 M, 5.8 × 10−8 M and 2.6 × 10-7 M. ConclusionPSSM analysis is a simple and efficient way to design synthetic phage-displayed libraries.

Haemophilia and Cancer: A Literature Review.

Opinions in the literature on the impact of cancer on patients with haemophilia are contradictory. There is a lack of data on the clinical presentation and management of cancer in patients with haemophilia (PWH). Papers were found following a comprehensive search in PubMed, Google Scholar, and Scopus using the terms "cancer" and "haemophilia" without time limits and using the English language as a filter. The references from all the retrieved original articles and reviews were assessed for additional relevant articles. The emergence of malignancies is one of the important causes of morbidity and mortality in PWH. In the past decade, the literature mainly focused on the epidemiology and outcome of blood-borne cancers in the haemophilia patient group, as the incidence of hepatitis B virus (HBV), hepatitis C (HCV), and HIV infection were high among them. However, with the introduction of recombinant clotting factor concentrates (CFCs), physicians now pay attention to non-virus-related malignancies. Bleeding and thrombotic complications are important causes of morbidity and mortality in critically ill patients with cancer; replacement therapy with factor VIII or IX or others should be maintained during antitumour treatment. Overall, managing cancer in patients with haemophilia requires careful evaluation and individualised planning involving a multidisciplinary team of physicians experienced in haematology, oncology, and surgery.

Current status of treatment and disease burden of a cohort of hemophilia B in China.

Hemophilia B is a rare X-chromosome linked hereditary bleeding disorder. Patients require lifelong treatment and it is costly, but there is a lack of research in China on the treatment and burden for this group. Our aim was to review the actual treatment pattern of hemophilia B patients in China, and describe the financial burden and other disease burden from the patient's perspective. Using data collected by the Beijing Hemophilia Home Care Center, descriptive statistics were made on the sociodemographic characteristics and treatment of patients. The annual drug costs were calculated according to the actual factor dosage and price. During the study period, 29.9% of the patients only received on-demand treatment, while the rest of the patients received varying numbers of prophylaxis treatment. The total cost of clotting factors for 341 patients in one year was 16.0 million CNY ($2.5 million), with 46990.8 CNY ($7283.7) per patient. The drug cost of prophylaxis was significantly higher than that of on-demand treatment. The amount of prothrombin complex concentrates used by patients was the largest, more than 5 times of recombinant coagulation factor IX. Based on the average annual wage and average working time of Chinese employees in 2021, the average annual wage loss of HB patients reached 31544.2 CNY ($4889.4). The results of the questionnaire showed that 77.1% and 65.3% of patients had chronic pain and acute pain of different frequencies. The level of prophylaxis for Chinese patients is low; safer and more effective recombinant drugs are not widely available. Patients also face a high burden of drug costs, as well as indirect costs that cannot be underestimated. Therefore, continued efforts are needed to improve the quality of life of patients by reducing their financial burden and promote standardized treatment.

Safety and Efficacy of Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Previously Untreated Patients with Hemophilia B.

Introduction Recombinant fusion protein linking coagulation factor IX (FIX) with albumin (rIX-FP) has been shown to be an effective, well-tolerated treatment for patients with severe hemophilia B who had previously received factor replacement therapy. This study investigated the safety and efficacy of rIX-FP in previously untreated patients (PUPs). Methods Patients with moderately severe/severe hemophilia B (≤2% FIX) previously untreated with FIX replacement products received rIX-FP (25-75 IU/kg) prophylaxis weekly or on-demand treatment over ≥50 exposure days (EDs). Primary outcomes were the number of patients who developed FIX inhibitors and mean incremental recovery (IR) following a 50 IU/kg dose of rIX-FP. Secondary outcomes included incidence of adverse events (AEs) and annualized bleeding rates (ABRs). Results In total, 12 PUPs with a median age of 0 years (range, 0-11 years) were treated with rIX-FP for a median of 50 EDs (6/12 prophylaxis; 6/12 on-demand then prophylaxis). Overall, 11/12 patients did not develop FIX inhibitors; one 11-year-old patient developed an inhibitor against FIX after 8 EDs and was ultimately withdrawn. Mean (standard deviation) IR was 1.2 (0.4, n = 8) (IU/dL)/(IU/kg). Of the 137 treatment-emergent AEs recorded, five were attributed to rIX-FP. On the prophylaxis regimen, median ABR was 1.0 (range, 0-3.9, n = 12). No thromboembolic events or deaths occurred during the study. Conclusion This study provides data to support the safety and efficacy of rIX-FP in PUPs requiring on-demand or prophylactic treatment for moderately severe/severe hemophilia B, consistent with results in previously treated patients. Overall, 1/12 patients developed an inhibitor against FIX.

Andexanet Alfa Neutralizes the Anticoagulant Effects of Unfractionated Heparin of Bovine, Ovine and Porcine Origin Almost as Protamine Sulfate.

Andexanet alfa (AA) - zhzo, recombinant coagulation factor Xa, is an approved antidote for oral Xa inhibitors (apixaban and rivaroxaban). Unfractionated heparin (UFH) is commonly used for therapeutic, interventional, and surgical indications. Protamine sulfate (PrSO4) is frequently used to neutralize UFH. This study aimed to investigate the comparative neutralization profiles of AA and PrSO4 for heparins of bovine, ovine, and porcine origin. The neutralization effect of PrSO4 at 25 µg/ml and AA at 100 µg/ml was studied on an approximate surgical/interventional concentration of heparin by supplementing whole blood with each of the heparins at 25 µg/ml. For the clotting profile (activated partial thromboplastin time: aPTT), amidolytic (anti-Xa and anti-IIa), and thrombin generation assay each of the heparin were supplemented from -10-0.62 µg/ml. In the whole blood ACT studies, all three heparins produced strong anti-coagulant effects (400-450 seconds) compared to saline (130-150 seconds). Both AA and PrSO4 almost fully neutralized the anti-coagulant effects of heparins (140-160 seconds). Both antidotes completely reversed the anticoagulant effects of all three heparins in the aPTT and thrombin generation assay. However, PrSO4 was more effective in neutralizing the anti-Xa, and anti-IIa effects than AA, which only partially neutralized these effects. Andexanet alfa at 100 µg/ml effectively neutralizes the therapeutic and surgical/interventional concentrations of heparins in in-vitro settings. While differences in the anti-Xa, and anti-IIa effects between heparins were noted, anti-coagulant effect of these agents in the aPTT assay were comparable. A similar neutralization profile was observed in the ACT and thrombin generation assays by both agents.

Pharmacokinetics of Recombinant Human Coagulation Factor Ⅷ Preparations in Patients with Severe Hemophilia A

To calculate the pharmacokinetic parameters of recombinant human coagulation factor Ⅷ using myPKFiT in patients with severe hemophilia A, and provide an individualized treatment plan for patients. A total of 42 patients with severe hemophilia A who were treated with recombinant human coagulation factor Ⅷ were included from January 2021 to December 2021. myPKFiT was used to calculate the pharmacokinetic parameters of FⅧ, and the individualized treatment plan for hemophilia A patients was formulated. The median age of 42 patients with severe hemophilia A was 31（16-50） years old, the average weight was 54.0±9.9 kg, the half-life of FⅧ was 12.05±1.6 h, the time to more than 1% of the baseline was 62.3±15.3 h, and the 0 bleeding rate after the guidance of myPKFiT was significantly increased from 39% to 49%, the Annual bleeding rate was reduced from 3.6±2.5 to 2.1±2.0, and the Annual joint bleeding rate was reduced from 3.2±2.2 to 1.9±0.9, all of which were statistically different (P<0.05). Individualized therapy in patients with severe hemophilia A who were guided by myPKFiT assay of pharmacokinetics parameters can significantly reduce the annual bleeding rate and annual joint bleeding rate of patients.

Pharmacokinetics, Safety and Preliminary Efficacy of Multiple Doses of Pegylated Recombinant Human Coagulation Factor VIII-Fc Fusion Protein (FRSW117) in Previously Treated Adult and Adolescent Subjects with Severe Hemophilia a: Results from an Open-Label, Multicenter, Phase 2 Study

Introduction ：Prophylaxis of severe hemophilia A (HA) with standard half-life Factor VIII (FVIII) products necessitates frequent administration, and low trough FVIII activity levels lead to higher risk of bleeds. FRSW117 is a PEGylated recombinant human coagulation factor VIII Fc fusion protein (PEGylated rhFVIII-Fc), in a phase 1 study, single-dose FRSW117 was well tolerated and provided a prominently longer t1/2 with FVIII activity maintaining at ≥ 1% for more than 7 days. This open-label, multicenter phase 2 study (NCT05265286) aimed to evaluate the PK, safety, and preliminary efficacy of multiple 4 doses of FRSW117 in previously treated subjects with severe HA. Methods ：Severe HA (FVIII:C &amp;lt;1%) patients aged 12 (inclusive) to 65 years, previously treated with FVIII products ≥ 150 exposure days (EDs) were enrolled in two cohorts (M1, 40IU/kg; M2, 50IU/kg), to receive 4 once-weekly doses of FRSW117 on day 1, 8, 15, and 22 (ED1 to ED4), respectively. The PK characteristics, safety, and immunogenicity of FRSW117 were evaluated. PK samples were collected pre-dose on day 1, 8, 15, 22, and at multiple times after infusion on day 1 and day 22. The primary endpoints were the PK parameters, the occurs of AEs, inhibitor development, and other immunogenicity profiles; the secondary endpoints were the bleeding episodes during multiple dosing. FVIII activity was determined using one-stage clotting assay. FVIII inhibitor was tested using the Nijmegen-modified Bethesda assay. PK analyses were performed using noncompartmental analysis (Phoenix WinNonlin 8.3). Results ：Between April 2022 and August 2022, a total of 15 male subjects were enrolled in cohort M1 (N=8) and M2 (N=7). 13/15 (86.7%) of the subjects were adults, 2 of them were adolescent, both in M1. The mean age was 28.1 (range: 13, 44) in M1 and 30.6 (range: 23, 36) in M2. 14 subjects completed the study, with 1 subject in M2 withdrew early after the PK sampling of ED1 due to personal reasons. Baseline-corrected PK parameters were summarized in Table 1. Geometric mean elimination half-life (t 1/2) of M1 and M2 were 29.536h and 31.545 h, respectively, consisting with the first-in-human single dose study. Area under the activity-time curve (AUC 0-t), and steady-state maximum concentration (C max) after 4 weekly doses for M1 and M2 were 4557.1 and 4937.9 h*IU/dL, 101.26 and 122.76 IU/dL, respectively. The mean FVIII activity at 168h after dose for M1 and M2 were summarized in Table 2, and it were 3.25 and 2.88 IU/dL on 168 h (7 day) after the dose on D22. Baseline-corrected FVIII activity over time of 2 cohorts are shown in Figure 1. The accumulation index based on AUC tau were 1.008 and 1.098, respectively, indicating there was minimal accumulation after 4 once-weekly doses. A total of 10 (66.7%,10/15) subjects reported 20 treatment emergent adverse events (TEAE) during the study. No ≥ grade 3 adverse events, serious adverse events (SAE), adverse event leading to treatment discontinuation, or AESI were reported. No positive FVIII inhibitor was detected during the study. Pre-existing Anti-PEG-rhFVIII-Fc antibodies (ADA) were observed in 4/15 (26.7%) subjects.Pre-existing anti-PEG antibodies were observed in 3/15 (20.0%) subjects. No treatment emergent ADA and anti-PEG antibodies were observed, no treatment-boost ADA and anti-PEG antibodies were observed in subjects with pre-existing ADA and anti-PEG antibodies. No significant impact of pre-existing ADA and/or anti-PEG antibodies on PK variable, safety profile and preliminary efficacy was observed. 12/15 (80.0%) patients experienced zero bleeding episodes during the 4-week FRSW117 treatment period (from day 1 through day 28, 7 days after D22 dosing). Three of 15 (20.0%) subjects experienced 6 bleeding events among which only 1 spontaneous bleeding episode in cohort M1. 2 bleeds episodes were treated with FRSW117 of mean dose of 30.01 IU/kg and both were controlled after one infusion, with a hemostatic response rate of 100%. Conclusion: The therapy of 4 once-weekly doses of FRSW117 displayed favorable safety profile and provided about 3% mean FVIII activity on day 7 postdose with minimal accumulation. These results suggest that FRSW117 may offer extended bleeding protection with weekly dose interval and support further assessment of FRSW117 in phase 3 study.

Development of a Novel L-Asparaginase with Enhanced Properties Using Ancestral Sequence Reconstruction

The overall survival of children with acute lymphoblastic leukemia (ALL) now exceeds 90% due to the precise disease risk stratification and intensification of multi-agent chemotherapy regimens. L-asparaginase (L-ASNase) is an indispensable biotherapeutic enzyme used in treatment of pediatric ALL. Discontinuation of L-ASNase treatment due to immunological or adverse reactions leads to significantly inferior disease-free survival (73% ±7% vs 92% ± 2%; P &amp;lt;0.01, Gupta et al. JCO 2020). Clinical L-ASNases are bacterial in origin, derived from either Escherichia coli or Erwinia chrysanthemi and are therefore highly immunogenic. Additionally, emerging data suggests that the concurrent glutaminase activity seen in bacterial asparaginases exacerbates its liver and pancreatic toxicity, especially in adults thereby limiting its extensive use beyond children. Therefore, finding alternative sources with preferable biochemical features remains paramount. The inferior catalytic properties of human L-ASNase restricts its functionality in ALL treatment. However, characterization has shown that guinea pig (GP) L-ASNase demonstrates significant anti-tumor properties and improved enzyme kinetics despite a 69.8% amino acid sequence identity with human L-ASNase, as compared to 30% for bacterial L-ASNases. Additionally, guinea pig L-ASNase has no glutaminase activity. Thus, to overcome the major deficiencies of bacterial L-ASNase and develop a more humanized form of L-ASNase we performed ancestral sequence reconstruction (ASR). ASR is a protein drug discovery / optimization platform that predicts ancient DNA and protein sequences from extant sequences. This approach permits higher-resolution mapping potentially highlighting functional resides. The objective therefore is to exploit functional diversity refined by natural selection using ASR to identify therapeutic variants with superior properties. Recent work on guinea pig (GP) L-ASNase (Schalk et al. J Biol Chem 2014) identified a low micromolar (μM) Michaelis constant (Km) at 57.7 ± 6.4 μM essential for hydrolyzing the extra-cellular pool of asparagine ~50 μM in human blood; thus, equipping us with the ideal mammalian L-ASNase ortholog to serve as a template to resurrect ancient ASNase sequences. Ancestral L-ASNase sequences were generated utilizing 54 extant L- asparaginase sequences, aligned using MUSCLE and an evolutionary tree inferred using MrBayes. A total of 53 ancestral nodes were identified, and the ten ancestral L-ASNase variants spanning the ancient primate and guinea pig (GP) lineage were resurrected. The sequence identity of these ancestral L-ASNase variants ranged from 81 to 98% when compared to human L-ASNase. E. coli codon optimized complementary DNA (cDNA) sequences were synthesized and subcloned intoan expression vector. Correctly cloned plasmids were transformed into E. coli BL21 (DE3) cells for protein expression. An-ASNase candidates were isolated by Ni 2+ affinity chromatography and then further purified by size exclusion chromatography. Asparaginase activity of the An-ASNase candidates were determined via a modified Nessler's reagent assay by using a continuous spectroscopic enzyme-coupled assay. Three of the ancestral L-ASNase candidates, An-88, An-104 and An-107 demonstrated excellent asparaginase activity when tested at an enzyme concentration of 0.1 mg/mL and an excess substrate concentration, with activity within a comparable range to the clinically relevant E. coli and Erwinia asparaginases. An-88 had 81% similarity whereas both An-104 and An-107 ASNases had 88% identity to human L-ASNase, which is in stark contrast to the only 30% similarity seen with bacterial L-ASNases. Detailed enzymatic characterization of these three lead drug candidates is currently being performed. Preliminary cytotoxicity data testing the ancestral L-ASNase candidates against a T-cell ALL cell line CCRF-CEM showed an expected dose response, with An-107 showing the highest cytotoxicity. Our findings demonstrate that ASR is an efficient protein drug design/optimization platform that we have now extended beyond our previous work with recombinant coagulation factors (Zakas et al. Nat Biotech 2017, Knight et al. Blood Adv 2021) to therapeutic enzymes; thereby, enabling the creation of novel recombinant L-ASNases with translational implications due to improved enzymatic specificity and reduced toxicity.

PB0650 Safety and Efficacy of Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Pediatric Patients with Hemophilia B: A Review of Results from Phase 3 Trial Studies

PB0650 Safety and Efficacy of Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Pediatric Patients with Hemophilia B: A Review of Results from Phase 3 Trial Studies

Rare factor deficiencies in children: A review of 23 cases from a single center

Objective: The prevalence of rare factor deficiency (RFD) is one in 500.000-2.000.000 in the general population. Different symptoms may occur from mild or moderate bleeding to severe and life-threatening bleeding. This study aimed to evaluate children with RFD in a single Turkish center.&#x0D; Materials and Methods: The records of children with RFD (Factor I, V, VII, X, XIII deficiency) were evaluated retrospectively.&#x0D; Results: Twenty-three cases (70% female) were reviewed. The mean age of patients was 9.52 years at review, and mean follow-up was 66.3 months. The most common factor (F) deficiencies were FVII (35%) and FX (35%). Parental consanguinity was present in 65%. The most common symptoms were mucocutaneous bleeding and epistaxis. Regarding treatment, fresh frozen plasma (FFP) was given to two patients, FXIII concentrate was given to one patient, and prothrombin complex concentrate (PCC) was given to two patients. Prophylaxis was started in patients with recurrent bleeding. Of the 16 receiving prophylaxis, three received FFP, seven received recombinant coagulation factor VIIa, and six received PCC.&#x0D; Conclusion: Treatment was given to a fifth of patients while nearly three-quarters received prophylaxis. As parental consanguinity was present in most of these patients, obtaining a detailed family history may aid in diagnosis.

Current status and future prospects of activated recombinant coagulation factor VIIa, NovoSeven®, in the treatment of haemophilia and rare bleeding disorders.

rFVIIa, a human recombinant activated coagulation factor VII, has been used worldwide for more than two decades for the treatment of bleeding episodes and prevention of bleeding in patients undergoing surgery/invasive procedures with congenital haemophilia A or B with inhibitors (CHwI A or B), acquired haemophilia (AH), congenital factor VII deficiency and Glanzmann thrombasthenia (GT), refractory to platelet transfusion. The approved dosage, administration and indication of rFVIIa in the US, Europe and Japan differ, depending on the needs of the patient population and regulatory practices. This review presents an overview of the current status and future prospects, including that from a Japanese perspective, of using rFVIIa in the treatment of approved indications. The efficacy and safety of rFVIIa in the approved indications has been demonstrated in several randomised and observational studies and data from registries. The overall incidence of thrombosis across all approved indications in a retrospective safety assessment of clinical trials and registries, prelicensure studies and postmarketing surveillance studies of rFVIIa use was 0.17%. Specifically, the risk of thrombotic events was 0.11% for CHwI, 1.77% for AH, 0.82% for congenital factor VII deficiency and 0.19% for GT. Emerging non-factor therapies such as emicizumab have changed the treatment landscape of haemophilia A, including preventing bleeding in patients with CHwI. However, rFVIIa will continue to play a significant role in the treatment of such patients, particularly during breakthrough bleeding or surgical procedures.

COMPARING THE EFFECTIVENESS OF CONCENTRATE OF ALL PROTHROMBIN COMPLEX FACTORS WITH RECOMBINANT HUMAN COAGULATION FACTOR VIIa IN THE TREATMENT OF BLEEDING AFTER CARDIAC SURGERY

Aim: The authors evaluated the effectiveness of treatment with recombinant human coagulation factor VIIa and concentrate of all prothrombin complex factors in patients with massive postoperative bleeding that could not be controlled with traditional therapy. Materials and Methods: In the period from 2020 to 2021, recombinant human coagulation factor VIIa was administered to 18 patients after cardiac surgery (group I), while the concentrate of all prothrombin complex factors was administered to 16 patients postoperatively (group II). During this period, 647 patients were operated on. The patients had normal coagulation screening tests (APTT, INR, TT, fibrinogen level, and PLT level) before surgery. Mean blood loss before and after administration of eptacog alfa and the total prothrombin complex concentrate was assessed. The mean dose of eptacog alfa was 30.95 mcg/kg b.w., and the total prothrombin complex factor concentrate dose was 14.17 mcg/kg b.w. After transfusion with red blood cell concentrate, fresh frozen plasma, and platelet concentrate, in the absence of improvement in the dynamics of postoperative drainage, it was decided to include recombinant human coagulation factor VIIa or a concentrate of all prothrombin complex factors in the treatment. Results: After administration of recombinant human coagulation factor VIIa at a dose of 30.95 mcg/kg b.w., bleeding stopped in 12 patients, but the remaining 6 patients required reoperation due to persistently high drainage. The decision to perform a rethoracotomy was made by a team of cardiothoracic surgeons and anesthesiologists, taking into account the dynamics of drainage (bleeding) and the hemodynamic stability of the patient. After the administration of concentrate of all prothrombin complex factors at a dose of 14.17 U/kg b.w., bleeding stopped in 12 patients. Four patients required reoperation due to persistent bleeding. Conclusions: Treatment with recombinant human coagulation factor VIIa and concentrate of all prothrombin complex factors is effective and safe for cardiac surgery patients.

Expression of the gene encoding blood coagulation factor VIII without domain B in E. coli bacterial expression system.

In this article, we have demonstrated the feasibility of generating an active form of recombinant blood coagulation factor VIII using an E. coli bacterial expression system as a potential treatment for hemophilia type A. Factor VIII (FVIII), an essential blood coagulation protein, is a key component of the fluid phase blood coagulation system. So far, all available recombinant FVIII formulations have been produced using eukaryotic expression systems. Mammalian cells can produce catalytically active proteins with all the necessary posttranslational modifications. However, cultivating such cells is time-consuming and highly expensive, and the amount of the obtained product is usually low. In contrast to eukaryotic cells, bacterial culture is inexpensive and allows the acquisition of large quantities of recombinant proteins in a short time. With this study, we aimed to obtain recombinant blood coagulation factor VIII using the E. coli bacterial expression system, a method not previously explored for this purpose. Our research encompasses the synthesis of blood coagulation factor VIII and its expression in a prokaryotic system. To achieve this, we constructed a prokaryotic expression vector containing a synthetic factor VIII gene, which was then used for the transformation of an E. coli bacterial strain. The protein expression was confirmed by mass spectrometry, and we assessed the stability of the gene construct while determining the optimal growth conditions. The production of blood coagulation factor VIII by the E. coli bacterial strain was carried out on a quarter-technical scale. We established the conditions for isolation, denaturation, and renaturation of the protein, and subsequently confirmed the activity of FVIII.

In vivo effect of rFVIII and rFVIIa in hemophilia A rats evaluated by the Tail Vein Transection Bleeding Model

BackgroundPreclinical bleeding models increase current hemophilia A (HA) knowledge and aid the development of new pharmacological treatments. There are several well-established mouse bleeding models, but limited options are available for rat models despite their high resemblance to human disease process. ObjectiveTo provide a comprehensive description of the tail vein transection (TVT) bleeding model in HA rats and examine the correlation between in vivo pharmacological efficacy and global hemostatic assays. MethodsThe TVT bleeding model was implemented in HA rats and used to perform dose-response studies with recombinant coagulation factors VIIa (rFVIIa) and VIII (rFVIII). After the TVT bleeding model, whole blood and plasma were collected from rats and evaluated with thrombin generation test (TGT) and rotational thromboelastometry (ROTEM). ResultsUsing the TVT bleeding model, the potency of rFVIII and rFVIIa treatments in HA rats were assessed, and the pharmacological windows established for rFVIII (≤15 U/kg) and rFVIIa (≤2.7 mg/kg). ED50 was estimated to be 1.75 U/kg for rFVIII and 0.37 mg/kg for rFVIIa, whereas complete normalization was observed with 15 U/kg and 2.7 mg/kg respectively. Furthermore, responses to rFVIII and rFVIIa in the TGT and ROTEM assays strongly correlated to in vivo pharmacological efficacy. ConclusionThe TVT bleeding model in HA rats is a useful tool to assess the pharmacodynamic effects of hemostatic compounds in vivo, and strongly correlates to results obtained with TGT and ROTEM in HA rats, adding further value to the HA rat model in preclinical research.

Biological activity of a new recombinant human coagulation factor VIII and its efficacy in a small animal model

Deficiency in human coagulation factor VIII (FVIII) causes hemophilia A (HA). Patients with HA may suffer from spontaneous bleeding, which can be life-threatening. Recombinant FVIII (rFVIII) is an established treatment and prevention agent for bleeding in patients with HA. Human plasma-derived FVIII (pdFVIII), commonly used in clinical practice, is relatively difficult to prepare. In this study, we developed a novel B-domain-deleted rFVIII, produced and formulated without the use of animal or human serum-derived components. rFVIII promoted the generation of activated factor X and downstream thrombin, and, similar to that of other available FVIII preparations, its activity was inhibited by FVIII inhibitors. In addition, rFVIII has ideal binding affinity to human von Willebrand factor. Activated FVIII (FVIIIa) could be degraded by activated protein C and lose its procoagulant activity. In vitro, commercially available recombinant FVIII (Xyntha) and pdFVIII were used as controls, and there were no statistical differences between rFVIII and commercial FVIII preparations, which demonstrates the satisfactory efficacy and potency of rFVIII. In vivo, HA mice showed that infusion of rFVIII rapidly corrected activated partial thromboplastin time, similar to Xyntha. Moreover, different batches of rFVIII were comparable. Overall, our results demonstrate the potential of rFVIII as an effective strategy for the treatment of FVIII deficiency.

ОПЫТ ПРИМЕНЕНИЯ ЭФМОРОКТОКОГА АЛЬФА У ДЕТЕЙ И ПОДРОСТКОВ: КЛИНИЧЕСКИЕ НАБЛЮДЕНИЯ

Despite availability of prophylactic therapy for hemophilia A with factor VIII concentrates with a standard half-life, patients continue to experience episodes of bleeding and joint damage. The reasons for this may be the relatively short half-life of the factor VIII drug and the low adherence of patients to treatment. The appearance of clotting factor concentrates with an extended half-life makes it possible to reduce the frequency of infusions and increase the residual activity of the deficient factor. The article presents clinical observations of the use of Efmoroctocog alfa (recombinant human coagulation factor VIII, Fc fusion protein (rFVIIIFc)) in a 16-year-old adolescent and a 7-year-old child with severe and moderate forms of hemophilia A. In order to select the most rational therapy regimen and evaluate the effectiveness of treatment, the authors have conducted individual assessments of patients’ pharmacokinetic (PK) parameters. The drug administration in both patients was twice per week. To assess individual PK, the WAPPS-Hemo was used in order to calculate individual PK parameters based on a small plasma samples collected during routine prophylactic treatment. During the PK study, 3 blood samples were taken to determine the level of factor VIII in a one-step method. In a 16-year-old patient, the half-life of Efmoroctocog alfa (t1/2) was 24.25 hours. The activity of factor VIII prior to the next injection was 7.4%. In addition, 81% of time the factor VIII activity was above 15%. In a 7-year-old patient, the t1/2 of the drug was 12.75 hours. The minimum residual activity of factor VIII was 2.1%, 86% of time the activity of factor VIII was above 3%. Conclusion: high efficacy and safety were demonstrated based on the results of the use of Efmoroctocog alfa in routine clinical practice in previously treated pediatric and adolescent patients with severe and moderate hemophilia A, as well as the reduction in the frequency of infusions per week from 3 to 2.

The Profile of Markers of Bone Turnover, Inflammation and Extracellular Neutrophil Traps on Bone Mass in Haemophilia and the Development of Haemophilic Arthropathy.

Background: The aim of the study is to evaluate selected biomarkers of bone turnover, inflammation, neutrophil trap and factors predisposing haemophiliacs to bone loss, and to analyse their relationship with clinical features, treatment and complications. Methods: The levels of interleukin 6 (IL-6); citrullinated histone (CH3); osteocalcin (BGLAP); bone alkaline phosphatase (BALP); N-terminal procollagen type I propeptide (P1NP); and C-terminal collagen type I telopeptide (C1CP) were examined in 60 patients with haemophilia. Results: The cut-off value for BGLAP is 26.41 ng/mL, and 929.7 pg/mL for CH3. There is a statistically significant difference between BGLAP, BALP, C1CP and CH3 concentrations, depending on the prophylaxis used. The median concentration of BGLAP in patients taking the factor on demand is 28.0 ng/mL, BALP 322.5 U/L, C1CP 191.2 ng/mL and CH3 1114.4 pg/mL. In patients taking recombinant coagulation factor VIII/IX as prophylaxis of bleeding, the median BGLAP concentrations are 35.9 ng/mL, BALP 280.9 U/L, C1CP 161.6 ng/mL and CH3 952.5 pg/mL. BGLAP and BALP concentrations are dependent on the development of haemophilic arthropathic. Conclusions: The concentrations of selected markers of bone turnover and NETs may help to identify patients at particular risk of developing haemophilic arthropathy and bone metabolic turnover abnormalities.

Acquired Hemophilia A in a Female: A Case Report

INTRODUCTION: Coagulation factor deficit is a very uncommon hemostatic condition in which a single component or numerous factors are lacking. Hereditary coagulation factor defects are autosomal recessive, meaning that they can affect both men and women. However, hemophilia A, caused by lack of clotting factor VIII (FVIII), is an X-linked condition. Acquired hemophilia A (AHA) is a bleeding disorder caused by autoantibodies to FVIII. It should be distinguished from congenital hemophilia, an inherited disorder caused by a mutation in the FVIII gene. Here, we report the first known case in Indonesia, a 24-year-old female diagnosed with AHA. CASE PRESENTATION: A 24-year-old woman was referred to our facility for prolonged epistaxis. She had no previous history of extended menstrual flow or frequent epistaxis episodes, and there was no history of epistaxis or prolonged bleeding in her family. Bleeding time and prothrombin time were both normal, but time to activate partial thromboplastin was longer. The patient was diagnosed with AHA after von Willebrand disease (VWD) was ruled out. DISCUSSION: In some rare situations, females can be affected by X-linked illnesses such as hemophilia A and B. This may be due to a carrier mother or affected father, skewed X chromosome inactivation, Turner syndrome, inhibitory antibodies (acquired hemophilia), or a random mutation on the active X chromosome. In such instances, treatment is challenging. The usual treatment of choice is recombinant coagulation factors. CONCLUSION: Although VWD is the most frequent hereditary bleeding problem in females, other rare disorders such as AHA may be implicated. Clinicians should be aware of this when faced with patients that lack a history of bleeding disorders. Furthermore, AHA should be considered as a differential diagnosis in every female patient suffering from hemorrhage. Therefore, a comprehensive diagnostic approach is needed.

Polyethylene glycol 20 kDa-induced vacuolation does not impair phagocytic function of human monocyte-derived macrophages.

Conjugation to polyethylene glycol (PEG) is commonly used to enhance drug delivery and efficacy by extending the half-life of the drug molecule. This has important implications for reducing treatment burden in diseases that require chronic prophylaxis, such as hemophilia. Clearance of PEG molecules with high molecular weights (≥ 40 kDa) has been reported to cause cellular vacuolation in mammals. Rurioctocog alfa pegol (PEGylated recombinant coagulation factor VIII) contains a 20-kDa PEG. This study investigated the effects of exposure to 20-kDa PEG (10 μg/ml to 10 mg/ml) on the morphology and function of human monocyte-derived macrophages (MDMs) in vitro. Exposure to PEG for 24 hours was associated with significant vacuolation only at concentrations of 1 mg/ml or more, which far exceed the levels associated with clinically relevant doses of rurioctocog alfa pegol. Immunofluorescence staining of PEG was detected in the cytoplasm of MDMs, indicating uptake into the cells. No impairment of MDM phagocytic activity (ability to ingest fluorescently labeled Escherichia coli) was observed with 24-hour exposure to PEG, even at concentrations associated with significant vacuolation. Furthermore, PEG exposure did not have significant effects on cytokine secretion in resting or lipopolysaccharide-stimulated MDMs, or on the expression of cell surface markers in stimulated MDMs. Cell viability was not affected by 24-hour exposure to PEG. In conclusion, vacuolation of human MDMs after exposure to 20-kDa PEG only occurred with PEG concentrations far in excess of those equivalent to clinically relevant doses of rurioctocog alfa pegol and did not affect MDM viability or functionality. Together, these results support the concept that PEG-mediated vacuolation is an adaptive cellular response rather than a toxic effect.