Stability, efficacy, and safety of continuously infused sucrose-formulated recombinant factor VIII (rFVIII-FS) during surgery in patients with severe haemophilia

Managing surgery in hemophilia with recombinant factor VIII Fc and factor IX Fc: Data on safety and effectiveness from phase 3 pivotal studies

Background

Surgical procedures impose hemostatic risk to people with hemophilia, which may be minimized by optimal factor (F) replacement therapy.

Methods

This analysis evaluates the efficacy and safety of extended half-life factor replacement recombinant FVIII and FIX Fc fusion proteins (rFVIIIFc and rFIXFc) during surgery in phase 3 pivotal (A-LONG/Kids A-LONG and B-LONG/Kids B-LONG) and extension (ASPIRE and B-YOND) studies. Dosing regimens were determined by investigators. Injection frequency, dosing, blood loss, transfusions, and hemostatic response were assessed.

Results

Forty-five major (n = 31 subjects) and 90 minor (n = 70 subjects) procedures were performed in hemophilia A; 35 major (n = 22) and 62 minor (n = 37) procedures were performed in hemophilia B. Unilateral knee arthroplasty was the most common major orthopedic procedure (hemophilia A: n = 15/34; hemophilia B: n = 8/24). On the day of surgery, median total dose in adults/adolescents was 81 IU/kg for rFVIIIFc and 144 IU/kg for rFIXFc; most major procedures required ≤2 injections (including loading dose). Through days 1-14, most major procedures had ≤1 injection/day. Hemostasis was rated excellent (rFVIIIFc: n = 39/42; rFIXFc: n = 29/33) or good (n = 3/42; n = 4/33) in evaluable major surgeries, with blood loss comparable with subjects without hemophilia. Most minor procedures in adults/adolescents required one injection on the day of surgery, including median loading dose of 51 IU/kg (rFVIIIFc) and 80 IU/kg (rFIXFc). No major treatment-related safety concerns were identified. No subjects developed inhibitors or serious vascular thromboembolic events.

Conclusions

rFVIIIFc and rFIXFc were efficacious and well tolerated for the management of perioperative hemostasis across a wide spectrum of major and minor surgeries in hemophilia.

Stability of Turoctocog Alfa, a Recombinant Factor VIII Product, during Continuous Infusion In Vitro

Objective  Turoctocog alfa is a recombinant factor VIII (rFVIII) for the prevention and treatment of bleeding in patients with hemophilia A, including those undergoing surgery and invasive medical procedures. This in vitro study evaluated the physical and chemical stability of turoctocog alfa during continuous infusion (CI) over 24 hours at 30°C.

Materials and Methods  The study was performed at 30°C ( ± 2°C). A CI system with pump speed set at either 0.6 or 1.5 mL/h was used to evaluate the stability of three turoctocog alfa strengths (500, 1,000, and 3,000 IU), equating to doses of 1.1 to 16.1 IU/h per kilogram of body weight. The following parameters were evaluated at selected time points between 0 and 24 hours: appearance of solution, clarity, pH, potency, purity, content, total high molecular weight proteins (HMWPs), and oxidized rFVIII.

Results  The mean potency of turoctocog alfa was maintained within the predefined acceptance criteria during CI for both pump speeds with all three strengths at 6, 12, or 24 hours (500 IU: ≥484 IU/vial; 1,000 IU: ≥1,014 IU/vial; and 3,000 IU: ≥3,029 IU/vial). Furthermore, the appearance of solution, clarity, pH, purity, content of turoctocog alfa, total HMWP, and oxidized forms were also within the predefined limits, and comparable to the reference samples (time = 0 hours) for the pump speeds and product strengths assessed.

Conclusion  Physical and chemical stability of turoctocog alfa was maintained during CI over 24 hours. There was only minor degradation or changes in any of the parameters tested. Potency was within the prespecified acceptance limits throughout 24 hours of infusion. These findings confirm the suitability of turoctocog alfa for CI.

Continuous infusion of recombinant activated factor VII: a review of data in congenital hemophilia with inhibitors and congenital factor VII deficiency

Introduction

Continuous infusion (CI) of clotting factors as a replacement therapy for perioperative hemostatic protection has been performed for many years, including with factors VIII and IX and recombinant activated factor VII (rFVIIa). This approach provides steady factor levels without requiring frequent administration of bolus doses.

Aim

To review safety, efficacy, and dosing data regarding CI of rFVIIa for hemostatic management of patients with congenital hemophilia with inhibitors (CHwI) or congenital factor VII deficiency (C7D).

Materials and methods

A literature review identified instances of CI of rFVIIa in patients with CHwI or C7D undergoing surgery or experiencing bleeding episodes. Data regarding safety, efficacy, and dosing were extracted.

Results

The safety and efficacy of 50 mcg/kg/h CI of rFVIIa following a 90 mcg/kg bolus injection, vs a standard bolus injection regimen, was reported for 24 patients with CHwI undergoing elective surgery in an open-label, randomized, Phase III trial. Efficacy was similar between CI and bolus injection groups at all postoperative time points assessed. Additionally, a postmarketing surveillance study reported effective (80%) and partially effective (20%) CI of rFVIIa in a Japanese cohort of ten patients with CHwI who underwent 15 surgical procedures. Finally, the safety and dosing of rFVIIa CI in 193 and 26 patients with CHwI and C7D, respectively, were reported in 11 prospective studies, 10 retrospective studies, and 30 case reports. No unexpected safety findings were reported.

Conclusion

rFVIIa CI has been performed safely and effectively in patients with CHwI and C7D undergoing surgery and during bleeding episodes in patients with CHwI.

Continuous infusion of simoctocog alfa in haemophilia A patients undergoing surgeries

INTRODUCTION

There are two major principles for coagulation factor replacement in the clinical management of surgical procedures in patients with haemophilia, repetitive bolus injections every 6-12 hours or administration of coagulation factor concentrates by continuous infusion.

AIM

The aim was to investigate the efficacy of simoctocog alfa (human-cl rhFVIII) delivered by continuous infusion for bleeding prophylaxis during surgery in patients with haemophilia A.

METHODS

We investigated the use of continuous infusion with simoctocog alfa in haemophilia A patients undergoing major surgical procedures at Oslo University Hospital from September 2015 to March 2018. The objectives were haemostatic outcome, in vivo recovery, stability over time at room temperature (3 days) and inhibitor development.

RESULTS

Simoctocog alfa demonstrated treatment success in terms of haemostatic efficacy in 100% of major surgeries used as CI: 87% (n=21) excellent; 13% (n=3) good. No erythrocyte transfusions were required in any patient, no adverse events occurred and no inhibitors developed. The product was stable for 3 days at room temperature without loss of activity. Mean in vivo recovery was 1.8 (0.3) (IU/mL/IU/kg).

CONCLUSION

Continuous infusion with simoctocog alfa was found to achieve good/excellent haemostatic efficacy in all procedures. No adverse events occurred and no inhibitors developed.

Long-acting recombinant factor VIII Fc fusion protein (rFVIIIFc) for perioperative haemostatic management in severe haemophilia A

The Phase 3 A-LONG and Kids A-LONG studies demonstrated the prolonged half-life of rFVIIIFc compared with rFVIII, and the safety and efficacy of rFVIIIFc in subjects with severe haemophilia A. Eligible subjects from A-LONG and Kids A-LONG continued rFVIIIFc treatment by enrolling in ASPIRE, an ongoing extension study. Based on combined data from the primary studies and ASPIRE interim data, the safety and efficacy of rFVIIIFc in subjects requiring surgery were evaluated. Perioperative dosing regimens were determined by investigators with guidance based on pharmacokinetic data and recommendations from a clinical dosing committee. In addition to dosing frequency, factor consumption, blood loss, transfusions, bleeding episodes, and haemostatic response were assessed. Across studies, 21 subjects underwent 23 evaluable major surgeries, including 19 orthopaedic surgeries; 41 subjects underwent 52 minor surgeries, including 30 dental procedures. No major and 10 minor surgeries were performed in paediatric subjects. Of the major (n = 22) and minor (n = 32) surgeries assessed for haemostatic response, all were rated as excellent or good by the investigator/surgeon. During most major surgeries (95.7 %), haemostasis was maintained with one rFVIIIFc infusion. Blood loss in major surgeries was consistent with similar surgeries in subjects without haemophilia. Across studies, rFVIIIFc was well tolerated; no subject developed an inhibitor.

Continuous infusion of coagulation factor concentrates during intensive treatment

In clinical management of bleeds and surgical procedures in patients suffering from bleeding disorders either repetitive bolus injections (BI) or continuous infusion (CI) can be used for coagulation factor replacement. Continuous infusion seems to be an attractive route of administration and may be considered if replacement therapy is required for more than 3 days. The strongest argument favouring continuous infusion is its superiority in providing the patient with a safe and constant level of the deficient coagulation factor by balancing input with clearance. Furthermore, several studies have shown that coagulation factor consumption may be reduced by CI compared to repetitive bolus injections (BI) since unnecessary peaks of factor level are avoided. Concerns have been raised whether continuous infusion of coagulation concentrates is associated with an increased risk of developing inhibitors. However, available data have so far not shown an increased risk for inhibitor development in severe haemophilia patients with more than 50 exposure days of coagulation factor concentrates. Further, previously reported complications when using CI such as phlebitis at the infusion site and pump failure are nowadays very seldom seen when small amounts of heparin are added to the infusion bag, and increased quality of the pumps are available. Over the last decades, numerous reports have confirmed CI to be a safe and effective mode of coagulation factor replacement even in the most challenging surgical procedures, such as total joint arthroplasties.

Comparison of continuous infusion versus bolus injection of factor concentrates for blood management after total knee arthroplasty in patients with hemophilia

Background

Total knee arthroplasty (TKA) has become the treatment of choice for end-stage hemophilic arthropathy of the knee. Theoretically in hemophilia A, perioperative continuous infusion (CI) of factor VIII (FVIII) would provide a more consistent FVIII level than general bolus injections (BI) in TKA. Current study was designed to evaluate the effectiveness of CI of coagulation factor concentrates during the perioperative period compared to BI.

Methods

A total of 42 TKAs were performed in 31 patients with severe hemophilia A. Under the supervision of a multidisciplinary hemophilia team, CI and BI were monitored during application of a standardized regimen. Perioperative clinical parameters including postoperative hemoglobin drop, drained blood volume, transfusion rate, total consumption of FVIII, and perioperative complications were assessed.

Results

The difference in the postoperative hemoglobin drop was significant between two groups with a lower decrease in the CI group (p = 0.002). The drained blood volume for postoperative 24 h was significantly lower in the CI than the BI groups (p = 0.037). Total consumption of factor concentrates for postoperative 5 days was greater in the CI group than in the BI group (p = 0.000). One postoperative hematoma and wound dehiscence occurred in BI group and no other complication developed.

Conclusions

Although good control of hemostasis could be achieved using either method during the perioperative period of TKA, CI seems more tolerable and effective than BI to provide perioperative blood management undergoing TKA in patients with hemophilia.

Trial registration

The study was retrospectively registered in WHO ICTRP under identifier KCT0002404 (date of registration: August 04, 2017).

Extended Stability and Sterility of Antihemophilic Factor Human

OBJECTIVES

Antihemophilic factor human is a factor VIII product used to supplement those with hemophilia. Recent data show treatment benefit and cost saving opportunities if factor products are administered as a continuous infusion rather than conventional bolus dose. This method has not been widely used given the lack of evidence for safe and effective use beyond 3 hours from preparation. The objectives of this study were to determine the physical and chemical stability and sterility of antihemophilic factor human over a 7-day period.

METHODS

Antihemophilic factor human was obtained from the manufacturer. Baseline stability and sterility were determined by factor activity levels along with bacterial and fungal cultures. These tests were also evaluated over a span of 7 days at room temperature and under refrigeration.

RESULTS

Each sample was inspected at the time of delivery and showed no visible signs of physical changes. Factor activity levels were maintained between 88% and 102% of baseline measurements. No growth was observed for bacterial or fungal cultures in any sample after 4 weeks of incubation.

CONCLUSIONS

Antihemophilic factor human maintained physical stability and chemical stability and remained sterile for the 7-day period, allowing extended stability and continuous infusions to be considered.

Baby hamster kidney cell-derived recombinant factor VIII: a quarter century of learning and clinical experience

INTRODUCTION

Management and care of individuals with hemophilia A advanced immensely with the introduction of recombinant factor VIII (rFVIII) replacement products. This review provides a historical overview of rFVIII development with a focus on Bayer's rFVIII (with albumin) and sucrose-formulated rFVIII (rFVIII-FS), the only rFVIII products cloned in baby hamster kidney (BHK) cells with >25 years of proven safety and efficacy. Areas covered: We review the advances in rFVIII technology and the efficacy and safety data for BHK-derived rFVIII/rFVIII-FS from clinical trials, investigator-initiated studies, and observational studies. Innovative products with new treatment potentials (eg, BAY 81-8973 and BAY 94-9027) built on this established safety and efficacy profile are also briefly discussed. The literature search strategy included targeted searches (PubMed) with manual article selection and other product-specific searches. Expert commentary: Development of rFVIII products and related improvements in viral safety and manufacturing efficiency have guaranteed an adequate supply of factor products worldwide and increased prophylaxis use. The net effects have been joint health preservation, reduction in morbidity and mortality, and quality-of-life enhancements. Current treatment challenges include lack of adherence to prophylaxis and inhibitor development; extended-half-life rFVIII products and non-FVIII replacement therapies in development may help overcome these challenges.

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.

Allometry of factor VIII and informed scaling of next-generation therapeutic proteins

Allometric scaling has been applied to the pharmacokinetics (PK) of factor VIII (FVIII), but published relationships are based on relatively small subsets of available data. Numerous next-generation forms of FVIII are being developed (e.g., Fc fusion, PEGylated, and liposomal formulations) and traditional PK scaling of these products would not incorporate the wealth of existing knowledge for current FVIII therapy in humans. We conducted a meta-analysis and developed allometric relationships of FVIII from over 100 PK studies collected from literature. Normalized Wajima curves were used to relate mean FVIII profiles between species. An "informed scaling" approach was derived for predicting first-in-human PK parameters and demonstrated with a case study for an Fc fusion FVIII. NCA values for FVIII PK were well described by the allometric equations CL = 6.59 W(0.85) and V(ss) = 65.0 W(0.97). A subset of studies characterized by two-compartment modeling showed strong linearity in scaling of total clearance (CL) and central volume, but more variability in distributional CL and peripheral volume. Wajima curves for FVIII superimposed across species and the disposition of Fc fusion FVIII in humans was well predicted by "informed scaling." This approach might be generally applicable for predicting human PK of next-generational therapeutics.

Treatment of an intraoral bleeding in hemophilic patient with a thermoplastic palatal stent - A novel approach

This is a case report of a 13-year old child diagnosed with hemophilia A. He reported with a bleeding wound in the middle part of the hard palate, due to trauma from a lead pencil. An intraoral palatal stent was planned to provide continuous pressure, stabilize the clot and allow local delivery of hemostatic agent. The stent was fabricated with a thermoplastic silicone rubber (biostar) under vacuum. The hemostatic agent used was one 500 mg capsule of tranxemic acid that was crushed and applied as a paste every 6 hourly. The patient was admitted under supervision for 3 days, where Recombinant factor VIII (rFVIII) intravenous infusion of 15-25 U/kg twice a day was given. Complete healing was observed in the traumatized area within 10 days. This article emphasizes on prenatal diagnosis, carrier screening and counseling of parents born with hemophilic children.