von Willebrand factor/factor VIII concentrate (Humate-P) for management of elective surgery in adults and children with von Willebrand disease

Outcomes Following Total Hip Arthroplasty in Patients Who Have Von Willebrand Disease Depend on Postoperative Anticoagulation

BACKGROUND

Von Willebrand disease (VWD) is the most common congenital bleeding disorder. This autosomal dominant condition arises from quantitative or qualitative defects of Von Willebrand factor. To our knowledge, this study leveraged a national database to characterize the largest VWD cohort of total hip arthroplasty (THA) patients to date, assessing 90-day postoperative adverse events and 5-year revision-free survival.

METHODS

Adult patients who underwent primary THA for osteoarthritis were identified from January 2010 to October 2021 in a nationwide database. Patients who had and did not have VWD were matched (4:1) on age, sex, and Elixhauser Comorbidity Index and compared with multivariable logistic regression. Patients were then categorized based upon venous thromboembolism (VTE) chemoprophylaxis prescription patterns to compare bleeding and thrombotic adverse events.

RESULTS

Of 544,851 THA patients, VWD was identified in 309 patients (0.06%). The matched cohorts contained 1,221 patients who did not have VWD and 306 patients who have VWD. On multivariable analysis, VWD patients had increased odds of 90-day VTE (odds ratio [OR] = 1.86) and hematoma (OR = 3.40) (P < .05 for all). No difference in 5-year revision-free survival was found. The VWD patients receiving aspirin or no prescriptions had greater odds of VTE (OR = 2.39, P = .048). Those on other chemoprophylaxis agents had greater odds of hematoma (OR = 4.84, P = .006).

CONCLUSIONS

Patients with VWD undergoing THA had increased odds of 90-day VTE if using aspirin or no prescriptions, or hematoma if using other chemoprophylaxis. There is a delicate balancing act of clotting versus bleeding that must be considered in managing such patients, but it was reassuring that no difference in overall 5-year revision-free survival was found.

Perioperative hemostasis management in patients with von Willebrand disease: an institutional experience

OBJECTIVES

Patients with von Willebrand disease (vWD) undergoing surgery are routinely treated with von Willebrand factor (vWF)/factor VIII (FVIII) concentrate to control bleeding risk, but consensus is lacking on optimal dosing. This study aimed to evaluate the efficacy and safety of tailored doses of vWF/FVIII concentrate according to intervention-associated bleeding risk in vWD patients undergoing surgery.

METHODS

This was a retrospective analysis of vWD patients who underwent surgical procedures at a haemophilia centre. Patients received vWF/FVIII concentrate with dosage and duration of treatment dependent on intervention type (dental, gynaecological, abdominal or orthopaedic/traumatic) and bleeding risk (moderate/high).

RESULTS

Eighty-three surgical procedures (42 patients) were included. Median preoperative loading doses of vWF/FVIII concentrate were 29.9 IU/kg and 35.7 IU/kg for interventions with moderate ( n  = 16) or high ( n  = 67) bleeding risk, respectively. The median perioperative dose was highest in orthopaedic or trauma-related surgery (140 IU/kg) and lowest in dental or gynaecological interventions (76.4 IU/kg and 80.0 IU/kg, respectively). During follow-up, no bleeding or other complications were observed in 95% of patients.

CONCLUSIONS

Individually tailored doses of vWF/FVIII concentrate according to intervention-associated bleeding risk were effective in preventing postoperative bleeding, with few complications observed. These doses may be used as guidance in routine clinical care.

Key Drivers of Coagulation Factor Use in Von Willebrand Disease During Hospitalization: An Overview of the French BERHLINGO Cohort

BACKGROUND

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. However, studies of hospitalisation patterns with replacement treatment are scarce.

OBJECTIVES

The aim of this study was to investigate the current therapeutic management of VWD and determine the key drivers of coagulation factor uses in patients during hospitalisation.

METHODS

Hopscotch-WILL was a multi-centric retrospective study conducted over a 48-month period in any patients with VWD. The data were collected from the BERHLINGO Research Database and the French Hospital database.

RESULTS

A total of 988 patients were included; 153 patients (15%) were hospitalised during 293 stays requiring treatment with von Willebrand factor (VWF) concentrates-pure or in association with Factor VIII (FVIII). Their median basal concentrations of VWF and FVIII were significantly lower than in untreated patients: VWF antigen < 30 IU/dL, VWF activity < 20 IU/dL and FVIII:C < 40 IU/dL. The median (interquartile range) concentrate consumption was similar between highly purified VWF or VWF combined with FVIII (72 [110] vs 57 [89] IU/kg/stay, p = 0.154). The use of VWF was highly heterogeneous by VWD type; type 3 had a particularly high impact on VWF consumption in non-surgical situations. The main admissions were for ear/nose/throat, hepato-gastroenterology, and trauma/orthopaedic conditions, besides gynaecological-obstetric causes in women.

CONCLUSIONS

The use of VWF concentrates is mostly influenced by low basal levels of VWF and FVIII, but also by VWD type or the cause for hospitalisation. These results could inform future studies of newly released recombinant VWF.

Pharmacokinetic-Pharmacodynamic Comparison of Recombinant and Plasma-Derived von Willebrand Factor in Patients with von Willebrand Disease Type 3

Background

Recombinant von Willebrand factor (rVWF, vonicog alfa, Vonvendi/Veyvondi, Takeda Pharmaceuticals USA, Lexington, MA) and several plasma-derived VWF/factor VIII (pdVWF/FVIII) concentrates are available for treating bleeding episodes in patients with von Willebrand disease (VWD).

Purpose

To develop population pharmacokinetic (PK)/pharmacodynamic (PD) models that describe VWF:ristocetin cofactor (VWF:RCo) activity and its relationship with FVIII activity (FVIII:C) over time following intravenous administration of either rVWF or a pdVWF/FVIII concentrate (VWF:RCo/FVIII:C 2.4:1) in patients with VWD; to use the final PK/PD models for an in silico comparison of rVWF and pdVWF/FVIII.

Methods

The population PK model for rVWF was based on data from four clinical studies in which rVWF was administered to adult patients with VWD type 1, 2 or 3 (phase 1: NCT00816660; phase 3: NCT01410227 and NCT02283268) or severe hemophilia A (phase 1: EudraCT 2011-004314-42). The PK and PK/PD models for pdVWF/FVIII were based on data from the phase 1 study (NCT00816660) in patients with type 3 VWD who received either rVWF plus recombinant FVIII (rFVIII, octocog alfa, ADVATE^®, Takeda Pharmaceuticals USA, Lexington, MA, USA) or pdVWF/FVIII.

Results

There was a marked difference in clearance following rVWF administration compared with pdVWF/FVIII in type 3 VWD, leading to a ~1.75 longer mean residence time (ie, persistence of VWF:RCo activity in the body) and half-life for rVWF versus pdVWF/FVIII. Simulations showed that following repeated administration of rVWF (50 IU/kg), a FVIII:C activity of >40 IU/dL can be maintained for the full 72 h dosing interval.

Conclusion

The slower elimination of VWF:RCo following rVWF administration results in a prolonged effect on FVIII turnover compared with pdVWF/FVIII administration.

Perioperative Outcomes of Patients with Bleeding Disorders Undergoing Major Surgery at an Academic Hemophilia Treatment Center

Persons with bleeding disorders (PwBD) are at high risk for bleeding with invasive procedures. However, the risk of bleeding in PwBD undergoing major surgery and outcomes of patients managed perioperatively at a hemophilia treatment center (HTC) are not well described. We performed a retrospective review of surgical outcomes among PwBD undergoing major surgery between January 1st, 2017 and December 31st, 2019 at the Cardeza Foundation Hemophilia and Thrombosis Center in Philadelphia, PA. The primary outcome was postoperative bleeding, assessed according to the ISTH-SSC's 2010 definition. Secondary outcomes included use of unplanned postoperative hemostatic therapy, LOS, and 30-day readmission rate. Results were compared to non-PwBD population from a surgical database, matched for surgery, age, and sex. During the study period, 50 PwBD underwent 63 major surgeries. The most common diagnoses were VWD (64%) and hemophilia A (20.0%). The most common surgical procedure category was orthopedic (33.3%), predominantly arthroplasties. Postoperatively,4.8% of procedures were complicated by major bleeding and 1.6% by non-major bleeding. The mean LOS was 1.65 days, and 30-day readmission rate was 1.6%. In comparison to matched, non-PwBD patients in a national surgical database undergoing the same procedures, study patients had a similar rate of bleeding complications per procedure (5.0% vs 1.04% P = .071, Fisher's exact test). PwBD undergoing major surgeries have low rates of major bleeding when receiving comprehensive care at an HTC. Bleeding and hospital readmission rates were similar to non-PwBD baseline in a large database.

Prophylactic management of patients with von Willebrand disease

Von Willebrand disease, the most common inherited bleeding disorder that affects both males and females, is due to quantitative or qualitative defects of the multimeric glycoprotein von Willebrand factor, which cause mucous membrane bleeding but also soft tissue bleeding owing to the secondary deficiency of factor VIII. The aim of treatment is to correct this dual defect of hemostasis. In addition to the episodic management of bleeding episodes, therapy includes their short- or long-term prevention. Short-term prophylaxis is mainly warranted in order to provide effective hemostatic coverage to patients undergoing surgery or invasive procedures and to affected women at the time of delivery or during menstruations associated with excessive bleeding. The aim of long-term prophylaxis is to prevent bleeding in particular categories of patients at increased risk of frequent and spontaneous bleeding in the joints, nose, and gastrointestinal tract.

It's difficult to say no: Development of a parenting booklet about physical activity restrictions and recommendations in pediatric hemophilia

Physical activity restrictions can be particularly difficult for children with hemophilia and their parents, as most children want to engage in the same activities as their friends or siblings. This study aimed to assess parents' need for a booklet on how to manage physical activity restrictions based on the self-determination theory and gather their suggestions for the booklet's improvement in a focus group. Data were analyzed using thematic analyses to highlight to what extent the needs of parents were met by the booklet, as well as their suggestions for improvement. A discussion on the methodology of the booklet's creation is also presented.

Population pharmacokinetics of the von Willebrand factor-factor VIII interaction in patients with von Willebrand disease

Recent studies have reported that patients with von Willebrand disease treated perioperatively with a von Willebrand factor (VWF)/factor VIII (FVIII) concentrate with a ratio of 2.4:1 (Humate P/Haemate P) often present with VWF and/or FVIII levels outside of prespecified target levels necessary to prevent bleeding. Pharmacokinetic (PK)-guided dosing may resolve this problem. As clinical guidelines increasingly recommend aiming for certain target levels of both VWF and FVIII, application of an integrated population PK model describing both VWF activity (VWF:Act) and FVIII levels may improve dosing and quality of care. In total, 695 VWF:Act and 894 FVIII level measurements from 118 patients (174 surgeries) who were treated perioperatively with the VWF/FVIII concentrate were used to develop this population PK model using nonlinear mixed-effects modeling. VWF:Act and FVIII levels were analyzed simultaneously using a turnover model. The protective effect of VWF:Act on FVIII clearance was described with an inhibitory maximum effect function. An average perioperative VWF:Act level of 1.23 IU/mL decreased FVIII clearance from 460 mL/h to 264 mL/h, and increased FVIII half-life from 6.6 to 11.4 hours. Clearly, in the presence of VWF, FVIII clearance decreased with a concomitant increase of FVIII half-life, clarifying the higher FVIII levels observed after repetitive dosing with this concentrate. VWF:Act and FVIII levels during perioperative treatment were described adequately by this newly developed integrated population PK model. Clinical application of this model may facilitate more accurate targeting of VWF:Act and FVIII levels during perioperative treatment with this specific VWF/FVIII concentrate (Humate P/Haemate P).

Toward Personalized Treatment for Patients with Low von Willebrand Factor and Quantitative von Willebrand Disease

The biological mechanisms involved in the pathogenesis of type 2 and type 3 von Willebrand disease (VWD) have been studied extensively. In contrast, although accounting for the majority of VWD cases, the pathobiology underlying partial quantitative VWD has remained somewhat elusive. However, important insights have been attained following several recent cohort studies that have investigated mechanisms in patients with type 1 VWD and low von Willebrand factor (VWF), respectively. These studies have demonstrated that reduced plasma VWF levels may result from either (1) decreased VWF biosynthesis and/or secretion in endothelial cells and (2) pathological increased VWF clearance. In addition, it has become clear that some patients with only mild to moderate reductions in plasma VWF levels in the 30 to 50 IU/dL range may have significant bleeding phenotypes. Importantly in these low VWF patients, bleeding risk fails to correlate with plasma VWF levels and inheritance is typically independent of the VWF gene. Although plasma VWF levels may increase to > 50 IU/dL with progressive aging or pregnancy in these subjects, emerging data suggest that this apparent normalization in VWF levels does not necessarily equate to a complete correction in bleeding phenotype in patients with partial quantitative VWD. In this review, these recent advances in our understanding of quantitative VWD pathogenesis are discussed. Furthermore, the translational implications of these emerging findings are considered, particularly with respect to designing personalized treatment plans for VWD patients undergoing elective procedures.

ASH ISTH NHF WFH 2021 guidelines on the management of von Willebrand disease

BACKGROUND

von Willebrand disease (VWD) is a common inherited bleeding disorder. Significant variability exists in management options offered to patients.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH), the International Society on Thrombosis and Haemostasis (ISTH), the National Hemophilia Foundation (NHF), and the World Federation of Hemophilia (WFH) are intended to support patients, clinicians, and health care professionals in their decisions about management of VWD.

METHODS

ASH, ISTH, NHF, and WFH formed a multidisciplinary guideline panel. Three patient representatives were included. The panel was balanced to minimize potential bias from conflicts of interest. The University of Kansas Outcomes and Implementation Research Unit and the McMaster Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing and updating systematic evidence reviews (through November 2019). The panel prioritized clinical questions and outcomes according to their importance to clinicians and patients. The panel used the GRADE approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 12 recommendations and outlined future research priorities.

CONCLUSIONS

These guidelines make key recommendations regarding prophylaxis for frequent recurrent bleeding, desmopressin trials to determine therapy, use of antiplatelet agents and anticoagulant therapy, target VWF and factor VIII activity levels for major surgery, strategies to reduce bleeding during minor surgery or invasive procedures, management options for heavy menstrual bleeding, management of VWD in the context of neuraxial anesthesia during labor and delivery, and management in the postpartum setting.

Effectiveness and safety of hFVIII/VWF concentrate (Voncento®) in patients with inherited von Willebrand disease requiring surgical procedures: the OPALE multicentre observational study

BACKGROUND

In patients with moderate to severe qualitative and quantitative von Willebrand disease (VWD), even minor surgical procedures can be associated with a risk of life-threatening bleeding. Treatment strategies vary according to the levels of von Willebrand factor (VWF) and Factor VIII (FVIII). The aim of this study was to evaluate the effectiveness and the safety of Voncento^® (CSL Behring, Marburg, Germany), a plasma-derived FVIII/VWF concentrate (ratio 1:2.4), during surgeries performed in patients with inherited VWD.

MATERIALS AND METHODS

The OPALE study, a French multicentre observational study, was carried out from May 2016 to May 2019. It evaluated and analysed patients with inherited VWD (any type) requiring treatment with Voncento^® who underwent surgery.

RESULTS

In total, 92 patients were enrolled, and 66 patients underwent 100 surgical procedures: 69 minor and 31 major surgeries conducted in 30 patients with type 1, 50 patients with type 2, and 20 patients with type 3 VWD. During minor surgeries, the median number of infusions was one (range: 1-9), the pre-operative loading dose was 41 IU VWF:RCo kg^-1 (range: 18-147), and the total dose was 63 (range: 18-594). During major surgeries, the number of infusions was 4 (range: 1-23), the pre-operative loading dose was 43 (range: 25-66) IU VWF: RCo kg^-1, and the total dose was 155 (range: 40-575). The median FVIII:C levels ranged from 78 to 165 IU dL^-1 during 5 days after minor surgeries and from 86 and 167 IU dL^-1 during 11 days after major surgeries. VW:RCo levels ranged between 35 and 65 IU dL^-1 and between 34 and 76 IU dL^-1 after minor and major surgeries, respectively. The overall clinical effectiveness was qualified as "excellent" or "good" in 99% of patients. No thrombotic events related to Voncento^® were recorded.

DISCUSSION

The present study suggests that Voncento^® is an effective and well-tolerated therapy for the peri-operative management of patients with all VWD types.

Dental invasive procedures in von Willebrand disease outpatients treated with high purity FVIII/VWF complex concentrate (Fanhdi®): experience of a single center

PURPOSE

To retrospectively assess the effectiveness and safety of customized hemostatic protocols using a plasma-derived, von Willebrand Factor (VWF)-containing Factor VIII concentrate (pdVWF/FVIII) in von Willebrand disease (VWD) patients undergoing dental invasive procedures.

METHODS

Protocol for each patient was drawn up by the Blood Unit based on the VWD type, disease severity, and type of treatment. pdFVIII/VWF infusions and doses were registered at 30-60 min before intervention (t0) and at 12-24-36-48-72 h after intervention (t12-t72) and up to day 7. Any peri- or postoperative bleeding, complication or adverse event was registered.

RESULTS

Forty-five dental procedures were performed on 20 VWD patients (six type-1, two type-2a, six type-2b, six type-3). Most pdFVIII/VWF infusions at t0 were 60 IU/kg (n = 7) and 50 IU/kg (n = 9). Subsequent infusions were mostly 30-50 IU/kg. No bleeding complications or adverse events were reported.

CONCLUSION

This study supports the safety and efficacy of pdFVIII/VWF to prevent peri- and postoperative bleeding after invasive oral procedures.

Subcutaneous Injection of Tranexamic Acid to Reduce Bleeding During Dermatologic Surgery: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial

BACKGROUND

Topical application, oral, and IV injection of tranexamic acid (TXA) have been used to reduce surgical bleeding.

OBJECTIVE

To evaluate the safety and efficacy of TXA injected subcutaneously to reduce bleeding during dermatologic surgery.

METHODS

In this double-blinded, placebo-controlled, randomized prospective study, 131 patients were randomized to subcutaneous injection of lidocaine 2% diluted 1:1 with either saline (placebo) or TXA 100 mg/1 mL before surgery. Before the second stage or closure, size measurements of bloodstain impregnation on Telfa and surgical wound size were recorded and analyzed using mixed-effects linear regression. Subjective evaluation of hemostasis was performed using 4-point scale grading and analyzed using Fischer's exact test.

RESULTS

One hundred twenty-seven patients completed the study. The bloodstain to surgical wound size ratio was smaller in the TXA group (1.77) compared with the placebo group (2.49) (p < .001). An improved effect of TXA on bleeding was observed in the subgroup of patients receiving anticoagulants (mean difference; 95% confidence interval; -0.83; -1.20 to -0.46 p < .001). The subjective hemostasis assessment was significantly better in the TXA group overall (p = .043) and anticoagulant subgroup (p = .001) compared with the placebo group.

CONCLUSION

Subcutaneous injection of TXA was safe, reduced bleeding during dermatologic surgery, and particularly effective for patients receiving anticoagulation treatment.

Management of von Willebrand disease in patients undergoing total hip and knee arthroplasty

Von Willebrand disease is the commonest bleeding disorder encountered in the medical and surgical field. As a result of the repetitive bleeding into the joints many patients suffer from arthropathy that can cause a significant amount of pain and functional limitation. Total joint arthroplasty is being utilised as the last resort in managing these patients; however, the presence of von Willebrand disease raises a number of dilemmas. In this review, we look at the effects of von Willebrand disease on joints and the perioperative management of von Willebrand disease patients undergoing total joint arthroplasty.

Surgical Risk on Patients with Coagulopathies: Guidelines on Hemophiliac Patients for Oro-Maxillofacial Surgery

BACKGROUND

Haemophilia is a disease of genetic origin, which causes a defect in blood coagulation. Under normal conditions, in the case of leakage from the blood vessels, the blood forms a clot that reduces or blocks the bleeding. This process involves the activation of several plasma proteins in a cascade-like species. Two of these proteins, produced in the liver, factor VIII and factor IX, are deficient or present a functional defect in people with haemophilia. Because of this deficit, the haemophiliacs easily suffer external and internal bleeding. Surgical treatment of these patients is to be observed, and often their treatment is delayed due to unclear guidelines and risks in treating these patients. The aim is to provide clear guidelines in the case of surgical treatment of these patients.

METHODS

In this study, we have considered all the guidelines that refer to the gold-maxillofacial surgery, focusing on the literature of the last 10 years.

RESULTS

Surely, this collection of guidelines will favor the choice of the clinician towards safer and predictable protocols. This study does not want to create a guideline but evaluates the literature of the last 10 years, and highlights the latest for the treatment of these patients., with the aim of informing the pathology and at the same time making the surgical maneuvers safer.

CONCLUSIONS

Despite the research of literature has produced few results, it was nevertheless possible to draw up a guideline thanks to additional information extrapolated from textbooks and other scientific articles. According to the guidelines, it is possible to proceed to the treatment of these patients, if with appropriate therapy in a safe and risk-free manner.

Analysis of current perioperative management with Haemate® P/Humate P® in von Willebrand disease: Identifying the need for personalized treatment

INTRODUCTION

Patients with Von Willebrand disease (VWD) are regularly treated with VWF-containing concentrates in case of acute bleeding, trauma and dental or surgical procedures.

AIM

In this multicentre retrospective study, current perioperative management with a von Willebrand factor (VWF)/Factor VIII (FVIII) concentrate (Haemate^® P) in patients with VWD was evaluated.

PATIENTS/METHODS

Patients with VWD undergoing minor or major surgery between 2000 and 2015, requiring treatment with a VWF/FVIII concentrate (Haemate^® P), were included. Achieved VWF activity (VWF:Act) and FVIII during FVIII-based treatment regimens were compared to predefined target levels in national guidelines.

RESULTS

In total, 103 patients with VWD (148 surgeries) were included: 54 type 1 (73 surgeries), 43 type 2 (67 surgeries) and 6 type 3 (8 surgeries). Overall, treatment resulted in high VWF:Act and FVIII levels, defined as ≥0.20 IU/mL above predefined levels. In patients with type 1 VWD, respectively, 65% and 91% of trough VWF:Act and FVIII levels were higher than target levels. In patients with type 2 and type 3 VWD, respectively, 53% and 57% of trough VWF:Act and 72% and 73% of trough FVIII levels were higher than target level. Furthermore, FVIII accumulation over time was observed, while VWF:Act showed a declining trend, leading to significantly higher levels of FVIII than VWF:Act.

CONCLUSION

High VWF:Act and accumulation of FVIII were observed after perioperative FVIII-based replacement therapy in patients with VWD, both underlining the necessity of personalization of dosing regimens to optimize perioperative treatment.

Advances in the diagnosis and treatment of Von Willebrand disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder, yet diagnosis and management remain challenging. Development and use of bleeding assessment tools allows for improved stratification of which patients may require further assessment and which patients are most likely to require treatment of their VWD. New options for laboratory assessment of von Willebrand factor (VWF) activity include a new platelet-binding assay, the VWF:GPIbM, which is subject to less variability than the ristocetin cofactor activity assay, and collagen-binding assays that provide insight into a different function of VWF. Genetic testing may be helpful in some cases where a type 2 VWD variant is suspected but is usually not helpful in type 1 VWD. Finally, treatment options for VWD are reviewed, including the use of recombinant VWF. Despite these advances, still more work is required to improve diagnosis, treatment, and quality of life for affected patients.

Advances in the diagnosis and treatment of Von Willebrand disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder, yet diagnosis and management remain challenging. Development and use of bleeding assessment tools allows for improved stratification of which patients may require further assessment and which patients are most likely to require treatment of their VWD. New options for laboratory assessment of von Willebrand factor (VWF) activity include a new platelet-binding assay, the VWF:GPIbM, which is subject to less variability than the ristocetin cofactor activity assay, and collagen-binding assays that provide insight into a different function of VWF. Genetic testing may be helpful in some cases where a type 2 VWD variant is suspected but is usually not helpful in type 1 VWD. Finally, treatment options for VWD are reviewed, including the use of recombinant VWF. Despite these advances, still more work is required to improve diagnosis, treatment, and quality of life for affected patients.

Safety of a pasteurized plasma-derived Factor VIII and von Willebrand factor concentrate: analysis of 33 years of pharmacovigilance data

BACKGROUND

Haemate-P/Humate-P (Humate-P) is a pasteurized human plasma-derived concentrate containing both Factor VIII and von Willebrand factor for treatment of hemophilia A and von Willebrand disease (VWD).

STUDY DESIGN AND METHODS

We analyzed the safety of Humate-P based on more than 33 years of postmarketing pharmacovigilance data, representing an estimated exposure of approximately 25,000 patient-years. The analysis comprises reports of potential adverse drug reactions (ADRs) from all sources, reported as part of routine pharmacovigilance at CSL Behring. ADRs considered clinically relevant or potential risks of Humate-P were identified based on defined and standardized Medical Dictionary for Regulatory Activities queries. Recognizing the limitations of spontaneous reporting, we also reviewed the literature, including clinical trials with mandatory reporting.

RESULTS

From 1982 to 2015, a total of 670 postmarketing cases had been reported via pharmacovigilance, for an overall reporting rate of approximately one ADR per 3900 administered standard doses. Of these cases, 343 involved ADRs considered clinically relevant risks (33 thromboembolic complications, 97 inhibitor formation, 110 hypersensitivity or allergic reactions) or potential risks (103 suspected virus transmissions) for Humate-P. Most thromboembolic complications occurred in patients undergoing surgery or with other known risk factors. Inhibitor formation occurred mostly in patients with hemophilia A (24 cases were high titer). Most patients with hypersensitivity or allergic reactions had VWD. None of the reported suspected virus transmission cases were confirmed to be associated with Humate-P. Reported results of company-sponsored studies showed a low incidence of adverse events possibly or probably related to Humate-P.

CONCLUSIONS

More than 33 years of pharmacovigilance data continue to support the safety of Humate-P.

Current challenges in the diagnosis and management of patients with inherited von Willebrand's disease in Italy: an Expert Meeting Report on the diagnosis and surgical and secondary long-term prophylaxis

Recent advances in the care of von Willebrand's disease (vWD) have allowed the majority of patients to be managed adequately. Even in the more severe forms, it is now possible to control recurrent bleeding through secondary long-term prophylaxis with von Willebrand factor-containing concentrates. Moreover, in the setting of surgical prophylaxis, the combination of interdisciplinary management and close patient monitoring yields a positive outcome in nearly all cases, although safety concerns remain. In clinical practice, the effectiveness of therapy is hindered by the difficulties in making a rapid, yet accurate diagnosis, in identifying the subgroup of bleeders who may benefit most from a specific strategy, and in selecting the optimal product and regimen.Since specific guidelines for heavy bleeders requiring short- and long-term prophylaxis are still lacking, sharing the experience of experts dealing with vWD patients on a daily basis is crucial to fill gaps in information relating to patient management. To address this important issue, 13 Italian haematologists met in Milan on April, 2, 2016 and in Florence on July, 9, 2016. A 30-question survey constituted the input to discuss (i) optimisation of the diagnostic workflow for vWD, (ii) the characteristics of patients who may benefit from secondary long-term prophylaxis (in particular with the purified von Willebrand factor concentrate with a low content of factor VIII), (iii) the key elements to consider when selecting a concentrate and (iv) the pre-operative and post-operative management of vWD patients. A summary of the main points covered is provided in this report.

Feasibility of the Von Willebrand disease PREVENT trial

BACKGROUND

Despite treatment, women with von Willebrand disease (VWD) have lower von Willebrand factor (VWF) levels and greater blood loss at delivery than controls. Current weight-based dosing does not account for the ~1.5-fold increase in blood volume in pregnancy.

METHODS

To evaluate the feasibility of a trial to prevent postpartum hemorrhage (PPH), we reviewed pre-pregnancy and 8th month VWF levels in women with VWD with and without PPH following vaginal delivery, assessed VWF concentrate use at delivery by U.S. hemophilia treatment center physician survey, and reviewed thrombosis risk with VWF concentrate by literature review. We determined trial interest and acceptability by structured interviews of physicians and patients. Analysis was by Student's t-test for continuous data, and chi-square or Fisher's exact test for discrete data.

RESULTS

PPH was associated with lower pre-pregnancy VWF:RCo, p<0.005; higher pre-pregnancy, 8th and 9th-month weight, each p<0.001; a family bleeding history, p=0.036; and VWF concentrate treatment, p=0.005. Surveyed physicians reported first-line therapy at delivery was VWF concentrate, at a mean dose 50IU/kg. A trial of a 1.5-fold volume-based dose increase was acceptable to physicians and patients, if it is safe and if costs and visits are minimized. A literature review determined thrombosis risk with VWF concentrate is low, 0.4%.

CONCLUSIONS

This study suggests pre-pregnancy VWF:RCo may predict PPH, but 50-80IU/kg VWF concentrate dosing may not prevent PPH. If pharmacokinetic modeling confirms volume-based dosing achieves VWF levels comparable to pregnant controls, it may be possible to determine if volume-modified VWF concentrate dosing will reduce PPH in VWD.

Laboratory monitoring of replacement therapy for major surgery in von Willebrand disease

Von Willebrand disease (VWD) is an inherited haemorrhagic disorder caused by a quantitative or qualitative defect of von Willebrand factor (VWF), a multimeric plasma glycoprotein that plays a key role in platelet adhesion to the subendothelium and acts as a carrier of factor VIII (FVIII) in blood. Patients with VWD experience bleeding symptoms that are mainly localized in mucous membranes and soft tissues, and their severity depends on the degree of the primary reduction in VWF and the secondary deficiency of FVIII in plasma. Because VWD patients are also at increased risk of perioperative bleeding, a prophylactic treatment aimed to correct the dual haemostatic defect (i.e. VWF and FVIII) is warranted. This review summarizes knowledge on the current management of patients undergoing major surgery, focusing on the peri-surgical laboratory monitoring of replacement therapy with VWF/FVIII concentrates. We suggest to monitor plasma levels of FVIII coagulant activity in the postoperative period rather than a surrogate maker of platelet-binding VWF activity as the ristocetin cofactor assay and its recent modifications.

Outcomes in Patients With Hemophilia and von Willebrand Disease Undergoing Invasive or Surgical Procedures

Adults with hemophilia A (HA), hemophilia B (HB), and von Willebrand disease (VWD) frequently require surgery and invasive procedures. However, there is variability in perioperative management guidelines. We describe our periprocedural outcomes in this setting. A retrospective chart review from January 2006 to December 2012 of patients with HA, HB, and VWD undergoing surgery or invasive procedures was conducted. Type of procedures, management including the use of continuous factor infusion, and administration of antifibrinolytics were reviewed. Adverse outcomes were defined as acute bleeding (<48 hours), delayed bleeding (≥48 hours), transfusion, inhibitor development, and thrombosis. We identified 59 patients with HA and HB. In all, 24 patients had severe hemophilia and 12 had mild/moderate hemophilia. Twelve patients had inhibitors. There were also 5 female carriers of HA and 6 patients with VWD. There were 34 major surgeries (26 orthopedic, 8 nonorthopedic) and 129 minor surgeries. Continuous infusion was used in 55.9% of major surgeries versus 8.5% of minor surgeries. Antifibrinolytics were administered in 14.7% of major surgeries versus 23.2% of minor surgeries. In all, 4 patients developed acute bleeding and 10 patients developed delayed bleeding. Delayed bleeding occurred in 28.6% of genitourinary procedures and in 16.1% of dental procedures. Five patients acquired an inhibitor and 2 had thrombosis. In conclusion, patients with HA, HB, or VWD had similar rates of adverse outcomes when undergoing minor surgeries or major surgeries. This finding underscores the importance of an interdisciplinary management and procedure-specific guidelines for patients with hemophilia and VWD prior to even minor invasive procedures.

A single-centre study of haemostatic outcomes of joint replacement in von Willebrand disease and control patients and an analysis of the literature

INTRODUCTION

Haemostatic assessments of patients with von Willebrand disease (VWD) who undergo total knee arthroplasty (TKA) and total hip arthroplasty (THA) have mainly relied on subjective parameters.

AIMS

To compare objective haemostatic outcomes of TKA/THA in VWD patients and controls without bleeding disorders.

METHODS

We retrospectively analysed haemostatic outcomes in VWD patients undergoing TKA/THA from 1993 to 2011 and compared them with two matched controls per operation. Using one-way analysis of variance, we tested the effect of VWD on bleeding risk after TKA and THA.

RESULTS

Twelve VWD patients (6 type 1, 3 type 2M, 1 each of types 2A/2B/3) undergoing 19 operations (12 TKA, 7 THA) were matched to 38 controls. One (5%) of 19 operations in VWD patients and none of the control operations met clinical criteria for major bleeding. Baseline and postoperative day 1 haemoglobin levels, postoperative blood loss, transfused red blood cells (RBCs) and mean hospitalization days were not significantly different. More VWD patients than controls received RBC transfusions [12 (63%) vs. 12 (32%)]. Only 9 (47%) VWD patients vs. 38 (100%) controls received pharmacologic VTE prophylaxis. No postoperative symptomatic VTE occurred in either group.

CONCLUSION

In this largest, single-institutional study, von Willebrand factor replacement based on daily levels resulted in low frequency of major bleeding in VWD patients after TKA/THA. RBC transfusion was more frequent compared with matched controls, but other objective measures of haemostasis were similar. Lack of sufficient details in published reports precluded comparison of haemostatic outcomes.

Practical aspects of factor concentrate use in patients with von Willebrand disease undergoing invasive procedures: a European survey

INTRODUCTION

The bleeding propensity in von Willebrand disease (VWD) is usually moderate or mild and patients with VWD do not need continuous treatment, but do require extra increased haemostatic cover when undergoing dental or surgical procedures. Desmopressin can be effective in certain patient groups and this has been considered in a previous publication.

AIM

This paper now seeks to evaluate current knowledge and practice in the use of factor concentrate in the management of VWD patients undergoing invasive procedures.

METHODS

A literature search was performed on the use of factor concentrates to cover invasive procedures and a survey of current practice in a number of specialist haematology centres across Europe represented by the European Haemophilia Strategy Board was conducted.

RESULTS

Our review of the literature and the results of the survey showed considerable heterogeneity in treatment regimens, and a lack of consistency in reporting of the variables that determine factor concentrate dosing and monitoring.

CONCLUSION

By analysing the literature, examining guidelines and using consensus deliberation, this survey allowed the group to develop recommendations for management of VWD patients undergoing invasive procedures.

Successful aortic aneurysm repair in a woman with severe von Willebrand (type 3) disease

von Willebrand disease type 3 (VWD3) is a rare but the most severe form of von Willebrand disease; it is due to almost complete lack of von Willebrand factor activity (VWF:RCo). It is inherited as autosomal recessive trait; whilst heterozygote carriers have mild, or no symptoms, patients with VWD3 show severe bleeding symptoms. In the laboratory, this is characterised by undetectable VWF:Ag, VWF:RCo, and reduced levels of factor VIII < 0.02 IU/dL. The bleeding is managed with von Willebrand/FVIII factor concentrate replacement therapy. In this rare but challenging case we report on the successful excision and repair of an ascending aortic aneurysm following adequate VWF/FVIII factor concentrate replacement using Haemate-P.

Utility of a high VWF: FVIII ratio in preventing FVIII accumulation: a study in VWF-deficient mice

Treatment of von Willebrand disease typically requires multiple infusions of von Willebrand factor (VWF)/factor VIII (FVIII) concentrate. Accumulation of FVIII is a clinical concern due to potential risk for thromboembolism. This study sought to determine whether VWF/FVIII concentrate of high VWF:FVIII ratio can prevent FVIII accumulation. VWF-deficient knockout mice received four 150 IU/kg VWF:ristocetin cofactor (RCo) infusions at 3-h intervals, with VWF/FVIII concentrates of a high (Haemate P/Humate-P) or low (Wilate) VWF:FVIII ratio. After each infusion, trough FVIII and VWF levels in plasma were determined. Separately, pharmacokinetic analysis was performed after single 250-IU/kg VWF:RCo infusions of each concentrate. Over the course of the four infusions, trough FVIII increased significantly in the group receiving Wilate (P < 0.001), but not Haemate P/Humate P (P = 0.058). After the first infusion, mean trough FVIII level in the Wilate group (31.7 IU/dl) was greater by 82% (P = 0.017) than that in the Haemate P/Humate P group (17.4 IU/dl). After the final infusion, mean trough FVIII of animals receiving Wilate (55.1 IU/dl) continued to exceed that of Haemate P/Humate P recipients (30.2 IU/dl) significantly (P < 0.001). Trough VWF levels were similar in the two groups. The VWF pharmacokinetics of the two concentrates coincided closely; however, the FVIII peak concentration and area under the curve were approximately twice as great in the mice treated with Wilate. In a murine model of severe von Willebrand disease, a VWF/FVIII concentrate with a high VWF:FVIII ratio prevented persistent exposure to elevated trough FVIII levels.

Evaluation of a rapid von Willebrand factor activity latex immuno assay for monitoring of patients with von Willebrand disease (VWD) receiving DDAVP or VWF replacement therapy

Haemostatic management of surgery in patients with von Willebrand disease (VWD) includes DDAVP or von Willebrand factor (VWF)-containing concentrates. Although the recommendations are for monitoring by VWF activity assays, it is quite common for clinicians to use factor VIII due usually to longer turnaround times required for VWF ristocetin cofactor assay (VWF:RCo) measurements. The aim of this study was to evaluate use of the rapid HaemosIL VWF activity (VWF:Act) latex immuno assay (LIA) on an automated coagulometer (ACL TOP(™) 700; Instrumentation Laboratory, Bedford, MA, USA) compared to platelet-based VWF:RCo assays in this setting. One hundred and sixty-seven plasma samples from 42 patients [Type 1 (n = 22), Type 2A (n = 2), Type 2B (n = 3), Type 2M (n = 10), Type 3 (n = 3)] and acquired von Willebrand syndrome (n = 2) with VWD treated with DDAVP or VWF-containing concentrates were included in the study. Method comparison and method bias were evaluated by Bland-Altman analysis (BA) and Passing and Bablok regression modelling respectively. BA of baseline samples (n = 39) showed a mean difference of -3.0 (±1.96 SD -25.2 to +19.4). Post (treatment) samples (n = 120) were separated into two groups. Group 1 contained samples with VWF:RCo levels 10 to ≤175 IU dL(-1) (n = 97) and group 2, samples with VWF:RCo levels >175 IU dL(-1) (n = 23). BA of group 1 postsamples showed a mean difference of +3.4 (±1.96 SD -44.6 to +51.5), and the BA of Group 2 samples was -23.9 (±1.96 SD -136.1 to +88.3). In conclusion, use of HaemosIL VWF:Act LIA test on an automated coagulometer is a reproducible and rapid assay that can be used as an alternative test for monitoring VWF replacement therapy, facilitating dose adjustments on a real-time basis.

Patients with disorders of thrombosis and hemostasis

Surgery, by definition, is a challenge to the hemostatic system. In addition, a surgical procedure may provoke inappropriate venous or arterial thrombosis, such as is suggested historically by Virchow's Triad. For these reasons, proper functioning of the hematologic system is integral in a successful and safe perioperative period. Patients with a disorder of either coagulation or hemostasis, therefore, present an exciting challenge to the preoperative physician. Diagnosis of a hematologic disorder may be more or less occult. A proper bleeding and clotting history can serve to elucidate such a disorder and is therefore paramount to the preoperative workup. For those patients with a previously diagnosed disorder of the hematologic system, appropriate laboratory investigation and a concise therapeutic plan for the day of surgery can help to minimize risks in the perioperative period.

Efficacy and safety of Wilate in paediatric VWD patients under 6 years of age - results of a prospective multicentre clinical study including recovery information

Treatment with exogenous von Willebrand factor (VWF) is indicated in patients with von Willebrand disease (VWD) in whom treatment with 1-deamino-8-d-arginine vasopressin/desmopressin is contraindicated. Wilate is a new generation plasma-derived concentrate of native VWF and coagulation factor VIII (FVIII) (in a physiological 1:1 ratio) developed for the treatment of VWD. This is the first study to report safety, efficacy and in vivo recovery (IVR) data from 15 paediatric patients less than 6 years of age who received Wilate for either prophylaxis, on-demand treatment or for treatment in surgical procedures during a prospective open-label trial (VWD type 1: 5, type 2A: 1, type 2B: 2, type 3: 6, unknown type: 1 patients). Analysis of IVR for VWF and FVIII suggested an appropriate and consistent rise in coagulation activity after Wilate administration. Overall efficacy was rated as excellent or good for 99.7% [prophylactic infusions] and 100% [bleeding episodes/surgical procedures]. More than 82% of bleeding episodes resolved after 1 day of treatment, and a Wilate dosage of 20-50 IU kg(-1) was sufficient to achieve haemostasis in 97% of bleeding episodes. All surgical procedures were successfully managed with Wilate. No thromboembolic events were observed during the study, and no patient developed anti-VWF antibodies or FVIII inhibitors. In conclusion, this study confirms both the expected IVR profile in paediatric patients and the excellent efficacy, tolerability and safety profile of Wilate observed previously in adults. Wilate showed excellent efficacy in the treatment of bleeding when used prophylactically or on-demand, and in the treatment of surgical procedures.

Quantification of perioperative changes in von Willebrand factor and factor VIII during elective orthopaedic surgery in normal individuals

von Willebrand's disease (VWD) patients undergoing major surgery are prophylactically treated to promote haemostasis. There is variability in perioperative clinical practice; however, most guidelines suggest replacing the deficient factor to a level of 1.0 IU mL(-1) (or 100%). A review of the literature reveals a paucity of well constructed descriptive data quantifying the changes in coagulation that occur in response to surgical stress. The aim of this study was to quantify the changes in haemostatic variables occurring in response to elective orthopaedic surgery in normal individuals. Eligible subjects >18 years of age undergoing total hip or knee replacement were recruited. Blood samples were drawn at five time points: baseline, preoperatively, 30 min after surgical incision, 30 min postoperatively, postoperative day (POD) 1. Analyses included t-tests and repeated measures anova. Overall 30 patients, 21 women and 9 men, with a mean age of 65 were included in the final analysis. All von Willebrand factor (VWF) variables were seen to significantly decrease intraoperatively and increase postoperatively. VWF multimers showed a statistically significant decrease in high molecular weight multimers intraoperatively and an increase postoperatively. On subgroup analysis, age, gender and anaesthesia type were significantly correlated with changes in VWF parameters. Data presented in the current study establish a physiological baseline for VWF parameters in the normal population and demonstrate mean VWF/factor VIII levels greater than 1.0 IU mL(-1) intraoperatively. As such, current management in VWD patients does not appear to mimic the normal physiological response to surgery.

Bleeding disorders in orthopedic surgery

With increasing recognition of the complications related to coagulopathies, it is of paramount importance for all orthopedic surgeons to possess a basic knowledge of common bleeding disorders. The evaluation of the coagulopathic patient requires a careful history, physical examination, and laboratory evaluation. Bleeding disorders commonly include quantitative and qualitative platelet and coagulation factor disorders and coagulation inhibitors. The management of these coagulopathies that can be encountered in elective and nonelective practice is often ignored. With appropriate knowledge and a multidisciplinary approach with hematologists and cardiologists, surgeons can perform minor and major orthopedic procedures safely and effectively.

Current management of patients with severe von Willebrand disease type 3: a 2012 update

Von Willebrand disease type 3 (VWD3) is the most severe form of this bleeding disorder due to the almost complete deficiency of von Willebrand factor (VWF). VWD3 is inherited as an autosomal recessive trait. While heterozygous carriers exhibit mild or no bleeding symptoms, most patients with VWD3, which is characterized by undetectable levels of VWF antigen (VWF:Ag) and reduced concentrations (<20 IU/dl) of factor VIII (FVIII), show severe bleeding symptoms. Although the incidence of VWD3 is rare, the condition is of considerable interest because of its severe clinical presentation, the need for replacement therapy and the risk of alloantibodies following infusion of plasma-derived VWF concentrates. This review, based on clinical experience, provides an update on the clinical, laboratory and molecular markers of VWD3 that can be useful for determining the optimal therapeutic approach in these patients.