Prolonged Circulation of Ultra-Large Von Willebrand Factor and a Reduction in ADAMTS13 Activity Promotes Microvascular Disease Following Traumatic Injury

Introduction: Increases in plasma von Willebrand Factor (vWF) levels, accompanied by decreases in its respective metalloprotease, ADAMTS13, have been demonstrated in diseases of microvascular injury. We hypothesized that following severe trauma, a burst of ultra-large vWF (UL-vWF) is released into the bloodstream by damaged endothelium, resulting in increased thrombogenicity due to circulating vWF multimers. We further hypothesized that traumatic injury would lead to a deficit of ADAMTS13, promoting the accumulation of UL-vWF forms and, ultimately, the increased risk of microvascular disease, such as acute kidney injury (AKI). Methods: A cohort of 37 severely injured trauma patients was analyzed for antigen levels of plasma vWF and ADAMTS13 at 0- and 24-hours after admission. Circulating vWF multimeric composition from both time points was determined by vertical agarose gel electrophoresis. Multivariate analyses were performed with data abstracted from the electronic medical records to identify further dependences. A similar analysis was also performed on plasma from a cohort of 8 patients with trauma induced AKI at 0-, 24-, and 72-hours after admission; these patients were well matched against trauma patients without AKI. Finally, we utilized a murine model of polytrauma and hemorrhage, in conjunction with qRT-PCR of ADAMTS13 in total liver RNA, to specifically address how the expression of ADAMTS13 is altered by the systemic effects of traumatic injury. Results: Circulating vWF levels were increased in severe trauma patients when compared to healthy controls at presentation (189% (110-263) vs. 95% (74-120)) and persisted through 24-hours (213% (146-257) vs. 132% (57-160)). Ultra-large vWF forms were elevated at both 0- and 24-hours when compared to pooled normal plasma ((10.0% (8.9-14.3) and 11.3% (9.1-21.2), respectively, vs 0.6%). The largest vWF forms within trauma patient plasma circulated at 33±4 dimers vs 18±1 dimer in length within pooled normal plasma. Severe trauma patient ADAMTS13 activity was decreased at 0-hours (66% (47-86) vs. 100% (98-100)) and at 24-hours (72.5% (56-87.3) vs 103% (103-103)) when compared to healthy patients. Furthermore, the proportion of circulating low molecular weight multimeric (LMWM) vWF to total circulating vWF forms was directly dependent upon ADAMTS13 activity at 24-hours (Decreased ADAMTS13 Activity: 20.4% (15.0-22.7) LMWM vWF vs Normal Activity: 25.8% (22.7-35.2) LMWM vWF). Strikingly, ADAMTS13 activity independently predicted the development of coagulopathy, correlating with presentation INR (ρ =-0.63), activated clotting time of thromboelastography (TEG) (ρ=-0.36), and TEG maximum amplitude (ρ=0.36). ADAMTS13 activity also closely correlated with injury severity (ISS) (ρ=-0.34) and blood product transfusion (ρ =-.45). The cohort of 8 trauma patients who went on to develop AKI showed a 1.54-fold (1.02-2.05) increase in plasma vWF antigen levels between 0 and 72 hours, while those who did not develop AKI showed no change in vWF levels over this time period. Furthermore, those who developed AKI demonstrated a smaller proportion of LMWM vWF in plasma than those who did not (25.4% (23.4-28.0) vs 31.2% (27.2-35.6)), suggesting the increased thrombogenicity of their circulating vWF forms. Finally, qRT-PCR of total liver RNA in 6 mice demonstrated a 2-fold decrease in ADAMTS13 RNA expression levels between the times immediately before and 24-hours after trauma. Altogether, these data indicate that both circulating ADAMTS13 and its production are deficient in the days following severe injury. Conclusions: Severe traumatic injury alters the circulating composition of ADAMTS13 and its target, vWF, shifting their equilibrium to one that promotes thrombosis. Not only is the concentration of circulating ADAMTS13 decreased following traumatic injury, but hepatic expression of the enzyme is lacking as well. In the immediate moments following injury, these mechanisms contribute to life-saving hemostasis; however, as these changes extend into the following days, the early hemostatic benefit quickly shifts to burden that may exacerbate microvascular disease. Disclosures Ragni: Bioverativ/Sanofi: Consultancy, Research Funding; Sangamo: Research Funding; Shire/Takeda: Consultancy, Other: Study drug; Alnylam/Sanofi: Consultancy, Research Funding; Bayer: Consultancy; Spark Therapeutics: Consultancy, Research Funding; ICER: Consultancy; OPKO: Research Funding; Biomarin: Consultancy, Research Funding. Rollins-Raval:Bayer, Inc: Membership on an entity's Board of Directors or advisory committees. Raval:Sanofi: Membership on an entity's Board of Directors or advisory committees; Bayer, Inc: Research Funding. Neal:Janssen Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees.

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HSCT-Associated Hepatic VOD Is Initiated With Preceding Appearance Of Unusually Large Von Willebrand Factor Multimers In Patient Plasmas

Blood ◽

10.1182/blood.v122.21.3625.3625 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3625-3625

Author(s):

Masaki Hayakawa ◽

Masanori Matsumoto ◽

Yumi Yoshii ◽

Hideo Yagi ◽

Hiroshi Kimura ◽

...

Keyword(s):

Body Weight ◽

Board Of Directors ◽

Plasma Levels ◽

Combination Regimen ◽

Adamts13 Activity ◽

Advisory Committees ◽

Von Willebrand ◽

Willebrand Factor ◽

Frozen Plasma ◽

Platelet Transfusions

Abstract Backgrounds and Aims Hepatic veno-occlusive disease (VOD) associated with hematopoietic stem cell transplantation (HSCT) is characterized by a clinical triad of jaundice (total bilirubin, >2 mg/mL), hepatomegaly with right upper quadrant pain, and ascites and/or unexplained body weight gain (>5% of baseline) within 30 days after operation. Although the pathogenesis of hepatic VOD has not been fully elucidated, the common pathological features are thrombi formed in hepatic central vein. We previously reported that a significant decrease of plasma ADAMTS13 activity was noted in patients undergoing HSCT, who subsequently developed VOD (Park et al, BMT 2002). Then, we showed that plasma antigen levels of von Willebrand factor (VWF) has been kept higher in HSCT-patients with VOD than in those without, and in fact prophylactic infusions of fresh frozen plasma (FFP) with a dose of 10 ml/kg body weight 3 times per week were effective to reduce the frequency of VOD occurrence in high risk patients (Matsumoto et al, BMT 2007). However, more recent studies by ours indicate that FFP infusion alone is not enough to totally eliminate the occurrence (unpublished). Recently, it has been shown that the treatment with recombinant soluble thrombomodulin (rTM) is sometimes highly efficient to reverse VOD progression. But its pharmacokinetics and regimen for the treatment has not been established. As a first step to elucidate a possible combination regimen of FFP and rTM to VOD patients, here we have analyzed the transitional changes of unusually large VWF multimers (UL-VWFMs). The UL-VWFMs are released from damaged endothelial cells and induce platelet hyperagglutination under high shear stress generated in microvasculatures, and are often observed in patient plasmas undergoing HSCT. Patients and Methods During 2011-2012, 45 patients were received allogenic HSCT in the second internal medicine department of our university hospital. None of these patients ,however, were received planned prophylactic FFP infusions, and as a result six patients undergoing allogenic cord blood transplantation (CBT) developed VOD. Clinical features of these 6 patients are shown in Table 1. Under approval of Ethics Committee of Nara Medical University, we consecutively collected patient's citrated plasmas (ca 2.5 ml) and stored at -80°C until use. Using these deep-frozen plasma samples, we here extensively analyzed plasma levels of ADAMTS13 activity (ADAMTS13:AC), VWF antigen (VWF:Ag), and VWF collagen binding activity (VWF: CBA), together with VWF multimer analysis. More importantly, we also measured the corrected platelet count increment (CCI) to evaluate the efficiency of Platelet trsnsfusions. Then, we comprehensively evaluated these data with routine clinical and laboratory findings. Results and Discussion 1) Plasma levels of ADAMTS13:AC were moderately but consistently decreased during two months after HSCT, whereas those of VWF:Ag were kept high, usually more than 200% and often 500% of the normal. 2) The UL-VWFMs appeared soon after HSCT, and continued at least until absolute neutrophil count (ANC) increased to >500 (usually 20-30 days after HSCT). 3) Until platelet engraftment (usually 40-60 days after HSCT), platelet transfusions (every 2-3 days interval) are usually performed to prevent the bleeding complications. During that period, the CCI values were consistently low, but those values were significantly increased during the administration of rTM. 4) Excess platelet transfusions before platelet engraftment induced the consumption of larger VWFMs in patient's plasmas, and often almost simultaneously hepatic VOD developed. Thus, platelet transfusions during the appearance of UL-VWFMs in patient's plasmas may induce platelet clumping in microvasculatures, and lead to the development of thrombotic complications including hepatic VOD. 5) The measurement of plasma levels of VWF:CB activity appeared to well predict the presence of UL-VWFMs. A representative case is shown in Figure. Thus, a combination regimen of FFP and rTM might be advisable when the patients show the early clinical signs of hepatic VOD and the laboratory data such as VWF:CBA suggest the presence of UL-VWFMs in patient's plasmas. Disclosures: Matsumoto: Alexion Pharma: Membership on an entity’s Board of Directors or advisory committees. Fujimura:Alexion Pharma: Membership on an entity’s Board of Directors or advisory committees; Baxter International Inc: Membership on an entity’s Board of Directors or advisory committees.

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Treatment of Haemophilia a (HA) Patients with Inhibitors: Immune Tolerance Induction with a Single Factor VIII/Von Willebrand Factor Concentrate in an Observational Immune Tolerance Induction Study (ObsITI)

Blood ◽

10.1182/blood-2018-99-114408 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 2482-2482

Author(s):

C. Escuriola Ettingshausen ◽

Erik Berntorp ◽

Yesim Dargaud ◽

Zeynep Gutowski ◽

Claude Negrier ◽

...

Keyword(s):

Board Of Directors ◽

Von Willebrand Factor ◽

Immune Tolerance ◽

Research Funding ◽

Tolerance Induction ◽

Advisory Committees ◽

Immune Tolerance Induction ◽

Inhibitor Titre ◽

Von Willebrand ◽

Willebrand Factor

Abstract Introduction and objectives: Development of neutralising inhibitors against factor VIII (FVIII) is one of the most serious and costly complications in the treatment of HA. An ongoing international, open-label, uncontrolled, multicentre observational study, ObsITI (ClinicalTrials.gov. NCT 02207894) started in 2005 to assess immune tolerance induction (ITI), the standard of care in patients with inhibitors. The study evaluates patient- and therapy-related variables on ITI course, outcome and morbidity in HA patients with inhibitors. ObsITI satellite studies additionally look at other factors related to tolerisation. Methods and Materials: As of February 2018, 193 patients from 20 countries undergoing ITI have been recruited in ObsITI. 152 patients completed the study and 41 are ongoing. A subgroup of more than 80 prospective patients were treated exclusively during the complete ITI course with a single plasma-derived (pd) FVIII concentrate that contains von Willebrand factor (VWF) in a VWF/FVIII ratio of 0.4 (Octapharma AG). According to the recommended Bonn protocol, low responders at ITI start received 50-100 IU FVIII kg-1 daily, or every other day; high responders received 100 IU FVIII kg-1 every 12 hours. Results: In this ongoing study, the majority of patients treated with the pdFVIII/VWF product achieved a negative inhibitor titre. ITI outcome was significantly correlated with the bleeding rate during ITI, the peak titre during ITI, the inhibitor titre at start of ITI >10 BU, and the number of poor prognosis factors. Conclusion: Treatment with this particular pdFVIII/VWF concentrate, mainly according to the Bonn protocol, resulted in a high ITI success rate in HA patients with inhibitors and corroborates previously published success rates (77.1% complete/partial success in 48 inhibitor patients undergoing ITI with the same product). Disclosures Escuriola Ettingshausen: SOBI: Honoraria, Research Funding; Shire: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Octapharma: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Novo Nordisk: Honoraria; Roche: Honoraria; Grifols: Honoraria; Pfizer: Honoraria; LFB: Honoraria. Berntorp:Octapharma: Consultancy; CSL Behring: Consultancy; Shire: Consultancy, Other: honoraria for lecturing . Negrier:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Octapharma: Honoraria, Research Funding; CSL Behring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; LFB: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sobi/Bioverativ: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxalta/Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Research Funding. Pavlova:Novo Nordisk: Honoraria; Octapharma: Honoraria. Oldenburg:Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees; Grifols: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biogen Idec: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biotest: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Swedish Orphan Biovitrum: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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Obtaining a Von Willebrand Evaluation at Time of Acute Heavy Menstrual Bleeding Presentation Leads to Overestimation of Von Willebrand Levels

Blood ◽

10.1182/blood-2019-127258 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 627-627

Author(s):

Megan C. Brown ◽

Michael H. White ◽

Robert F. Sidonio

Keyword(s):

Factor Viii ◽

Board Of Directors ◽

Research Funding ◽

Heavy Menstrual Bleeding ◽

Menstrual Bleeding ◽

Quality Improvement Initiative ◽

Advisory Committees ◽

Von Willebrand ◽

Willebrand Factor

Background: Acute heavy menstrual bleeding (HMB) is common for adolescent females, with about a quarter of menstruating females seeking care for HMB over a 3-year time period (O'Brien et al, Blood 2018). Inherited bleeding disorders are common in this adolescent population, identified in 24.6% referred for hematologic evaluation (Zia et al, Blood 2016). The timing and contents of the hemostatic workup for acute HMB in adolescents is extrapolated from adults, although the causes of acute HMB varies significantly between adult women and adolescents. A consensus statement by the American College of Obstetrics and Gynecology recommends obtaining a variety of hemostatic tests including CBC, von Willebrand studies, factor VIII, prothrombin time, partial thromboplastin time, fibrinogen, and thyroid stimulating hormone at the time of presentation (Committee Opinion 557, ACOG 2011). Factor VIII and Von Willebrand studies are known to be increased in the setting of physiologic stress and supplemental estrogen use, questioning their diagnostic accuracy in the setting of acute bleeding. Repeat testing is often required for diagnosis of von Willebrand disease A von Willebrand factor antigen (VWF:Ag) or von Willebrand factor ristocetin cofactor level over 100IU/dL has been shown to have a negative predictive value (NPV) of 95%.(Doshi et al, ASH 2018). Methods: As part of a quality improvement initiative to improve the evaluation and management of adolescents with HMB at Children's Healthcare of Atlanta (CHOA), we instituted an acute HMB protocol for emergency department (ED) and inpatient use. This protocol was implemented at all CHOA emergency departments in metropolitan Atlanta. Subjects were included if they presented with acute HMB as determined by an adapted Philip Menorrhagia Screening Tool. Subjects with a previously diagnosed bleeding disorder, ITP, active rheumatologic disease, cancer, or anticoagulant use were excluded. Descriptive statistics were used to summarize demographics and clinical characteristics. Patients with a positive Philip screen underwent a uniform bleeding inventory and a standardized set of laboratory tests based on the adult consensus statement. Inpatient and outpatient treatments were standardized by hemoglobin level and symptomology. Follow up with hematology and gynecology was encouraged for all. Data was extracted using various heavy menstrual bleeding ICD-10 codes from January 1, 2017 to December 31, 2018. Individuals with von Willebrand studies at baseline and follow up were identified. T-tests and Wilcoxon rank sum tests were utilized to compare VWF:Ag, VWF:RCo and Factor VIII as baseline and follow up. Results: Over a 2-year period, 232 adolescent girls were seen in CHOA EDs for acute HMB with 88 (37.9%) requiring admission and 6 (2.6%) requiring intensive care. The population was primarily African American (63%) with a median age at presentation of 14.8 years (IQR 13.1-16.7). The majority of adolescents had the core hemostatic labs drawn (55.6%) as described per protocol. Thirty-six individuals had baseline and follow up VWD studies. Those with repeat VWD studies were younger (median 13.2 years vs 15.0 years), more commonly white (44.4% vs 21.2%), were more likely to have been admitted (83.3% vs 29.6%) and more likely to have had a hematology follow up appointment (63.4% vs 7.8%). Mean and median VWF:Ag, VWF:RCo and Factor VIII were significantly higher at presentation with HMB than at follow up. Of those with a baseline VWF:Ag and/or VWF:RCo >100, there was a 96.4% NPV for the diagnosis of VWD. For individuals whose initial VWF:Ag and VCWF:RCo were both >100, there was 100% NPV. Conclusions: Among the adolescents cared for at our institution with acute HMB who had confirmatory VWD testing, initial VWF:Ag and VWF:RCo >100 ruled out VWD based on repeat testing. However, poor adherence with hematology or gynecology follow-up may give false reassurance against a diagnosis of VWD. Further improvements of our quality improvement initiative will include a limited hemostatic workup at presentation with a focus on improved adherence to follow up and subsequent hemostatic evaluation. Disclosures White: National Hemophilia Foundation: Other: Shire Clinical Fellowship Program. Sidonio:Kedrion: Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Takeda-Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genetech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Biomarin: Membership on an entity's Board of Directors or advisory committees; Uniqure: Membership on an entity's Board of Directors or advisory committees.

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Von Willebrand Factor to Prevent Postpartum Hemorrhage

Blood ◽

10.1182/blood.v128.22.1400.1400 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1400-1400 ◽

Cited By ~ 1

Author(s):

Nicoletta Machin ◽

Margaret V. Ragni ◽

Andra H. James ◽

Craig D. Seaman ◽

Lynn M. Malec ◽

...

Keyword(s):

Blood Loss ◽

Board Of Directors ◽

Research Funding ◽

Structured Interviews ◽

First Line ◽

Vascular Medicine ◽

Advisory Committees ◽

Thrombosis Risk ◽

Von Willebrand ◽

Willebrand Factor

Abstract Background: Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is characterized by deficient and/or defective von Willebrand factor (VWF) which results in spontaneous and traumatic mucosal bleeding. In women with VWD, pregnancy is associated with excess blood loss and poor quality of life. Recently, a prospective cohort study by James et al Haemophilia 2015, determined that even when treatment is given, women with VWD had lower VWF levels, greater blood loss at delivery, and lower hematocrit than controls without VWD. The reason for this finding remains unknown. Current VWF dosing is weight-based, but does not account for the ~1.4-1.5-fold increase in blood volume during pregnancy. To address this, we conducted a feasibility study for a prospective, randomized phase III trial comparing weight-based, 50 IU/kg, with volume-based, 80 IU/kg, VWF to prevent postpartum hemorrhage (PREVENT PPH Trial). Methods: To establish trial feasibility: 1) we compared pre-pregnancy and 8th-month VWF levels in women with VWD with and without PPH (≥500 cc blood loss in the 1st 24 hours) following vaginal delivery; 2) we evaluated VWF dosing in women with PPH in the James study; 3) we assessed thrombosis risk and VWF concentrate dose by literature review; 4) we surveyed current practice regarding VWF concentrate use at delivery by U.S. hemophilia treatment center (HTC) MDs; and 5) we conducted structured interviews of MDs and VWD patients to determine trial acceptability. Analysis was by Student's t-test for continuous data, and Fisher's exact test for discrete data. Results:In the Retrospective VWD-PPH Study of 16 women with VWD (14 type 1; 2 type 2) undergoing vaginal delivery, PPH was associated with higher pre-delivery weight, pre: 88.1 vs. 67.6 kg; 8thmonth: 99.9 vs. 75.0 kg; and delivery: 104.0 vs. 78.6 kg, all p<0.005; and a family bleeding history, 75.0% vs. 12.5%, p=0.041. Women with PPH had lower pre-pregnancy VWF:RCo, 0.34 IU/ml vs. 0.48 IU/ml, non-significant, p=0.067; similar 8th month VWF:RCo, 1.31 IU/ml vs. 1.45 IU/ml, p=0.484, and were more likely to be treated with VWF, 75.0% vs. 37.5%, p=0.315. Pre-pregnancy bleeding score (BS) correlated directly with EBL (blood loss) at delivery, r=0.663, p=0.005. VWF Dosing Data from James co-authors indicated a mean VWF dose of 46 IU/kg (median 50 IU/kg), range 28-83 IU/kg, at delivery, followed by 3.8 days (median 3 days), range 2-19 days, postpartum treatment. The Literature Review identified 13 publications between 1992-2015 reporting pharmacokinetic, safety, and/or efficacy studies in a total of 570 patients (none pregnant) at VWF doses 10-222 IU/kg. Thrombosis rate was low, 0.4%, including 2 of 353 (0.6%) receiving plasma-derived (pd) VWF and none of 95 (0%) receiving recombinant (r) VWF: these two patients included one with injection-site phlebitis and one with a remote postoperative VTE, each receiving VWF≤100 IU/kg. An HTC Survey distributed to 70 MDs, 19 (27.1%) of whom responded, 16/18 (88.9%) reported VWF was first-line therapy at delivery, mean dose 50 IU/kg; DDAVP was the most common second-line therapy in 7/17 (41.2%), and anti-fibrinolytic therapy was third-line, 8/10 (80.0%). All 19 indicated interest and willingness to participate in a trial comparing weight-based, 50 IU/kg, vs. 1.6-fold higher volume-based, 80 IU/kg, VWF at delivery. In Structured Interviews of 18 MDs and 18 VWD patients, the trial was acceptable to MDs if staff costs are covered, if the drug is safe re thrombosis, if there are sufficient patients, and if there is obstetrician collaboration to facilitate in-hospital dosing and blood draws. The trial was also acceptable to VWD patients if the drug is safe for mother and child, if childcare and travel costs are covered, and if visits are minimized in the postpartum period. Conclusions: The findings of this feasibility study indicate that pre-pregnancy VWF:RCo may be a better predictor of PPH than 8thmonth VWF:RCo. High pre-delivery weight which is associated with high blood volume may increase PPH, possibly through dilution of VWF levels. A VWF dose of ~50 IU/kg, which is the first line of therapy at delivery and the current standard of practice, may not prevent PPH. Thrombosis risk with VWF in published studies is low even at doses >80 IU/kg. Drug safety, local obstetric collaboration, and coverage of staff, travel, and childcare costs are critical issues to address in trial design. Disclosures Ragni: SPARK: Research Funding; Genentech: Research Funding; Tacere Benitec: Consultancy; Vascular Medicine Institute: Research Funding; OPKO: Research Funding; Novo Nordisk: Research Funding; Alnylam Pharmaceuticals: Consultancy, Research Funding; Baxalta: Research Funding; Biogen: Consultancy, Research Funding; Biomarin: Consultancy; Shire: Consultancy; CSL Behring: Research Funding. James:Intramural University of Ghana Research Fund: Research Funding; Vanderbilt University Medical Center Gift Funds: Research Funding. Malec:Biogen: Consultancy; Vascular Medicine Institute: Research Funding; Biogen: Research Funding; Baxalta: Research Funding. Kessler:Octapharma: Consultancy, Research Funding; Novo Nordisk: Consultancy, Research Funding; Grifols: Consultancy; Genentech: Consultancy, Research Funding; Biogen: Consultancy; Bayer: Consultancy, Research Funding; Pfizer: Consultancy; Baxalta: Consultancy, Research Funding; LFB: Other: Member of DSMB. Kouides:CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees; Baxalta: Consultancy. Neff:Shire: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: DSMB Chair for research study; ABIM: Other: Hematology Exam committee; CSL Behring: Membership on an entity's Board of Directors or advisory committees; HEMA Biologics: Membership on an entity's Board of Directors or advisory committees. Philipp:Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Other: Data Safety Monitoring Board. Brooks:Gilead Sciences: Research Funding.

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Pharmacokinetics of a Recombinant Von Willebrand Factor in Patients with Severe Von Willebrand Disease

Blood ◽

10.1182/blood.v126.23.2293.2293 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2293-2293

Author(s):

Margaret V Ragni ◽

Giancarlo Castaman ◽

Joan Cox Gill ◽

Peter Kouides ◽

Miranda Chapman ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Phase 1 ◽

Pharmacokinetic Profile ◽

Phase 3 ◽

Advisory Committees ◽

Fviii Activity ◽

Von Willebrand ◽

Dose Levels ◽

Willebrand Factor

Abstract Introduction Recombinant von Willebrand factor (rVWF, vonicog alfa, BAX 111), which is manufactured using a plasma-free method (Turecek et al Semin Thromb Hemost 2010), may provide an important alternative replacement therapy for VWD subjects. In contrast to plasma-derived (pd) VWF concentrates, BAX 111 contains a high ratio of high molecular weight (HMW) and ultralarge VWF multimers (ULM), which improve platelet and collagen binding and enhance FVIII stabilization (Kragh et al Thromb Res 2014), and may therefore be associated with better hemostatic outcomes and simplify bleeding management in VWF patients for a variety of clinical conditions. As BAX 111 is a pure VWF product, it is also not restricted to co-administration with coagulation factor VIII (FVIII). The pharmacokinetic profile of BAX 111 has been evaluated in two prospective trials (phase 1 and phase 3) in adults with severe VWD. Methods The pharmacokinetic profile of BAX 111 (with vs. without rFVIII; and BAX 111:rFVIII compared with a pdVWF:pdFVIII) in subjects with VWD, evaluated in a non-bleeding state, was determined in two clinical trials by assessment of ristocetin co-factor activity (VWF:RCo), VWF antigen (VWF: Ag); collagen-binding activity (VWF:CB), FVIII activity, and VWF multimer activity. Lower doses were examined in the first-in-human phase 1 dose-finding study, and the expected therapeutic doses (as recommended for licensed pdVWF-containing concentrates) of 50 IU VWF:RCo/kg and 80 IU VWF:RCo/kg (for major bleeding episodes) were selected for further evaluation in phase 3. PK assessments were also repeated after 6 months with the 80 IU VWF:RCo/kg dose. Results The PK profile of BAX 111 has been evaluated in a total of 56 unique subjects with severe VWD. A rapid increase in VWF:RCo was observed after a single infusion of BAX 111. There was no apparent dose-dependency at a wide range of dose levels (20 IU, 50 IU and 80 IU VWF:RCo/kg) and BAX 111 PK was not affected by administration together with rFVIII in the crossover study with the 50 IU VWF:Co/kg dose (Figure 1). A tendency toward a longer mean terminal half-life (T1/2) of VWF:RCo for BAX 111:rFVIII as compared with a pdVWF:pdFVIII was observed in the phase 1 study (23.6 h for 20 IU BAX 111:rFVIII, 19.3h for 50 IU BAX 111:rFVIII) and the mean T1/2 at 50 IU VWF:RCo/kg in the phase 3 study (19.6 h for BAX 111:rFVIII and 21.9 h for BAX 111) is also considerably longer than that of pdVWF products (Batlle et al Blood Coagul Fibrinolysis 2009). PK parameters were similar for the first (19.1 h) and second (21.2 h) assessment in the repeated PK study at 80 IU VWF:RCo/kg. VWF:CB parameters were comparable to VWF:RCo across dose levels in the phase 1 study (15.7 h for 20 IU BAX 111:rFVIII, 24.4h for 50 IU BAX 111:rFVIII) and phase 3 study (19.3h for BAX 111:rFVIII and 18.3h for BAX 111 at 50 IU; 18.8h for 80 IU in the first assessment and 20.9h 80 IU in the second assessment). ULMs were detected after 15 minutes post-infusion of BAX 111 (earliest time point measured), followed by a substantial decline due to rapid degradation by endogenous ADAMTS13 between 12 and 24 hours. A substantial increase in FVIII activity was observed after infusion with BAX 111 and BAX 111:rFVIII, followed by a secondary rise in FVIII activity after 12 hours due to the stabilization of endogenous FVIII, which was more pronounced for BAX 111:rFVIII than for pdVWF:pdFVIII (geometric mean ratio for AUC0-inf = 1.36 [90% Clopper-Pearson confidence interval: 0.93; 1.99]), and similar for BAX 111 alone as compared with BAX 111:rFVIII, confirming the ability of BAX 111 to stabilize endogenous FVIII:C. Conclusion BAX 111 has an enhanced PK profile compared to plasma-derived concentrates and there is no apparent dose dependency over a wide dose range (20 IU, 50 IU, 80 IU VWF:RCo/kg). The ULM present in BAX 111 may be more effective in stabilizing endogenous FVIII, and therefore BAX 111 may have the potential for less-frequent administration compared with plasma-derived VWF concentrates, and for FVIII-independent dosing after the initial infusion or in non-emergency bleeds. Disclosures Ragni: Biogen: Research Funding; Biomarin: Research Funding; Genentech Roche: Research Funding; Vascular Medicine Institute: Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; SPARK: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding; Bristol Myers Squibb: Research Funding; Tacere Benitec: Membership on an entity's Board of Directors or advisory committees; Bayer: Research Funding; Dimension: Research Funding; CSL Behring: Research Funding; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Castaman:Bayer, Baxalta, CSL Behring, Kedrion, Novo Nordisk, and Pfizer: Membership on an entity's Board of Directors or advisory committees. Gill:Bayer: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees. Kouides:CSL Behring: Membership on an entity's Board of Directors or advisory committees. Chapman:Baxalta: Employment. Sytkowski:Baxalta: Employment. Obermann-Slupetzky:Baxalta: Employment. Presch:Baxalta: Employment. Fritsch:Baxalta: Employment. Ewenstein:Baxalta: Employment.

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Novel Insights into the Clinical Phenotype and Pathophysiology Underlying Low VWF Levels: The Low Von Willebrand Factor in Ireland Cohort (LoVIC) Study

Blood ◽

10.1182/blood.v128.22.873.873 ◽

2016 ◽

Vol 128 (22) ◽

pp. 873-873

Author(s):

Michelle Lavin ◽

Sonia Aguila ◽

Sonja Schneppenheim ◽

Niall Dalton ◽

Jamie M O'Sullivan ◽

...

Keyword(s):

Board Of Directors ◽

Von Willebrand Factor ◽

Research Funding ◽

Molecular Mechanisms ◽

Assessment Tools ◽

Bleeding Tendency ◽

Advisory Committees ◽

Von Willebrand ◽

Willebrand Factor

Abstract Cohort studies have identified VWF gene mutations in ~65% of patients with type 1 Von Willebrand Disease (VWD). However, in patients with mild reductions in Von Willebrand Factor (VWF) levels, VWF mutations are less common and linkage studies suggest that the reduced plasma VWF levels are often independent of the VWFgene. Important clinical questions therefore remain unanswered regarding diagnosis and management of patients with Low VWF (levels 30-50 IU/dL). Evidence-based diagnostic criteria are needed for establishing the diagnosis of Low VWF, and the relationship between Low VWF levels and bleeding phenotype needs to be defined. Furthermore, the molecular mechanisms responsible for the reduced plasma VWF levels remain unclear. To address these questions, we established the Low VWF Ireland Cohort (LoVIC) study. In contrast to previous Type 1 VWD studies, this prospective longitudinal cohort study recruited only patients with Low VWF levels, (defined by bleeding history and lowest VWF levels 30-50 IU/dL on two occasions, three months apart) and recruited 140 adult Irish patients. Although Bleeding Assessment Tools (BATs) have been used in type 1 VWD, their utility has not been studied in patients with Low VWF. As determined using either the ISTH BAT or the Condensed MCMDM-1 VWD score, we observed significant bleeding histories in the majority of LoVIC patients. For example, among female patients (n=112), 77% had positive ISTH BAT scores (≥6) and 72% had positive MCMDM-1 scores (≥4). Importantly, bleeding tendency did not correlate with plasma VWF levels within the 30-50 IU/dL range. To further investigate this bleeding phenotype, hemostatic studies (including platelet aggregation and coagulation factor assays) were performed. Additional mild coagulation defects were identified in only 10 subjects. Furthermore, abnormal multimer patterns were identified in only 3 patients. To investigate the pathophysiology underlying Low VWF levels, plasma FVIII:C and VWF propeptide (VWF:pp) levels were defined. Interestingly, plasma FVIII:C/VWF:Ag ratios were significantly increased in LoVIC patients compared to normal controls (mean 1.3 versus 1.07; p<0.001). In contrast, increased plasma VWF:pp/VWF:Ag ratios > 3 were observed in only 6% of the total cohort. Taken together, these data demonstrate that the reduced plasma VWF levels in patients with Low VWF are predominantly attributable to decreased VWF synthesis and/or secretion rather than enhanced VWF clearance. To determine whether quantitative and/or qualitative abnormalities in platelet (plt)-VWF may influence bleeding phenotype in patients with Low VWF, we studied plt-VWF:Ag and VWF:CB in 50 consecutive LoVIC patients. In keeping with the hypothesis that reduced VWF synthesis plays a key role in the pathogenesis underlying Low VWF levels, plt-VWF:Ag and plt-VWF:CB levels were both significantly reduced in LoVIC patients compared to controls (mean plt-VWF:Ag 0.16 versus 0.21 IU/109/L, p<0.05; mean plt-VWF:CB 0.18 versus 0.34 IU/109/L, p<0.001). To further study the molecular mechanisms underlying Low VWF levels, plasma VWF:Ag and VWF:RCo responses following desmopressin (DDAVP) administration were examined. In 88% of patients, the post-DDAVP peak levels exceeded 100 IU/dL. Importantly, the response to DDAVP was also sustained with both VWF:Ag and VWF:RCo above 100 IU/dL after 4 hours in 72% subjects. These DDAVP responses demonstrate that Weibel Palade body stores of VWF are maintained in patients with Low VWF, and that the regulated pathway of VWF secretion is intact. Furthermore, the sustained plasma VWF response observed following DDAVP supports the hypothesis that enhanced VWF clearance does not play a major role in the pathogenesis of Low VWF levels. In conclusion, we demonstrate that Low VWF levels are associated with a significant bleeding phenotype. In addition, we further show that in the majority of patients with Low VWF levels, the bleeding phenotype cannot be explained by the presence of concomitant bleeding disorders. Finally, our novel data demonstrate that Low VWF levels are due in large part to reductions in VWF synthesis and/or constitutive secretion. Although enhanced VWF clearance may contribute to the pathophysiology in a minority of individuals with Low VWF, the absolute reduction in VWF plasma half-life is usually mild and not sufficient to significantly impact upon the duration of DDAVP-induced VWF response. Disclosures Lavin: Baxalta: Consultancy, Research Funding. O'Sullivan:Pzifer: Research Funding. O'Connell:Baxalta: Consultancy, Research Funding. James:Octapharma: Research Funding; Bayer: Research Funding; CSL Behring: Research Funding; Biogen: Consultancy; Basalt: Consultancy. Di Paola:CSL BEhring: Consultancy; Biogen: Consultancy. O'Donnell:Bayer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novo Nordisk: Research Funding, Speakers Bureau; Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Leo Pharma: Speakers Bureau; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees.

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Assessing the Safety of Various VWF Regimens in Patients with Clinically Severe VWD: A Natural History Study

Blood ◽

10.1182/blood-2019-128318 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1132-1132

Author(s):

Robert F. Sidonio ◽

Angela C. Weyand ◽

Dunlei Cheng ◽

Crystal Watson

Keyword(s):

Board Of Directors ◽

Study Design ◽

Real World ◽

Research Funding ◽

Laboratory Data ◽

Severe Bleeding ◽

Advisory Committees ◽

On Demand ◽

Type 3 ◽

Von Willebrand

Background: Von Willebrand disease (VWD) is the most common inherited bleeding disorder in humans affecting up to 1% of the population, while symptomatic prevalence is likely closer to 0.1%. A deficiency of von Willebrand factor (VWF) can be quantitative (type 1 or type 3) or qualitative (type 2) and lead to a bleeding diathesis of variable intensity roughly correlating with functional activity. Diagnosis can be challenging due to variable penetrance and large influence of multiple pre-analytic variables and a wide testing coefficient of variation. Treatment for VWD is focused on replacement of defective or deficient VWF with a plasma-derived or recombinant VWF-containing product, release and elevation of endogenous stores of VWF with Desmopressin (DDAVP), or prevention of premature fibrinolysis with an antifibrinolytic, such as aminocaproic acid. Although there is relative consensus on the management of mild VWD, there is scarce literature about the optimal treatment of patients with severe disease, especially in regard to factor replacement. Real World evidence for the use of primary (prior to significant bleeding) or secondary (following development of significant bleeding) prophylaxis is lacking with the majority of studies relying heavily on retrospective data. Additionally, ongoing VWD prophylaxis studies typically only allow participants to enroll if they previously have not been on prophylaxis, limiting our ability to learn about this growing population of patients. Study Design and Methods: Approximately 1,900 VWD patients were identified in the ATHNdataset with a VWF:Ag or VWF:RCo of ≤ 30%, with ~170 of these on prophylaxis. This group, in addition to those VWD patients with clinically significant bleeding and ≤ 40% of normal VWF:Ag or VWF:RCo, provide a potential unmet opportunity to examine prophylaxis and treatment patterns. Furthermore, a standardized laboratory assessment (including a standardized diagnostic battery, genetic evaluation of VWF gene, and inhibitor testing) will provide significant enrichment of the ATHNdataset by fully characterizing patients that are highly likely to utilize factor concentrates. Inclusion criteria are patients with severe VWD defined as type 3 VWD, or VWF:RCo, VWF:GP1bM or VWF:Ag≤ 30%, patients with clinically severe VWD as defined by VWF:Rco, VWF:GP1bM or VWF:Ag ≤ 40% with severe bleeding phenotype requiring recurrent use of factor concentrates, and co-enrollment in the ATHNdataset. Patients with platelet-type or acquired VWD are excluded. The primary objective is to assess the safety of various VWF regimens for different indications (on-demand, surgery, and prophylaxis) in adult and pediatric patients with clinically severe VWD. Safety is measured by the number of reported events as defined by the European Haemophilia Safety Surveillance (EUHASS) program. Secondary objectives are to enrich and analyze data from clinically severe congenital VWD patients by collecting laboratory data; to establish sub-studies for patients who are treated with VWF products on demand or who have started on or switched to a particular VWF containing product; to evaluate the use of factor replacement as prophylaxis in a cohort of severe VWD participants over 6 month time periods; to describe bleeding events, changes in overall bleeding, and annualized bleed rate as measured by the International Society on Thrombosis and Haemostasis (ISTH) Bleeding Assessment Tool (BAT) and if applicable the Pictorial Bleed Assessment Chart (PBAC); and to describe real-world effectiveness of VWD treatment as measured by health care utilization and quality of life measures (PROMIS® and V-WIQ questionnaires). Descriptive statistics will be calculated to analyze the primary and secondary outcomes. For each categorical variable, its frequency and percentage will be reported. In terms of a continuous measurement, its mean, median, standard deviation, interquartile range, minimum, and maximum values will be disclosed. The study will attempt to enroll a target number of at least 50 participants who are receiving VONVENDI but will not mandate the use of VONVENDI. More study design details are outlined in Table 1. Disclosures Sidonio: Genetech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda-Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Biomarin: Membership on an entity's Board of Directors or advisory committees; Uniqure: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Kedrion: Research Funding.

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A Large-Pore IEF Gel Electrophoresis Separates the Complex in Both of ADAMTS13 Bound to VWF and to the IgG Autoantibodies From the Unbound in Plasma Milieu

Blood ◽

10.1182/blood.v118.21.1160.1160 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1160-1160

Author(s):

Masanori Matsumoto ◽

Ayami Isonishi ◽

Yuji Hori ◽

Masaki Hayakawa ◽

Kenji Soejima ◽

...

Keyword(s):

Board Of Directors ◽

Gel Electrophoresis ◽

Von Willebrand Disease ◽

Adamts13 Activity ◽

Advisory Committees ◽

Normal Plasma ◽

Large Pore ◽

Severe Deficiency ◽

Type 3 ◽

Von Willebrand

Abstract Abstract 1160 Backgrounds and Aims: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening generalized disorder caused by a deficiency of ADAMTS13 activity due to its gene mutations (Upshaw-Schulman syndrome), and/or acquired autoantibodies to this enzyme. ADAMTS13 specifically cleaves the peptide bond between Tyr1605 and Met1606 within the A2 domain of von Willebrand factor (VWF). Recent studies with immunoprecipitation methods using anti-VWF antibody coated beads indicated that a small portion (3–4% of the total) of plasma ADAMTS13 is bound to VWF (Feys HB et al. JTH 7:2088, 2009). This experiment determined the amount of ADAMTS13 bound to VWF in an indirect fashion, but the complex may dissociate during washing procedures or by conformation change after binding to the antibody. Thus, we used an isoelectric focusing (IEF) to separate the complex in a direct fashion. However, the molecular size of VWF-ADAMTS13 complex is assumed to be enormously huge, and therefore a regular polyacrylamide IEF gel does not properly work. So, we employed a large-pore composite IEF gel consisting 0.75% agarose and 1.25% polyacrylamide containing 2% of Pharmalyte (pI range 3.0–10). By this method followed by western blot detection using a non-neutralizing anti-ADAMTS13 monoclonal antibody (WH2-11-1), we identified that an ADAMTS13-VWF complex is detected as a sharp band at pI 7.4. The specificity of this band was identified by a lack in plasma of type 3 von Willebrand disease (VWD), and a new emergence of the band in type 3 VWD plasma spiked with purified VWF (Hori et al, 57th ISTH meeting, P-MO-479). We applied this IEF analysis to detect the complex of ADAMTS13-its autoantibodies. Patients and Methods: ADAMTS13 activity was measured by chromogenic act-ELISA, and acquired idiopathic (ai-) TTP with severe deficiency of ADAMTS13 activity due the presence of its autoantibodies is a target in this study. VWF and ADAMTS13 were purified from normal plasma. A large-pore composite IEF gel electrophoresis was performed as previously described. Results and Discussion: Two forms of ADAMTS13, unbound (pI 5.3) and bound (pI 7.4) to VWF in a volume of 10 uL normal plasma (NP), were directly identified on the IEF gel followed by western blotting (Fig. left). Each plasma of type 3 VWD or USS lacked the complex (VWF-ADAMTS13) band with pI 7.4, but it was generated in vitro just after spiking the purified VWF or ADAMTS13 to the respective deficient plasma by the IEF (Fig. not shown). Next, when a volume of 3uL NP was analyzed, only one band with pI of 5.3 (5.1–5.5) was observed. In ai-TTP patients with severe deficiency of ADAMTS13 activity (<3% of the control), plasma had no or faint band of ADAMTS13 (Fig. middle). However, when we mixed the equal volume of patient plasma with ai-TTP with severe deficiency of ADAMTS13 activity and NP, the results on IEF gel showed appearance of 3 major bands with pIs of 5.3, 5.9 and 6.5, together with other many minor bands, and the unbound (free) ADAMTS13 almost disappeared (Fig. right). Then, the IgG purified from patient plasma of ai-TTP was mixed with NP or purified ADAMTS13, the complex band had a pI of 5.9 (5.5–6.3). These results indicated a possibility that the IEF analysis could be used to detect the autoantibodies to ADAMTS13, regardless of the neutralizing or non-neutralizing counterparts, in a totally different fashion to the enzyme immunoassay. Disclosures: Matsumoto: Alexion Pharma: Membership on an entity's Board of Directors or advisory committees. Soejima:The Chemo-Sero-Therapeutic Research Institute: Employment. Fujimura:Baxter BioScience: Membership on an entity's Board of Directors or advisory committees; Alexion Pharma: Membership on an entity's Board of Directors or advisory committees.

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Profile of Mutations Identified in the 3WINTERS-IPS Project on European & Iranian Patients with Previously Diagnosed Type 3 Von Willebrand Disease.

Blood ◽

10.1182/blood-2018-99-114702 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1184-1184

Author(s):

Luciano Baronciani ◽

Flora Peyvandi ◽

Anne Goodeve ◽

Reinhard Schneppenheim ◽

Zahra Badiee ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Advisory Board ◽

Von Willebrand Disease ◽

Compound Heterozygous ◽

Advisory Committees ◽

Type 3 ◽

Von Willebrand ◽

Two Populations ◽

Iranian Patients

Abstract Background: The type 3 Von Willebrand International RegistrieSInhibitor Prospective Study (3WINTERS-IPS) is a no-profit, investigator initiated, multicenter, European-Iranian observational, retrospective and prospective study on patients with diagnosis of type 3 VWD. Patients with type 3 von Willebrand Disease (VWD3) have markedly reduced levels of von Willebrand factor (VWF) and very severe bleeding phenotype. Due to the recessive inheritance pattern, VWD3 is by definition a rare bleeding disorder (1:Million) but its prevalence may increase in countries like Iran with consanguineous marriages. Aim: To identify the VWF genetic defects in a cohort of European and Iranian patients with previously diagnosed VWD3 enrolled into the 3WINTERS-IPS project. Methods: Patients classified locally as VWD3 were enrolled in the study following informed consent. 141 patients were from 9 different European countries and 119 patients were from the Islamic Republic of Iran. Plasma/buffy-coat samples were sent to expert labs to confirm patient's laboratory phenotype and to perform molecular analysis. PCR and Sanger sequencing/ next generation sequencing and multiplex-ligation dependent probe amplification were used in Hamburg, Sheffield and Milan to confirm previously identified variants or to seek previously unidentified variants. Results: DNA samples from 122 patients from Europe and 114 patients from Iran were analyzed at the molecular level. Of the 236 VWD3 patients under evaluation 24 are still in progress. Of the 212 fully evaluated patients 139 were homozygous (EU/IR=46/93) and 43 were compound heterozygous (EU/IR=36/7). In the remaining 30 patients no variants were identified in 19 samples (EU/IR=6/13) and only one variant was found in the remaining 11 cases (EU/IR=10/1). 135 (EU/IR=82/53) different gene defects were identified among the 375 (EU/IR=174/201) alleles found in this study. Of these 135 variants identified 51(EU/IR=22/29) were not reported on the www.ensembl.org database. The distribution of the different type of variants identified in the two populations is shown in the Figure. The two charts are showing quite similar percentages of the variants identified, with a main exception for the Small deletions and Small insertions. Only five variants are shared among the two populations. Three of these are the "hotspot" variants at the Arg codon, p.Arg1659* (EU/IR=9/8), p.Arg1853* (EU/IR=2/3) and p.Arg2535* (EU/IR=1/2). However, a missense variant , p.Cys275Ser (EU/IR=1/2) and a large deletion, delEx1_Ex5 (EU/IR=1/2) were also found in both populations. Fifteen variants were recurrent and were found in 154 alleles, whereas 49 variants were found only once in the heterozygous state (EU/IR=40/9) and 50 variants were found only twice, mainly in the homozygous state (EU/IR=25/25). Six large deletions were identified (delEx1_Ex3, delEx1_Ex5, delEx14_Ex15, delEx17, delEx35_Ex52 and delEx1_Ex52) and a duplication (dupEx1_Ex28), nevertheless 52 alleles with missense variants were identified (EU/IR=20/32). Discussion: As expected, the majority of the Iranian patients were found to be homozygous (Homozygous/Compound Heterozygous=93/7) reflecting a high rate of consanguinity, nevertheless half of the European patients were found to be homozygous (Homozygous/Compound Heterozygous=46/36). The European populations demonstrated a higher heterogeneity of variants with 82 different variants among the 175 mutated alleles vs 53 different variants among the 201 mutated alleles identified in the Iranian population. Nevertheless, a higher number of previously unreported variants was found in the Iranian population (29) vs the European one (22), probably due to bias of previous investigations performed in European patients. Figure Figure. Disclosures Peyvandi: Ablynx: Other: Member of Advisory Board, Speakers Bureau; Shire: Speakers Bureau; Roche: Speakers Bureau; Grifols: Speakers Bureau; Grifols: Speakers Bureau; Novo Nordisk: Speakers Bureau; Sobi: Speakers Bureau; Sobi: Speakers Bureau; Novo Nordisk: Speakers Bureau; Kedrion: Consultancy; Novo Nordisk: Speakers Bureau; Octapharma US: Honoraria; Novo Nordisk: Speakers Bureau; Sobi: Speakers Bureau; Ablynx: Other: Member of Advisory Board, Speakers Bureau; Kedrion: Consultancy; Novo Nordisk: Speakers Bureau; Kedrion: Consultancy; Ablynx: Other: Member of Advisory Board, Speakers Bureau; Octapharma US: Honoraria; Shire: Speakers Bureau; Roche: Speakers Bureau; Kedrion: Consultancy; Kedrion: Consultancy; Ablynx: Other: Member of Advisory Board, Speakers Bureau; Octapharma US: Honoraria; Octapharma US: Honoraria; Sobi: Speakers Bureau; Roche: Speakers Bureau; Octapharma US: Honoraria; Shire: Speakers Bureau; Sobi: Speakers Bureau; Roche: Speakers Bureau; Roche: Speakers Bureau; Shire: Speakers Bureau; Ablynx: Other: Member of Advisory Board, Speakers Bureau; Grifols: Speakers Bureau; Grifols: Speakers Bureau; Grifols: Speakers Bureau; Shire: Speakers Bureau. Schneppenheim:CSL Behring: Consultancy; SHIRE: Consultancy. Berntorp:Octapharma: Consultancy; CSL Behring: Consultancy; Shire: Consultancy, Other: honoraria for lecturing . Eikenboom:CSL: Research Funding. Mannucci:Bayer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kedrion: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Grifols: Speakers Bureau; Alexion: Speakers Bureau; Baxalta/Shire: Speakers Bureau; Novo Nordisk: Speakers Bureau. Mazzucconi:Baxalta-Shire: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Novartis,: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Novo Nordisk: Consultancy, Speakers Bureau; CSL Behring: Consultancy, Speakers Bureau. Oldenburg:Swedish Orphan Biovitrum: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Grifols: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biogen Idec: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biotest: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Clinical Study to Investigate the Efficacy and Safety of Wilate during Prophylaxis in Previously Treated Patients with Von Willebrand Disease (VWD)

Blood ◽

10.1182/blood-2019-128339 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4931-4931

Author(s):

Robert F. Sidonio ◽

Bruce A. Schwartz

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Prophylactic Treatment ◽

Von Willebrand Disease ◽

Advisory Committees ◽

Previously Treated Patients ◽

Previously Treated ◽

Type 3 ◽

Von Willebrand

Background: Inherited von Willebrand disease (VWD) is the most common inherited hemorrhagic disorder, with an estimated prevalence of 1 in every 100 individuals. Type 1 and type 3 (the most severe form) are characterized by a quantitative deficiency of von Willebrand factor (VWF) and type 2 arises from a qualitative deficiency of VWF. Treatment of VWD depends on the type and severity of the disease. Severe bleeding is reported in patients with all subtypes, leading to progressive joint disease as well as diminished quality of life (QoL). VWF/factor VIII (FVIII) concentrates have become the mainstay of VWD treatment for these patients with severe disease or for those patients in whom other treatments (e.g., desmopressin) are ineffective or contraindicated but this is broadly applicable only for on demand treatment. Aims: The primary objective of this study is to determine the efficacy of VWF/FVIIII concentrate in the prophylactic treatment of previously treated patients with type 3, type 2 (except 2N), or severe type 1 VWD. Secondary objectives of this study will be to collect data to 1) Assess the VWF:Ac and VWF:Ag incremental IVR of VWF/FVIIII concentrate over time and, 2) Assess the safety and tolerability of VWF/FVIIII concentrate in this indication. The study will also examine, the efficacy of VWF/FVIIII concentratein the treatment of breakthrough bleeding episodes (BEs), and in surgical prophylaxis, as well as the QoL during prophylaxis with VWF/FVIIII concentrate. Methods: The study is planned to enroll 28 patients aged ≥6 years and with VWD type 1, 2A, 2B, 2M, or 3. Eligible patients must be receiving on-demand treatment with a VWF-containing product, with at least 1, and an average of ≥2, documented spontaneous BEs per month in the preceding 6 months requiring treatment with a VWF-containing product. This will be assessed as part of a run-in observational study to collect the bleeding profile prior to the start of prophylaxis. From the beginning of the study, patients will receive prophylactic treatment with VWF/FVIIII concentrate for 12 months and record all BEs in a patient diary. Based on these data, the frequency of BEs and the annualized bleeding rate (ABR) under prophylactic treatment will be calculated. Treatment efficacy of BEs will be assessed by the patient (together with the investigator in case of on-site treatment) using a 4-point scale (excellent, good, moderate, none) In patients that undergo surgeries, efficacy of VWF/FVIIII concentratewill be assessed at the end of surgery by the surgeon and at the end of the postoperative period by the haematologist. In both cases, predefined assessment criteria will be used. In addition, an overall assessment of efficacy will be made at the end of the postoperative period by the investigator. Results: Data will be monitored on an ongoing basis and the study is expected to end Q2 2021. Conclusions: Prophylactic treatment in other congenital bleeding disorders is widely accepted as the standard of care to prevent bleeding and preserve QoL in patients but to date, this form of treatment in VWD is not well characterized. This study will provide data on the efficacy of prophylactic treatment in reducing the rate of bleeding and on the impact of prophylaxis on the QoL in VWD patients. Disclosures Sidonio: Genetech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda-Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; Biomarin: Membership on an entity's Board of Directors or advisory committees; Octapharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kedrion: Research Funding; Uniqure: Membership on an entity's Board of Directors or advisory committees. Schwartz:Octapharma: Employment.

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