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SAN DIEGO – Several groups of researchers are examining cohorts of von Willebrand disease (VWD), looking at its pathogenesis and molecular causes, as well as ways to improve treatment strategies.
At the biennial summit of the Thrombosis & Hemostasis Societies of North America, Robert F. Sidonio Jr., MD, MSc, highlighted the efforts underway, including the Zimmerman Program for the Molecular and Clinical Biology of VWD study (ZPMCB-VWD), a large grant project funded by the National Institutes of Health.
At the time of publication, there were more than 700 index cases and more than 2,200 families in the study. It includes data from 8 primary centers and 23 secondary centers. The goals are to characterize the molecular causes of VWD and the examine the fidelity of diagnosis, “which is a critical component of the study,” said Dr. Sidonio, clinical director of the hemostasis/thrombosis program at Children’s Healthcare of Atlanta.
When the ZPMCB-VWD investigators examined the correlation of bleeding phenotype and the genotype, the found that as the level of VW factor goes down, the bleeding score generally goes up, but it becomes a little bit flat in the 20-30 IU/dL range.
“Where we spend a lot of our time is with patients who have levels of 30%-50%, which can be quite heterogeneous,” Dr. Sidonio said.
Another finding made out of the ZPMCB-VWD project was the discovery of the single nucleotide polymorphism p.D1472H, which was noted to be more common in African American patients and leads to low Von Willebrand Ristocetin Cofactor (VWF:RCo) and VWF:RCo/VWF:Ag ratio, but does not increase the bleeding score.
The fidelity of diagnosis was another key finding to come out of ZPMCB-VWD. Most type 1 VWD cases were identified by low VWF:RCo. There was poor correlation between historical and current assays (r2 = 0.22), and diagnostic labs improved after central lab testing.
Next, Dr. Sidonio discussed findings from RENAWI 1 and 2, which are Italian registries of about 1,000 VWF patients that were organized by 12 centers in 2002. The goals are to evaluate the natural history of VWD in Italy and to characterize treatment strategies. According to preliminary findings from the researchers, the biological response to desmopressin (DDAVP) was 69% in those with VWD1, 26% in those with VWD2A, 20% in those with VWD2B, 33% in those with VWD2M, 71% in those with VWD2N, and 0% in those with VWD3 (Blood 2014;123:4037-44).
These researchers also found that a mean bleeding score of 3.5 corresponds to a VWF:RCo score of 30 U/dL or greater. “This indicates that there is something slightly different about patients that are above and below that threshold,” Dr. Sidonio said. “I think that’s something we’ve all been struggling with: trying to understand where the differences are and how aggressively we should be treating our patients with mild VWD.”
Another effort, The Willebrand in the Netherlands’ study (WiN), is a prospective cohort trial of about 700 patients with types 1, 2, and 3 VWD from 12 centers in that country (Blood 2008;112:4510). It was the first large study to use VWF propeptide (pp) to discriminate between severe type 1 and type 3 VWD. It also found that type 2 VWD is more characterized by increased clearance in VWF in contrast to type 1 VWD, leading to higher VWFpp/VWF:Ag ratio. In addition, in type 1 VWD, antigen rates increased about 3.5 U/dL per decade, RCo increased about 9.5 U/dL per decade, and Factor VIII: C increased about 7.1 U/dL per decade (J Thromb Haemost. 2014; 12[7]:1066-75).
“I don’t think we have a study to be able to follow patients for 20 years or so, knowing that we rely on the assays that we were using 20 years ago,” Dr. Sidonio said. “That’s a challenge at a lot of our centers, but we know that VWF generally rises with age in mild VWD patients.”
In patients with definitively diagnosed type 2 VWD, no age-related VWF or FVIII changes were observed. The researchers also observed an increase in surgical bleeding and GI bleeding in elderly VWD patients.
In the meantime, the Canadian Type 1 VWD study was one of the first to elucidate the complexity of the pathogenesis of type 1 VWD. It identified CLEC4M as playing a role in VWF clearance, with polymorphisms contributing to the variability of VWF.
More data collection is underway through a partnership between the Centers for Disease Control and Prevention and the American Thrombosis and Hemostasis Network (ATHN).
The CDC Universal Data Collection Project gathered surveillance data on bleeding disorders on patients from 1998-2011. The goals were to characterize bleeding complications, monitor safety of blood-based products to manage bleeding, identify health issues in need of additional research, evaluate bleeding disorders over the lifespan, and evaluate quality of life. In 2006, the ATHN was formed to provide stewardship of the secured national database housed at the CDC. To date, at least 34,000 patients have opted in to the data set, which includes demographic and clinical data used for research.
In a separate, phase 4 study of about 130 patients funded by Shire and led by Dr. Sidonio and Angela C. Weyand, MD, researchers will conduct a “real-world” safety and efficacy study of prophylaxis for severe VWD. Known as ATHN 9, the study includes patients currently enrolled in the ATHN data set. Treatment regimen is at the discretion of patients’ providers, and patients will be followed for up to 2 years from the start of enrollment. The study’s primary aim is to collect data on effectiveness and safety, including adverse events of various VWF regimens in adult and pediatric patients with severe congenital VWD.
Another effort is the Medical and Scientific Advisory Council (MASAC) Working Group, of which Dr. Sidonio is a member. The first meeting took place in July of 2016. The goals include making improvements to diagnostic testing and laboratory standards, assessing existing standards of care and clinical practice guidelines, developing educational programming, conducting research to better understand and develop effective treatments for VWD, and collaborating with partner organizations.
Dr. Sidonio reported that he has participated in advisory boards for Shire, CSL Behring, Biogen/Bioverativ, Pfizer, Emergent Solutions, Roche/Genentech, Aptevo, Novo Nordisk, Hema Biologics, and Octapharma. He also has received investigator-initiated grant funding from Bioverativ, Grifols, Kedrion, and Shire.
SAN DIEGO – Several groups of researchers are examining cohorts of von Willebrand disease (VWD), looking at its pathogenesis and molecular causes, as well as ways to improve treatment strategies.
At the biennial summit of the Thrombosis & Hemostasis Societies of North America, Robert F. Sidonio Jr., MD, MSc, highlighted the efforts underway, including the Zimmerman Program for the Molecular and Clinical Biology of VWD study (ZPMCB-VWD), a large grant project funded by the National Institutes of Health.
At the time of publication, there were more than 700 index cases and more than 2,200 families in the study. It includes data from 8 primary centers and 23 secondary centers. The goals are to characterize the molecular causes of VWD and the examine the fidelity of diagnosis, “which is a critical component of the study,” said Dr. Sidonio, clinical director of the hemostasis/thrombosis program at Children’s Healthcare of Atlanta.
When the ZPMCB-VWD investigators examined the correlation of bleeding phenotype and the genotype, the found that as the level of VW factor goes down, the bleeding score generally goes up, but it becomes a little bit flat in the 20-30 IU/dL range.
“Where we spend a lot of our time is with patients who have levels of 30%-50%, which can be quite heterogeneous,” Dr. Sidonio said.
Another finding made out of the ZPMCB-VWD project was the discovery of the single nucleotide polymorphism p.D1472H, which was noted to be more common in African American patients and leads to low Von Willebrand Ristocetin Cofactor (VWF:RCo) and VWF:RCo/VWF:Ag ratio, but does not increase the bleeding score.
The fidelity of diagnosis was another key finding to come out of ZPMCB-VWD. Most type 1 VWD cases were identified by low VWF:RCo. There was poor correlation between historical and current assays (r2 = 0.22), and diagnostic labs improved after central lab testing.
Next, Dr. Sidonio discussed findings from RENAWI 1 and 2, which are Italian registries of about 1,000 VWF patients that were organized by 12 centers in 2002. The goals are to evaluate the natural history of VWD in Italy and to characterize treatment strategies. According to preliminary findings from the researchers, the biological response to desmopressin (DDAVP) was 69% in those with VWD1, 26% in those with VWD2A, 20% in those with VWD2B, 33% in those with VWD2M, 71% in those with VWD2N, and 0% in those with VWD3 (Blood 2014;123:4037-44).
These researchers also found that a mean bleeding score of 3.5 corresponds to a VWF:RCo score of 30 U/dL or greater. “This indicates that there is something slightly different about patients that are above and below that threshold,” Dr. Sidonio said. “I think that’s something we’ve all been struggling with: trying to understand where the differences are and how aggressively we should be treating our patients with mild VWD.”
Another effort, The Willebrand in the Netherlands’ study (WiN), is a prospective cohort trial of about 700 patients with types 1, 2, and 3 VWD from 12 centers in that country (Blood 2008;112:4510). It was the first large study to use VWF propeptide (pp) to discriminate between severe type 1 and type 3 VWD. It also found that type 2 VWD is more characterized by increased clearance in VWF in contrast to type 1 VWD, leading to higher VWFpp/VWF:Ag ratio. In addition, in type 1 VWD, antigen rates increased about 3.5 U/dL per decade, RCo increased about 9.5 U/dL per decade, and Factor VIII: C increased about 7.1 U/dL per decade (J Thromb Haemost. 2014; 12[7]:1066-75).
“I don’t think we have a study to be able to follow patients for 20 years or so, knowing that we rely on the assays that we were using 20 years ago,” Dr. Sidonio said. “That’s a challenge at a lot of our centers, but we know that VWF generally rises with age in mild VWD patients.”
In patients with definitively diagnosed type 2 VWD, no age-related VWF or FVIII changes were observed. The researchers also observed an increase in surgical bleeding and GI bleeding in elderly VWD patients.
In the meantime, the Canadian Type 1 VWD study was one of the first to elucidate the complexity of the pathogenesis of type 1 VWD. It identified CLEC4M as playing a role in VWF clearance, with polymorphisms contributing to the variability of VWF.
More data collection is underway through a partnership between the Centers for Disease Control and Prevention and the American Thrombosis and Hemostasis Network (ATHN).
The CDC Universal Data Collection Project gathered surveillance data on bleeding disorders on patients from 1998-2011. The goals were to characterize bleeding complications, monitor safety of blood-based products to manage bleeding, identify health issues in need of additional research, evaluate bleeding disorders over the lifespan, and evaluate quality of life. In 2006, the ATHN was formed to provide stewardship of the secured national database housed at the CDC. To date, at least 34,000 patients have opted in to the data set, which includes demographic and clinical data used for research.
In a separate, phase 4 study of about 130 patients funded by Shire and led by Dr. Sidonio and Angela C. Weyand, MD, researchers will conduct a “real-world” safety and efficacy study of prophylaxis for severe VWD. Known as ATHN 9, the study includes patients currently enrolled in the ATHN data set. Treatment regimen is at the discretion of patients’ providers, and patients will be followed for up to 2 years from the start of enrollment. The study’s primary aim is to collect data on effectiveness and safety, including adverse events of various VWF regimens in adult and pediatric patients with severe congenital VWD.
Another effort is the Medical and Scientific Advisory Council (MASAC) Working Group, of which Dr. Sidonio is a member. The first meeting took place in July of 2016. The goals include making improvements to diagnostic testing and laboratory standards, assessing existing standards of care and clinical practice guidelines, developing educational programming, conducting research to better understand and develop effective treatments for VWD, and collaborating with partner organizations.
Dr. Sidonio reported that he has participated in advisory boards for Shire, CSL Behring, Biogen/Bioverativ, Pfizer, Emergent Solutions, Roche/Genentech, Aptevo, Novo Nordisk, Hema Biologics, and Octapharma. He also has received investigator-initiated grant funding from Bioverativ, Grifols, Kedrion, and Shire.
SAN DIEGO – Several groups of researchers are examining cohorts of von Willebrand disease (VWD), looking at its pathogenesis and molecular causes, as well as ways to improve treatment strategies.
At the biennial summit of the Thrombosis & Hemostasis Societies of North America, Robert F. Sidonio Jr., MD, MSc, highlighted the efforts underway, including the Zimmerman Program for the Molecular and Clinical Biology of VWD study (ZPMCB-VWD), a large grant project funded by the National Institutes of Health.
At the time of publication, there were more than 700 index cases and more than 2,200 families in the study. It includes data from 8 primary centers and 23 secondary centers. The goals are to characterize the molecular causes of VWD and the examine the fidelity of diagnosis, “which is a critical component of the study,” said Dr. Sidonio, clinical director of the hemostasis/thrombosis program at Children’s Healthcare of Atlanta.
When the ZPMCB-VWD investigators examined the correlation of bleeding phenotype and the genotype, the found that as the level of VW factor goes down, the bleeding score generally goes up, but it becomes a little bit flat in the 20-30 IU/dL range.
“Where we spend a lot of our time is with patients who have levels of 30%-50%, which can be quite heterogeneous,” Dr. Sidonio said.
Another finding made out of the ZPMCB-VWD project was the discovery of the single nucleotide polymorphism p.D1472H, which was noted to be more common in African American patients and leads to low Von Willebrand Ristocetin Cofactor (VWF:RCo) and VWF:RCo/VWF:Ag ratio, but does not increase the bleeding score.
The fidelity of diagnosis was another key finding to come out of ZPMCB-VWD. Most type 1 VWD cases were identified by low VWF:RCo. There was poor correlation between historical and current assays (r2 = 0.22), and diagnostic labs improved after central lab testing.
Next, Dr. Sidonio discussed findings from RENAWI 1 and 2, which are Italian registries of about 1,000 VWF patients that were organized by 12 centers in 2002. The goals are to evaluate the natural history of VWD in Italy and to characterize treatment strategies. According to preliminary findings from the researchers, the biological response to desmopressin (DDAVP) was 69% in those with VWD1, 26% in those with VWD2A, 20% in those with VWD2B, 33% in those with VWD2M, 71% in those with VWD2N, and 0% in those with VWD3 (Blood 2014;123:4037-44).
These researchers also found that a mean bleeding score of 3.5 corresponds to a VWF:RCo score of 30 U/dL or greater. “This indicates that there is something slightly different about patients that are above and below that threshold,” Dr. Sidonio said. “I think that’s something we’ve all been struggling with: trying to understand where the differences are and how aggressively we should be treating our patients with mild VWD.”
Another effort, The Willebrand in the Netherlands’ study (WiN), is a prospective cohort trial of about 700 patients with types 1, 2, and 3 VWD from 12 centers in that country (Blood 2008;112:4510). It was the first large study to use VWF propeptide (pp) to discriminate between severe type 1 and type 3 VWD. It also found that type 2 VWD is more characterized by increased clearance in VWF in contrast to type 1 VWD, leading to higher VWFpp/VWF:Ag ratio. In addition, in type 1 VWD, antigen rates increased about 3.5 U/dL per decade, RCo increased about 9.5 U/dL per decade, and Factor VIII: C increased about 7.1 U/dL per decade (J Thromb Haemost. 2014; 12[7]:1066-75).
“I don’t think we have a study to be able to follow patients for 20 years or so, knowing that we rely on the assays that we were using 20 years ago,” Dr. Sidonio said. “That’s a challenge at a lot of our centers, but we know that VWF generally rises with age in mild VWD patients.”
In patients with definitively diagnosed type 2 VWD, no age-related VWF or FVIII changes were observed. The researchers also observed an increase in surgical bleeding and GI bleeding in elderly VWD patients.
In the meantime, the Canadian Type 1 VWD study was one of the first to elucidate the complexity of the pathogenesis of type 1 VWD. It identified CLEC4M as playing a role in VWF clearance, with polymorphisms contributing to the variability of VWF.
More data collection is underway through a partnership between the Centers for Disease Control and Prevention and the American Thrombosis and Hemostasis Network (ATHN).
The CDC Universal Data Collection Project gathered surveillance data on bleeding disorders on patients from 1998-2011. The goals were to characterize bleeding complications, monitor safety of blood-based products to manage bleeding, identify health issues in need of additional research, evaluate bleeding disorders over the lifespan, and evaluate quality of life. In 2006, the ATHN was formed to provide stewardship of the secured national database housed at the CDC. To date, at least 34,000 patients have opted in to the data set, which includes demographic and clinical data used for research.
In a separate, phase 4 study of about 130 patients funded by Shire and led by Dr. Sidonio and Angela C. Weyand, MD, researchers will conduct a “real-world” safety and efficacy study of prophylaxis for severe VWD. Known as ATHN 9, the study includes patients currently enrolled in the ATHN data set. Treatment regimen is at the discretion of patients’ providers, and patients will be followed for up to 2 years from the start of enrollment. The study’s primary aim is to collect data on effectiveness and safety, including adverse events of various VWF regimens in adult and pediatric patients with severe congenital VWD.
Another effort is the Medical and Scientific Advisory Council (MASAC) Working Group, of which Dr. Sidonio is a member. The first meeting took place in July of 2016. The goals include making improvements to diagnostic testing and laboratory standards, assessing existing standards of care and clinical practice guidelines, developing educational programming, conducting research to better understand and develop effective treatments for VWD, and collaborating with partner organizations.
Dr. Sidonio reported that he has participated in advisory boards for Shire, CSL Behring, Biogen/Bioverativ, Pfizer, Emergent Solutions, Roche/Genentech, Aptevo, Novo Nordisk, Hema Biologics, and Octapharma. He also has received investigator-initiated grant funding from Bioverativ, Grifols, Kedrion, and Shire.
EXPERT ANALYSIS FROM THSNA 2018