Research Studies

Dr. Jessica Garcia is currently a pediatric hematology/oncology fellow at the Medical College of Wisconsin/Children's Hospital of Wisconsin. Her clinical mentor is Dr. Joan Gill, Director of the Comprehensive Center for Bleeding Disorders (CCBD) in Milwaukee, Wisconsin.  Dr. Garcia's primary research mentor will be Dr. Veronica Flood, with Dr. Bob Montgomery as her secondary research mentor. Dr. Garcia attended medical school and completed her pediatric residency at the University of Illinois College of Medicine at Peoria/Children's Hospital of Illinois. During her pediatric residency, Dr. Garcia worked with Dr. de Alarcon studying the mechanisms underlying the thrombocytosis seen with iron deficiency anemia in an animal model. As a NHF-Baxalta Clinical Fellow, Dr. Garcia will receive specialized training in hemostasis and thrombosis, available through the Comprehensive Center for Bleeding Disorders (CCBD) and Blood Research Institute (BRI). Her research will focus on the biology of von Willebrand factor.

Background/Objective:

Hemophilia is a bleeding disorder caused by the body’s inability to accomplish the natural clotting process. People with hemophilia experience bleeds because there is an inadequate amount of thrombin due to a deficiency in factor VIII or IX. Thrombin is critical to clotting and sealing the wound; it converts fibrinogen into fibrin, establishing a network to help more platelets accumulate. Thrombin activity is regulated by antithrombin. Fitusiran is a subcutaneously administered investigational RNA interference (RNAi) therapeutic targeting antithrombin with the goal of improving thrombin generation to promote clotting in people with hemophilia A or B with and without inhibitors. Interim data from the Phase 1 study showed fitusiran was generally well tolerated and administration of monthly fitusiran led to dose-dependent antithrombin lowering, improvement in thrombin generation, and decrease in bleeding frequency. We will report interim safety, pharmacodynamics, and clinical activity of fitusiran from the Phase 2 extension study.

Methods:

The Phase 2 extension study (NCT02554773) includes people with hemophilia A or B with and without inhibitors, previously dosed in the Phase 1 (NCT02035605) study. Participants receive monthly, fixed subcutaneous doses of fitusiran, 50 mg or 80 mg. Primary endpoints include safety and tolerability; secondary endpoints include antithrombin activity, thrombin generation and exploratory evaluation of bleed events.

Summary of Results:

As of May 2017, 33 participants were enrolled in the study and had received continuous dosing of up to 14 months. Previously reported data showed that fitusiran was generally well tolerated, with no serious adverse events related to study drug and no thromboembolic events. Once-monthly subcutaneous dosing achieved dose-dependent antithrombin lowering of ~80% and thrombin generation levels approaching levels similar to participants without hemophilia. Exploratory post-hoc analysis of bleed events showed median annualized bleed rate (ABR)=1 in participants without inhibitors and median ABR=0 in participants with inhibitors. Bleed events were successfully managed with either replacement factors or bypassing agents. Updated safety, tolerability and clinical activity will be presented.

Conclusions:

Emerging clinical data suggest that fitusiran may be a promising investigational prophylactic therapy to promote appropriate clotting and reduce the frequency of bleeding in people with hemophilia A or B with and without inhibitors.

Background:

Accurate measurement of factor VIII (FVIII) activity in patients with hemophilia A is important for patient monitoring and treatment decisions. Discrepancies in results using different assays or reagents to measure prolonged–half-life factor products have been recognized. BAY 94-9027 is a prolonged–half-life FVIII product site-specifically conjugated with a 60-kDa polyethylene glycol molecule (2×30 kDa branched).

Objective:

A global field study was conducted to assess the ability of clinical laboratories to measure BAY 94-9027 activity in spiked hemophilic plasma samples using their in-house or specific assays.

Design/Method:

In this 2-part study, laboratories received sample sets (3–4 per laboratory) of 26 blinded samples in randomized order for analysis. Each set consisted of triplicate test samples of BAY 94-9027 or a comparator (antihemophilic factor [recombinant] plasma/albumin-free method [rAHF-PFM (Advate® ); Shire]) spiked at low (<10 IU/dL), medium (10–50 IU/dL), and high (50–100 IU/dL) concentrations in pooled hemophilic plasma. Normal control plasma and unspiked hemophilic plasma in triplicate were positive and negative controls, respectively. Two additional blinded samples matching 2 of the other 24 samples in the set were included in each set to decrease the predictability of each set. Laboratories analyzed test samples using their in-house assays (one-stage, chromogenic, or both), reagents, and standards (part 1). In part 2, all laboratories tested 2 additional sample sets using 2 activated partial thromboplastin time kits (Pathromtin® and HemosIL® SynthASil) previously shown to accurately measure BAY 94-9027 and full-length FVIII. FVIII recovery and FVIII levels were primary and secondary endpoints, respectively.

Results:

Fifty-two laboratories in North America, Europe, and Israel participated in the study. In part 1, 49 laboratories tested samples using the one-stage assay, 16 used the chromogenic assay, and 13 used both assays. The reagents routinely used for measuring FVIII activity varied among participating laboratories. Mean FVIII recovery ranged from 75.1%‒103.2% for BAY 94-9027 and 94.6%‒114.7% for rAHF-PFM across all concentrations and reagents using the one-stage assay. As expected based on previously published data, the PTT-A and HemosIL® APTT-SP kits underestimated BAY 94-9027 at all concentrations. More accurate one-stage results were generated using the Pathromtin® and SynthASil kits, as shown in part 2 of the study. For the chromogenic assay, mean FVIII recovery ranged from 104.4%‒117.1% for BAY 94-9027 and 87.7%‒107.8% for rAHF-PFM across all concentrations.

Conclusion:

BAY 94-9027 can be accurately monitored using the chromogenic assay and select commonly used one-stage assay kits without need of a conversion factor.

Objective:

Physicians prescribing Factor VIII for haemophilia A patients are presented with an array of dose and dose frequency in the package insert making it difficult to precisely prescribe. To clarify the treatment outcome across products, a model of the published half-life was used to provide the expected % IU/dl +/- SD at 24, 48, 72, and 96 hours post dose at a normalized dose and at the high end of the recommended dosage (dose and freq.).

Methods:

Eleven rFVIII products recently marketed in the US were assessed using a model of the halflife +/- SD to calculate the expected %IU/dl +/- SD at 24, 48, 72, and 96 hrs post-dose. Terminal half-life data for adults was obtained from each published package insert (PI). The one-stage clotting assay data was used for all except Afstyla© (chromogenic assay only). Variance reported as coefficient of variation or confidence intervals was converted to standard deviation.

The first comparison was made using a standard dose of 50 IU/kg across all products. The second comparison used the maximum recommended dose and frequency for routine prophylaxis defined in the PI. Full data sets and curves of %IU/dl+/-SD under standard doses of 50 IU/kg and under maximum dose and frequency for routine prophylaxis have been generated.

Summary:

Graphing the single dose comparison (50 iu/kg) revealed 3 general clusters and one outlier at 24 hrs post dose. The first cluster had 4 products with a mean range of 21-25 %IU/dl at 24 hrs post dose. The second cluster had 5 products with a range of 30-32 %IU/dl at 24 hrs. The third cluster had 1 product (Eloctate©) with 43% IU/dl at 24 hrs. The outlier (Nuwiq©) showed exceptional variance compared to others and removed from discussion.

Expected %IU/dl was recalculated using the most frequent and highest dose recommended for individual products. Assessing the –SD value: 10 of 10 products achieved > 1% trough at 24 hrs; 8 of 10 at 48 hrs; 2 of 10 at 72 hrs; and 1 of 10 at 96 hrs. Note at 72hrs, only 2 of 10 products achieve minimal trough at –SD level when 4 of 10 claim q3day dosing.

Conclusions:

Initial dosing for routine prophylaxis relies on the mean half-life. The PK parameters are based on only 18 to 30 patients under well-controlled conditions. There is waste on both sides of the PK half-life distribution curve. Would it be reasonable to assure minimal breakthrough bleeds and less over-dosage by initiating treatment with a personal PK profile for each patient in order to identify the correct dose and frequency? This model could be used to find optimal dose and frequency with input from a personalized product half-life.

Objectives:

The primary aims of this study are to 1) evaluate the prevalence of depression and anxiety among adult persons with hemophilia (PWH) and 2) explore relationships between depression, anxiety, chronic pain, and adherence to clotting-factor treatment.

Method:

This study used a subset of data from the IMPACT QoL II, a one-time, cross-sectional survey of 200 adults (age >18) with self-reported diagnosis of either Hemophilia A or B who were able to read, write, and speak English. The study was approved by the IRB in the primary investigator’s institution. Participants were a convenience sample recruited at bleeding disorders conferences in 2013-2014 and issued a randomly generated identification number to ensure anonymity. The 139-item survey was completed electronically through SurveyMonkeyTM on a study computer tablet. Participants were given $20 upon completion of the survey, which took 15-45 minutes to complete. The subset of variables evaluated for this analysis included the Faces of Pain Scale-Revised (FPS-R) (chronic pain), level of control over pain each participant feels they have, adherence to clotting factor measured by total scores (higher score=lower adherence) on the VERITAS-PRO or VERITAS-PRN, anxiety measured by the GAD- 7, depression measured by the PHQ-9, and self-report of ever receiving a diagnosis of depression and/or anxiety. The cut-off score for presence of moderate to severe depression or anxiety was 10 on both the PHQ-9 and the GAD-7, scores which have been validated by previous literature in other populations. Lower vs. higher adherence was defined by VERITAS scores in the highest and lowest quartile respectively.

Summary:

Participants with lower treatment adherence (VERITAS score >57) were more likely to have PHQ-9 scores >10 (P=0.02). GAD-7 scores >10 also demonstrated a trend to be associated with lower treatment adherence (P=0.15). 28% of participants reported a diagnosis of depression, but 53% with PHQ-9 scores >10 had not been diagnosed with depression. Similarly, 22% reported a diagnosis of anxiety but 52% with GAD-7 scores >10 had not been diagnosed. Participants who reported non-control of pain were more likely to have PHQ-9 scores or GAD-7 scores >10 (P=0.001 and P=0.013 respectively). There were significant correlations between PHQ-9 and GAD-7 (Rho=0.76, P<0.0001), PHQ-9 and FPS-R (chronic pain) (Rho=0.31, P=0.003), and GAD-7 and VERITAS (P=0.005). These data indicate that depression and anxiety are associated with greater severity of chronic pain, and depression is associated with poorer adherence to clotting factor treatment regimen (prophylaxis or other regimen). Both depression and anxiety appear to be under-diagnosed in PWH.

Objective:

To identify sociodemographic, clinical and treatment characteristics associated with the quality of life (QoL) of individuals with hemophilia B (HB) using longitudinal data in the HUGS Vb cohort.

Methods:

Between 2009-2012, 148 persons with HB were enrolled into HUGS Vb, a prospective cohort study examining individuals seen at ten federally supported U.S. hemophilia treatment centers (HTCs). Participants or parents of pediatric enrollees completed periodic surveys; data from 107 individuals with at least three follow-up surveys, clinician charts and dispensing records were included in the analyses. Data were analyzed at baseline and 6-month intervals across 2 years, yielding 5 time points. Periodic QoL assessments (SF-12 for adults and PedsQL for children), self-reported pain, employment and insurance status, time lost from work/school and treatment regimen were collected. Descriptive statistics and Spearman’s correlation coefficient test were used to examine the associations.

Summary:

Forty-six percent of the sample had severe HB; 50% were children (2-17 years). Among those with severe HB, 64% of children and 50% of adults treated prophylactically. 58% of adults were employed full-time. Individuals with mild hemophilia missed more work/school days due to disease-related issues (8 days) than those with moderate hemophilia (2 days) or severe hemophilia (3 days, P=0.03). QoL scores were similar over time among those using prophylactic and on-demand treatment for both adults and children. Median adult Mental Component Scores (MCS) and Physical Component Scores (PCS) measured at 5 time points ranged from 53.0 to 55.1 for MCS and 45.5 to 50.5 for PCS, with no significant changes observed over time. However, adults employed full-time had significantly higher median PCS at each time point than those working less than full-time (all Ps<0.05). Adults who reported pain had significantly lower median PCS than those who reported no pain/pain only when bleeding at each time point (all Ps<0.03). Median MCS remained similar between the two groups. Overall, we observed no longitudinal differences in children’s total PedsQL scores (range of median: 81.2-92.4) or in functioning subscales. However, among 18 children with QoL scores at both baseline and 24 months, missed school days were significantly correlated with decreased social functioning over time (rho=0.73, P<0.001). 8% of children who reported pain had consistently lower median total QoL scores than those reporting no pain/pain only when bleeding, despite having access to insurance and prophylactic treatment.

Conclusions:

Longitudinal data collected by HUGS Vb provide a valuable opportunity to examine the association of HB patient characteristics with measures of QoL in a multi-state sample. These data demonstrate that lower QoL was consistently associated over time with multiple factors, including absence from school, unemployment and pain. Continued analysis of this cohort will increase our understanding of the challenges faced by persons with HB.

Objective:

My Life, Our Future (MLOF) seeks to advance understanding of hemophilia by developing the MLOF Research Repository, a resource for use in scientific study. To strengthen the database and improve clinical care for females, MLOF expanded in 2016 to collect data and samples from potential and confirmed carriers.

Methods:

MLOF is a collaboration between the American Thrombosis and Hemostasis Network (ATHN) (educates HCPs, collects and protects genetic data, manages ATHNdataset, manages research review committee), Bloodworks Northwest (BWNW) (performs genetic testing and analysis, manages MLOF Research Repository), National Hemophilia Foundation (educates patients and the community), and Bioverativ (provides scientific collaboration and sponsorship). Patients enrolled in MLOF can contribute their de-identified clinical information and specimens (DNA, RNA, plasma and serum) to the MLOF Research Repository. The patients’ hemophilic genetic data (F8 or F9 variant) and specimens are stored at BWNW and their clinical data in the ATHNdataset. For carrier project participants, an ISTH Bleeding Assessment Tool score is determined, and for confirmed carriers factor levels are obtained and recorded in ATHN Clinical Manager. Upon enrollment of 5,000 participants, the MLOF Research Repository was opened to U.S-based investigators in February 2017. Investigators were encouraged to partner with a participating hemophilia treatment center (HTC) on projects for clinical translational support. An independent, international, multidisciplinary panel of experts was convened to review research proposals, evaluating project feasibility, scientific merit and potential contribution to the bleeding disorders community.

Summary:

To date, 97 HTCs are actively participating in MLOF and have enrolled 8,246 patients. Of those, 83% (6,857), including 723 confirmed carriers, have consented to research. The samples of 427 additional females consenting to research are pending evaluation; 1,643 females have participated in MLOF. The first MLOF Research Repository cycle received 9 Letters of Intent and 7 were chosen for full proposal review. The final selection of studies will be announced to the community in June 2017.

Conclusions:

Combining and analyzing genetic and clinical data via this database may allow researchers to solve unmet needs in patients with hemophilia, including understanding inhibitor development, bleeding severity or aiding in identifying new therapeutic targets. By considering molecular drivers of disease and genetic variability, this approach could lead to more individualized treatment through advancement of precision medicine. Global expansion of the MLOF Research Repository is planned for 2018. Carrier testing may help females manage their bleeding disorder and may aid in family planning. Related to research, females provide a unique control group for males with hemophilia on natural history, modifier genes inside and outside the coagulation system, and epigenetic factors affecting outcomes.