Klaus Bonazza received his Ph.D. in chemistry from Vienna University of Technology. He is currently a postdoctoral researcher at Boston Children's Hospital and appointed at Harvard Medical School, mentored by Dr. Timothy Springer. His field of interest is the ultra-large concatemeric protein von Willebrand factor (VWF), which accounts for the adaptability of hemostasis to different flow conditions in the blood vessels.
At moderate, physiological flow VWF has a packed, "bird nest's" shape whereas strong elongational flow conditions, occurring downstream of vascular restrictions or injuries, induce a transition to a threat-like, elongated state. On top of this overall unpacking, tensile forces, which are exerted on the chain and transmitted by its A1 domain, cause local conformational changes which activate binding of thrombocyte receptor Glycoprotein Ib (GPIbα) to initiate coagulation. With his JGP fellowship award, Dr. Bonazza will pioneer a new method to obtain structural insights into force dependent VWF unpacking, A1 deformation and GPIbα binding based on hydrogendeuterium exchange under elongational flow conditions.
Objective:
Hepatitis C virus (HCV) infection is a significant health problem for patients with bleeding disorders due to the absence of highly effective HCV screening of blood products prior to the early 1990s. The aim of this analysis was to evaluate the safety and efficacy of the ribavirin-free regimen of glecaprevir/pibrentasvir (G/P) among patients with a history of bleeding disorders.
Methods:
Data from 11 Phase 2 and 3 registrational studies conducted across 18 countries worldwide were included. HCV genotype (GT) 1–6-infected patients with compensated liver disease received G/P for 8, 12 or 16 weeks. The sustained virologic response 12 weeks after end of treatment (SVR12) rate and safety are reported.
Results:
Sixty-two patients with history of bleeding disorders were identified, the most common disorder being hemophilia (37%, [23/62]). The remaining 63% (39/62) of patients had other disorders, including Von Willebrand disease. The cohort was 76% (47/62) male and 89% (54/62) white race with a mean age of 50.5 years (standard deviation ± 12.1). Additionally, 23% (14/62) had compensated cirrhosis. The HCV genotype breakdown among the patients was: GT1, 39%; GT2, 18%; GT3, 21%; GT4, 13%, GT5, 8%; GT6, 2%. In addition to bleeding disorders, a medical history of anemia was reported in 16% (10/62) of patients. SVR12 was achieved in 100% (62/62) of patients. Adverse events (AEs) were reported in 68% (42/62) of patients, and 37% (23/62) of patients experienced an AE assessed as possibly related to study drugs. Serious AEs (SAE) were reported in 3 (5%) patients, none being assessed as related to the study drugs; 2 of these SAEs (1 per patient) were associated with the underlying bleeding disorder. There was 1 (2%) AE leading to discontinuation of study drug (dyspepsia); the patient went on to achieve SVR12. There was 1 (2%) non-treatment emergent death reported, occurring 60 days after the last dose of study drug. Post-baseline grade ≥3 laboratory abnormalities occurred in 3 patients: one each in hemoglobin, aspartate aminotransferase and bilirubin (all n = 1; 2%), without concurrent elevations in alanine aminotransferase.
Conclusions:
G/P achieved a 100% SVR12 rate in patients with a history of bleeding disorders and demonstrated a favorable safety profile, thus providing support for treatment of chronic HCV infection with the G/P regimen in this patient population.
Background:
Emicizumab was approved by the FDA in 2017 for routine prophylaxis in PwHA with inhibitors. HAVEN 1, a phase III study in adolescent and adult PwHA with inhibitors, demonstrated that emicizumab prophylaxis significantly reduced annualized treated bleed rate by 87% (P<0.001) vs no prophylaxis. In this retrospective, post-hoc analysis, we examined the use of BPAs to treat breakthrough bleeds before and after emicizumab initiation in HAVEN 1.
Methods:
HAVEN 1 patients were included from emicizumab-treated Arms A (previously treated with only episodic BPA) and C (previously treated with prophylactic BPA) and who had participated in the non-interventional study (NIS). In both studies, bleed and treatment data collection were comparable. In the study protocol, no guidance for the treatment of bleeds was provided; and hemostatic efficacy was not measured, thus optimal treatment of bleeds cannot be accurately assessed. Additionally, only data before October 7th, 2016 are included in this analysis to better represent treatment patterns before amended BPA guidance was provided. We describe the total number of patients and bleeds, number of infusions per bleed, and the cumulative dose/kg per bleed before and after emicizumab initiation.
Results:
This analysis (48 total patients) included 24 patients each from Arm A and Arm C who participated in the NIS prior to enrollment in the HAVEN 1 trial. On average, patients received numerically fewer activated prothrombin complex concentration (aPCC) infusions with lower cumulative doses while on emicizumab as compared to prior to emicizumab administration. In Arm A, 11 bleeds were treated with aPCC resulting in an average of 1.2 aPCC infusions/ bleed and an average cumulative aPCC dose/ bleed of 95.9 U/kg while on emicizumab as compared to 136 bleeds resulting in an average of 1.7 infusions/ bleed and cumulative dose 134 U/kg prior to emicizumab. Similar findings were seen in Arm C (bleeds, aPCC infusion/cumulative dose numbers: 14,2.3/166.6 U/kg on emicizumab compared to 205, 2.6/189 U/kg prior to emicizumab.) Fewer bleeds were treated with rFVIIa and no clear trend was seen regarding how rFVIIa was used to treat bleeds. In Arm A, 11 bleeds were treated with rFVIIa resulting in an average of 1.5 infusions/ bleed and cumulative dose 212.2 µg/kg on emicizumab, vs 97 bleeds, 1.4 infusions/ bleed and cumulative dose 181.6 µg/kg prior. In Arm C, 14 bleeds were treated with rFVIIa resulting in 4.4 infusions/ bleed and cumulative dose 555.6 µg/kg on emicizumab vs 58 bleeds, 8.6 infusions/ bleed and cumulative dose 1829 µg/kg prior.
Conclusions:
Treatment of bleeds with aPCC in HAVEN 1 resulted in numerically fewer infusions and lower cumulative doses of aPCC per bleed while on emicizumab when compared to bleeds treated prior to emicizumab initiation. Treatment of bleeds with rFVIIa showed no clear trend.
As a social worker at Gulf States Hemophilia & Thrombophilia Treatment Center, I have the privilege of serving patients across their lifespan. I would like to initiate grass roots education about hemophilia in Houston, Texas, by offering educational programming to specialized health care professionals who work directly with the aging population in nursing homes and assisted living communities. This would include executive directors and administrators of these facilities as well as direct clinical staff.
Objective:
BAY 94-9027 is an extended–half-life recombinant factor VIII (FVIII) product. Efficacy in maintaining hemostasis during major surgery was evaluated in a subset of patients with severe hemophilia A in the phase 2/3 PROTECT VIII study.
Methods:
Patients aged 12–65 years requiring major surgery during PROTECT VIII or its ongoing extension were included in the analysis. Patients with severe hemophilia A undergoing major surgery who were not enrolled in PROTECT VIII but met all study inclusion and exclusion criteria also were eligible to participate. BAY 94-9027 dosing during the perioperative period was based on preoperative pharmacokinetic measurements and adjusted at the physician’s discretion. Types of procedures and duration of surgeries, BAY 94-9027 consumption on the day of surgery, intraoperative blood loss, surgeon assessment of hemostasis during surgery, and need for blood transfusion were evaluated.
Summary:
17 patients (median [range] age, 37 [13–61] years) underwent 20 major surgeries, including 15 orthopedic surgeries (9 joint replacements [hip, n=1; knee, n=6; ankle, n=2], 2 open synovectomies, 3 arthroscopies, and 1 thigh hematoma evacuation), 3 complex dental extractions, 1 penile prosthesis, and 1 inguinal hernia repair at data cutoff (January 2015). Median (range) surgical duration was 102 (17‒217) minutes, and median (range) total dose used on day of surgery, including preoperative, intraoperative, and postoperative infusions on that day, was 72.4 (43‒136) IU/kg. Median (range) number of FVIII infusions on the day of surgery was 2 (1–3), with 40% of procedures requiring only 1 infusion (preoperative) on that day. Following a median (range) presurgical dose of 52.1 (41–64) IU/kg, the median (range) FVIII level (chromogenic assay; measured in a central laboratory) immediately before the second infusion was 71.6 (44–140) IU/dL; median (range) time between the presurgical and second infusions was 12.3 (3.6–50.0) hours. Hemostasis during surgery was good (13/20; 65%) or excellent (7/20; 35%) for all procedures. Intraoperative blood loss was within expected ranges for all surgeries (median [range], 50 [0–1000] mL), and blood transfusions were required in 4 patients undergoing knee surgeries.
Conclusions:
BAY 94-9027 is efficacious in maintaining hemostasis during major surgeries in adolescents and adults with severe hemophilia A. Excellent or good hemostasis with blood loss as expected was achieved in all surgical procedures, which included major orthopedic surgeries (75% of all procedures), with 40% of patients requiring only a single infusion of BAY 94-9027 on the day of surgery.
Dr. Shi is a Professor of Pediatric Hematology at the Medical College of Wisconsin and an Investigator of Blood Research Institute at the BloodCenter of Wisconsin. She earned her MD from Fujian Medical University in China in 1990 and her Ph.D. in 1998. Dr. Shi’s research focus is to formulate innovative therapeutic approaches for the treatment of hemophilia A, a genetic bleeding disorder caused by a lack of the critical blood clotting protein, factor VIII (FVIII). One of her research programs funded by the National Institutes of Health, National Heart, Lung, and Blood Institute, is to develop platelet-specific gene transfer strategies for the treatment of hemophilia A and hemophilia A with neutralizing antibodies. In the project supported by the NHF Bridge Grant, Dr. Shi will investigate the potential effect of the FVIII carrier protein, von Willebrand factor, on FVIII immune responses in hemophilia A. Dr. Shi expects that results from her studies will aid the design of more effective protocols to prevent FVIII immune responses and to induce FVIII immune tolerance in patients with HA.
Objective:
BAY 94-9027 is an extended–half-life recombinant factor VIII (FVIII) product. In the PROTECT VIII Kids trial, BAY 94-9027 was efficacious for the prevention and treatment of bleeding episodes in previously treated children with severe hemophilia A. We report interim long-term efficacy and safety data from the PROTECT VIII Kids extension study.
Methods:
In PROTECT VIII Kids, previously treated patients (PTPs) aged <12 years with severe hemophilia A received BAY 94-9027 prophylaxis twice weekly (25‒60 IU/kg), every 5 days (45‒60 IU/kg), or every 7 days (60 IU/kg). Patients completing ≥50 exposure days (EDs) and ≥6 months in the main study or a 12-week safety substudy (part 2) that enrolled PTPs aged <6 years could continue in the optional extension for an additional ≥50 EDs.
Summary:
Fifty-nine of 73 patients treated with BAY 94-9027 in PROTECT VIII Kids (main study or part 2) continued in the extension (median [range] age at enrollment in the main study, 5.0 [2–11] years). At data cutoff (January 2018), patients had a median (range) of 1456 (351–1665) days in the trial (main study or part 2 plus extension). Patients in the extension received prophylaxis twice weekly (n=20), every 5 days (n=20), every 7 days (n=8), or switched prophylaxis frequency during the extension (variable frequency; n=11). Median (range) dose/infusion was 52.1 (19–62) IU/kg. Median annualized bleeding rate (ABR) for total bleeds was 1.8 for all patients and 0.8, 1.1, 2.1, and 3.2 for those treated twice weekly, every 5 days, every 7 days, or with varying frequency, respectively. Median ABR for joint bleeds in all patients was 0.7. During the extension, 3 patients (5.1%) experienced treatment-related adverse events (AEs) classified as mild (n=1), moderate (n=1), or severe (n=1). One patient discontinued because of a serious AE that was not related to treatment. No confirmed FVIII inhibitors or anti-PEG antibodies were observed; no patients had sustained levels of detectable PEG in plasma.
Conclusions:
Long-term treatment (up to ~4.5 years) with BAY 94-9027 prophylaxis was efficacious and well tolerated in previously treated pediatric patients with severe hemophilia A.
