Emicizumab for Severe VON Willebrand Disease (VWD) and VWD/Hemophilia A
Von Willebrand Disease (VWD) is the most common inherited bleeding disorder affecting up to 0.1% of the population, is usually characterized by mucocutaneous bleeding, HMB, surgical bleeding or other hemostatic challenges. Severe bleeding events require VWF concentrates administered solely through intravenous access. Emicizumab (Hemlibra) is a monoclonal bispecific antibody developed to bind activated FIX and FX and mimic FVIII cofactor functionality. Hemlibra is administered via subcutaneous injection rather than intravenous infusion. The hypothesis of this study is that Emicizumab is safe and efficacious for prophylaxis in severe VWD and concomitant VWD/hemophilia patients.
• Signed informed consent
• Age 0 and older (infants weighing ≥3 kg)
• ability to comply with protocol in investigators judgement
• diagnosis of: severe VWD type 3, or VWD with VWF antigen, activity or collagen binding \</= 20 U/dl or variant VWD confirmed by genetic mutation and VWF ag, activity or CB \< 50 U/dl based on historical medical records of study site.
• diagnosis of VWD/hemophilia A defined as VWF:ag, activity or CB \<50 U/dl, and mild moderate or severe hemophilia A(defined by ISTH criteria) based on historical medical records of the study site.
• plan to be adherent to emicizumab prophylaxis during the study
• Patient's bleeding phenotype necessitating prophylaxis per treating provider recommendations.
• Patient on current prophylaxis for VWD or VWD/hemophilia A may enroll if they are currently on a non-emicizumab agent, and if it has been \> 18 months since last off-label dose of emicizumab, and are willing to discontinue current prophylaxis.
• For menstruating individuals: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods that result in a failure rate of \< 1% per year during the study period. A menstruating individual is considered to be of childbearing potential if they are post-menarchal, have not reached a postmenopausal state (12 continuous months of amenorrhea with no identified cause other than menopause), and have not undergone surgical sterilization (removal of ovaries and/or uterus).
⁃ Examples of highly effective contraceptive methods with a failure rate of \< 1% per year include proper use of combined oral or injected hormonal contraceptive, bilateral tubal ligation, male sterilization, hormone-releasing intrauterine devices, and copper intrauterine devices. The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the patient. Periodic abstinence (e.g., calendar, ovulation, symptothermal, or post-ovulation methods) and withdrawal are not acceptable methods of contraception.