Von Willebrand Disease Minimize Menorrhagia (VWDMin) Trial

Background: Von Willebrand disease (VWD) is the most common inherited bleeding disorder, affecting 1% of the population, and characterized by deficient or defective von Willebrand factor (VWF). Among women with VWD, up to 80% have heavy menstrual bleeding (HMB), many of whom have depleted iron stores and iron deficiency anemia with reduced physical functioning, anxiety, depression, and poor quality of life. HMB is a serious problem causing significant health burden for those affected. The lack of effective therapies for menorrhagia is a major unmet healthcare need in women with VWD: in up to 30% desmopressin (DDAVP), combined oral contraceptives (COCs) hormones, or the recommended non-hormonal agent, tranexamic acid (Lysteda®, TA) may be ineffective or poorly tolerated. VWF concentrates, including plasma-derived VWF (pdVWF, Humate-P®) and recombinant VWF (rVWF, Vonvendi®) safely reduce bleeds in VWD, but few data exist on VWF use in menorrhagia, and no prospective trials are available to guide treatment. As rVWF has higher purity, potency, and a longer half-life than pdVWF, this phase III trial will compare rVWF with TA in reducing menorrhagia in women with type 1 VWD.

Methods: This is an NHLBI-funded U01 phase III multicenter, prospective, randomized, crossover trial in to compare IV rVWF vs. po TA in reducing menorrhagia in type 1 VWD, clinicaltrials.gov, NCT02606045. Women with type 1 VWD, VWF:RCo<0.50 IU/dL and menorrhagia, defined as pictorial blood assessment chart score (PBAC)>100 in at least one of the last two cycles, are eligible. Exclusions include hypothyroidism, past thrombosis, and renal disease. Subjects are randomized to rVWF 40 IU/kg IV day 1 vs. TA 1300 mg po three times daily days 1-5 in each of two consecutive cycles. The order of treatment is determined by randomization: in Group 1, rVWF is given in cycles 1 and 2, and TA in cycles 3 and 4; while in Group 2, TA is given in cycles 1 and 2, and rVWF in cycles 3 and 4. A rescue dose day of rVWF 40 IU/kg may be given day 2 of cycles in which rVWF is given. The primary endpoint is a 40-point reduction in PBAC, a validated measure of menstrual loss, after 2 cycles. As rVWF is a greater burden (IV, cost), to show it is superior to TA, it should improve PBAC 40 points more from baseline than TA. Secondary endpoints are cycle severity, cycle length, QoL (SF-36, Ruta, CDC-HRQ0L-14, CES-D), and satisfaction survey. Treatment response will also be compared with VWF assays and VWF genotype. Safety is assessed by number of rescue doses, other bleeding, thrombosis, and allergic reaction. Our research hypothesis is that rVWF will be superior, producing a greater improvement, by at least 40 points, in PBAC, than TA. We also hypothesize that rVWF will be as safe, tolerable, and acceptable as TA, and that VWF assays and VWF genotype will predict response to treatment. A sample size of 60 (inflated to 66 for 5% attrition) will provide 84% power to detect a difference in improvement of 40 points between rVWF and TA. Analysis will be by intent-to-treat analyses, with a two-tailed alternative hypothesis with type 1 error rate of 0.05, a 4-period 2-group (AABB/BBAA) crossover design, and an estimated between-subject standard deviation (SD) of 63 points and within subject SD of 100 points.

Results: A total of 442 potential subjects have been identified at 19 participating HTCs, of whom 33 (7.5%) are eligible, and 2 enrolled. The most common reason for ineligibility is use of an IUD (15.6%), COCs (9.4%), age <18 years (6.2%), pregnancy (6.2%), breastfeeding (6.2%), and VWF prophylaxis (3.1%). Nursing services have been contracted for weekend rVWF infusions. In-person site visits include hands-on web portal training, including a password-protected, FDA-validated data entry system, eSYSDM, use of real-time data form completion by tablet, infusion tracking and training, real-time cycle reporting, patient-training checklists, and protocol training and monitoring. Local gynecologists have been invited to refer potentially eligible patients.

Discussion: In conclusion, rVWF is a high-purity VWF concentrate with a longer half-life than pdVWF. In this multicenter phase III trial, rVWF is being compared to the current non-hormonal standard, TA, to reduce menorrhagia in adult women with type 1 VWD. rVWF is safe and effective in prevention and treatment of bleeds, and this trial will determine if rVWF reduces menorrhagia to a degree sufficient to justify its IV route and cost.