Bleeding Incidence in VWD Patients Undergoing On-Demand Treatment

The total annualized bleeding rate (TABR) will be calculated as the total number of spontaneous bleeds, traumatic BEs, and other BEs occurring in the time period between the start of data collection for each patient and the Study Completion Visit, divided by the duration (in years) between the start of data collection and the Study Completion Visit. Surgery periods, and BEs occurring within these surgery periods, will be excluded from the calculation of TABR.

Spontaneous annualized bleeding rate (SABR), calculated in analogy with TABR. This includes all bleeding episodes that occurred spontaneously.

Data on the consumption of the VWF-containing product (VWF/FVIII IU/kg per month per patient) used for routine on-demand treatment

The efficacy assessment of bleeding episodes at the end of a BE was evaluated on a 4 point scale by the patient/legal guardian (together with the Investigator in case of on-site treatment) including the four items 'excellent,' 'good,' moderate,' and 'none.' The assessment was excellent when bleeding was completely stopped within 3 days in case of minor bleed, within 7 days in case of major bleed, and within 10 days in case of gastrointestinal bleed; Good when bleeding was completely stopped, but time and/or dose slightly exceeded expectations ; Moderate when bleeding could be stopped only by significantly exceeding time and/or dose expectations; and None when bleeding could be stopped only by using other VWF-containing products.

Effectiveness of VWF-containing product in surgical prophylaxis based on the proportion of surgeries successfully treated. Overall treatment efficacy will be assessed at the end of the postoperative period by the treating physician using predefined criteria of 'Excellent', 'Good', 'Moderate/Poor' or 'None'.

QoL assessment based on the results from the PROMIS-29 survey to monitor and evaluate the physical, mental, and social health in all patients, using a scale of a minimum score of 0 and a maximum score of 10, with higher scores representing a better outcome. The survey covers seven domains from the most relevant areas of self-reported health (depression, anxiety, physical function, pain interference, fatigue, sleep disturbance and ability to participate in social roles and activities) for the majority of people with chronic illness. PROMIS scores have a mean of 50 and standard deviation (SD) of 10 in a referent population. Full details of cut off points for each domain can be found here: https://www.healthmeasures.net/score-and-interpret/interpret-scores/promis/promis-score-cut-points

QoL assessment based on the results from the SF-36v2 questionnaire to measure functional health and well-being in patients ≥16 years. SF-36v2 ranks 8 different domains using a scale standardized with a scoring algorithm to obtain a score ranging from 0 to 100.The eight health domains include physical functioning (PF), role physical (RP), bodily pain (BP), general health problems (GH), vitality (VT), social functioning (SF), role emotional (RE) and general mental health (MH). Higher scores indicate better health status, and a mean score of 50 has been articulated as a normative value for all scales.

QoL assessment based on the results from a SF-10 parent-completed questionnaire for patients ≥5.5 and <16 years of age, in order to score physical and psychosocial health. SF-10 uses norm-based scoring where scales have a standardized mean value of 50 and standard deviation of 10.

Joint health status will be assessed using the Hemophilia Joint Health Score (HJHS), which has been specifically validated for the assessment of the clinical outcome in VWD. HJHS evaluates six index joints to produce a score between 0-124. Higher scores indicate worse joint health.

Bleeding information from each menstrual period while in this study will be collected using the Pictorial Blood Loss Assessment Chart (PBAC). The PBAC will be provided to all female patients of child-bearing potential. The data documented in the PBAC and the investigator-calculated final score will be recorded in the eCRF. The PBAC records pad and tampon use (as either light [1 point], medium [5 points], or heavy [10 points] flow), clots (small [1 point] or large [5 points]), and flooding episodes (1 point each) which can be recorded as many times as necessary any day of the month. The PBAC is scored from 0 (no bleeding) onwards, with a score of >100 defining abnormal coagulation and heavy menstrual bleeding (corresponds to >80ml of blood loss per menstrual cycle).

Noxious and unintended reactions arising from the use of Wilate will be monitored throughout the study.