VWD
Treatment of Bleeding Episodes
Clinical efficacy of WILATE in the control of bleeding in patients with inherited VWD that did not respond to desmopressin acetate was determined in four prospective, open-label, non-controlled clinical studies (excluding PK study) in 70 patients; mean age 37 years (range 5–77), 37 type 3 VWD, and 30 male. Treated BEs were analyzed for efficacy using additional criteria* other than the 4-point hemostatic efficacy scale (excellent, good, moderate and none).
*Treatment of the BE was classified as successful if none of these criteria were met: treated with another VWF-containing product (excluding whole blood), blood transfusion required, for BE requiring > 1 day of treatment the follow-up daily dosage of WILATE was ≥ 50% above the initial dose, treatment duration of > 4 days in severe BEs, treatment duration of > 3 days in moderate BEs, treatment duration of > 2 days in minor BEs (other than gastrointestinal for all severities), the last efficacy rating was 'moderate' or 'none'.
Among these 70 patients, 45 (11 aged 5-16 years) received on demand treatment for BEs.
Table 16 Proportion of Successful Treatments of Bleeding Episodes with WILATE
| Number of BEs* | Number of successfully treated BEs (%) |
| All patients (n=45)* | 1068 | 898 (84.1) |
| Patients 5–16 years (n=11) | 234 | 205 (87.6%) |
*A BE may involve bleeding at multiple sites.
* In these 45 patients with BEs, 93% of the successfully treated BEs occurred in VWD type 3 patients (n=25).
The majority of BEs (83%)were treated for 1-3 days, with mean doses of 24 IU/kg to 28 IU/kg. In patients with GI bleeds, the duration for product use to control bleeding was longer (up to 7 days), with a mean initial dose of 43 IU/kg and mean subsequent doses of 36 IU/kg.
In a separate study, 12 children < 6 years with severe VWD (VWF:RCo <20%) (3 type 2A, 1 type 2B, and 8 type 3) were treated with routine prophylaxis. Ten patients had 47 treated BEs, the majority of which were nose BEs (66%) and minor (96%). Treated BEs were analyzed for efficacy using a 4-point hemostatic efficacy scale (excellent, good, moderate and none). Treatment success was achieved for all BEs. Of these 47 treated BEs, 44 (93.6%) BEs were treated with 1 infusion and 3 (6.4%) were treated with 2 infusions. The mean dose per BE was 58.7 IU/kg, while the median was 52.9 (range 30.9 – 153.8) IU/kg
Perioperative Management
A prospective, open-label, single-arm, uncontrolled, multi-center clinical study was conducted to investigate the safety and hemostatic efficacy of WILATE in 28 patients (19 female and 9 male) ages 12 to 74 years (median = 36) who underwent 30 surgeries. Three patients were 12 to 17 years old and 4 were > 65 years. Six patients had type 1 VWD, 1 type 2A, 1 type 2B, and 20 type 3 VWD. Efficacy was assessed at the conclusion of surgery by the surgeon and at 24 hours following completion of the final maintenance dose by the hematologist using a 4-point efficacy scale (excellent, good, moderate, or none) based on estimated expected versus actual blood loss and transfusion requirements. An independent data monitoring committee (IDMC) conducted a post hoc adjudication. In the event the IDMC’s assessment differed from that of the surgeon and/or investigator-hematologist, the IDMC assessment was accepted.
Twenty-one surgeries were major (e.g. orthopedic joint replacement, cesarean section and vaginal deliveries, laminectomy, tonsillectomy, appendectomy, 3rd molar extractions) and 9 were minor (e.g. menisectomy, teeth extractions other than 3rd molars, septoplasty, biopsy). Seven (3 major, 4 minor) were in type 1 VWD patients, 2 (1 major, 1 minor) in type 2 (A/B) VWD patients, and 21 (17 major, 4 minor) in type 3 VWD patients.
Dosing was individualized based on IVR results performed before surgery. The mean loading dose for major surgeries was 54.7 IU/kg (median 55.5; range 36-69) and 41.9 IU/kg (median 37.5; range 27−77) for minor surgeries. The mean maintenance dose was 29.6 IU/kg (median 30; range 8-63) for major surgeries and 21.6 IU/kg (median 20.6; range 14-38) for minor surgeries.
Efficacy of WILATE in surgical procedures was assessed by the surgeon at the conclusion of surgery and by the investigator-hematologist at 24 hours following completion of the final maintenance dose. Efficacy of WILATE was assessed using a stringent and objective 4-point ordinal efficacy scale (excellent, good, moderate, or none) based on estimated expected versus actual blood loss, transfusion requirements and post-operative bleeding and oozing. A rating of excellent or good was required to declare the outcome a success. An independent data monitoring committee (IDMC) additionally conducted an independent post hoc adjudication of intra- and post-operative assessments made by the surgeon/investigator-hematologist. In situations where the IDMC’s assessment differed from that of the surgeon and/or investigator-hematologist, the IDMC assessment took priority. The overall efficacy was 96.7% with treatment success in all minor surgeries and 95.2% in major surgeries. Treatment success was achieved in all type 3 and type 2 VWD and was 85.7% in type 1 patients. One treatment failure was reported in a major surgery in a type 1 patient.
In 4 clinical trials, there were 14 pediatric patients who underwent 23 surgeries (3 patients aged 0 to 2 years, 5 patients aged 2 to 5 years, 3 patients aged 6 to 12 years, and 3 patients aged 12 to 16 years). Treatment success was achieved in all procedures (17 minor and 6 major).
Routine prophylaxis
A prospective, non-controlled, international, multi-center clinical study was conducted to demonstrate that WILATE is efficacious in bleeding prophylaxis in 33 patients with VWD. The total annualized bleeding rates (ABR) under prophylactic treatment was compared to ABRs recorded for the same patients during a lead-in, prospective non-interventional, on-demand treatment study. The median age was 18 years (range 7 to 61); 19 patients (57.6%) were male and 14 (42.4%) were female; 97% were white and 3% Black or African American. Nine patients were 6 to 11 years, 6 were 12 to 16 years, and 18 were > 17 years. Six patients had severe type 1 VWD, 5 type 2A VWD, and 22 type 3 VWD. Patients were treated for 12 months with a dose of 20-40 IU/kg WILATE 2 to 3 times per week.at a mean dose of 30.57 IU/kg. Within the 15 pediatric patients (9 type 3, 3 type 2, and 3 type 1), the total ABR decreased from 32.59 during on-demand treatment to 3.73 during routine prophylaxis in the 9 patients 6 to 11 years and from 28.99 to 4.28 in the 6 patients 12 to 16 years.
Table 17 Annualized Bleeding Rate (ABR) in Patients ≥ 6 years under Prophylaxis
| Bleeding Type | on-demand treatment (n=33)# | prophylaxis treatment (n=33) |
| ABR (± SD) - all types of bleeds (excluding menstrual bleeds) | 33.38 ± 23.61 | 5.24 ± 7.75 |
| ABR (± SD) - spontaneous bleeds | 24.42 ± 20.05 | 3.23 ± 5.92 |
| ABR (± SD) – joint bleeds | 7.56 ± 11.51 | 0.53± 1.48 |
| ABR (± SD) – other bleeds† | 0.13 ± 0.51 | 0.15 ± 0.56 |
# Data were collected during a 6 months lead-in, prospective, non-interventional, on-demand treatment study.
†“Other bleeds” under on-demand treatment include bleeds related to eruption of teeth and infection tonsilitis. “Other bleeds” under prophylactic treatment include bleeds related to allergic rhinitis, post infection tonsilitis or to hemorrhoids.
A separate phase 3 clinical study evaluated the efficacy and safety of routine prophylaxis with WILATE in 12 children < 6 years with severe VWD (VWF:RCo <20%). The median age was 2 years (range 1 to 5); 6 patients were male and 6 were female; 10 patients were white and 2 were Middle Eastern (Arab). Four patients had type 2 VWD (3 type 2A and 1 type 2B), and 8 had type 3 VWD. Patients received WILATE 2–3 times per week at doses of 30–50 IU/kg over 12 months with a mean dose of 54 IU/kg.
Table 18 Annualized Bleeding Rate (ABR) in Patients <6 Years under Prophylaxis
| Bleeding Type | All BEs (full analysis set) | Treated BEs (full analysis set) |
| ABR (± SD) - all types of bleeds* | 4.6 ± 6.1 | 3.7 ± 5.1 |
| ABR (± SD) - spontaneous bleeds | 0.9 ± 1.2 | 0.7 ± 1.1 |
| ABR (± SD) – traumatic bleeds | 1.4 ± 1.7 | 1.2 ± 1.7 |
| ABR (± SD) – joint bleeds | 0.08 ± 0.28 | 0.08 ± 0.28 |
| ABR (± SD) – other bleeds** | 2.3 ± 6.6 | 1.7 ± 5.4 |
*All types of bleeds includes spontaneous bleeds, traumatic bleeds, and other bleeds.
**Other bleeds include oral bleeds when eating solid food, bleeds during needle insertion into the port system, allergy related nose bleeds, and a nose bleed related to virosis.
Hemophilia A
Treatment of bleeding episodes
The study on routine prophylaxis also evaluated the efficacy of WILATE in the treatment of BEs with doses adjusted to the severity of the bleed. Treatment efficacy was assessed using the predefined criteria of excellent, good, moderate or none.
Fifty-seven BEs were treated with WILATE; 15 (26.3%) were minor, 32 (56.1%) were moderate, 10 (17.5%) were major and 0 (0%) were life-threatening. Fourty-eighy BEs (84.2%) were treated with 1 or 2 infusions successfully.
Three additional studies assessed treatment of BEs in 37 patients with hemophilia A. These patients were treated with at least 50 exposure days for 6 months with 95% of BEs treated successfully.
Routine prophylaxis
The efficacy of WILATE in routine prophylaxis was evaluated in a prospective, open-label, multicenter clinical study in which adults and adolescents aged 12-15 years were treated during 6 months of prophylaxis with 20-40 IU/kg WILATE, mean dose 32 IU/kg. Within 55 patients (50 adults and 5 adolescents), 30 (54.6%) patients had 0 BEs, 12 (21.8%) had 1, 4 (7.3%) had 2, 4 (7.3%) had 3, and 5 (9%) ≥ 5.
Table 19 Annualized Bleeding Rate in Adult and Pediatric Patients under Prophylaxis
| Adults (n=50) | Adolescents (n=5) |
| ABR - spontaneous bleeds | 1.67 ± 3.11 | 0 |
| ABR- all types of bleeds | 2.39 ± 3.77 | 0.4 ± 0.89 |