Here is the design of a clinical trial:

Official Title: Enhancement of the Haemostatic Effect of Platelets in the Presence of High Normal Concentrations of Von Willebrand Factor

Included conditions:
- Bleeding

Study Armgroups:
- {'label': 'Platelet transfusion with Wilate ®', 'type': 'EXPERIMENTAL', 'interventionNames': ['Drug: Wilate']}
- {'label': 'Platelet transfusion with Placebo', 'type': 'PLACEBO_COMPARATOR', 'interventionNames': ['Other: Placebo']}

Interventions:
- {'type': 'DRUG', 'name': 'Wilate', 'description': "Wilate ® will be given with platelets in cases of severe bleeding. Wilate ® is a 1:1 balanced mixture of von Willebrand Factor (2'000 IU) and Coagulation factor VIII (2'000 IU) and as such has anti-haemorrhagic potential. It is extracted from plasma, freeze-dried and virus-inactivated.", 'armGroupLabels': ['Platelet transfusion with Wilate ®']}
- {'type': 'OTHER', 'name': 'Placebo', 'description': 'Empty placebo will be given with platelets in cases of severe bleeding.', 'armGroupLabels': ['Platelet transfusion with Placebo']}

Primary Outcomes:
- {'measure': 'Number of blood products', 'description': 'Number of blood products (fresh frozen plasma (FFP), red blood cells (RBC)) according to groups.', 'timeFrame': '48 hours'}

Please estimate the sample size based on the assumption: 
Power of 80%, significance level of 5%, negative binomial regression, covariates included: blood loss, number of blood products transfused within 12 h before administration, anticoagulants administered 7 days before, site of bleeding, level of thrombocytes at baseline
Determination of sample size
        A total of 120 (each group 60) patients are needed to detect a 50% reduction of the number of blood products subsequently transfused within two days in patients with WilateÂ® compared to placebo. The sample size is calculated for a power of 80 % and a significance level of 5% for an estimate of the treatment effect evaluated with a negative binomial regression. To improve the precision of the treatment effect, the following covariates will be included: blood loss, number of blood products transfused within 12 h before administration of the study drug, anticoagulants administered 7 days before, the site of bleeding and the level of thrombocytes at baseline. The sample size calculation is based on a simulation applying resampling techniques on historical clinical data of 150 USB patients that meet the inclusion criteria.