Here is the design of a clinical trial:

Official Title: Dose Reduction of the New Generation Biologicals (IL17 and IL23 Inhibitors) in Psoriasis: A Pragmatic, Multicentre, Randomized, Controlled, Non-inferiority Study - BeNeBio Study

Included conditions:
- Psoriasis
- Psoriasis Vulgaris

Study Armgroups:
- {'label': 'Dose reduction', 'type': 'EXPERIMENTAL', 'description': 'Dose reduction by interval prolongation in 2 steps to a maximum decrease of 50% of the original dose when disease activity (PASI) and quality of life index (DLQI) remain low.', 'interventionNames': ['Drug: Secukinumab', 'Drug: Ixekizumab', 'Drug: Brodalumab', 'Drug: Guselkumab', 'Drug: Risankizumab', 'Drug: Tildrakizumab', 'Drug: Bimekizumab']}
- {'label': 'Normal dose', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients will continue treatment with the normal/maintenance dose of the biologicals.', 'interventionNames': ['Drug: Secukinumab', 'Drug: Ixekizumab', 'Drug: Brodalumab', 'Drug: Guselkumab', 'Drug: Risankizumab', 'Drug: Tildrakizumab', 'Drug: Bimekizumab']}

Interventions:
- {'type': 'DRUG', 'name': 'Secukinumab', 'description': 'Maintenance/normal dose is 300 mg/4 weeks. First dose reduction step: 300 mg/6 weeks. Second dose reduction step: 300 mg/8 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Cosentyx']}
- {'type': 'DRUG', 'name': 'Ixekizumab', 'description': 'Maintenance/normal dose is 80 mg/4 weeks. First dose reduction step: 80 mg/6 weeks. Second dose reduction step: 80 mg/8 weeks', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Taltz']}
- {'type': 'DRUG', 'name': 'Brodalumab', 'description': 'Maintenance/normal dose is 210 mg/2 weeks. First dose reduction step: 210 mg/3 weeks. Second dose reduction step: 210 mg/4 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Kyntheum']}
- {'type': 'DRUG', 'name': 'Guselkumab', 'description': 'Maintenance/normal dose is 100 mg/8 weeks. First dose reduction step: 100 mg/12 weeks. Second dose reduction step: 100 mg/16 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Tremfya']}
- {'type': 'DRUG', 'name': 'Risankizumab', 'description': 'Maintenance/normal dose is 150 mg every 12 weeks. First dose reduction step: 150mg/18 weeks. Second dose reduction step: 150mg/24 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Skyrizi']}
- {'type': 'DRUG', 'name': 'Tildrakizumab', 'description': 'Maintenance/normal dose is 100 mg or 200 mg every 12 weeks. First dose reduction step: 100 mg or 200 mg/18 weeks. Second dose reduction step: 100 mg or 200 mg/24 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Ilumetri']}
- {'type': 'DRUG', 'name': 'Bimekizumab', 'description': 'Maintenance/normal dose is 320 mg/8 weeks. First dose reduction step: 320 mg/12 weeks. Second dose reduction step: 320 mg/16 weeks.', 'armGroupLabels': ['Dose reduction', 'Normal dose'], 'otherNames': ['Bimzelx']}

Primary Outcomes:
- {'measure': 'Non-inferiority of the incidence proportion of persistent flares (Psoriasis Area and Severity Index (PASI) >5 for ≥ 3 months).', 'timeFrame': '18 months'}

Please estimate the sample size based on the assumption: 
One-sided testing with α = 0.025, power (1 − β) = 0.8, and a randomization ratio of 2:1 (DR vs. UC). Dropout rate is assumed to be 10%.
Power and sample size analyses
        The primary outcome is non-inferiority of persistent flares (PASI >â5 for â¥ 3âmonths) in the intervention group with a non-inferiority margin of 15%. If the upper limit of the 95% confidence interval of the difference in persistent flares between the intervention group versus control group exceeds 15% at 18âmonths of follow-up, it must be concluded that non-inferiority could not be demonstrated for DR [36]. A margin of 15% was chosen based on clinical grounds, and on previous DR studies [8, 37]. Inherent to the intervention, there could be a small increase in disease flares (i.e., loss of disease control) as drug dosages are lowered. However, it is expected, based on other studies [8, 35], that most flares will be easy to control in the end without residual damage for patients, for example by reintroduction of a higher dose or switch to another biologic. It is therefore expected that persistent flares will not occur very frequently, as has also been shown in the CONDOR trial [8]. In addition, in the UC arm, there will be disease flares as well, as PASI scores might fluctuate over time and some patients might experience loss of effectiveness of their biologic [38]. The chosen non-inferiority margin of 15% is to some extent arbitrary, but refers to a clinically acceptable difference in persistent flares. Of note, the point estimate should be much lower than the margin of 15%, because the margin refers to the upper limit of the 95% confidence interval of the difference in persistent flares which should not exceed 15%. Therefore, we found a margin of 15% (hence a point estimate <<â15%) for the difference in persistent flares acceptable, especially because we know that effectiveness could often be regained in patients with persistent flares in studies on other biologics [8, 35]. With an expected chance of being able to reduce biologic dosages in >â50% of patients [8], the benefit-harm ratio seems well balanced by accepting this anticipated increase of persistent flares in patients undergoing DR compared to UC.
        With this margin, one-sided testing (Î± = 0.025; 1 â Î² = 0.8) and a randomization ratio of 2:1 DR versus UC, we calculated that 222 patients need to be included to reject the null-hypothesis of inferiority. Taking a drop-out rate of 10% into account, 244 patients need to be included, with 162 in the DR arm and 82 in the UC arm.