Here is the design of a clinical trial:

Official Title: A Phase II, Placebo Controlled, Double Blind, Randomised Clinical Trial To Assess The Safety And Tolerability Of 30mg/kg Daily Ursodeoxycholic Acid (UDCA) In Patients With Parkinson's Disease (PD)

Included conditions:
- Parkinson's Disease

Study Armgroups:
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'description': '2:1 in favour of UDCA', 'interventionNames': ['Drug: Ursonorm']}
- {'label': 'Ursonorm (Ursodeoxycholic acid)', 'type': 'EXPERIMENTAL', 'description': 'UDCA 30 mg/kg daily, tablet form taking orally , administered 3 monthly for 12 months, dose titration during the 1st month will occur.', 'interventionNames': ['Drug: Ursonorm']}

Interventions:
- {'type': 'DRUG', 'name': 'Ursonorm', 'description': 'Ursodeoxycholic acid', 'armGroupLabels': ['Placebo', 'Ursonorm (Ursodeoxycholic acid)'], 'otherNames': ['UDCA']}

Primary Outcomes:
- {'measure': 'Number of Participants with Incidence of Treatment-Emergent Adverse Events', 'description': 'Safety of a 56-week UDCA Intervention will be assessed by measuring the number of participants with adverse events that are related to treatment.', 'timeFrame': 'Timepoint: start of treatment to 56 weeks (visit 6)'}
- {'measure': 'Number of Participants with Incidence of Serious Adverse Events', 'description': 'Safety of a 56-week UDCA Intervention will be assessed by measuring the number of participants with serious adverse events.', 'timeFrame': 'Timepoint: start of treatment to 56 weeks (visit 6)'}
- {'measure': 'Number of Participants that complete the study', 'description': 'Safety of a 56-week UDCA Intervention will be assessed by measuring the number of participants that complete the study.', 'timeFrame': 'Timepoint: start of treatment to 56 weeks (visit 6)'}

Please estimate the sample size based on the assumption: 
The study is a pilot and is not powered to statistically compare the SAE rate between the groups. The sample size has not been adjusted for lost to follow-up, but participants withdrawing or lost to follow-up will be replaced. The study is not formally powered for secondary or exploratory outcomes, and interpretation will focus on observed trends and confidence intervals.
Sample size
        The primary outcome of interest for this study is the safety and tolerability of UDCA which will be assessed by comparing the rate of SAEs in the UDCA and placebo groups, alongside review of adverse treatment reactions and study completion. As the study is a pilot, it is not powered to compare the SAE rate between the groups statistically, but any SAEs in either group will be presented descriptively, the placebo group providing a baseline against which to view any SAEs in the UDCA group. Should this study result in no SAEs then it would be of interest to determine how likely it is that a larger study would find an intolerable rate of SAEs. For this purpose, we will consider the rate of SAEs reported in the exenatide PD trial to be tolerable and acceptable (ie, 20%).15 In this study, should no SAEs be found in the group receiving UDCA (n=20) then the likelihood that the true SAE rate is less than 20% is 0.990778.
        The sample size has not been prospectively adjusted to account for any lost to follow-up. Instead, as the trial is of a relatively short duration we have instead allowed for any participants withdrawing from the study or lost to follow-up before the completion of 12 weeks of treatment to be replaced with a new participant.
        The study has not been powered formally for the secondary or exploratory outcome measures, therefore, interpretation will concentrate on observed trends and confidence intervals for estimated differences. The data collected for the secondary and exploratory outcomes will allow the estimation of the effect size and variance in each outcome to facilitate formal power calculations for future phase III studies. Of note, there is currently no longitudinal clinical trial data using either 31P-MRS or our sensor-based approached quantification of motor impairment. The collection of such data is critical to allow high-quality future trial design using these novel outcome measures.