Here is the design of a clinical trial:

Official Title: A Multicentre Phase II Randomised Trial of Durvalumab (MEDI4736) Versus Physician's Choice Chemotherapy in Recurrent Ovarian Clear Cell Adenocarcinomas (MOCCA)

Included conditions:
- Ovarian Clear Cell Carcinoma

Study Armgroups:
- {'label': 'standard chemotherapy', 'type': 'ACTIVE_COMPARATOR', 'description': "Patients on physician's choice of chemotherapy are allowed to receive any systemic chemotherapy either as a single agent or in combination. However, biologics( including bevacizumab) and oral tyrosine kinase inhibitors will not be allowed for patients on this arm", 'interventionNames': ['Drug: standard chemotherapy']}
- {'label': 'durvalumab', 'type': 'EXPERIMENTAL', 'description': 'Patients on durvalumab will be given at 1500mg fixed dose every 4 weeks for 24 months', 'interventionNames': ['Drug: durvalumab']}

Interventions:
- {'type': 'DRUG', 'name': 'durvalumab', 'description': 'Durvalumab will be given at 1500mg fixed dose every 4 weeks for 24 months or until the appearance of significant treatment-related toxicity or disease progression', 'armGroupLabels': ['durvalumab']}
- {'type': 'DRUG', 'name': 'standard chemotherapy', 'description': 'chemotherapy treatment will be administered as per local institutional guidelines', 'armGroupLabels': ['standard chemotherapy']}

Primary Outcomes:
- {'measure': 'Progression free survival', 'description': 'Progression free survival (PFS) is defined as the time from the first day of treatment to the first observation of radiological or clinical disease progression or death due to any cause or last follow-up. The progression will be defined by RECIST criteria v1.1 for patients on the chemotherapy arm which includes first instance of more than 20% increase in the sum of diameters or unequivocal progression in non-target disease. The sum of the diameters (longest for non-nodal lesions, short axis for nodal lesions) is calculated at baseline and at each tumor assessment.', 'timeFrame': '4 years'}

Please estimate the sample size based on the assumption: 

Sample size
          The target sample size was 46 patients.