Here is the design of a clinical trial:

Official Title: Study of the Therapeutic Response and Survival of Patients with Metastatic Colorectal Cancer (stage IV) and Treated According to the Guidelines of a Chemosensitivity Test, Oncogramme®

Included conditions:
- Colorectal Cancer Metastatic
- Chemotherapy

Study Armgroups:
- {'label': 'Usual care', 'type': 'NO_INTERVENTION', 'description': 'Patient is followed within the usual care for stage 4 colorectal cancer'}
- {'label': 'Oncogramme®', 'type': 'EXPERIMENTAL', 'description': 'For patients in the Oncogramme® group, chemotherapy will be adapted to Oncogramme® results.', 'interventionNames': ['Other: Oncogramme®']}

Interventions:
- {'type': 'OTHER', 'name': 'Oncogramme®', 'description': 'Patient is followed within the usual care for stage 4 colorectal cancer, but an Oncogramme test will be made and chemotherapy will be adapted to the results.', 'armGroupLabels': ['Oncogramme®']}

Primary Outcomes:
- {'measure': 'Occurrence of the progression or death of the patient.', 'description': 'The event studied is the occurrence of the progression or death of the patient during the year following the inclusion in the study. The progression of the patient is determined by the RECIST (Response Evaluation Criteria in Solid Tumors).', 'timeFrame': 'Year 1'}

Please estimate the sample size based on the assumption: 
significance level of 0.05, power of 80%, and a 20% addition for non-assessable patients
Sample size calculation
        Based on a 1-year PFS of 15% in the control arm, and 30% in the OncogrammeÂ®-assisted arm, a log-rank test evaluated the total number of patients to include at 204 (with a significance level of 0.05 and a power of 80%). Sample size ratio is 1:1, meaning that each arm should include 102 patients. Taking into consideration the eventuality of non-assessable patients, 20% has been added to the initial sample size, which eventually reached 256. Based on clinical data observed at Limoges hospital, it has been estimated that the study should include 5 patients per month, allowing to reach the target population of 256 patients in a 48-month timeframe.