Here is the design of a clinical trial:

Official Title: Biological-guided Metronomic Chemotherapy as Maintenance Strategy in Responders After Induction Therapy in Metastatic Colorectal Cancer

Included conditions:
- Colorectal Cancer

Study Armgroups:
- {'label': 'Capecitabine metronomic chemotherapy', 'type': 'EXPERIMENTAL', 'description': 'Capecitabine 500mg/m2 bid po qd', 'interventionNames': ['Drug: Capecitabine']}
- {'label': 'Capecitabine standard dosage chemotherapy', 'type': 'ACTIVE_COMPARATOR', 'description': 'Capecitabine 1000mg/m2 bid po d1-d14,q3w', 'interventionNames': ['Drug: Capecitabine']}

Interventions:
- {'type': 'DRUG', 'name': 'Capecitabine', 'description': 'Oral fluorouracil', 'armGroupLabels': ['Capecitabine metronomic chemotherapy', 'Capecitabine standard dosage chemotherapy'], 'otherNames': ['Xeloda']}

Primary Outcomes:
- {'measure': 'Progression Free Survival 1 (PFS1)', 'description': 'from enrollment to progression', 'timeFrame': '10 months'}
- {'measure': 'Progression Free Survival 2 (PFS2)', 'description': 'from randomization to progression', 'timeFrame': '4 months'}

Please estimate the sample size based on the assumption: 
The study assumes a dropout rate of 20%, 80% power, and a one-sided significance level (Î±) of 0.025.
Sample size calculation
        This project is a non-inferiority study. The patients are allocated to the capecitabine metronomic chemotherapy group (experimental group) and the capecitabine conventional chemotherapy group (control group) in a ratio of 1:1. The non-inferiority boundary in PFS was defined at 1.40 in reference to the results of the trial reported by Luo et al. [19]. The HR for the capecitabine maintenance group versus the observation group in the trial was 0.54 and the reciprocal was 1.85, which leads to 1.43 as 50% survival benefit. So, the boundary of 1.4 was used in this study. Considering a dropout rate of 20%, we estimated that 386 patients (193 in each group) would be needed to achieve 80% power at a one-sided value of Î± = 0.025 (significance level).