Here is the design of a clinical trial:

Official Title: Efficacy and Safety of Trifluridine/Tipiracil in Combination With Irinotecan as a Second Line Therapy in Patients With Cholangiocarcinoma

Included conditions:
- Cholangiocarcinoma

Study Armgroups:
- {'label': 'Treatment', 'type': 'EXPERIMENTAL', 'description': 'Combination of Lonsurf® and Irinotecan', 'interventionNames': ['Combination Product: Combination of Lonsurf® and Irinotecan']}

Interventions:
- {'type': 'COMBINATION_PRODUCT', 'name': 'Combination of Lonsurf® and Irinotecan', 'description': 'Trifluridine/Tipiracil (Lonsurf®) and Irinotecan\n\n* Trifluridine/Tipiracil will be administered at a dose of 25 mg/m2 / dose twice daily on days 1-5 followed by a 9-days recovery period from day 6 trough day 14 of each 14-days treatment cycle.\n* Irinotecan will be administered at the same time as Trifluridine/Tipiracil (Lonsurf®) on day 1 of each cycle at a dose of 180 mg/m2 / dose.', 'armGroupLabels': ['Treatment']}

Primary Outcomes:
- {'measure': 'Median progression free survival (PFS)', 'description': 'Median progression free survival (PFS)', 'timeFrame': 'through study completion, an average of 1 year (~4 months intervention + 6 months Follow Up)'}

Please estimate the sample size based on the assumption: 
Exponential failure time, censoring rate of 0.04 per month, and inclusion of 3 dropouts/invalid cases
Sample size determination
        Sample size consideration for this study is based on the precision of the survival estimate for the outcome progression-free survival. Based on previous results with the combination of Irinotecan and 5-FU therapy in patients with biliary tract cancers we assume a median survival time of 3Â months. Assuming an exponential failure time with a median survival of 3Â months (hazard rate: 0.23 per month) and a censoring rate of 0.04 per month, a total sample size of 28 patients (including 3 calculated drop outs and invalid cases) results in an expected standard error of 0.09 for the 3Â months survival.