This is a prospective, single arm, open label, non-randomized, exploratory, multi-centre pilot study with median progression free survival as primary outcome.

In total 28 patients (including 3 calculated drop outs and invalid cases) with advanced cholangiocellular carcinoma after failure of a gemcitabine based first-line therapy will be enrolled at 5 centres.

To examine the efficacy of a combination therapy of Trifluridine/Tipiracil and Irinotecan in patients with advanced, non resectable or metastatic cholangio- and gallbladder carcinoma after failure to respond to a previous gemcitabine treatment.

The study will be accompanied by a translational research program:

Before treatment and after each radiological tumor assessment (Q6W) blood and stool will be collected and extensive panels of biomarkers will be accessed.

This is a prospective, single arm, open label, non-randomized, exploratory, multi-centre pilot study with median progression free survival as primary outcome.

In total 28 patients (including 3 calculated drop outs and invalid cases) with advanced cholangiocellular carcinoma after failure of a gemcitabine based first-line therapy will be enrolled at 5 centres.

To examine the efficacy of a combination therapy of Trifluridine/Tipiracil and Irinotecan in patients with advanced, non resectable or metastatic cholangio- and gallbladder carcinoma after failure to respond to a previous gemcitabine treatment.

The study will be accompanied by a translational research program:

Before treatment and after each radiological tumor assessment (Q6W) blood and stool will be collected and extensive panels of biomarkers will be accessed.

Patients will be treated until radiological progression. In average this will be about 4 months. A follow up is planned every 3 months up to 6 months to asses life quality and progression data.

Inclusion Criteria:

1. Written informed consent incl. participation in translational research and any locally-required authorization (EU Data Privacy Directive in the EU) prior to performing any protocol-related procedures, including screening evaluations

2. Age ≥ 18 years at time of study entry

3. Histologically or cytologically confirmed, non-resectable, locally advanced or metastatic cholangiocarcinoma or gall bladder carcinoma

4. Measurable or assessable disease according to RECIST 1.1

5. Documented disease progression after prior gemcitabine or gemcitabine containing therapy. Examples of permitted therapies include, but are not limited to: a) Single agent gemcitabine); b) Any gemcitabine-based regimen, with or without maintenance gemcitabine

6. Eastern Cooperative Oncology Group (ECOG) performance status 0-1

7. Ability to take medications orally

8. Adequate blood count, liver-enzymes, and renal function:

   • Absolute neutrophil count (ANC) > 1,500 cells/μL without the use of hematopoietic growth factors; and Platelet count ≥ 100 x 109/L (>100,000 per mm3) and Hemoglobin > 9 g/dL (blood transfusions are permitted for patients with hemoglobin levels below 9 g/dL)
   • Serum total bilirubin ≤ 1.5x upper normal limit (ULN) (biliary drainage is allowed for biliary obstruction; elevated bilirubin should be caused by obstruction not impaired liver function as assessed by albumin and international normalised ratio (INR) values):
   • Albumin levels ≥ 3.0 g/dL
   • Patients not receiving therapeutic anticoagulation must have an INR< 1.5 ULN and partial thromboplastin time (PTT) < 1.5 ULN within 7 days prior to inclusion. The use of full dose anticoagulants is allowed as long as the INR or PTT is within therapeutic limits (according to the medical standard in the institution) and the patient has been on a stable dose for anticoagulants for at least three weeks at the time of inclusion.
   • aspartate aminotransferase (AST) (SGOT) and Alanine transaminase (ALT) (SGPT) ≤ 5 x institutional upper limit of normal
   • Serum Creatinine ≤ 1.5 x ULN and a calculated glomerular filtration rate ≥ 30 mL per minute Adequate renal and bone marrow function

9. In case of liver cirrhosis: Child-Pugh A

10. Women of childbearing potential must have a negative pregnancy test and must agree to adequate birth control if conception is possible. Males must agree to adequate birth control

Exclusion Criteria:

1. Age < 18 years
2. Central nerve system (CNS) metastases
3. Active, uncontrolled infection
4. Additional malignancy within the past 2 years (except adequately treated in-situ carcinoma of the cervix or non-melanoma skin cancer)
5. Clinically significant gastrointestinal disorders including bleeding, inflammation, occlusion, or diarrhea > grade 1
6. Any condition or comorbidity that, in the opinion of the investigator, would interfere with evaluation of study treatment or interpretation of patient safety or study results
7. Known hypersensitivity to Trifluridine/Tipiracil or Camptothecin (CPT)-11 or their components
8. Medication that is known to interfere with any of the agents applied in the trial
9. Pregnancy or lactating female
10. Prior partial or total gastrectomy
11. Previous radio- or radiochemotherapy, previous transarterial chemoembolisation (TACE), radiofrequency ablation (RFA) or selective intraarterial radiotherapy (SIRT) within 3 months prior to inclusion (except radiation for bone metastases)
12. Patients who might be dependent on the sponsor, site or the investigator
13. Patients who have been incarcerated or involuntarily institutionalized by court order or by the authorities § 40 Abs. 1 S. 3 Nr. 4 AMG.
14. Patients who are unable to consent because they do not understand the nature, significance and implications of the clinical trial and therefore cannot form a rational intention in the light of the facts [§ 40 Abs. 1 S. 3 Nr. 3a German drug law (AMG)].