The effects of the proton pump inhibitor esomeprazole on the bioavailability of regorafenib in patients with a metastatic colorectal cancer (mCRC) or gastrointestinal stromal tumour (GIST).

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 14

Inclusion Criteria

1. Age >= 18 years
2. Histological or cytological confirmed diagnosis of mCRC or GIST
3. ECOG Performance Status <= 1
4. Signed Informed Consent Form prior to screening evaluations
5. No concurrent (over the counter) use of other acid reducing drugs, other than esomeprazole 40mg (PPIs, H2As and/or antacids) once daily during the study
6. No concurrent medication or supplements which can interact with esomeprazole or regorafenib during the study period
7. Abstain from grapefruit, grapefruit juice, herbal dietary supplements, and herbal tea during the study period.
8. Adequate baseline patient characteristics

Exclusion Criteria

1. Pregnant or lactating patients
2. Patients with known impaired drug absorption (e.g. gastrectomy and achlorhydria)
3. Known serious illness or medical unstable conditions that could interfere with this study
4. Patients with evidence or history of any bleeding diathesis, irrespective of severity
5. Cardiac history ( recent myocardial infarction, unstable or new-onset angina, uncontrolled cardiac arrhythmias)
6. Uwillingness to abstain from grapefruit (juice), (herbal) dietary supplements, herbals, over-the-counter medication (except for paracetamol and ibuprofen) and other drugs known to seriously interact with esomeprazole and regorafenib during the study period.
7. Unwillingness to abstain from acid beverages such as jus d*orange and other acidic beverages in the morning during regorafenib treatment in this study.
8. Known hypersensitivity to any of the study drugs, study drug classes, or excipients in the formulation.
9. Symptomatic CNS metastases or history of psychiatric disorder that would prohibit the understanding and giving of informed consent.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>To determine the influence of esomeprazole on the AUC of regorafenib in<br /><br>patients with mCRC or GIST.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>1. Other pharmacokinetic outcomes (i.e. clearance (CL), maximum concentration<br /><br>(Cmax) and time to Cmax (tmax)).<br /><br>2. To evaluate the incidence and severity of side-effects of treatment with<br /><br>regorafenib in absence and presence of esomeprazole</p><br>