TADA: A Study on the Impact of Rabeprazole-induced Elevated Stomach pH on APO-Dabigatran Exposure in Healthy Volunteers
Study Details
Study Description
Brief Summary
Open-label, crossover study recruiting 46 healthy male volunteers comparing the absorption of APO-dabigatran 150 mg per oral (PO) in the absence or presence of a proton pump inhibitor. Participants will serve as their own control when comparing dabigatran exposure in the absence or presence of the proton pump inhibitor, Rabeprazole 20 mg.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 4 |
Detailed Description
Non-valvular atrial fibrillation (AF) and venous thromboembolism (VTE) affect hundreds of thousands of Canadians and many millions worldwide. Affected patients are routinely treated with oral anticoagulants. Vitamin K antagonists (VKAs) were the only orally available anticoagulants for more than 60 years. Over the past decade, Direct Acting Oral Anticoagulants (DOACs) have increasingly replaced VKAs for treatment of patients with AF or VTE because of similar or superior efficacy and safety, and greater convenience. One of these new agents, dabigatran etexilate, has now come off patent in Canada, and at least one generic made by Apotex has been approved by Health Canada.
Prior to their introduction into clinical use, the development of an orally active direct thrombin inhibitors (DTIs) proved technically difficult because it required the conversion of a small, water soluble, poorly absorbable, active site-directed molecule into a fat-soluble prodrug that is transformed back to the active drug after intestinal absorption. In the case of dabigatran, this was achieved by administering it as an oral prodrug, dabigatran etexilate. When administered as the pro-drug, the bioavailability of dabigatran is pH-dependent and is optimal at low pH. To overcome the issue with pH-dependency of drug absorption, dabigatran capsules contain drug pellets, which are made up of a tartaric acid core coated with dabigatran etexilate, thereby maintaining an acid micro-environment (1, 2). After absorption the prodrug is metabolized to the active form dabigatran through esterases that are ubiquitous in the body.
Many patients taking oral anticoagulants are elderly and have an increased gastric pH (3), often as a result of commonly prescribed co-medications such as proton pump inhibitors (PPIs). Optimization of the formulation of originator Pradaxa® (dabigatran etexilate) provides consistent absorption in elderly patients, independent of gastric pH (1, 4), as was demonstrated in phase III trials where consistent outcomes were achieved in the young and elderly, and in the presence and absence of PPI therapy(5).
Generic formulations of dabigatran etexilate are required to demonstrate bioequivalence to the originator in healthy volunteers in order to receive regulatory approval in Canada. According to Canadian regulations and Health Canada, bioequivalence trials do not usually require testing in older patients with an altered gastric pH or in patients taking a PPI (6). The sophisticated pharmaceutical formulation of Pradaxa® ensures stable and reliable absorption despite its low solubility under elevated pH. Pradaxa® has a bioavailability of 6.5% (4, 7) and even any seemingly small alteration in absorption resulting from a change in formulation may significantly affect drug levels. Lower drug levels could lead to an increase in thrombotic events, and higher drug levels could increase bleeding. The European Union (EU) product specific guideline for dabigatran etexilate, however, does require additional bioequivalence studies with elevated gastric pH by means of PPI pre-treatment(8).
APO-Dabigatran is one of the first generic formulations of dabigatran etexilate to be introduced into the Canadian market. APO-Dabigatran compared with Pradaxa® demonstrated similar bioavailability in healthy volunteers, fulfilling the requirements as a generic alternative to the original compound. Unlike Pradaxa®, APO-Dabigatran is formulated using fumaric acid and it is unclear whether this produces a similar pharmacokinetic profile to that of Pradaxa in patients with altered gastric pH, for example in the elderly or those taking a PPI.
This study objective is to determine in healthy volunteers whether concomitant PPI therapy impairs absorption of APO-dabigatran 150 mg and thereby reduces drug blood levels.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: APO-Dabigatran Single dose 150mg APO-Dabigatran given with 24 hours of Pharmacokinetic (PK) testing post dose |
Drug: APO-Dabigatran 150mg
Absorption of APO-Dabigatran post single dose
|
| Other: APO-Dabigatran and Rabeprazole 4-7 doses of rabeprazole followed by single dose 150mg APO-Dabigatran given with 24 hours of Pharmacokinetic (PK) testing post dose |
Drug: RABEprazole 20 Mg Oral Delayed Release Tablet
Absorption of APO-Dabigatran measured with and without influence of rabeprazole
Drug: APO-Dabigatran 150mg
Absorption of APO-Dabigatran post single dose
|
Outcome Measures
Primary Outcome Measures
- 24-hour APO-Dabigatran exposure by peak concentration [24 Hours]
As measured by peak concentration (Cmax)
- 24-hour APO-Dabigatran exposure [24 Hours]
As measured by area under the curve (AUC)
Secondary Outcome Measures
- Area under the curve Dilute Thrombin time (dTT) [24 hours]
dilute thrombin time measured at 0 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, 24 hours to calculate AUC and maximum
- Maximum Dilute Thrombin time (dTT) [24 hours]
dilute thrombin time measured at 0 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, 24 hours to calculate AUC and maximum
- Area under the curve activated partial thromboplastin time (aPTT) [24 hours]
activated partial thromboplastin time measured at 0 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, 24 hours to calculate AUC and maximum
- Maximum activated partial thromboplastin time (aPTT) [24 hours]
activated partial thromboplastin time measured at 0 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, 24 hours to calculate AUC and maximum
Eligibility Criteria
Criteria
Inclusion Criteria:
-
20 to 40 years old
-
Body mass index 18-30 kg/m2
-
Male. Those able to father a child must be ready and able to use highly effective methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly. A list of contraception methods meeting these criteria is provided in the patient information sheet.
Exclusion Criteria:
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Any documented history of heart, lung, liver, kidney, gastrointestinal, genitourinary, musculoskeletal or endocrine disorders or other systemic illness not specifically listed.
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Regular use of any medications or herbal supplements/remedies (e.g. St. John's wort).
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Laboratory values outside of reference range that may compromise safety or validity of the trial.
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Smoking or alcohol consumption such that the investigators feel that they will not be able to comply with the trial protocol.
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Measures at screening outside of the reference ranges for systolic and diastolic blood pressure (>140/90) and pulse rate (>90/min).
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Patients who are not expected to comply with the protocol requirements or not expected to complete the trial as scheduled (includes any condition that, in the investigator's opinion, makes the patient an unreliable trial participant).
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Previous enrollment in this trial.
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Currently enrolled in another investigational device or drug trial, or less than 30 days since ending another investigational device or drug trial(s), or receiving other investigational treatment(s)
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | The Population Health Research Institute | Hamilton | Ontario | Canada | L8L 2X2 |
Sponsors and Collaborators
- Population Health Research Institute
- Hamilton Health Sciences Corporation
Investigators
- Principal Investigator: John Eikelboom, MBBS, MSc, Population Health Research Institute
Study Documents (Full-Text)
None provided.More Information
Additional Information:
- Inc. A. APO-dabigatran Product Monograph.
- Dabigatran etexilate hard capsule 75mg, 110mg, 150mg product-specific bioequivalence guidanc
Publications
- Connolly SJ, Ezekowitz MD, Yusuf S, Eikelboom J, Oldgren J, Parekh A, Pogue J, Reilly PA, Themeles E, Varrone J, Wang S, Alings M, Xavier D, Zhu J, Diaz R, Lewis BS, Darius H, Diener HC, Joyner CD, Wallentin L; RE-LY Steering Committee and Investigators. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009 Sep 17;361(12):1139-51. doi: 10.1056/NEJMoa0905561. Epub 2009 Aug 30. Erratum in: N Engl J Med. 2010 Nov 4;363(19):1877.
- Coppens M, Eikelboom JW, Gustafsson D, Weitz JI, Hirsh J. Translational success stories: development of direct thrombin inhibitors. Circ Res. 2012 Sep 14;111(7):920-9. doi: 10.1161/CIRCRESAHA.112.264903. Review.
- Hurwitz A, Brady DA, Schaal SE, Samloff IM, Dedon J, Ruhl CE. Gastric acidity in older adults. JAMA. 1997 Aug 27;278(8):659-62.
- Sarah S. The pharmacology and therapeutic use of dabigatran etexilate. J Clin Pharmacol. 2013 Jan;53(1):1-13. doi: 10.1177/0091270011432169. Epub 2013 Jan 24. Review.
- Stangier J. Clinical pharmacokinetics and pharmacodynamics of the oral direct thrombin inhibitor dabigatran etexilate. Clin Pharmacokinet. 2008;47(5):285-95. Review.
- Weitz JI, Earl KM, Leblanc K, Semchuk W, Jamali F. Establishing Therapeutic Equivalence of Complex Pharmaceuticals: The Case of Dabigatran. Can J Cardiol. 2018 Sep;34(9):1116-1119. doi: 10.1016/j.cjca.2018.05.023. Epub 2018 Jun 5.
- TADA_1910_V1.9