Drug Interaction Study of Apixaban With Cyclosporine or Tacrolimus in Transplant Recipients

Solid organ transplantation is a lifesaving option for many patients with end-stage organ disease. After transplant surgery, patients must take immunosuppressive therapy, which carries significant risk for drug-drug interactions and adverse medication-related events. Transplant recipients are at an increased risk for co-morbidities traditionally managed with warfarin, such as venous thromboembolism and atrial fibrillation. Apixaban has the potential to provide safer and more effective treatment, without additional monitoring of the INR, but it has not been studied in conjunction with anti-rejection agents in this population. Apixaban is metabolized by CYP3A4 and P-gp and BCRP transporters. As part of their immunosuppressive therapy, solid organ transplant recipients are maintained on calcineurin inhibitors, which are weak CYP3A4 as well as potent P-gp and BCRP inhibitors. A study was recently undertaken to evaluate the potential drug-drug interaction between cyclosporine or tacrolimus and apixaban in healthy subjects (ClinicalTrials.gov Identifier: NCT03083782) . The results indicated that the change in apixaban exposure was not clinically relevant. PK studies in healthy volunteers are a first step for determining the nature and extent of potential drug-drug interactions. However, follow-up studies in the actual patient populations are essential for ensuring safety and tolerability, and providing clinicians the confidence to use these combinations. The purpose of this study is to confirm the pharmacokinetic characteristics and safety of apixaban in combination with tacrolimus and cyclosporine in stable kidney and lung transplant recipients.