Exploratory Drug Interaction Study Between SMIs and DOACs

Study Overview
=================
Brief Summary
-----------------
The main objective of this study is to investigate the effect of small molecule inhibitors (SMIs), used in targeted therapy for tumours, on direct oral anticoagulants (DOACs).

Detailed Description
-----------------
Patients who receive anticoagulant therapy in the form of a direct oral anticoagulant (DOAC) and simultaneously receive anti-cancer targeted therapy with a small molecule inhibitor (SMI), potentially have an increased risk on thromboembolic complications and bleeding events due to interfering drug-drug interactions. Some SMIs influence CYP3A4 and/or p-glycoprotein (p-gp) for which DOACs are substrates. In this study, the effect of theoretically relevant SMIs on the pharmacokinetics, efficacy and safety of DOACs in patients with solid tumours will be investigated. For this purpose, plasma concentration analyses will be performed.

Official Title
-----------------
Real-world Exploratory Evaluation of the Potential Drug-drug Interaction Between Anticancer Small Molecule Inhibitors and Direct Oral Anticoagulants in Patients With Solid Tumours and Exploration of the Role of Therapeutic Drug Monitoring

Conditions
-----------------
Solid Tumor, Cancer, Lung

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Diagnosed with a solid tumour 18 years of age or older Patients receive or start treatment with an SMI-DOAC combination, that may cause a clinically significant DDI at the level of CYP3A4 and/or P-gp, based on the SmPC Combined use of a DOAC-SMI combination is expected to be continued at the same dose for at least three weeks The DOAC is used for at least seven days and the SMI has already been used for at least 21 days at time of blood collection to ensure steady-state Patients receive a DOAC at maintenance dose Exclusion Criteria: Unable to understand the information in the patient information letter Any concurrent medication beside the SMI and DOAC that is known to strongly inhibit or induce CYP3A4 or P-gp Patients who are pregnant or lactating

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1<br>Patients in group 1 already receive a DOAC and will start treatement with an SMI. Blood samples will be drawn before start of the SMI and during concomittant use with the SMI. | |
| Group 2<br>Patients in group 2 already use a potentially relevant DOAC-SMI combination or already use an SMI and start with a DOAC. In this group, blood samples are taken after the start of concomittant use of the DOAC-SMI combination. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| DOAC trough concentration | DOAC trough concentration before and during concomitant use with an SMI | At least 7 days after start DOAC use and in combination with an SMI at steady-state (after at least 21 days) | 
| DOAC peak concentration | DOAC peak concentration before and during concomitant use with an SMI | At least 7 days after start DOAC use and in combination with an SMI at steady-state (after at least 21 days) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Thromboembolic and bleeding events during follow-up | Thromboembolic and bleeding events during follow-up | within 6 months after the last blood sampling | 
| SMI trough concentration during concomitant use with a DOAC | SMI steady-state trough concentration during concomintant use with a DOAC | After the start of the DOAC use in combination with an SMI at steady-state (after at least 21 days) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
direct oral anticoagulant, targeted therapy, small molecule inhibitors, Therapeutic drug monitoring