Dried Blood SPOT Analysis of Everolimus in Cancer Patients (SPOT-study)

Study Overview
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Brief Summary
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Everolimus shows a large interpatient variability with fixed dose administration. These very different exposure levels between individuals can result in supratherapeutic or subtherapeutic exposure levels and consequently in over- or undertreatment, respectively. Dose individualization based on the measured drug concentration could theoretically result in less toxicity and more efficacy. Nowadays everolimus exposure is determined by everolimus concentration in whole blood. Therefore, a vena puncture is always necessary. This is invasive and requires patients to come to the hospital. It would be convenient for patients to have their everolimus blood concentration determined by dried blood spot (DBS) analysis. With DBS only a single drop of blood from the finger is necessary, which can be done at home and sent by regular mail for analysis. Previous studies have shown the feasibility of this approach. In patients with cancer treated with everolimus 10mg once daily, the correlation between everolimus DBS concentrations and whole blood concentration is yet unknown. Therefore, the investigators want to determine the everolimus concentration collected with DBS from a finger prick with everolimus concentration from whole blood and everolimus concentration collected with DBS from whole blood. In addition, possibly a relatively high everolimus concentration in saliva could be correlated with the incidence and severity of oral mucositis. Determination of drug concentration in saliva has also been proven to be feasible before. Therefore, in this study the investigators want to determine whether the everolimus concentration in saliva correlates with the incidence of oral mucositis and how everolimus concentration in saliva correlates with everolimus concentration in whole blood.

Official Title
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Dried Blood SPOT Analysis of Everolimus in Cancer Patients

Conditions
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Breast Cancer, Renal Cell Carcinoma

Intervention / Treatment
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* Drug: Everolimus


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients currently treated with everolimus for any type of cancer Patients from whom it is possible to collect blood samples At least 18 years of age Able and willing to sign the Informed Consent Form prior to study assessments. Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Everolimus|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation everolimus concentration DBS with whole blood | Correlation between trough everolimus concentration from DBS analysis collected with finger prick with trough everolimus concentration in whole blood, measured at any time during everolimus treatment | Up to 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation everolimus concentration whole blood with saliva | Correlation between trough everolimus concentration from whole blood with trough everolimus concentration in saliva, measured at any time during everolimus treatment | Up to 2 years |