The study includes an observational pharmacokinetic study and an interventional medication adherence study. The purpose of this study is 1) to describe the concentration-time profiles of targeted anticancer drugs and to characterize the concentration-effect/toxicity relationships in the target population of patients (observational study) and 2) to characterize patterns of adherence to oral targeted anticancer drugs and identify key-driver modifiable adherence factors in patients participating in an adherence program (interventional study).

Targeted anticancer therapies are often prescribed at the same dosage regimen in all patients. However, it is known that the marked interindividual variability in drug level may affect treatment outcomes. Several factors are known to modulate drug levels, such as weight, genetics host-drug and drug-drug interaction. The identification of these factors could give the possibility to propose better adjusted dosage regimens according to patient's individual characteristics. Moreover, the presence of high or low drug concentrations may partially explain toxicity or lack of efficacy of targeted anticancer drugs in some patients. The characterization of the relationship between drug levels and treatment response (efficacy and toxicity) would allow an optimized and a more individualized patient management with targeted anticancer drugs.

Oral targeted therapies must be taken on the long term and adherence issues have been shown to compromise treatment efficacy. Side effects and lifestyle management are among factors affecting treatment adherence. The characterization of adherence over time and the identification of factors susceptible to improve it will represent a great benefit for healthcare professionals and patients.

Inclusion Criteria:

• Cancer patients to whom a targeted anticancer therapy is prescribed

Exclusion Criteria:

• Patients incapable of judgment or participants under tutelage