This is a prospective validation study, multicenter, open-label, single-arm study, evaluating the concordance between capillary microsampling (using the VAMS Mitra device) and venous sampling in patients undergoing CDK4/6 therapy.
Adult patients (≥ 18 years) with breast cancer.
Patients currently receiving ribociclib, abemaciclib, or palbociclib.
Patients capable of performing capillary sampling (with or without assistance).
Patient information and signing of informed consent.
Patients with altered mental status or psychiatric disorder that, in the opinion of the investigator, would preclude a valid patient informed consent.
Persons deprived of their liberty or under guardianship.