2022 · Journal of pharmaceutical and biomedical analysis · paywalled
Volumetric absorptive microsampling (VAMS) for the quantification of ten kinase inhibitors and determination of their in vitro VAMS-to-plasma ratio
Zimmermann et al.
The finding, in our words
A validated VAMS method quantified ten kinase inhibitors from 20 µL dried capillary blood with linearity (R² 0.994) and six-week room-temperature stability. In vitro VAMS-to-plasma conversion factors were established, and the method proved applicable for clinical routine and home self-collection by patients, enabling remote therapeutic drug monitoring in oncology.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
In AML and CLL, 91% of VAMS venetoclax results fell within 20% of plasma after individualised haematocrit correction; in home sampling, 18 of 21 patients self-sampled independently and 76% of returned samples were analysable, which shows home microsampling is workable, though the authors ask for multicentre validation.
VAMS matched serum for the kinase inhibitors nilotinib, cabozantinib, dabrafenib and ruxolitinib, r 0.94–0.97, with serum reliably predictable for the first three, and 93% of at-home samples were collected correctly: at-home VAMS shown feasible for routine cancer-drug monitoring.
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.
A review of 39 studies found that dried blood spot and volumetric absorptive microsampling show promising results for therapeutic drug monitoring of oral targeted anticancer drugs. The authors state that external validation remains crucial to confirm reliability, citing haematocrit effects and sample stability as key challenges.
This study established conversion methods for estimating plasma concentrations from whole blood VAMS samples for seven out of ten oral anticancer drugs, finding good agreement between capillary and venous samples. Patients reported a positive experience with home sampling using this microsampling technique.