2024 · International journal of molecular sciences · open access
Quantification of Letrozole, Palbociclib, Ribociclib, Abemaciclib, and Metabolites in Volumetric Dried Blood Spots: Development and Validation of an LC-MS/MS Method for Therapeutic Drug Monitoring
Cecchin et al.
The finding, in our words
An optimised LC-MS/MS method for quantifying letrozole, CDK4/6 inhibitors and metabolites in volumetric dried blood spots showed acceptable accuracy, precision and haematocrit independence. The method supports home sampling and includes conversion models to estimate plasma concentrations, making decentralised therapeutic drug monitoring feasible for oncology patients.
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.
Levens et al., Clinical Pharmacokinetics (paywalled) · source ↗
A 2025 review maps 28 microsampling devices, from dried spots and volumetric absorptive tips to upper-arm liquid capillary collectors, and names what a laboratory must control before their results are used: the haematocrit effect in non-volumetric dried samples, interstitial fluid from finger milking, volume, haemolysis and transport stability. Regulators on both sides of the Atlantic ask for the same two things, a device the patient can use safely and a sample fit for the test.
LC-MS/MS measurement of imatinib and its active metabolite from volumetric dried blood spots collected via HemaXis DB10 and Capitainer B demonstrated analytical precision across hematocrits from 22% to 55% alongside 43-day ambient stability. Clinical evaluation across 52 paired samples showed high agreement with plasma concentrations, verifying both devices as reliable options for decentralised therapeutic drug monitoring.
Orleni et al., Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (paywalled) · source ↗
An LC-MS/MS assay accurately quantified osimertinib and its active metabolites from volumetric dried blood spots collected with the hemaPEN device across a 30% to 60% haematocrit range. Drug levels in dried blood spots showed high concordance with plasma measurements in non-small cell lung cancer patients, with dried spots demonstrating superior room-temperature stability over ten days compared with plasma.
Venkatesh et al., Therapeutic drug monitoring · source ↗
Microsampling reduces sample volume, invasiveness, logistics and biohazard risk while improving stability and enabling at-home self-sampling, yet clinical adoption remains slow and requires standardisation and harmonisation to realise its patient-centric and decentralised potential.
Thangavelu et al., Analytical science advances · source ↗