Promising Tools to Facilitate the Implementation of TDM of Biologics in Clinical Practice

At-home volumetric absorptive microsampling (VAMS) for anti-seizure medicines was feasible and reliable, with strong correlations to clinic VAMS and low bias for lacosamide, lamotrigine and levetiracetam; quantitative dried blood spot (qDBS) was a reliable alternative in the ambulatory setting, though older age reduced sampling quality.

Real-world evaluation of capillary microsampling for drug monitoring of anti-seizure medications — Cancellerini et al., Epilepsia (paywalled) · source ↗

• vams
• venous-agreement
• acceptability
• blood
• qdbs
• tdm
• self-collection
• dried
• capillary

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.

Clinical Application of Volumetric Absorptive Microsampling for Therapeutic Drug Monitoring of Oral Targeted Anticancer Drugs — Meertens et al., Therapeutic drug monitoring · source ↗

• vams
• volumetric
• venous-agreement
• acceptability
• blood
• tdm
• self-collection
• dried
• oncology
• capillary
• validation

VAMS microsampling found no significant difference from venous blood for tacrolimus in paediatric patients; samples were stable for 14 days, with average difference between paired at-home samples of 0.12 ± 0.94 ng/mL.

VAMS and parallel-reaction-monitoring mass spectrometry for tacrolimus trough measurements at home in paediatric heart-transplant patients — Zhao et al., J. Mass Spectrometry and Advances in the Clinical Lab · source ↗

• vams
• venous-agreement
• acceptability
• blood
• dbs
• tdm
• self-collection
• dried
• capillary
• pediatric
• immunosuppressants
• 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.

Clinical validation and feasibility of VAMS for monitoring of nilotinib, cabozantinib, dabrafenib, trametinib and ruxolitinib — Zimmermann et al., J. Pharmaceutical and Biomedical Analysis (paywalled) · source ↗

• vams
• venous-agreement
• acceptability
• blood
• tdm
• self-collection
• haematocrit
• dried
• oncology
• capillary
• validation

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.

Clinical Validation of Venetoclax Volumetric Microsampling in Leukemia, with Whole-Blood-to-Plasma Conversion and Self-Microsampling Feasibility — Levens et al., Clinical Pharmacokinetics (paywalled) · source ↗

• vams
• venous-agreement
• blood
• dbs
• tdm
• self-collection
• haematocrit
• dried
• oncology
• capillary
• validation