Once you have
ordered your ToxNav test
The below schematic outlines the processes which take place after you place an order
1
- Patients offered fluoropyrimidine chemotherapy
- ToxNav test requested by clinician
2
- Blood sample taken (EDTA)
- Sample requisition form and blood sample sent to laboratory
3
- Sample and requisition form received and logged by laboratory
- DNA extracted
4
- Sanger sequencing carried out to detect genotype of 20 variants
- Data managed via secure server
5
- Results transmitted from lab to OCB analysis suite
- Data imported to ToxNav software
6
| Phenotype (genotype) | Implications for treatment | Dosing recommendations |
|---|---|---|
| Homozygous for wild-type allele, or normal, high DPYD activity | Normal DPYD activity 'normal" risk for toxicity | Use label-recommended dosage and administration |
| Heterozygous, or intermediate activity | Decreased DPYD activity increased risk for severe or even fatal drug toxicity | Start with at least a 50% dose reduction, followed by titration of dose based on toxicity cr pharmacokinetic test |
| Homozygous, or deficient activity | Complete DPYD deficiency increased risk for severe or even fatal drug toxicity | Select alternative drug |
7
- ToxNav Report received by clinician and risk category discussed with patient
- Personalised chemotherapy decision made