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Oxford Cancer Biomarkers announces European expansion of chemotherapy toxicity test & independent real-world evidence of patient benefit

ToxNav®, a CE-marked in vitro diagnostics product is now registered in the European database on medical devices (EUDAMED). 

Independent study publication highlights patient benefits, cost-savings and opportunity for ToxNav® to address potential health inequalities in current approaches to DPYD testing.

OXFORD, UK – 26th September 2022 – Oxford Cancer Biomarkers Ltd (OCB) announces that ToxNav®, its proprietary pharmacogenomics test for predicting genetic susceptibility to toxicity from fluoropyrimidine-based chemotherapy, is now available to clinicians in Europe following registration in the EUDAMED database.  The European Medicines Agency recommends DPYD testing before all fluoropyrimidine-based chemotherapy (including 5-FU, Capecitabine and tegafur).

OCB also reports publication of an independent study by Oxford University Hospitals NHS Trust and Oxford University, representing the first evidence in the real world setting that upfront screening for DPYD variants using ToxNav® can help reduce the risk of potentially life-threatening toxicity and side-effects that negatively impact quality of life and tolerance to treatment. ToxNav® testing and dose management as guided by the ToxNav® test report can also lead to substantial hospital cost savings for cancer patients treated with fluoropyrimidine chemotherapy, including over £20,000 of cost savings for those with critical toxicity risk.

The results of the analysis are published in BMC Cancer.

The Clinical Pharmacogenetics Implementation Consortium (CPIC) currently recommends testing of four variants of the DPYD gene.  However, at least 40–50% of patients continue to have severe toxicity after 5-FU or Capecitabine even if they test negative for the four CPIC variants.  The four CPIC variants are also predominantly found in Caucasian populations and variants more prevalent in populations of African descent are less represented, raising ethical questions about health inequalities.

ToxNav® tests for 20 variants, including those linked with the most critical toxicity risks which are not included in the CPIC recommendations. The expanded ToxNav® panel gives broader coverage of variants more prevalent in non-Caucasian populations and of those that materially impact patient quality of life and adherence to treatment, such as hand foot syndrome.

Results from this real-world study indicate that upfront testing with ToxNav® appears to reduce the toxicity burden of Capecitabine and 5-FU in cancer patients and can lead to substantial hospital cost savings.  The study also indicates that ToxNav® may have prevented a proportion of the non-cardiac chemotherapy-related deaths through better toxicity management.  In addition, participants in the ToxNav® group had a reduced likelihood of experiencing pain for more than 4 days a week (50% less).  OCB will investigate this real-world finding further through its focus on the impact of chemotherapy treatment on quality of life.

Internationally renowned Prof David Kerr CBE, oncologist and co-founder of OCB commented
“We are delighted that ToxNav® is now available to our colleagues in Europe and it is exciting to see independent confirmation of the value of ToxNav® in real-world clinical practice.  By taking a broader approach to testing of genetic variants, as clinicians we can offer our patients a more robust test that can help guide treatment decisions which directly impact the most serious life-threatening side-effects and important quality-of-life choices. Crucially, we can also start to address the inequalities in toxicity burden among cancer patients of different ethnic backgrounds.”

About Fluoropyrimidine-based chemotherapy
Treatment with chemotherapies is a complicated balance between maximising effectiveness while minimising the effects of toxicity on the patient.  Fluoropyrimidines are chemotherapy drugs used to treat numerous cancers (including breast, colorectal and gastric cancers) but cause severe or life-threatening adverse effects for around 10-40% of treated patients. These effects include nausea, vomiting, diarrhoea, inflammation of the mouth and gut, low white blood cells (neutropenia) and death.

Patients with rare gene variants in the dihydropyrimidine dehydrogenase (DPYD) enzyme are significantly more likely to experience these adverse effects because they metabolise fluoropyrimidine-based chemotherapy drugs more slowly and between 0.5 and 2% of people will die from genetic susceptibility to 5-FU.  Testing for the presence of these DPYD gene variants before patients start fluoropyrimidine-based chemotherapy enables clinicians to reduce the dose or select alternative therapies for these patients.

About ToxNav®
ToxNav® is a genetic test that detects variants in the DPYD and TYMS/ENOSF1 genes and uses proprietary software to analyse the combination of variants, generating a clinical report that clinicians can use to guide management of treatment dose decisions for fluoropyrimidine-based chemotherapy.  The second generation ToxNav® test, launched in August 2020, includes all four genetic variants of DPYD recommended in the CPIC clinical guidelines in 2018, along with 15 additional variants in DPYD and one in ENOSF1.  Oxford Cancer Biomarkers has an active discovery pipeline to constantly assess important additional variants that should be incorporated into the ToxNav® test to ensure the most robust panel is made available to patients.

About Oxford Cancer Biomarkers Ltd (OCB)
Oxford Cancer Biomarkers is a spin-out from the University of Oxford, developing and commercialising a suite of AI-enabled diagnostic tools that harness the analytical capabilities of digital pathology and pharmacogenomic markers to optimise cancer treatment pathways.  The company has built a world class team consisting of industry professionals, leading scientists and oncologists and has launched two products – ToxNav® and OncoProg® – into global markets.  OCB continues to expand its portfolio with novel biomarkers and proprietary algorithms that enable clinicians to make personalised treatment recommendations based on real-world evidence and empower patients to make better-informed decisions about their own cancer therapy.

Contact details
Oxford Cancer Biomarkers Ltd   Tel:  +44 1865 784743
Enquiries:   Joanna Smart – Executive Chair
For more information please visit the Oxford Cancer Biomarkers’ website at

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