Oregon Health & Science University (OHSU) will introduce new educational initiatives on the risks of prescribing the chemotherapy drug capecitabine to patients with DPD deficiency as part of a lawsuit settlement.
The settlement was reached with Joanne McIntyre, whose husband David died as a result of severe capecitabine toxicity. David carried variations in the gene DPYD, which encodes the DPD enzyme. DPD is involved in metabolism of fluoropyrimidine drugs, including capecitabine. Variants in DPYD, such as those that David carried, can inactivate the DPD enzyme, leading to DPD deficiency. Patients with DPD deficiency are unable to properly metabolize capecitabine and other fluoropyrimidines, and are at risk of experiencing severe drug toxicity. In David's case, this toxicity was fatal.
PharmGKB has annotations of several clinical guidelines for capecitabine and DPYD, including those from CPIC and the DPWG. These guidelines uniformly recommend either a dose reduction or selection of an alternative drug in patients with DPD deficiency.
OHSU will hold seminars to educate clinicians on the risks associated with DPD deficiency, how to identify severe capecitabine toxicity in patients and how to administer the antidote. They will also include a module on the topic in their fellowship program and provide a written resource guide to staff in their oncology department. Going forward, patients identified as candidates for capecitabine chemotherapy will be informed of the risks associated with DPD deficiency and, where appropriate, will be offered testing.
We at PharmGKB applaud Joanne's singular dedication to saving patients' lives and OHSU's commitment to implement these changes. Resources on capecitabine pharmacogenomics, including annotations on clinical guidelines for the use of DPYD genotypes in capecitabine prescribing, can be found at the PharmGKB capecitabine drug page.