Outcomes Study: Implementing a Health-System Specialty Pharmacist-Led Pharmacogenomic Protocol for DPYD Genetic Testing to Optimize Capecitabine Safety

Members of our team had the opportunity to present a new poster abstract, "Implementing a Health-System Specialty Pharmacist-Led Pharmacogenomic Protocol for DPYD Genetic Testing to Optimize Capecitabine Safety", at the NASP 2025 Annual Meeting & Expo.

Authors:

Diana Nguyen, PharmD; Andrew Wash, PharmD, PhD; Ana Lopez Medina, PharmD, PhD; Casey Fitzpatrick, PharmD; Abbey Hunter, PharmD, CSP; Katie Jo Cash, PharmD, CSP; Kristin Hutchinson, PharmD, CSP; Jessica Mourani, PharmD

Background:

• DPYD gene variants can lead to a deficiency in dihydropyrimidine dehydrogenase, an enzyme involved in the breakdown of fluoropyrimidine-based chemotherapy agents (e.g., capecitabine) and increase the risk of severe adverse events 16-fold.¹
• Preemptive pharmacogenomic testing can mitigate these risks and is recommended to identify high-risk patients prior to therapy initiation.²
• Adoption is limited in the US due to challenges such as cost and reimbursement, inadequate healthcare training, and conflicting recommendations in clinical guidelines.³
• Health-system specialty pharmacy (HSSP) teams can play a key role in ensuring medication safety and optimal outcomes by confirming that pharmacogenomic testing was completed, when appropriate, prior to initiating medication.

Objectives:

• To describe an HSSP's role in a multidisciplinary protocol for preemptive pharmacogenomic testing of DPYD metabolizer status prior to capecitabine initiation.
  

Read about the team's findings by downloading the outcomes study below.

¹ De Mattia E, Silvestri M, Polesel J, et al. Rare genetic variant burden in DPYD predicts severe fluoropyrimidine- related toxicity risk. BiomedPharmacother. 2022;154:113644. doi:10.1016/j.biopha.2022.113644

² Chenchula S, Atal S, Uppugunduri CRS. A review of real-world evidence on preemptive pharmacogenomic testing for preventing adverse drug reactions: a reality for future health care. Pharmacogenomics J . 2024;24(2):9. doi:10.1038/s41397-024-00326-l

³ Virelli CR, Mohiuddin AG, Kennedy JL. Barriers to clinical adoption of pharmacogenomic testing in psychiatry: a critical analysis. Transl Psychiatry. 2021 Oct 6;11(1):509. doi: 10.1038/s41398-021-01600-7. PMID: 34615849; PMCID: PMC8492820.