Adherence to international pharmacogenomic recommendations in pediatric cancer care: a cohort analysis embedded...

Pharmacogenomic (PGx) testing can optimize drug efficacy and minimize toxicity, but prescriber adherence to PGx recommendations remains unclear. We aimed to quantify clinician adherence to international PGx recommendations in a cohort of pediatric oncology patients.

We reviewed files of children with PGx recommendations generated through the MARVEL-PIC (NCT05667766) trial. Patients were included if ≥12 weeks had passed since their PGx report was released to clinicians. Prescribing events were identified for actionable and relevant PGx recommendations and classified as "explicitly followed," "inadvertently followed," or "not followed." Adherence was assessed by patient, drug, and recommendation.

2,063 PGx recommendations were available for 216 patients. Sixty‑four (3.1%) recommendations were actionable and relevant to 44 patients and 10 drugs within the 12-week study period. Recommendations were explicitly followed in 57/288 (19.8%) events, inadvertently followed in 145 (50.3%) events, and not followed in 86 (29.9%) prescribing events. Mercaptopurine demonstrated the highest explicit adherence (87.5%). No significant associations were observed between adherence and age group, disease group, drug type, or strength of recommendation.

Adherence to PGx recommendations was very low, highlighting a need to understand barriers to PGx implementation, increase education of healthcare professionals, and consider clinical decision support tools to facilitate adherence.