The program at St. Jude Children’s Research Hospital focuses on a group of patients seeking specialized care for relapsed acute childhood leukemia, a situation in which drug treatment regimens are complex and defined.58 The Vanderbilt PREDICT program uses algorithms derived from EHR data to identify patients “at risk” of receiving clopidogrel, warfarin, or simvastatin within the next three years.59 Each program generates genotypes at multiple known variant sites across multiple pharmacogenes, embeds variant data in the EHR, and develops clinical decision support that fires when a drug is prescribed to a patient with a variant. The Vanderbilt program reported that 91% of the first 10,000 subjects studied carried a potentially actionable variant for one of 5 drug-gene pairs, and that high-risk genotypes were present in 4.8% of subjects;60 these data argue for a preemptive multiplexed approach since even with only 5 drug-genes pairs, most subjects have some actionable variant for some drug.
