Precision Medicine

Precision Medicine

1. Definition, terminology & conceptual scope

• Precision medicine (used interchangeably with personalized medicine, stratified medicine, individualized medicine) capitalises on knowledge of an individual's molecular, genomic, cellular, clinical, behavioural, physiological, and environmental parameters to inform the prevention, diagnosis, and treatment of disease (Vogel 4e V4 Part XIX, Personalized Medicine, p.4235).
• Operationally, precision medicine is the discipline of delivering "the right drug, at the right dose, to the right patient, at the right time" — the primary mission of the clinical pharmacologist (Atkinson 4e Ch.36, pp.694–695).
  • The "right time" dimension includes both timing within a treatment course (e.g., the optimal sequence of therapies) and the temporal control of exposure (Atkinson 4e Ch.36, p.695).
• The past decade has "ushered in precision medicine, also known as stratified or personalized medicine, in which genetic information is used to guide drug and dosing selection for subgroups of patients or individual patients in medical practice" (Hibma & Giacomini, Pharmacogenomics ch., pp.77–78).
• Pharmacogenomics (PGx) forms the basis of precision medicine through the use of genetic information to select the right drug at the right dose at the right time, thereby tailoring therapy to optimise drug efficacy, promote adherence, and minimise side effects while reducing costs (Vogel 4e V4 Part XIX, p.4235).
• Boundary with pharmacogenetics/pharmacogenomics (the mechanistic discipline): pharmacogenomics is the mechanistic study of DNA/RNA variation as related to drug response (FDA definition; Shargel 8e Ch.21, p.1); precision medicine is the clinical framework that operationalises PGx plus biomarkers, multi-omics, companion diagnostics, real-world evidence, digital tools, and trial design into routine prescribing. Precision medicine is therefore broader than, and downstream of, pharmacogenetics.
• Precision medicine is aspirationally framed as P4 medicine — predictive, preventive, personalized, and participatory (Hood et al., cited in Vogel 4e V4 Part XIX, p.4236). This framing motivates a preemptive/predictive rather than purely reactive posture (see §6).
• The conceptual engine of precision medicine is stratification: replacing the "one-size-fits-all"/average-patient prescribing paradigm with treatment tailored to a molecularly or phenotypically defined subgroup (or individual) most likely to benefit and least likely to be harmed (Hibma & Giacomini, p.77; Atkinson 4e Ch.36, pp.696–697).
• Distinguish from adjacent terms:
  • Personalized medicine — historically the earlier synonym; some restrict it to individual-level care whereas "stratified medicine" denotes subgroup-level care; in FDA/clinical-pharmacology usage the terms are used interchangeably (Vogel 4e V4 Part XIX, p.4235; Hibma & Giacomini, p.78).
  • Precision dosing — the quantitative sub-discipline of getting the dose (not just the drug) right for the individual (§11).
  • Precision oncology — application of the framework to cancer, where somatic tumour molecular profile (not only germline genotype) drives drug choice (§9).