Evidence-Based Impact

Clinical Use Cases

Real-world evidence and landmark studies demonstrating how pharmacogenomics improves clinical outcomes.

30%

Reduction in adverse drug events

40%

Fewer medication switches

$1,700

Average savings per patient/year

99%

Of people carry actionable variants

Sources: PREDICT Study, St. Jude PG4KDS, PREPARE Trial

Landmark Clinical Studies

Vanderbilt PREDICT Program

10,000+ patients • Ongoing since 2010

One of the first large-scale preemptive PGx programs. Integrated genetic testing into EHR with clinical decision support alerts.

Key Findings:

  • • 91% of patients had ≥1 actionable gene-drug interaction
  • • Clopidogrel: 25% reduction in cardiovascular events in guided group
  • • Simvastatin: Significant reduction in myopathy risk

St. Jude PG4KDS

Pediatric Oncology • Since 2011

Pharmacogenomics for Kids Drug Safety program. Preemptive testing for all pediatric cancer patients to prevent adverse events.

Key Findings:

  • • TPMT testing: Prevented severe myelosuppression from thiopurines
  • • NUDT15 variants identified in Asian populations
  • • Model for pediatric PGx implementation nationwide

PREPARE Study (EU-PACT)

6,944 patients • 7 European Countries • 2023

Largest randomized controlled trial of preemptive PGx testing. 12-gene panel across multiple therapeutic areas.

Key Findings:

  • 30% reduction in adverse drug reactions
  • • Clinically significant across all drug categories
  • • Cost-effective implementation demonstrated

Mayo Clinic RIGHT Protocol

Right Drug, Right Dose, Right Time

Integrated PGx testing into primary care workflow. Demonstrated feasibility of large-scale implementation in routine practice.

Key Findings:

  • • 99% of patients had ≥1 actionable PGx variant
  • • EHR alerts led to 80%+ prescriber adherence
  • • Successful integration into routine workflow

Real Clinical Scenarios

Major Depressive Disorder

Patient failed 3 SSRIs over 18 months with intolerable side effects or lack of efficacy.

PGx Finding

CYP2D6: Ultra-rapid metabolizer

Patient metabolizes standard doses too quickly, never reaching therapeutic levels.

Clinical Action

Switched to escitalopram (CYP2C19-metabolized)

Achieved remission within 8 weeks

Post-Stent Antiplatelet Therapy

62-year-old patient receiving coronary stent. Standard protocol: clopidogrel 75mg daily.

PGx Finding

CYP2C19: *2/*2 (Poor Metabolizer)

Cannot activate clopidogrel prodrug. High risk of stent thrombosis.

Clinical Action

Prescribed ticagrelor (not CYP2C19 dependent)

No cardiovascular events at 1 year

Post-Surgical Pain

Patient scheduled for knee replacement. Opioid-based pain management planned.

PGx Finding

CYP2D6: *1/*1xN (Ultra-rapid)

Rapidly converts codeine → morphine. High risk of respiratory depression.

Clinical Action

Avoided codeine/tramadol. Used morphine with careful dosing.

Safe, effective pain control achieved

Colorectal Cancer Chemotherapy

58-year-old patient starting 5-fluorouracil (5-FU) based chemotherapy regimen.

PGx Finding

DPYD: *2A heterozygous

Reduced DPD enzyme activity. High risk of severe/fatal fluoropyrimidine toxicity.

Clinical Action

Started at 50% dose reduction per CPIC guidelines

Completed therapy without severe toxicity

HIV Antiretroviral Therapy

New HIV diagnosis. Abacavir-containing regimen being considered.

PGx Finding

HLA-B*57:01: Positive

5-8% risk of severe, potentially fatal hypersensitivity reaction to abacavir.

Clinical Action

Abacavir contraindicated. Alternative NRTI selected.

Hypersensitivity reaction prevented

Peer-Reviewed Evidence

Lancet (2023)

PREPARE study demonstrated 30% reduction in clinically relevant adverse drug reactions with preemptive PGx panel.

Swen et al., Lancet 2023;401:1085-1095

JAMA (2019)

CYP2C19-guided antiplatelet therapy reduced major cardiovascular events in acute coronary syndrome patients.

Claassens et al., JAMA 2019;322:1-8

Clin Pharmacol Ther (2021)

CPIC guidelines now cover 25+ gene-drug pairs with evidence-based dosing recommendations.

Relling et al., Clin Pharmacol Ther 2021

NEJM (2008)

HLA-B*57:01 testing before abacavir virtually eliminated hypersensitivity reactions in HIV patients.

Mallal et al., N Engl J Med 2008;358:568-79

Genet Med (2022)

Economic analysis showed PGx-guided prescribing saves $916-$4,382 per patient over 5 years.

Verbelen et al., Genetics in Medicine

J Clin Psychiatry (2020)

PGx-guided antidepressant selection improved remission rates by 50% in treatment-resistant depression.

Greden et al., J Clin Psychiatry

The evidence is clear: pharmacogenomics improves outcomes and reduces harm.

Clinician Resources