A systematic review and meta-analysis of toxicity and treatment outcomes with pharmacogenetic-guided dosing compared to standard of care BSA-based fluoropyrimidine dosing

Background Serious and potentially life-threatening toxicities can occur following 5-fluorouracil/capecitabine exposure. Patients carrying Dihydropyrimidine Dehydrogenase (DPYD) variant alleles associated with decreased enzymatic function are at a greater risk of early/severe 5-fluorouracil/capecitabine toxicity. The objective of this systematic review/meta-analysis was to evaluate treatment outcomes between Pharmacogenetics Guided Dosing (PGD) versus non-PGD and within PGD (DPYD variant allele carriers versus wild type). Methods A systematic review/meta-analysis of original publications indexed in Ovid Medline, Ovid Embase, and the Cochrane CENTRAL (Wiley) library from inception to 7-Dec-2020. Eligible studies evaluated at least one pre-defined treatment outcome measures (toxicity/hospitalisations/survival/overall response/quality of life). Results Of 1090 identified publications, 17 met predefined eligibility criteria. The meta-analysis observed reduced incidence of grade 3/4 overall toxicity (Risk Ratio [RR] 0.32 [95% Cl 0.27-0.39], p < 0.00001) and grade 3/4 diarrhoea (RR 0.38 [95% Cl 0.24-0.61], p < 0.0001) among PGD versus non-PGD cohorts. Within PGD cohorts, there was no statistical differences for overall response rates (complete/partial) (RR 1.31 [95% Cl 0.93-1.85], p = 0.12). Similar results were found with stable disease (RR 1.27 [95% Cl 0.66-2.44], p = 0.47). Conclusion PGD improves patient outcomes in terms of grade 3/4 toxicity, in particular overall toxicity and diarrhoea, without impacting on treatment response. Registration number The study is registered with PROSPERO, registration number CRD42020223768.

Automated summary

Pharmacogenetics Guided Dosing (PGD) improves treatment outcomes by reducing the incidence of toxicities, particularly overall toxicity and diarrhea, without impacting treatment response in patients receiving 5-fluorouracil/capecitabine therapy.