Social and scientific implications of pharmacogenetic testing

Abstract

Advances in pharmacogenetics (PGx) provide potential for expansion of the role of pharmacists and physicians to achieve precision medicine. The objectives of the research were to: i) assess the perception of pharmacists and physicians regarding PGx testing, ii) develop, disseminate and evaluate PGx information among pharmacists and physicians, and iii) compare PGx information in official product labelling between the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for oncology drugs. The methodology involved: i) Development, psychometric evaluation and dissemination of a self-administered questionnaire to assess awareness, attitudes, education and PGx testing in practice. The questionnaire was disseminated to pharmacists in all areas of practice and physicians practicing in oncology, cardiology, neurology, psychiatry, general and family medicine after ethics approval. Dissemination was undertaken: a) online via social media groups (pharmacists n=835, physicians n=984) and the mailing list of the Malta College of Family Doctors (n=198), b) personally by the researcher in community pharmacies, private clinics and at Mater Dei Hospital (n=135), and c) during two local medical conferences (n=60). ii) Development and validation of a tutorial Pharmacogenetics: A tool for precision medicine and evaluation form. The tutorial and evaluation form were disseminated online to pharmacists (n=835) and physicians (n=984) via social media groups and delivered as a live presentation during a workshop organised by the Malta Medicines Authority. iii) Identification of oncology drugs with PGx implications from the Government Formulary List with a ‘Testing required’ label annotation in Pharmacogenomics Knowledgebase and comparison of PGx information in the FDA drug label and EMA Summary of Product Characteristics (SmPC) of the identified drugs. Descriptive statistics for the questionnaire and evaluation form were performed and mean rating scores (1-lowest to 5-highest) were calculated for Likert-type questions. Results included: i) 292 complete responses - 179 pharmacists (64% female, 36% male) and 113 physicians (50% female, 50% male). Pharmacists (91%) and physicians (76%) were aware of the term ‘PGx testing’. Physicians (3.62) agreed more than pharmacists (3.31) that PGx testing is applicable in their practice (p=0.006). Pharmacists (1.93) and physicians (1.65) perceived themselves to be insufficiently competent in PGx testing (p=0.005). ii) The tutorial evaluation form was completed by 66 participants (57 online, 9 live presentation) - 33 pharmacists (25 female, 8 male) and 33 physicians (15 female, 18 male). Pharmacists agreed more than physicians that the material presented may help to improve the application of theory to practice (4.30/3.97, p=0.027) and enhance their skills in PGx (4.33/3.94, p=0.007). Pharmacists (4.45) are more likely to follow future tutorials on PGx than physicians (3.70) (p<0.001). iii) Differences in the presence of PGx information between the FDA drug label and EMA SmPC were identified for anastrozole, erlotinib, lenalidomide, rasburicase, tamoxifen, trametinib, and tretinoin. Pharmacists and physicians who participated in this study were aware of PGx, agreed that PGx is applicable in their practice and identified the need for further training. Participants recognised that PGx information presented in the tutorial has the potential to improve the clinical application of PGx. Differences in PGx information in official product labelling for oncology drugs point to the need for enhanced regulatory harmonisation.