High-resolution HLA genotyping and severe cutaneous adverse reactions in lamotrigine-treated patients.

BACKGROUND: Severe cutaneous adverse reactions (SCARs) are associated with over 200 medicines including lamotrigine, an antiepileptic drug. Previous studies have suggested the involvement of immune mechanisms in the development of drug-induced SCARs. METHODS: High-resolution HLA genotyping was performed for 65 patients of European ancestry treated with lamotrigine (22 cases with lamotrigine-induced SCARs and 43 controls on lamotrigine without SCAR-related symptoms). Association of HLA genetic variants with SCARs in these patients were evaluated by contrasting allele frequencies between the cases and the controls for each of 112 HLA four-digit alleles. RESULTS: Five alleles were observed with higher frequencies in the cases compared with the treated controls with exact P values less than 0.05. These include B*5801 (P = 0.037), previously reported to be associated with allopurinol-induced SCARs. Marginal association evidence was also observed for alleles Cw*0718 and DQB1*0609, both of which were strongly correlated with B*5801. Other alleles identified were A*6801 (P = 0.012) and DRB1*1301 (P = 0.045). In contrast to the study of carbamazepine-induced Stevens-Johnson syndrome in Han Chinese patients, none of the cases carried B*1502. Accounting for the large number of hypothesis tests conducted, none of the associations identified were statistically significant. CONCLUSION: No single major HLA-related genetic risk factor was identified for lamotrigine-induced SCARs in patients of European origin. Only suggestive evidence was obtained for B*5801, A*6801, Cw*0718, DQB1*0609, and DRB1*1301. Confirmation of these results in a larger, independent sample is needed to determine whether any of the HLA alleles identified are truly associated with the development of lamotrigine-induced SCARs.

Returning genetic research results to individuals: points-to-consider.

This paper is intended to stimulate debate amongst stakeholders in the international research community on the topic of returning individual genetic research results to study participants. Pharmacogenetics and disease genetics studies are becoming increasingly prevalent, leading to a growing body of information on genetic associations for drug responsiveness and disease susceptibility with the potential to improve health care. Much of these data are presently characterized as exploratory (non-validated or hypothesis-generating). There is, however, a trend for research participants to be permitted access to their personal data if they so choose. Researchers, sponsors, patient advocacy groups, ethics committees and regulatory authorities are consequently confronting the issue of whether, and how, study participants might receive their individual results. Noted international ethico-legal guidelines and public policy positions in Europe and the United States are reviewed for background. The authors offer 'Points-to-Consider' regarding returning results in the context of drug development trials based on their knowledge and experience. Theses considerations include: the clinical relevance of data, laboratory qualifications, informed consent procedures, confidentiality of medical information and the competency of persons providing results to participants. The discussion is framed as a benefit-to-risk assessment to balance the potential positive versus negative consequences to participants, while maintaining the integrity and feasibility of conducting genetic research studies.

Pharmacogenetics and pharmacogenomics in drug development and regulatory decision making: report of the first FDA-PWG-PhRMA-DruSafe Workshop.

The use of pharmacogenetics and pharmacogenomics in the drug development process, and in the assessment of such data submitted to regulatory agencies by industry, has generated significant enthusiasm as well as important reservations within the scientific and medical communities. This situation has arisen because of the increasing number of exploratory and confirmatory investigations into variations in RNA expression patterns and DNA sequences being conducted in the preclinical and clinical phases of drug development, and the uncertainty surrounding the acceptance of these data by regulatory agencies. This report summarizes the outcome of a workshop cosponsored by the Food and Drug Administration (FDA), the Pharmacogenetics Working Group (PWG), the Pharmaceutical Research and Manufacturers of America (PhRMA), and the PhRMA Preclinical Safety Committee (DruSafe). The specific aim of the workshop was to identify key issues associated with the application of pharmacogenetics and pharmacogenomics, including the feasibility of a regulatory "safe harbor" for exploratory genome-based data, and to provide a forum for industry-regulatory agency dialogue on these important issues.