European and international experts debate subgroup analysis at EMA workshop

The European Medicines Agency last week assembled for the first time some 50 experts in subgroup analysis from Europe and the USA, in a one-day scientific workshop. The experts included representatives from regulatory authorities, a health technology assessment agency, academia and pharmaceutical industry, and discussed standards and methodology for the planning, conducting and reporting of subgroup analysis.

Subgroup analyses are an important tool in the assessment of confirmatory trials in marketing authorization applications, and appropriate statistical methods are key for a sound clinical interpretation of subgroup results, says the EMA. Subgroup analyses are used for assessment of internal consistency, to try to identify patient groups with the most favourable benefit-risk profile or to try to rescue trials that 'fail' based on the full analysis. Subgroups may be pre-specified in the trial protocol, based on demographic, genomic or disease characteristics (eg, sub-entities of a disease that are widely recognized within the medical community) or may materialize based on a need or desire to further explore study results.

CHMP preparing guideline