Efficiency or speed cannot be the only justification for complex or adaptive clinical trial designs, according to a key European regulatory committee.

Complex trial protocols should describe how the objectives specific to each sub-protocol contribute to the whole trial’s objectives, the Heads of Medicine Agencies (HMA) clinical trials advisory committee said in recommendations designed to get drugmakers and regulators thinking about the next evolution in drug development.

HMA is a network of the heads of regulatory authorities for drugs in the European Economic Area which collaborates with the European Medicines Agency and the European Commission.