Concerns about regulatory acceptance are the biggest barrier to the implementation of adaptive clinical trials, according to a global survey run by Perceptive Informatics.

The eClinical subsidiary of US-based contract research organisation (CRO) Parexel conducted the survey during a recent webinar, organised with statistical specialist and partner Cytel, on ‘Optimising Adaptive Trial Designs: Using Simulation Methodologies to Overcome Challenges’. More than 500 biopharmaceutical professionals, covering a broad range of clinical, statistical and regulatory functions, were in attendance.

Adaptive trial designs allow sponsors to adjust parameters such as dose selection or sample size in the light of accumulating safety or efficacy data. The aim is to accelerate clinical development and improve its efficiency, better target experimental therapies to responsive patient groups, and reduce the number of patients exposed to inappropriate or ineffective drugs.

The US Food and Drug Administration (FDA) referred to adaptive designs in its March 2004 paper setting out a ‘Critical Path’ for accelerating and streamlining medical product development. The FDA subsequently committed to issuing draft guidance on adaptive trials, although this has yet to emerge after nearly three years of waiting.

Among the respondents to the Perceptive Informatics survey – who could choose more than one type of stumbling block to adaptive trials – more than 35% cited regulatory acceptance concerns as a barrier, over 33% blamed lack of understanding of new techniques, and more than 28% saw rapid access to clinical endpoint data as a problem.

Other barriers cited by the respondents included understanding and implementing complex statistical methodologies, as well as difficulties with supply chain management and estimating medication supplies.

“Formal FDA guidance on adaptive trials implementation is expected later this year and should help to alleviate regulatory acceptance concerns,” commented Dr Bill Byrom, senior director, product strategy for Perceptive Informatics.