Active Biotech AB thought it had found a suitable group of patients in its Phase II trials who would respond to its ETEC vaccine to treat enterotoxigenic E. coli-associated diarrhea in travelers. But following last week's failure of its Phase III trial, the company plans to pore through the new data to find a better population and better end points.

Meanwhile, the failure of ACTI's trial is a learning opportunity for Peptide Therapeutics Group plc, which last week finished Phase I trials of its own ETEC vaccine.