On 13 March, at Northwick Park Hospital in London, six healthy men were given a drug that was being tested on humans for the first time. Within hours they were suffering a drop in blood pressure, swellings and excruciating pain, and were soon admitted to intensive care. Graham Easton looks at the future of drug trials following the catastrophe of TGN1412. Will research into such sophisticated drugs be halted because of these adverse effects, or can we learn and adapt future drugs so that events like this never happen again? Repeated from Tuesday