INTERNATIONAL experts in immunology and toxicity are being consulted in an attempt to understand better the unique set of symptoms showing in the drug trial victims.

As two of the men, one named as Ryan Wilson, 21, of Highbury, North London, continued to fight for their lives on life support machines, doctors said that the state of the other volunteers involved in the disastrous trial, run by the US firm Parexel, had improved slightly. Scientists told The Times, however, that the drug to blame, a monoclonal antibody, would be likely to remain in their systems for weeks, if not months.

The clinician in charge of their treatment at Northwick Park Hospital, northwest London, admitted that the exact nature of their conditions had not been encountered before. He said that international advice had been sought to help to work out the best way to proceed with their treatment.

The men suffered inflammation that then affected other parts of their bodies, including their internal organs, after they were injected with the novel drug TGN1412.

Raste Khan, one of the volunteers given a placebo, said: “They took blood samples from everybody. Then they dosed people at two-minute intervals. Roughly five minutes after everyone had been given the drug, the first person who was given the drug started to shake. He took his top off, he looked like he was burning up, and rubbed his head.

“Several minutes later, it missed me and went to the third person. He started doing similar things but he vomited on several occasions. He came back to consciousness but was hyperventilating. He looked like he was in the worst pain.

“Then No 4 went through similar symptoms. He took several steps and collapsed. He said, ‘I can’t control myself. I need to use the toilet.’ After that it was like a vomiting bath or something. Nurses had a big black liner for them to vomit in. People were fainting and coming back to consciousness. The gentleman on my left was screaming, saying his back was hurting. It was horrible.

“I feel guilty that I had the placebo. It was like Russian roulette. I was doing it for the money. But £2,000 is not worth your life.”

Ganesh Suntharalingam, the clinical director of intensive care, said that some symptoms were recognisable, but the combination was not.

He added that it was too early to say whether the men would make a full recovery. “There is an inflammatory process going on that seems to have been triggered by something,” he said. “That process started to affect other parts of the body so we have two jobs to do. One is to try to treat the inflammation and the other is to deal with the consequences of it.”

Times Recommends

• Time-worn Freddie gives up Test matches
• Brighton company 'involved in cyber attack'
• The art of survival: it's all in the mind