21.   They are the first phases in the biggest programme of clinical trials ever undertaken.

22.   This will mostly be used in clinical trials, although some is expected to go to those with official medical approval.

23.   Until now, the drug was only available to people taking part in clinical trials.

24.   The drug must first be tested in clinical trials to see if it works on other cancers.

25.   They have been treated with this drug in clinical trials.

26.   Since then, Wellcome has been scaling up production to prepare for clinical trials.

27.   Two rival laser surgery systems are undergoing clinical trials in the U.S.

28.   The first clinical trials were expected to begin next year.

29.   Queensland heroin users will be able to detoxify rapidly on Naltrexone after a two-year clinical trial of the controversial drug begins in Brisbane this week.