1.   Various drugs have proved ineffective against the virus.

2.   He hopes the new drug will prove beneficial to many people.

3.   These drugs have proved effective in other chronic pain syndromes.

4.   Both drugs proved useful, but in limited contexts, said Chabner, who saw the hype about them when he worked at the NCI.

5.   A federal jury Wednesday absolved Biogen Corp. of allegations that the company misled shareholders by touting the prospects of an experimental drug that later proved disappointing.

6.   But drugs have proven a potent political fix.

7.   But it also hit hard times before many others, when its first-generation cancer drug, a monoclonal antibody, proved disappointing during extensive clinical trials.

8.   Despite the simplicity of the concept, anti-sense drugs have proved difficult to produce.

9.   For many people, the drugs prove too toxic, leading them to miss doses, and possibly promoting drug resistance.