1.   Approval is by no means certain, despite two rounds of late-stage clinical tests that appear to demonstrate the Serono drug works.

2.   Scientists have been trying to get a better picture of how the drug works.

3.   Some panel members said further studies are needed to prove the drug really works.

4.   Studies have shown that the drug works.

5.   The central question in the case was whether Burroughs could assert a patent claim before it knew whether the drug worked.

6.   The drug works by walling off the bacteria from the other cells, so that they cannot affect the rest of the body.

7.   The drug works by increasing levels of serotonin in the brain.

8.   She says younger users often expect the drug to work immediately although its affects can take up to an hour so they take more, which increases the risks.

9.   And frustrated federal regulators may not be able to tell if a drug works well enough to place on the market.

10.   And there was indirect evidence that the drug was working.