The unanswered questions

WASHINGTON - The FDA Antiviral Drugs Advisory Committee deliberations last week about Hoffmann-La Roche's Invirase protease inhibitor included discussions beyond the immediate question of approval to broader issues relating to the ability and incentives to speed improved versions of the drug to patients.

One of the most serious concerns about Invirase (saquinavir) is the product's lack of bioavailability. Roche reported last week that the maximum bioavailability is 4 percent when the compound is taken just after a meal and declines to zero on an empty stomach. The company said it did not know how much or what kind of food would optimize bioavailability, so it advised consumption of a high fat meal prior to taking Invirase. ...