AIDS TREATMENT NEWS Issue #214, January 6, 1995

On January 5, Syntex (a Palo Alto, California pharmaceutical company recently acquired by Hoffmann-La Roche) announced that the U.S. Food and Drug Administration had approved oral ganciclovir for marketing.

Ganciclovir (Cytovene() has long been an approved drug widely used for treating CMV retinitis, which if untreated causes blindness in persons with advanced AIDS. A major disadvantage of ganciclovir has been that it had to be given intravenously every day. In addition to the expense and inconvenience, the intravenous administration can increase certain side effects, including serious infections.

Treatment with ganciclovir involves two stages: induction therapy (usually twice-daily intravenous infusions for two to three weeks), followed by maintenance therapy, usually one infusion per day. Eventually the maintenance therapy is likely to fail; then the induction may be repeated, or the patient may be treated with another intravenous drug, foscarnet.

The newly-approved oral drug can be used for maintenance in some patients; however, intravenous treatment is still necessary for induction.

Maintenance with the oral drug is somewhat less effective than with the intravenous; in clinical trials, the average time to disease progression was five to twelve days faster with the oral drug. Therefore the FDA indicated oral ganciclovir only for those "for whom the risk of more rapid disease progression is balanced by the benefit associated with avoiding daily IV infusions." And many of the side effects of intravenous ganciclovir are still present with the oral drug, especially hematological toxicities; therefore blood tests are necessary with the oral as with the intravenous treatment.

Oral ganciclovir is taken either three times a day or six times a day, with food.