NEW DRUG APPROVALS: AEROSOL PENTAMIDINE, GANCICLOVIR, AND ERYTHROPOIETIN (EPO)

This month the FDA approved three drugs important in AIDS treatment.

Aerosolized Pentamidine

On June 15 the FDA gave full approval to LyphoMed Inc. of Rosemont, IL for marketing aerosolized pentamidine to prevent pneumocystis -- not only for patients who have already had pneumocystis, but also for anyone who has T-helper cell counts of 200 or less. The drug already had "treatment IND" status -- official approval for early release of a treatment for a serious or life- threatening condition -- but some insurance companies had used lack of final marketing approval as an excuse to deny reimbursement. The new approval announced this month should make it possible for many more patients to obtain the drug.

Ganciclovir

On June 26, Syntex Corporation of Palo Alto, CA announced that the FDA had approved ganciclovir for treatment of CMV retinitis in persons with AIDS or other immune deficiencies. This approval resulted from negotiated compromises to end the very difficult situation of this drug (see AIDS TREATMENT NEWS #71, December 16, 1988). This case, now hopefully behind us, made it much more difficult for persons with AIDS to receive compassionate use of other drugs.

The current approval will also allow physicians to prescribe ganciclovir for other CMV infections, such as colitis or pneumonia, although efficacy has not been officially established for these illnesses. Physicians may be reluctant to prescribe the drug for these "off label" uses, and insurance companies may refuse to pay.

The approval also removes an obstacle to research with other CMV treatments. Because it is unusual to get permission to use more than one experimental drug in the same trial, it would have been difficult to test other treatments such as foscarnet using ganciclovir as a control group. But since it was generally accepted that ganciclovir was effective, it was not ethical to use a placebo, either. Since no drug was approved for CMV, and yet one was generally known to work, it was not possible to have a control group for efficacy tests of any other potential treatments. The new approval should break this research deadlock.

Erythropoietin (EPO)

Because this treatment for anemia has been involved in complex contract and pricing disputes, the drug has two separate approvals at this time. One will make it available to some persons with AIDS at no cost. The other makes it available to any patient who needs it, for AIDS or other conditions, but the official indication is only for kidney disease, so insurance companies will probably refuse to pay for other patients under that program.

The AIDS-related approval is a "treatment IND" obtained by Ortho Pharmaceutical Corporation, for its brand of EPO, Eprex. According to Ortho, the treatment IND was granted after earlier trials showed that the drug reduced anemia, and eliminated the need for transfusions in two thirds of the patients using it. EPO is used to treat anemia caused by AZT, or anemia caused directly by HIV.

At this time the AIDS patients eligible to receive EPO under the treatment IND must have a hematocrit less than 30 percent, and less than 500 mu/ml of EPO in their blood. (EPO is a hormone found naturally in the body.) They must also be patients of one of the 30 physicians who are already part of Ortho's EPO program. The company plans to enroll other physicians later.

Meanwhile, any physician can prescribe EPO for any patient who needs it, under an earlier (June 1, 1989) full marketing approval given to Amgen Inc (a competitor of Ortho Pharmaceutical) for Epogen, its brand of EPO. But since the official approval for this brand is only for kidney disease, the cost of this very expensive drug will probably not be reimbursed when it is used to treat anemia from other causes.