AEROSOL PENTAMIDINE, GANCICLOVIR RECOMMENDED FOR APPROVAL

On May 1 an advisory committee of outside experts set up by the Food and Drug Administration recommended full new-drug approval for aerosol pentamidine, used for prevention of pneumocystis. The next day, the committee recommended similar approval for ganciclovir (DHPG) for treating CMV retinitis. Official approvals are expected within several weeks or months.

What will be the practical effect of these approvals of drugs which have already been available under a variety of arrangements?

For aerosol pentamidine, full approval will help with insurance reimbursement. Until now, some insurance companies and government agencies have refused to pay for the treatment, claiming that it was "experimental". Others have paid, since the cost of preventing pneumocystis with aerosol pentamidine is far less than the cost of treating it in a hospital. It is widely suspected that companies which refused to pay have calculated that they could save money in the long run by having their clients die.

For ganciclovir, approval will allow the manufacturer to charge for the drug, currently provided free under a treatment IND. We do not know what the price will be. Insurance presumably will pay since the drug will be approved, but many do not have insurance, or do not have policies which cover prescription drugs.

One advantage of the approval is that physicians will be allowed to use ganciclovir to treat CMV infection in the intestines or elsewhere besides the retina, even though the FDA approval will not specifically cover such use. Physicians may be reluctant to prescribe for such "unlabeled" uses, however, and insurance companies may refuse to pay.

Another advantage of the approval of ganciclovir is that it will now become possible to conduct a trial to compare this drug directly with foscarnet for treating CMV retinitis, a trial specifically recommended by the advisory committee. Until now such a trial has been blocked by the prohibition against using more than one "experimental" drug in the same study.