PI Perspective #19

September 1996     View PDF

Cidofovir Approved

On June 26, 1996 the Food and Drug Administration (FDA) approved Cidofovir (Vistide) for the treatment of CMV retinitis. Cidofovir is administered intravenously once every two weeks. This is an advantage over other systemic therapies (drugs that have activity throughout the body) because people do need a surgically implanted catheter, which is often a source for bacterial infections. It is still unknown whether cidofovir will be effective against CMV outside the eye.

Cidofovir has activity in test tubes against CMV, herpes viruses, including zoster, Epstein-Barr virus and human papilloma virus. It is also active against CMV which is resistant to either ganciclovir or foscarnet, but is unlikely to be active against CMV which is resistant to both.

While no studies have compared cidofovir to approved CMV therapies such as ganciclovir or foscarnet, results from the studies that have been conducted are encouraging. Approval of cidofovir was based on two studies showing that immediate cidofovir therapy can delay CMV progression. Additionally, one of the studies found that 5mg/kg of cidofovir was significantly better than a 3mg/kg dose. The 5mg/kg dose is recommended for the treatment of CMV retinitis.

Cidofovir is an attractive alternative to other systemic CMV therapies for the treatment of CMV retinitis. It will certainly provide a better quality of life with the reduced dosing schedule and the fact that a surgically implanted catheter will not be required. However, cidofovir will have to be used cautiously because of the potential for serious kidney toxicity.

Gilead Sciences, the developers of cidofovir, has set up a Patient Assistance Program (1-800-445-3235) for people with no insurance or have questions regarding reimbursement.