AIDS Drug DDC Inferior to AZT, Study Determines : Health: Disappointed manufacturer halts research a year early but says medication still shows promise when used in combination with other compounds.
When used alone, the experimental AIDS drug DDC is inferior to AZT, the standard medication used to treat the disease, according to a national study of more than 600 patients with AIDS and related conditions.
Researchers found that the death rate for patients receiving DDC, or dideoxycytidine, was so much higher than for those taking AZT that DDC’s manufacturer, Hoffman-La Roche of Nutley, N.J., halted the study Dec. 23, a year earlier than planned. Many AIDS experts and patients in the study are aware of the results, but a public announcement has yet to be made.
“We certainly had hoped that the results would be better. . . . We all want effective treatments but we can’t make this particular compound better than it is,” said Paul Oestreicher, a spokesman for Hoffman-La Roche. He said he was “in the process of putting together” a communication about the results.
Oestreicher said the disappointing results would not affect the company’s application with the U.S. Food and Drug Administration to market DDC for patients who are unable to take AZT and for use in combination with AZT. He said that the company is “still very excited about the compound.” The application was filed in October, 1991.
DDC has been highly touted since June, 1987, when federal researchers cited preliminary data at the Third International Conference on AIDS showing that the medication might be as effective as AZT but less toxic. Subsequently, DDC researchers have discovered significant side effects, such as a painful nerve condition known as peripheral neuropathy.
DDC is being used by about 6,000 AIDS patients under an expanded access program sponsored by Hoffman-La Roche. Almost all these patients had adverse reactions to AZT or failed to benefit from it.
The new study was a direct comparison of the two AIDS medications. Patients were randomly assigned to treatment with either DDC or AZT. Over the course of the study, there were 59 deaths in the 320 patients on DDC, compared to 33 deaths in the 315 patients on AZT. The median treatment time was 10.2 months for patients receiving DDC and 12.4 months for patients receiving AZT. All the patients were at comparable stages of the disease.
Patients on AZT also had greater increases in the number of T-4 cells in their blood. These are critical immune system cells that are destroyed by the human immunodeficiency virus, which causes AIDS.
Patients in the study are being offered the options of switching to AZT or staying on DDC, Oestreicher said.
A separate federally supported study involving more than 1,000 HIV-infected patients is under way to compare the combination of DDC and AZT to treatment with either drug by itself. Oestreicher said some patients in this study were continuing to be treated with DDC alone. He said it was possible that this would be re-evaluated.
A pilot study of 56 patients, published in the Annals of Internal Medicine earlier this month, found that the combination of AZT and DDC appeared promising.
AZT and another anti-AIDS drug, DDI, are the only medications approved by the FDA to treat the HIV infection. DDI, which was approved in October, 1991, is approved for patients who are unable to take AZT because of side effects such as anemia, or who get worse despite AZT treatment.
