A head-to-head comparison between two protease inhibitors found virtually no difference in treating very advanced cases of AIDS -- both achieved a mortality rate of only 9% after one year, according to Stefano Vella of the Instituto Superiore Di Sanita in Rome.

In Session B17 today, Vella will present the results of a clinical trial involving 1,300 patients with a mean CD4 count of 19, who were randomly assigned to receive either ritonavir or indinavir. The trial revealed more side effects associated with the ritonavir arm of the study, with more subjects dropping out. But this did not appear to significantly affect the endpoints of the clinical trial: AIDS events and death.

"This study was organised before HAART was widely available in Europe," Vella emphasised in an interview. He mentioned the study was designed so "the drugs could be added to treatment options if the patient had no other alternatives."

Due to ethical concerns, there was no comparative arm in which patients received no treatment. However, compared to other cohorts with similar CD4 levels, study participants did remarkably well. "I think we saved lives," Vella said. "There are two main points here. One is that even when the patients had been heavily pretreated, the protease inhibitors still worked. The other is that the two protease inhibitors were essentially similar in their effects."

this story can also be found in The Bridge, the onsite print newspaper

In the same session, Margaret Fischl of the University of Miami will report on a study in which three-drug combinations were compared with two-drug therapies for safety and efficacy. Abacavir (1592) combined with 3TC and ZDV was compared with a 3TC/ZDV combination in a randomised, double-blind clinical trial, in which 86 treatment-naive participants were placed on the two-drug regime, while 87 were given three drugs simultaneously. At 16 weeks, Fischl said, 75% of the abacavir group displayed suppressed HIV DNA, compared with 35% of the 3TC/ZDV cohort. "This suppression appeared to be distributed across the viral load at entry," Fischl stated.

Based on preliminary data, she said the three-drug regimen does reduce the growth of the virus, and the incidence of drug resistance appears low.

"This study will have implications for treatment-naive patients," Fischl indicated. "It shows for the first time that if you target HIV with [three nucleosides], you can suppress it." Fischl said this approach gives physicians and people with HIV additional regimens to try first, leaving other options including non-nucleoside reverse transcriptase inhibitors (NNRTI) or protease inhibitors, for the future.

Fischl noted that her 48 week study could only pinpoint relatively short-term effects; longer-range studies remain to be done.

back