(AIDSmeds.com)—Early results from a 48-week clinical trial comparing Norvir® (ritonavir)-boosted Invirase® (saquinavir) to Kaletra® (lopinavir plus ritonavir) suggests that the protease inhibitors are potentially equal in terms of viral load reductions. The 24-week data, presented this week at the Eighth International Congress on Drug Therapy in HIV Infection (HIV-8) in Glasgow and highlighted in a press release from Hoffmann-La Roche, also indicate that patients taking Norvir-boosted Invirase are less likely to experienced elevated lipids than those taking Kaletra.

The GEMINI study is a 48-week Phase III clinical trial designed to compare standard twice-daily doses of Norvir-boosted Invirase and Kaletra, both combined with Truvada® (tenofovir plus emtricitabine) in 337 HIV-positive people starting HIV treatment for the first time. The primary goal, or endpoint, of the trial is to assess the number of patients with viral loads below 50 after 48 weeks of treatment.

The early study results, reflecting 24 weeks of data involving the first 150 patients enrolled, were presented at HIV-8 by Jihad Slim, MD, of St. Michael’s Medical Center in Newark.

After six months of treatment, approximately 75% of patients in the Kaletra group had viral loads below 50, compared to 68% of patients taking Norvir-boosted Invirase. The difference between the two groups was not statistically significant, meaning it could have been due to chance.

Of significant interest to Dr. Slim and his fellow study authors, 24 weeks of Norvir-boosted Invirase therapy was less likely to be associated with high cholesterol (greater than 200 mg/dL) or high triglyceride (greater than 400 mg/dL) levels compared to Kaletra. Only 4% of Norvir-boosted Invirase-treated patients developed high cholesterol compared to 25% of those taking Kaletra. Similarly, only 1% of those in the Invirase group had high levels of triglycerides, compared to 9% of those in the Kaletra group. These differences between the two groups were statistically significant.

Dr. Slim also noted fewer gastrointestinal side effects among those treated with Norvir-boosted Invirase (14%) compared to those taking Kaletra (23%).

Final 48-week data from the GEMINI study will be presented in the future.