02/18/10

PRN Report from 17th CROI:  “Quad” 24-week Data

Information regarding the highly anticipated “quad” formulation of elvitegravir (EVG) boosted with cobicistat (GS-9350), tenofovir (TDF), and emtricitabine (FTC) was presented Wednesday at CROI 2010 in San Francisco by Dr. Calvin Cohen.

Dr. Cohen described the two ongoing, prospective studies evaluating the use of “quad.” One arm of the study focused on a comparison of “quad” with combination efavirenz/TDF/FTC (Atripla®) while the other evaluated the effect of GS-9350 boosting of a regimen of atazanavir (ATV) and FTC/TDF when compared with traditional boosting of this regimen with ritonavir (RTV). In previous studies, GS-9350 has been shown to boost levels of ATV to similar concentration as those achieved by traditional RTV boosting.

“Quad” was shown to have non-inferiority when compared to Atripla® in efficacy with a primary endpoint of HIV viral load of <50 copies/mL. “Quad” had a lower rate of study-related drug adverse events than Atripla®. Incidence of gastrointestinal toxicity, increases in triglycerides and cholesterol were evaluated at 24 weeks and found to be similar for both Atripla® and “quad.”

GS-9350 was found to have similar efficacy to RTV-boosted regimens of ATV. Both regimens achieve similar rate of virologic suppression at 24 weeks and were found to have a similar adverse effect profile. Of note, patients in the GS-9350 were found to have more episodes of increase in serum creatinine, which was thought to be secondary to GS-9350 inhibition of secretion of creatinine rather than actual decrease in glomerular filtration rate.

Both arms showed promising data for a new once-daily combination therapy for the treatment of HIV. Phase 3 trials of “quad” will commence in the spring.

Reference:
Calvin Cohen et al. Single-tablet, Fixed-dose Regimen of Elvitegravir/Emtricitabine/Tenofovir Disoproxil Fumarate/GS-9350 Achieves a High Rate of Virologic Suppression and GS-9350 Is an Effective Booster. Presented at 17th Conference on Retroviruses and Opportunistic Infections; San Francisco, CA. Oral Abstract 58LB.

Source: Reporting from San Francisco for PRN News: A.C. Demidont, DO