TORONTO, Aug. 17  -- This month, The Lancet published results of a study showing that HIV regimens using LEXIVA (Telzir) Tablets+ritonavir or Kaletra (lopinavir/ritonavir) Capsules both given twice-daily had comparable (non-inferior) efficacy and tolerability in adults who had no previous exposure to HIV medicines. Parts of this study were also presented at this week's International AIDS Conference in
Toronto, Canada.

The publication of the 48-week clinical study known as KLEAN (Kaletra vs. LEXIVA with Epivir(R) (lamivudine) and Abacavir in ART-Naive patients) was announced today by GlaxoSmithKline and Vertex Pharmaceuticals Incorporated, the companies that co-discovered LEXIVA. LEXIVA is indicated for the treatment of HIV infection in adults in combination with other antiretroviral medications. Once-daily administration of LEXIVA/r is not recommended for PI-experienced patients.

"Protease inhibitors continue to be a key component of antiretroviral therapy and this new information reinforces the efficacy and safety of LEXIVA/r for treatment-naive patients with HIV," said Joseph Eron, Jr., MD, Professor of Medicine, Division of Infectious Diseases, University of NorthCarolina at Chapel Hill.

Study Explained
he publication reported results from the KLEAN study, a randomized, open-label, multicenter, international phase IIIb trial comparing LEXIVA/r twice-daily to lopinavir/r twice-daily in treatment-naive patients. The study included 878 patients with HIV-1 RNA (vRNA) greater than or equal to 1,000 copies/mL (c/mL) and any CD4+ cell count during the pre-trial screening. Patients were randomized to receive either LEXIVA/r or lopinavir/r twice daily, administered with EPZICOM(TM) (abacavir/lamivudine) once daily, with 434 patients in the LEXIVA/r arm and 444 in the lopinavir/r arm.

Primary endpoints were the proportion of subjects with vRNA <400 c/mL at week 48 and treatment discontinuations due to adverse events. These results were analyzed according to intent to treat xposed TLOVR (Time to Loss of Virologic Response). Protocol-defined virologic failure was defined as failure to achieve HIV RNA <400 c/mL by week 24 or confirmed rebound greater than or equal to 400 c/mL. Seventy-seven percent of the patients (676) completed the study, with 12 percent and 10 percent of patients discontinuing treatment due to adverse events in the LEXIVA/r and Kaletra arms, respectively.

LEXIVA/r administered twice-daily was shown to be non-inferior to lopinavir/r given twice-daily over 48 weeks. At 48 weeks 73 percent (315) of the patients treated with LEXIVA/r achieved vRNA <400 c/mL, and 71 percent (315) of the patients in the lopinavir/r arm achieved this measurement by week 48. At 48 weeks 66 percent (285) of the patients treated with LEXIVA/r and 65 percent (288) of the lopinavir/r patients achieved vRNA <50 c/mL. The median CD4 cell increase in patients at 48 weeks was 176 c/mL in patients who received LEXIVA/r and 191 c/mL in patients who received lopinavir/r.

The most frequently reported drug related Grade 2 - 4 adverse events reported in the study included diarrhea (13 percent, 11 percent), nausea (6 percent, 5 percent) and abacavir hypersensitivity reaction (6 percent, 4 percent) in the study arms containing LEXIVA/r and lopinavir/r, respectively. Similar increases in fasting lipid values were also observed in both regimens. Adverse events in this study were consistent with thosedescribed in the product information for LEXIVA and Kaletra.