Atazanavir (Reyataz)

Published June 23, 2003; Updated July 10, 2014
Susa Coffey, MD
http://hivinsite.ucsf.edu/InSite?page=ar-03-07
Selected References
1. Sanne  I, Piliero  P, Squires  K, Thiry  A, Schnittman  S; AI424-007 Clinical Trial Group.
Results of a phase 2 clinical trial at 48 weeks (AI424-007): a dose-ranging, safety, and efficacy comparative trial of atazanavir at three doses in combination with didanosine and stavudine in antiretroviral-naive subjects. J Acquir Immune Defic Syndr. 2003 Jan;32(1):18-29
[PubMed ID: 12514410]
Abstract:
Three dose levels of the protease inhibitor (PI) atazanavir (200, 400, and 500 mg once daily) were compared with nelfinavir (750 mg three times daily) when given both as monotherapy and in combination with didanosine and stavudine in 420 antiretroviral-naive subjects infected with HIV-1. Subjects received monotherapy for 2 weeks, followed by combination therapy for 46 weeks. After 48 weeks, mean change from baseline in HIV RNA (-2.57 to -2.33 log 10 copies/mL), the proportion of subjects with HIV RNA <400 copies/mL (56%-64%) and <50 copies/mL (28%-42%), and mean increases in CD4 cell count (185-221 cells/mm 3) were comparable across treatment groups. Diarrhea was two to three times more common in the nelfinavir group (61% of subjects) than in the atazanavir groups (23%-30% of subjects, <.0001 versus nelfinavir), and jaundice occurred only in atazanavir-treated subjects (6%, 6%, and 12% in the 200-, 400-, and 500-mg groups, respectively) ( <.03 for all atazanavir regimens vs. nelfinavir). Mean percent change from baseline in fasting low-density lipoprotein (LDL) cholesterol was significantly less in the atazanavir groups (-7% to 4%) than in the nelfinavir group (31%) ( <.0001). In conclusion, once-daily atazanavir is a potent, safe, and well tolerated PI that rapidly and durably suppresses HIV RNA and durably increases CD4 cell count in antiretroviral-naive subjects. Through 48 weeks, atazanavir was not associated with clinically relevant increases in total cholesterol, fasting LDL cholesterol, or fasting triglycerides. In comparison, nelfinavir was associated with prompt, marked, and sustained elevations in these parameters of a magnitude that suggests they are clinically relevant.
2. Murphy  RL, Sanne  I, Cahn  P, Phanuphak  P, Percival  L, Kelleher  T, Giordano  M.
Dose-ranging, randomized, clinical trial of atazanavir with lamivudine and stavudine in antiretroviral-naive subjects: 48-week results. AIDS. 2003 Dec;17(18):2603-14
[PubMed ID: 14685054]
Abstract:
OBJECTIVE: To compare the efficiency and safety of atazanavir and nelfinavir in antiretroviral-naive patients. DESIGN: Randomization to atazanavir 400 mg or 600 mg once daily; nelfinavir 1250 mg twice a day, plus lamivudine and stavudine. METHODS: A blinded (to the atazanavir dose), 48-week trial in patients with HIV-1 RNA > or = 2000 copies/ml, CD4 cell count > or = 100 x 10(6) cells/l. Primary end-point: change in HIV-1 RNA from baseline at 48 weeks. Secondary end-point: subjects with HIV-1 RNA < 400, and < 50 copies/ml, CD4 cell count changes, adverse events. RESULTS: The 467 randomized subjects had comparable baseline characteristics across treatments. With atazanavir 400 mg, 600 mg and nelfinavir, respectively, mean changes in HIV-1 RNA (log10 copies/ml) from baseline to 48 weeks were -2.51, -2.58, -2.31; HIV-1 RNA < 400 copies/ml [intent-to-treat population (ITT), non-completion = failure (NC = F)], 64%, 67%, 53%; HIV-1 RNA < 50 copies/ml (ITT NC = F), 35%, 36%, 34%; mean CD4 cell count increased comparably at 48 weeks (234 x 10(6), 243 x 10(6), 211 x 10(6) cells/l). Adverse events were similar across treatments with the exception of diarrhea (more frequent with nelfinavir) and jaundice (more frequent with atazanavir). Mean changes from baseline to 48 weeks were: fasting low density lipoprotein cholesterol, +5.2%, +7.1% and +23.2% (at 56 weeks) and fasting triglycerides (48 weeks), +7.2%, +7.6% and +49.5%, in the atazanavir 400 mg, 600 mg, and nelfinavir groups, respectively (P < 0.01, atazanavir versus nelfinavir). CONCLUSIONS: Atazanavir is a potent, safe, well tolerated, and effective once-daily protease inhibitor with low pill burden (two capsules/day). Lipid changes with atazanavir were significantly less than with nelfinavir, however, clinical significance of these finding in terms of decreased cardiovascular risk is unknown.