A prospective, randomized trial of structured treatment interruption for patients with chronic HIV type 1 infection.

BACKGROUND: Structured treatment interruption was evaluated in 74 patients who had been pretreated with antiretrovirals, consisting of 2 nucleoside reverse-transcriptase inhibitors (NRTIs) for 1 year followed by 3 years of highly active antiretroviral therapy containing a protease inhibitor. METHODS: Patients with a CD4 cell count of > or =350 cells/microL and a plasma viral load of <50 copies/mL were randomized to 3 therapy arms: (1) continuous therapy, (2) CD4 cell count-guided theory, and (3) week-on/week-off (WOWO) therapy. The efficacy and safety of structured treatment interruption and antiretroviral use were evaluated in human immunodeficiency type 1 (HIV-1)-infected patients. The study end points were percentage of patients who developed AIDS or who died and a CD4 cell count of > or =350 cells/microL. Intergroup differences were analyzed using analysis of variance and Kruskal-Wallis tests. RESULTS: Baseline characteristics at the start of the structured treatment interruption were similar. At week 48, no patient had died, and 1 patient in the WOWO group had an AIDS-defining condition. The proportions of patients with a CD4 cell count of > or =350 cells/microL were 100%, 87%, and 96% in treatment arms 1, 2, and 3, respectively. The percentages of weeks of antiretroviral use were 100%, 41.1%, and 69.8% in arms 1, 2, and 3, respectively. The adverse events were not significantly different among arms (P=.27). Thirty-one percent of patients in the WOWO group experienced virological failure. CONCLUSION: WOWO therapy maintained a CD4 cell count of > or =350 cells/microL in almost all patients but was associated with high virological failures rates (possibly resulting from previous dual-NRTI therapy), indicating that this strategy is less useful. Receipt of CD4 cell count-guided therapy resulted in comparable clinical outcomes to continuous therapy and may save antiretroviral-associated costs, but this needs to be confirmed by a larger trial.

Pharmacokinetics of lower doses of saquinavir soft-gel caps (800 and 1200 mg twice daily) boosted with itraconazole in HIV-1-positive patients.

OBJECTIVE: The pharmacokinetics of 800 mg and 1200 mg of saquinavir soft-gel caps (SQV-SGC) twice daily plus 100 mg itraconazole once daily were compared to 1400 mg SQV-SGC twice daily without itraconazole. METHODS: The pharmacokinetics of SQV were determined in 17 randomly selected patients on 1400 mg twice daily SQV-SGC without itraconazole and after 2 weeks with lower SQV-SGC doses plus itraconazole. SQV plasma concentrations were determined by HPLC. Pharmacokinetic parameters were calculated by a non-compartmental model. RESULTS: Median (+IQR) area under plasma concentration-versus-time curve (AUC0-12h) were 3.33 (1.96-7.34), 4.29 (3.14-7.67) and 4.07 (2.76-4.49) mg/l x h for SQV 1400 mg without itraconazole, SQV 1200 mg with itraconazole and SQV 800 mg with itraconazole, respectively. These differences were not statistically significant. The median Cmin was above the proposed minimum effective concentration of 0.05 mg/l for all three regimens. CONCLUSION: SQV-SGC 800 mg or 1200 mg twice daily boosted with 100 mg of itraconazole once daily resulted in adequate SQV pharmacokinetics not significantly different from SQV-SGC 1400 mg twice daily.

Pharmacokinetics of once-daily saquinavir hard-gelatin capsules and saquinavir soft-gelatin capsules boosted with ritonavir in HIV-1-infected subjects.

OBJECTIVE: To investigate the pharmacokinetics of once-daily saquinavir (SQV) hard-gelatin capsule (HGC)/ritonavir (RTV), 1600/100 mg, compared with once-daily SQV soft-gelatin capsule (SGC)/RTV, 1600/100 mg. METHODS: We evaluated 13 randomly selected HIV-1-infected subjects taking once-daily SQV SGC/RTV, 1600/100 mg, plus dual nucleoside reverse transcriptase inhibitors (NRTIs) in this pharmacokinetic (PK) substudy. Subjects took 1 week of SQV HGC/RTV and NRTIs, followed by steady-state SQV PK determinations. Subjects then changed to SQV SGC/RTV and NRTIs for 1 week, followed again by steady-state SQV PK determinations. Area under the plasma concentration versus time curve (AUC), maximum concentration (C(max)), minimum concentration (C(min)), time to C(max), and elimination half-life were calculated. RESULTS: There was no significant difference in AUC values between HGCs and SGCs, with a median (plus interquartile range [IQR]) of 50.0 (42.6-71.5) versus 35.5 (28.0-50.2) mg/L/h, respectively ( =.056). Intersubject variability resulted in 4 of 13 subjects on the SQV SGCs and 2 of 13 subjects on the SQV HGCs having a C(min) below the minimum effective concentration of 0.05 mg/L. CONCLUSION: Once-daily SQV HGCs, 1600 mg, boosted with once-daily RTV, 100 mg, resulted in PK parameters that were similar to those observed with 1600 mg of SQV SGC/100 mg RTV once daily. Once-daily SQV HGC/RTV, 1600/100 mg, may be easier to use in developing countries and may increase access where drug costs can be less, the capsule size is smaller, and the need for refrigeration is lessened.

Simplifying protease inhibitor therapy with once-daily dosing of saquinavir soft-gelatin capsules/ritonavir (1600/100 mg): HIVNAT 001.3 study.

OBJECTIVE: To determine the feasibility of switching therapy for HIV-1-infected patients with plasma viral loads of <50 HIV-1 RNA copies/mL who are receiving twice-daily saquinavir soft-gelatin capsules (SQV-SGC) plus dual nucleoside reverse transcriptase inhibitors (NRTIs) to a regimen containing once-daily SQV-SGC/ritonavir (RTV). DESIGN: Therapy for patients with plasma viral loads of <50 copies/mL after 2 years of treatment with twice-daily SQV-SGC (1400 mg) plus zidovudine/lamivudine or didanosine/stavudine was switched to once-daily SQV-SGC/RTV (1600/100 mg) with continuing NRTI treatment. METHODS: Safety and efficacy (determined by plasma viral load and CD4 cell count) were evaluated (week 24). For 12 patients, steady-state plasma pharmacokinetics of SQV was determined (week 4). RESULTS: Once-daily SQV-SGC/RTV was well tolerated. No patient changed regimens. After 24 weeks, 64 (93%) of 69 patients had plasma viral loads of <50 copies/mL (the remaining 5 patients had plasma viral loads of <300 copies/mL). The median CD4 cell count increased from 534/mL at the start of once-daily SQV-SGCs/RTV to 695/mL after 24 weeks (p <.001). Compared with the preceding 24 weeks of treatment with twice-daily SQV-SGC, the CD4 cell count improved significantly during once-daily SQV-SGC/RTV therapy (p <.001). All patients maintained SQV trough concentrations (C(24h)) of >0.05 mg/L. Median values for the area under the plasma concentration-versus-time curve from 0 to 24 hours (AUC(0-24h)), maximal concentration (C(max)), and C(24h) for SQV were 48.1 (h.mg)/L, 6.98 mg/L, and 0.17 mg/L, respectively. Body weight was inversely correlated with SQV AUC(24h) and C(24h) (p <.01). CONCLUSIONS: Clinical and pharmacokinetic data support once-daily SQV-SGC/RTV (1600/100 mg) with two NRTIs as a convenient and safe therapeutic regimen to maintain viral suppression and immune function in HIV-1-infected patients with plasma viral loads of <50 copies/mL.