The 48-week efficacy of once-daily saquinavir/ritonavir in patients with undetectable viral load after 3 years of antiretroviral therapy

Objectives To evaluate the efficacy and safety of once-daily saquinavir-soft-gel-capsules/ritonavir (SQV-SGC/ RTV) 1600 mg/100 mg plus dual nucleoside reverse transcriptase inhibitors (NRTIs) in HIV-infected patients with plasma viral load (pVL) < 50 HIV-1 RNA copies/mL following 3 years of antiretroviral therapy. Methods A total of 69 patients with pVL < 50 copies/mL after 162 weeks of antiretroviral treatment started SQV-SGC/RTV 1600 mg/ 100 mg once-daily while continuing dual NRTIs. Previous treatment consisted of 66 weeks of treatment with a half/full dose of zidovudine (ZDV)/zalcitabine (ddC), followed by 2 years of SQV-SGC twice a day (bid) plus ZDV/lamivudine (3TC) or didanosine (ddI)/ stavudine (d4T). Efficacy (pVL), safety and immunological changes (CD4 cell counts) were evaluated after 48 weeks in this open-label, single-arm prospective study. Results SQV-SGC/RTV once-daily was well tolerated. No patient changed regimens or was lost to follow-up. After 48 weeks, 63 of 69 patients (91%) had pVL < 50 copies/mL (five of the six remaining patients had pVL < 400 copies/mL, and one patient had an unexplained rise to 39 500 copies/mL, which decreased to < 50 copies/mL 12 weeks later). Median CD4 count increased from 534 cells/,UL at the start of the SQV-SGC/RTV once-daily treatment to 664 cells/PL (P < 0.001). Compared to the preceding 48 weeks on bid SQV-SGC, the CD4 cell count improved significantly on once-daily SQV-SGC/RTV (P < 0.001). Conclusions These data support the use of SQV-SGC/RTV 1600 mg/ 100 mg once-daily with two NRTls as a convenient, safe and cost-saving regimen to maintain viral suppression and CD4 counts for 48 weeks in this preselected cohort on highly active antiretroviral therapy (HAART) with pVL < 50 copies/mL. The CD4 count rise may be a result of continued immune reconstitution in patients with well-controlled infection.