The SPICE study: 48-week activity of combinations of saquinavir soft gelatin and nelfinavir with and without nucleoside analogues. Study of Protease Inhibitor Combinations in Europe.

Objectives: To compare the efficacy and safety of saquinavir soft gelatin capsules (SQV-SGC) and nelfinavir (NFV), with or without two concomitant nucleoside reverse transcriptase inhibitors (NRTIs), in an exploratory objective to identify populations most likely to benefit from quadruple therapy.

Design: Phase II/III, open-label, randomized, parallel-arm, multicenter trial.

Participants: Enrollment included 157 protease inhibitor-naive adults (> or = 13 years) with HIV-1 RNA > or = 10,000 copies/ml; 132 participants completed 48 weeks of therapy.

Interventions: SQV-SGC 1200 mg, NFV 750 mg, SQV-SGC 800 mg plus NFV 750 mg, all with two NRTIs, and SQV-SGC 800 mg plus NFV 750 mg alone, all three times daily for 48 weeks.

Main Outcome Measures: Proportion of participants with HIV-1 RNA <50 copies/ ml (16 and 48 weeks); time to virologic relapse (48 weeks).

Results: Proportions of patients with HIV RNA <50 copies/ml were not statistically significantly different between arms at 16 or 48 weeks, although trends favored the quadruple-therapy arm. In patients experiencing virologic relapse, time to relapse was statistically significantly longer in the quadruple-therapy arm than in the other three arms (p = .007). Quadruple therapy provided benefit in NRTI-experienced patients and those with viral loads above the median value at baseline. Adverse events were mainly mild gastrointestinal disorders in all treatment arms.

Conclusions: Quadruple therapy, including SQV-SGC and NFV, gave a more durable response than triple therapy with either single protease inhibitor. Quadruple therapy might particularly benefit NRTI-experienced patients and those with high baseline viral loads.