ABSTRACT
The additional 48-week optional treatment extension of the T-20 versus Optimized Regimen Only (TORO) studies evaluated long-term safety and efficacy of enfuvirtide (ENF) through week 96 in patients receiving ENF plus optimized background (OB) and patients switching to ENF plus OB from OB alone. Patient randomization was 2:1 to ENF plus OB (n = 663) and OB (n = 334), of which 89.7% and 89.8% were male, 89.3% and 88.6% were Caucasian, and median age was 41 and 42 years, respectively. HIV risk factors were comparable between the ENF plus OB and OB groups with the major factors being 65.2% versus 66.2% homosexual contact, 17.8% versus 19.8% heterosexual contact, 4.1% versus 4.8% bisexual contact, respectively, and 6.9% injection drug use in both groups. OB patients were allowed to switch to ENF plus OB at virologic failure before week 48 and required to switch at week 48 to continue in the study (n = 230). Efficacy and safety assessments were conducted for each group. At week 96, 55% of ENF plus OB subjects completed the study and 26.5% achieved a viral load of less than 400 copies per milliliter (17.5% achieved less than 50 copies per milliliter). Viral load and CD4 mean change from baseline was -2.1 and -1.1 log(10) HIV-1-RNA copies per milliliter and +166 and +116 CD4 cells/mm(3) for ENF plus OB and switch patients, respectively. No new ENF-related safety issues emerged in weeks 48-96. Injection site reactions led to discontinuation in 7% and 10% of ENF plus OB and switch patients, respectively. In conclusion, these data demonstrate durable efficacy and safety of ENF over 96 weeks and that early use of ENF in combination with other agents for the treatment of antiretroviral-experienced HIV-infected subjects is beneficial.
Subject(s)
Anti-HIV Agents , HIV Envelope Protein gp41 , HIV Fusion Inhibitors , HIV-1/drug effects , Peptide Fragments , Anti-HIV Agents/administration & dosage , Anti-HIV Agents/adverse effects , Anti-HIV Agents/therapeutic use , CD4 Lymphocyte Count , Drug Administration Schedule , Drug Therapy, Combination , Enfuvirtide , Female , HIV Envelope Protein gp41/administration & dosage , HIV Envelope Protein gp41/adverse effects , HIV Envelope Protein gp41/therapeutic use , HIV Fusion Inhibitors/administration & dosage , HIV Fusion Inhibitors/adverse effects , HIV Fusion Inhibitors/therapeutic use , HIV Infections/drug therapy , HIV Infections/immunology , HIV Infections/virology , Humans , Male , Peptide Fragments/administration & dosage , Peptide Fragments/adverse effects , Peptide Fragments/therapeutic use , RNA, Viral/blood , Time Factors , Treatment Outcome , Viral LoadABSTRACT
BACKGROUND: The T-20 Versus Optimized Background Regimen Only (TORO) 1 and TORO 2 clinical trials are open-label, controlled, parallel-group, phase 3 studies comparing enfuvirtide plus an optimized background (OB) of antiretrovirals (n = 661) with OB alone (n = 334) in treatment-experienced HIV-1-infected patients. METHODS: The primary objective at week 48 was to investigate durability of efficacy, as measured by the percentage of patients maintaining their week 24 response or improving. Efficacy analyses used the intent-to-treat population. RESULTS: A total of 73.7% of patients randomized to the enfuvirtide group remained on treatment through week 48 versus 21.3% originally randomized to the control group. At week 48, a higher proportion of week 24 responders maintained their response or were new responders in the enfuvirtide group than in the control group in each responder category: HIV-1 RNA level > or =1.0 log(10) change from baseline, <400 copies/mL and <50 copies/mL (37.4%, 30.4%, and 18.3% in the enfuvirtide group vs. 17.1%, 12.0%, and 7.8% in the control group, respectively; P < 0.0001 for all comparisons). CD4 cell count increases from baseline were twice as great in the enfuvirtide group as in the control group. CONCLUSION: These data demonstrate durable efficacy of enfuvirtide plus OB over 48 weeks.
