In the main analysis of efficacy (TLOVR, switch equals failure; MG-132 concentration per protocol population),

the percentage of patients with HIV RNA < 50 copies/mL by week 144 was 72% (88 of 122) in the DRV/r arm vs. 78% (94 of 121) in the DRV/r + 2NRTIs arm. In this analysis, the difference in efficacy between the arms was −5.6% in favour of the DRV/r +2NRTIs arm, with 95% confidence intervals (CIs) of −16.5% to +5.4%: this result did not show noninferiority for DRV/r monotherapy vs. DRV/r + 2NRTIs, but there was also no significant difference in efficacy between the treatment arms. Of the treatment failures in this per protocol analysis, 20 patients in the DRV/r arm vs. 13 in the DRV/r + 2NRTIs arm had a confirmed elevation in HIV RNA > 50 copies/mL at least once during the trial. Similar results were obtained when the same endpoint was analysed for the ITT population: there were 21 and 13 patients with these elevations, respectively. In the multivariate logistic regression analysis of the TLOVR

switch equals failure endpoint, the most significant predictor of treatment failure was HCV coinfection at baseline (P = 0.008). Patients with HCV coinfection at baseline were 2.7 times more likely to show treatment failure during the trial. Figure 1a shows the efficacy results from the TLOVR switch equals failure Proteasome inhibition analysis for the subgroups of patients with and without HCV coinfection at baseline. For patients who were not coinfected, the response rates by week 144 were 79% (78 of 99) for the monotherapy arm and 78% (83 of 106) for the DRV/r + 2NRTIs arm. However, for patients with HCV coinfection at baseline, the response rates were 44% (10 of 23) in the DRV/r monotherapy arm and 73% (11 of 15) in the DRV/r + 2NRTIs arm. The TLOVR switch equals failure analysis classifies patients as treatment failures if there is any confirmed

elevation in HIV RNA during the study. All patients with these HIV RNA elevations were followed up to week 144, where possible. In the strict ITT (switches not considered failures) analysis, patients were defined as treatment successes if the HIV Tolmetin RNA was < 50 copies/mL at the week 144 visit, even if there had been elevations in HIV RNA at earlier time-points or switches in therapy. Patients were treatment failures if the HIV RNA was > 50 copies/mL at week 144, or if the patient had no available data at this time-point. Of the 21 patients in the DRV/r arm who had confirmed HIV RNA elevations during the trial using the ITT TLOVR endpoint, 14 (67%) had HIV RNA < 50 copies/mL at week 144. Of the other seven patients, three had HIV RNA < 50 copies/mL at their last visit (week 96 or 128), and four patients had detectable but low-level HIV RNA at week 144 (50, 82, 69 and 112 copies/mL, respectively). Overall, 12 of 21 patients with HIV RNA elevations in the DRV/r arm had their antiretroviral treatment changed after a confirmed HIV RNA elevation.