[Darunavir/cobicistat monotherapy. Experience in a tertiary hospital].

Objective: Ritonavir-boosted protease inhibitor (IP/r) monotherapy: darunavir/ritonavir (DRV/r) or lopinavir/ritonavir (LPV/r) monotherapy is only provided in the major treatment guidelines in pretreated patients to prevent toxicity associated with nucleoside/nucleotide reverse transcriptase inhibitor (NRTI), reduce costs and simplify antiretroviral treatment. To start IP/r monotherapy, according to GESIDA guidelines 2016, patients need to meet the following criteria: absence of chronic hepatitis B, plasma viral load <50 copies/ mL for at least 6 months and absence of protease inhibitors mutations or previous virologic failures to IP/r. Currently, there are no studies that evaluate the efficacy and safety of darunavir/cobicistat (DRV/COBI) monotherapy.

Methods: This prospective study analyzed pretreated HIV patients with DRV/r monotherapy that were switched to DRV/COBI monotherapy. The aim of the study is to describe the effectiveness and safety of the DRV/COBI monotherapy.

Results: Seventy-eight patients were evaluated. Patients had a median of 31.29 months of DRV/r monotherapy before DRV/COBI monotherapy. Nine of the 78 patients developed "blips" (plasma viral load: 50-200 copies/ml) and four patients had plasma viral load ≥200 copies/mL. An 83.3% (65/78) of the patients remained with undetectable plasma viral load. As for safety, there were no significant differences in lipid profile, liver function (transaminases) and renal function between DRV/r and DRV/COBI monotherapy.

Conclusions: DRV/COBI monotherapy seems to be effective and safe (lipid profile, liver and kidney function). However, it will be necessary to design specific studies comparing DRV/r vs DRV/COBI monotherapy to confirm these results.