DRIVESHAFT: Darunavir/Ritonavir In HIV-infected Virologically-suppressed Experienced Subjects

Darunavir is a nonpeptidic protease inhibitor with a high genetic barrier to resistance that evolved from a prototype compound synthesized using structure-based design strategies. Once-daily darunavir at 800mg boosted with 100mg of ritonavir is an effective antiretroviral agent indicated for HIV-infected treatment-naïve patients. In treatment-experienced patients, darunavir was initially approved for twice-daily administration boosted with twice-daily ritonavir at 600mg and 100mg, respectively. Recently, once-daily darunavir/ritonavir was approved for use in treatment-experienced adult patients with viremia with no darunavir resistance mutations. In treatment-experienced patients with viral suppression, switching from an antiretroviral taken twice-daily to a once-daily dose is an attractive option to promote greater patient acceptability and adherence, and potentially minimize side effects and toxicities. Because of darunavir/ritonavir's high genetic barrier to resistance and well-established safety profile at a once-daily dose, switching patients with virologic suppression from twice-daily darunavir/ritonavir to once-daily darunavir/ritonavir will likely confer attributes more favorable to patients through a simplified dosing schedule and lower potential for lipid elevation without the loss of virologic control. DRIVESHAFT is a 48-week Phase 4, randomized, open label, comparative study. The study will be conducted in 60 HIV-1 infected, antiretroviral experienced, virologically-suppressed patients on regimens containing darunavir 600mg/ ritonavir 100mg twice-daily and a minimum of two other antiretrovirals, with a history of 0-1 darunavir-associated resistance mutations. Subjects will be randomized 1:1 to switch to darunavir 800mg/ ritonavir 100mg once-daily or continue on their current regimen. Rates of virologic suppression of once-daily darunavir/ritonavir regimens relative to darunavir/ritonavir twice-daily regimens will be compared, and safety, change from base