Cobicistat
Cobicistat (formerly GS-9350) is a recent pharmacokinetic enhancer with no antiviral function, which still inhibits CYP3A, although more specifically than in vitro Ritonavir [51]. Cobicistat is indicated in conjunction with other antiretroviral agents to increase systemic exposure of atazanavir or darunavir (once daily dosing regimen) in the care of HIV-1 infection. Growing systemic antiretroviral exposure (ARVs) without increasing dose allows for improved patient outcomes and a reduced profile of side effects. In Phase I trials, cobicistat was shown to be a comparable therapeutic enhancer to ritonavir in combination with atazanavir, integrase inhibitor elvitegravir, or midazolam (a CYP3A test substrate) [52]. An atazanavir / cobicistat dependent regimen provided efficacy and protection comparable to an atazanavir / ritonavir regimen in phase II studies [50]. However, a randomized trial at the Shanghai Public Health Clinical Center (SPHCC) evaluating Cobicistat for COVID-19 has shown that it has not been successful and can be reassessed.