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.