Fostemsavir

Fostemsavir (BMS-663068) is an experimental HIV entry inhibitor and a prodrug of temsavir (BMS-626529). It is under development by Bristol-Myers Squibb for use in the treatment of HIV infection. By blocking the gp120 receptor of the virus, it prevents initial viral attachment to the host CD4+ T cell and entry into the host immune cell; its method of action is a first for HIV drugs. Because it targets a different step of the viral lifecycle, it offers promise for individuals with virus that has become highly resistant to other HIV drugs. Since gp120 is a highly conserved area of the virus, the drug is unlikely to promote resistance to itself via generation of CD4-independent virus.