An ultra-long-acting dimeric bictegravir prodrug defined by a short pharmacokinetic tail.

Nayan, Mohammad Ullah; Sillman, Brady; Das, Srijanee; Hanson, Brandon W; Sultana, Ashrafi; Le, Nam Thai Hoang; Deodhar, Suyash; Gowda, Bhoomika et al. · Nat Commun · 2026

basic_science · Level V

Where this comes from

Abstract

Ultra-long-acting (ULA) antiretroviral parenteral formulations, with low injection volumes, high resistance barriers, and short pharmacokinetic (PK) tails, can transform HIV-1 therapeutics. Here, we converted bictegravir (BIC), a potent daily oral antiretroviral drug, into monomeric and homodimeric ester prodrugs. The homodimeric prodrug nanosuspension, NMXBIC, shows sustained plasma BIC levels > 16 times the protein-adjusted 95% inhibitory concentration (PA-IC<sub>95</sub>) for six months after a single injection in Sprague Dawley rats. The results paralleled a short PK tail with the potential for late dose forgiveness. The monomeric prodrug nanosuspension, NM2BIC, shows lower year-long plasma BIC concentrations above PA-IC<sub>95</sub> after a single injection. After repeated injections, NMXBIC and NM2BIC are well tolerated in New Zealand White rabbits. NMXBIC's physicochemical properties and high BIC loading/unit mass of the prodrug contribute to its unique ULA PK profile. These results support its development as a ULA formulation for HIV-1 treatment and prevention.

Medical subject headings