Assessing Boron-Pleuromutilin AN11251 for the Development of Antibacterial Agents

Pleuromutilins are a group of antibiotics derived from the naturally occurring compound. The recent approval of lefamulin for both intravenous and oral doses in humans to treat community-acquired bacterial pneumonia has prompted investigations in modifying the structure to broaden the antibacterial spectrum, enhance the activity, and improve the pharmacokinetic properties. AN11251 is a C(14)-functionalized pleuromutilin with a boron-containing heterocycle substructure. It was demonstrated to be an anti-Wolbachia agent with therapeutic potential for Onchocerciasis and lymphatic filariasis. Here, the in vitro and in vivo PK parameters of AN11251 were measured including PPB, intrinsic clearance, half-life, systemic clearance, and volume of distribution. The results indicate that the benzoxaborole-modified pleuromutilin possesses good ADME and PK properties. AN11251 has potent activities against the Gram-positive bacterial pathogens tested, including various drug-resistant strains, and against the slow-growing mycobacterial species. Finally, we employed PK/PD modeling to predict the human dose for treatment of disease caused by Wolbachia, Gram-positive bacteria, or Mycobacterium tuberculosis, which might facilitate the further development of AN11251.