ACHN-975 TFA is a selective LpxC inhibitor and exhibits a subnanomolar LpxC inhibitory activity. ACHN-975 TFA is against a wide range of gram-negative bacterias with low MIC values (≤1 μg/mL)[1].

ACHN-975 is against Enterobacteriaceae spp with an IC50 of 0.02 nM[1].ACHN-975 is against Enterobacteriaceae spp, Pa, and Ab with MIC90 values of 1, 0.5, and >64 μg/mL, respectively[1].ACHN-975 is potently against the P. aeruginosa isolates tested, inhibiting 100% of the isolates at an MIC of ≤2 μg/ml. It against Pseudomonas aeruginosa with an MIC50 and MIC90 of 0.06 and 0.25 μg/ml, respectively[2].ACHN-975 is against six P. aeruginosa isolates, it against P. aeruginosa APAE1064, APAE1232, and APAE1064 isolates with MIC values of 0.12, 0.06 and 0.06 μg/ml, respectively[2].LpxC is highly conserved in gram-negative bacteria and catalyzes the first committed step of lipid A biosynthesis. LpxC is the bacterial enzyme Zinc-dependent metalloamidase UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase[1].

ACHN-975 TFA (intraperitoneal administration; 5-30 mg/kg; single dose) leads to a steady reduction in bacterial titers in the first 4 h following treatment for all dosing groups. The sampling shows that the level of free drug in this model drops below the ACHN-975 MIC for this isolate (0.25 μg/ml) by 2 h after treatment with the 10 mg/kg dose and by 4 h after treatment with the 30 mg/kg dose[2]. Animal Model: Neutropenic mouse thigh model with P. aeruginosa ATCC 27853[2]

[1]. Kalinin DV, et al. Insights into the Zinc-Dependent Deacetylase LpxC: Biochemical Properties and Inhibitor Design. Curr Top Med Chem. 2016;16(21):2379-430. [2]. Krause KM,et al. Potent LpxC Inhibitors with In Vitro Activity against Multidrug-Resistant Pseudomonas aeruginosa.Antimicrob Agents Chemother. 2019 Oct 22;63(11). pii: e00977-19.