Activity of the Novel Aminomethylcycline KBP-7072 and Comparators against 1,057 Geographically Diverse Recent Clinical Isolates from the SENTRY Surveillance Program, 2019

KBP-7072 is a novel broad-spectrum tetracycline (aminomethylcycline) antibacterial in clinical development (oral and intravenous formulations) for the treatment of acute bacterial skin and skin structure infections, community-acquired bacterial pneumonia, and complicated intra-abdominal infections. KBP-7072 is active against many of the World Health Organization priority pathogens. In this study, KBP-7072 and tetracycline class comparators were susceptibility tested against 1,057 geographically diverse surveillance isolates from 2019 according to Clinical and Laboratory Standards Institute (CLSI) guidelines. KBP-7072 demonstrated potent in vitro activity against Gram-positive and Gram-negative bacterial pathogens. KBP-7072 was active against Staphylococcus aureus (MIC(50/90), 0.06/0.12 mg/liter), methicillin-resistant S. aureus (MIC(50/90), 0.06/0.12 mg/liter), S. lugdunensis (MIC(50/90), 0.03/0.03 mg/liter), and other coagulase-negative staphylococci (MIC(50/90), 0.06/0.25 mg/liter). KBP-7072 was active against Enterococcus faecalis (MIC(50/90), 0.03/0.06 mg/liter) and vancomycin-susceptible and -nonsusceptible E. faecium (MIC(50/90), 0.03/0.03 mg/liter); Streptococcus pneumoniae (MIC(50/90), ≤0.015/0.03 mg/liter), including penicillin- and tetracycline-resistant strains; S. agalactiae (MIC(50/90), 0.03/0.06 mg/liter), including macrolide-resistant strains; S. pyogenes (MIC(50/90), 0.03/0.03 mg/liter); and viridans group streptococci, including S. anginosus group (MIC(50/90), ≤0.015/0.03 mg/liter) isolates. KBP-7072 inhibited 90.2% (MIC(50/90), 0.25/2 mg/liter) of all Enterobacterales isolates, including expanded-spectrum β-lactamase-phenotype strains at ≤2 mg/liter. KBP-7072 demonstrated potent activity against Acinetobacter baumannii-calcoaceticus species complex and Stenotrophomonas maltophilia isolates (MIC(50/90) values, 0.5/1 mg/liter), Haemophilus influenzae (MIC(50/90), 0.12/0.25 mg/liter; 100.0% inhibited at ≤0.25 mg/liter), and Moraxella catarrhalis (MIC(50/90), 0.06/0.06 mg/liter). Based on MIC(90) values, KBP-7072 in vitro activity was generally superior to that the other tetracycline class comparators tested. The potent activity of KBP-7072, including resistant organism groups, merits further clinical investigation in infections where these organisms are likely to occur.