Motsch J, de Oliveira CM, Stus V, et al. - Researchers conducted a randomized, controlled, double-blind, phase 3 trial including hospitalized patients with hospital-acquired/ventilator-associated pneumonia, complicated intraabdominal infection, or complicated urinary tract infection caused by imipenem-nonsusceptible (but colistin- and imipenem/relebactam-susceptible) pathogens in order to evaluate imipenem/relebactam for treating imipenem-nonsusceptible infections. Imipenem/relebactam was provided to 31 patients and colistin+imipenem to 16 patients for 5–21 days. Favorable overall response (defined by relevant endpoints for each infection type) in the modified microbiologic intent-to-treat (mMITT; n = 21 imipenem/relebactam, n = 10 colistin+imipenem) population (qualifying baseline pathogen and ≥ 1 dose study treatment) was the primary endpoint. Clinical response, all-cause mortality, and treatment-emergent nephrotoxicity were the secondary endpoint. Among cases, qualifying baseline pathogens were Pseudomonas aeruginosa (77%), Klebsiella spp. (16%), other Enterobacteriaceae (6%). Outcomes suggest that for carbapenem-nonsusceptible infections, imipenem/relebactam is an efficacious and well-tolerated treatment option. They observed favorable overall response in 71% imipenem/relebactam and 70% colistin+imipenem cases, day 28 favorable clinical response in 71% and 40%, and 28-day mortality in 10% and 30%, respectively.