A Study of Efficacy and Safety of Intravenous Cefiderocol (S-649266) Versus Imipenem/Cilastatin in Complicated Urinary Tract Infections

Inclusion Criteria: * Hospitalized male and female patients ≥ 18 years * Clinical diagnosis of either complicated urinary tract infections (cUTI) with or without pyelonephritis or acute uncomplicated pyelonephritis * cUTI diagnosed with a history of ≥ 1 of the following: * Indwelling urinary catheter or recent instrumentation of the urinary tract * Urinary retention (caused by benign prostatic hypertrophy) * Urinary retention of at least 100 mL or more of residual urine after voiding (neurogenic bladder) * Obstructive uropathy * Azotemia caused by intrinsic renal disease (blood urea nitrogen and creatinine values greater than normal laboratory values) OR Pyelonephritis and normal urinary tract anatomy, ie, acute uncomplicated pyelonephritis AND At least 2 of the following signs or symptoms: * Chills or rigors or warmth associated with fever (temperature greater than or equal to 38 degrees Celsius) * Flank pain (pyelonephritis) or suprapubic/pelvic pain (cUTI) * Nausea or vomiting * Dysuria, urinary frequency, or urinary urgency * Costo-vertebral angle tenderness on physical examination AND All subjects had to have urinalysis evidence of pyuria demonstrated by 1 of the following: * Dipstick analysis positive for leukocyte esterase * ≥ 10 white blood cells (WBCs) per μL in unspun urine, or ≥ 10 WBCs per high power field in spun urine * Positive urine culture within 48 hours prior to randomization containing ≥10\^5 colony forming unit (CFU)/mL of a Gram-negati…