This is a Phase III, randomized, double-blind, multicenter, non-inferiority study to evaluate the efficacy, safety, and tolerability of FEP-TAZ vs. meropenem in the treatment of hospitalized adults with cUTI or AP.

Approximately 1004 hospitalized adult subjects (≥18 years of age) diagnosed with cUTI or AP will be enrolled in the study. The diagnosis of cUTI or AP will be based on a combination of clinical symptoms and signs plus the presence of pyuria

Subjects will be randomized in a 1:1 ratio according to an Interactive Response Technology (IRT) electronic system to receive either FEP-TAZ 4 g (2 g cefepime + 2 g tazobactam) IV every eight hours (q8h) or meropenem 1 g IV q8h. FEP-TAZ will be administered as 2 consecutive infusions of 2 g (1 g cefepime + 1 g tazobactam)

Inclusion Criteria:

Meet the following clinical criteria for either cUTI or AP:

A. cUTI:

1. Have at least TWO of the following new-onset or worsening symptoms or signs:

   Fever (oral, tympanic, or rectal temperature >38°C [>100.4°F]), which must be observed and documented by a health care provider Nausea or vomiting Dysuria, increased urinary frequency, or urinary urgency Lower abdominal, suprapubic, or pelvic pain

2. Have at least ONE complicating factor

B. AP, defined as acute flank pain (onset within 7 days prior to randomization) or costovertebral angle tenderness on physical examination, plus at least ONE of the following new-onset or worsening symptoms or signs:

3. Evidence of pyuria within 48 h prior to randomization,

Exclusion Criteria:

1. Known or suspected disease or condition that, in the opinion of the investigator, may confound the assessment of efficacy.
2. Receipt of potentially-effective systemic antibacterial therapy within 72 h prior to randomization
3. Rapidly progressive or terminal illness with a high risk of mortality due to any cause, including but not limited to acute hepatic failure, respiratory failure, or septic shock, such that the subject is unlikely to survive the study period