Study Comparing the Safety and Efficacy of Intravenous CXA-201 and Intravenous Meropenem in Complicated Intraabdominal Infections

Approximately, 500 subjects will be enrolled into this study, randomized 1:1 to receive
CXA-201 and metronidazole or comparator (meropenem). Subject participation will require a
minimum commitment of 38 days and a maximum of 45 days. An End of Treatment (EOT) visit will
occur within 24 hours following the last dose of study drug administration/drug
discontinuation. A Test of Cure (TOC)/Safety visit will be conducted 26 to 30 days following
the first dose of study drug administration. A Last Follow-up (LFU) visit will be conducted
38 to 45 days after the first dose of study drug.

Inclusion Criteria:

- Diagnoses of cIAI.

- Subject requires surgical intervention (e.g., laparotomy, laparoscopic surgery, or
percutaneous draining of an abscess) within 24 hours of (before or after) the first
dose of study drug.

Exclusion Criteria:

- Simple appendicitis; acute suppurative cholangitis; infected necrotizing pancreatitis;
pancreatic abscess; or pelvic infections.

- Complicated intraabdominal infection managed by staged abdominal repair (STAR), open
abdomen technique including temporary closure of the abdomen, or any situation where
infection source control is not likely to be achieved.

- Use of systemic antibiotic therapy for IAI for more than 24 hours prior to the first
dose of study drug, unless there is a documented treatment failure with such therapy.

- Have a concomitant infection at the time of randomization, which requires non-study
systemic antibacterial therapy in addition to IV study drug therapy. (Drugs with only
gram-positive activity [e.g., daptomycin, vancomycin, linezolid] are allowed).

- Severe impairment of renal function (estimated CrCl < 30 mL/min), or requirement for
peritoneal dialysis, hemodialysis or hemofiltration, or oliguria (< 20 mL/h urine
output over 24 hours).

- The presence of hepatic disease at baseline.

- Considered unlikely to survive the 4 to 5 week study period.

- Any rapidly-progressing disease or immediately life-threatening illness (including
respiratory failure and septic shock).

- Have a documented history of any moderate or severe hypersensitivity or allergic
reaction to any β-lactam antibacterial (a history of a mild rash followed by
uneventful re-exposure is not a contraindication to enrollment), including
cephalosporins, carbapenems, penicillins, or ß-lactamase inhibitors, or metronidazole,
or nitroimidazole derivatives.

- Women who are pregnant or nursing.