Study of S-649266 or Best Available Therapy for the Treatment of Severe Infections Caused by Carbapenem-resistant Gram-negative Pathogens

This study is designed to provide evidence of efficacy of S-649266 in the treatment of
serious infections in adult patients with either hospital-acquired pneumonia
(HAP)/ventilator-associated pneumonia (VAP)/healthcare-associated pneumonia (HCAP),
complicated urinary tract infection (cUTI), or bloodstream infections (BSI)/sepsis caused by
carbapenem-resistant Gram-negative pathogens.

Inclusion Criteria:

- Patients with clinically documented infection (HAP/VAP/HCAP, cUTI, or BSI/sepsis)
caused by a Gram-negative pathogen with evidence of carbapenem resistance

- Patients who have been treated previously with an empiric antibiotic regiment and
failed treatment, both clinically and microbiologically, are eligible for the study,
if they have an identified carbapenem-resistant Gram-negative pathogen which has
either been shown to be nonsusceptible in vitro to each of the antibiotic(s) of the
empiric antibiotic regimen or been grown from a culture performed after at least 2
days of the empiric antibiotic regimen

- Patient is male (no contraception required) or female and meets one of the following
criteria:

- Surgically sterile by hysterectomy and/or bilateral oophorectomy or bilateral
salpingectomy or tubal ligation for the purpose of contraception for at least 6
weeks with appropriate documentation of such surgery

- Postmenopausal (defined as older than 45 years of age with cessation of regular
menstrual periods for 6 months and confirmed by a follicle-stimulating hormone
level of > 40 mIU/mL, or amenorrhea for at least 12 months)

- Of childbearing potential and using combined (estrogen and progestogen) or
progestogen-only hormonal contraception associated with inhibition of ovulation
(including oral, intravaginal, injectable, implantable, and transdermal
contraceptives), or an intrauterine device (IUD), or intrauterine
hormone-releasing system (IUS) for the entire duration of the study

- Of childbearing potential and practice abstinence as a preferred and usual
lifestyle, and agrees to continue practicing abstinence from Screening and for
the entire duration of the study

- Of childbearing potential, whose sole heterosexual partner has been successfully
vasectomized and agrees to not have other heterosexual partners for the entire
duration of the study

- Patients meeting specific criteria for each infection site

Exclusion Criteria:

1. Patients who have a history of any moderate or severe hypersensitivity or allergic
reaction to any β-lactam (Note: for β-lactams, a history of a mild rash followed by
uneventful re-exposure is not a contraindication to enrollment)

2. Patients who need more than 3 systemic antibiotics as part of best available therapy
(BAT) for the treatment of the Gram-negative infection (patients with mixed
Gram-positive or anaerobic infections may receive appropriate concomitant narrow
spectrum antibiotics [eg, vancomycin, linezolid, metronidazole, clindamycin])

3. Patients with coinfection caused by invasive aspergillosis, mucormycosis or other
highly lethal mold

4. Patients who have central nervous system (CNS) infection (eg, meningitis, brain
abscess, shunt infection)

5. Patients with infection requiring > 3 weeks of antibiotic treatment (eg, bone and
joint infection, endocarditis)

6. Patients with cystic fibrosis or moderate to severe bronchiectasis

7. Patients in refractory septic shock defined as persistent hypotension despite adequate
fluid resuscitation or despite vasopressive therapy at the time of Randomization

8. Patients with severe neutropenia, ie, polymorphonuclear neutrophils (PMNs) < 100
cells/μL

9. Female patients who have a positive pregnancy test at Screening or who are lactating

10. Patients with Acute Physiology and Chronic Health Evaluation II (APACHE II) score > 30

11. Patients who have received a potentially effective antibiotic regimen for the
carbapenem-resistant Gram-negative infection for a continuous duration of more than 24
hours in cUTI, or 36 hours in HAP/VAP/HCAP or BSI/sepsis during the 72 hours leading
to Randomization

12. Patients with any condition or circumstance that, in the opinion of the investigator,
would compromise the safety of the patient or the quality of the study data

13. Patients who have received another investigational drug or device within 30 days prior
to study entry

14. Patients who have previously been randomized in this study or received S-649266

15. Patients receiving peritoneal dialysis

16. Patients meeting specific exclusion criteria for each infection site