Efficacy and Safety of Imipenem+Cilastatin/Relebactam (MK-7655A) Versus Colistimethate Sodium + Imipenem+Cilastatin in Imipenem-Resistant Bacterial Infection (MK-7655A-013)

Inclusion Criteria:

- Hospitalization that requires treatment with IV antibiotic therapy for a new,
persistent or progressing bacterial infection involving at least 1 of 3 primary
infection types (HABP, VABP, cIAI, or cUTI)

- Positive culture data from the primary infection-site specimen collected within 1 week
of study entry. At least one of the suspected causative pathogens from the specimen
meets all of the following: 1) identified as a Gram-negative bacterium, 2)
culture-confirmed imipenem resistance (and colistin resistance for Group 3 only), 3)
culture-confirmed susceptibility to imipenem/relebactam and to colistin (for Groups 1
and 2 only)

- Not of reproductive potential, or of reproductive potential and agrees to avoid
becoming pregnant or impregnating a partner by complying with one of the following: 1)
practice abstinence, or 2) use of acceptable contraception during heterosexual
activity

Exclusion Criteria:

- Concurrent infection that would interfere with evaluation of the response to the study
antibiotics

- Received treatment with any form of systemic colistin for >24 hours within 72 hours
before initiation of study drug (for Groups 1 and 2 only)

- HABP or VABP caused by an obstructive process

- cUTI which meets any of the following: 1) complete obstruction of any portion of the
urinary tract, 2) known ileal loop, 3) intractable vesico-ureteral reflux, 4) presence
of an indwelling urinary catheter which cannot be removed at study entry

- History of serious allergy, hypersensitivity, or any serious reaction to listed
antibiotics (per-protocol)

- Female who is pregnant or is expecting to conceive (or a male partner of a female who
is expecting to conceive), is breastfeeding, or plans to breastfeed before completion
of the study

- Anticipated treatment with any of the following during the study: valproic acid or
divalproex sodium, or concomitant systemic (e.g. IV, oral or inhaled) antimicrobial
agents with known Gram-negative bacterial coverage

- Currently undergoing hemodialysis or peritoneal dialysis

- Participated or anticipates participating in any other clinical study involving
administration of investigational medication up to 30 days before screening or during
the course of the trial

- Concurrent endocarditis, osteomyelitis, meningitis, prosthetic joint infection,
disseminated fungal infection, or active pulmonary tuberculosis