GSK1322322 Versus Linezolid in the Treatment of Acute Bacterial Skin and Skin Structure Infection

This study will determine the safety, tolerability and efficacy of GSK1322322 verses Linezolid in subjects with Acute Bacterial Skin and Skin Structure Infection (ABSSSI).

This is a phase IIa, multicenter, randomized, parallel group, double-blind, double dummy study to assess the safety, tolerability, and efficacy of GSK1322322 when given as 1500mg twice daily over a 10-day period versus linezolid (600mg twice daily for 10 days) in adults with suspected Gram positive Acute Bacterial Skin and Skin Structure Infection who are not currently receiving antibacterial therapy. Subjects will be randomized (2:1) to GSK1322322 or linezolid. This study consists of a screening visit, a 10-day treatment period, and follow-up evaluations 7 and 28 days following the last dose.

Eligibility Criteria:
Inclusion Criteria:

* Male or female subject age 18 years or older at the time of signing the informed consent
* Male subjects must agree to use one of the contraception methods listed
* A female is eligible to enter and participate in this study if she is of non-childbearing potential
* The subject has a diagnosis of ABSSSI defined as one of the following: wound infection with cellulitis that has developed within 30 days of surgery or trauma; abscess with cellulitis, or cellulitis that has developed in no more than 7 days before enrollment with worsening over the past 48 hours OR in the investigator's opinion the patient's condition warrants systemic oral antibiotic therapy
* The subject has at least 2 additional signs and symptoms of skin infection: purulence, erythema with or without induration, fluctuation, heat/localized warmth, and pain/tenderness
* The subject has at least 1 systemic marker of infection: Lymphadenopathy, Fever (\>38 degrees Celsius), White Blood Cell elevation, or Creatinine Reactive Protein (CRP) \>Upper Limit of Normal (ULN)
* The subject has given written, informed, dated consent to participate in the study
* QTcB or QTcF \< 450 msec; or QTc \< 480 msec in subjects with Bundle Branch Block
* Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) \< 2xULN; and bilirubin \< 1.0xULN

Exclusion Criteria:

* Current or chronic history of liver disease, or known hepatic or biliary abnormalities
* The subject has been diagnosed with Acquired immune deficiency syndrome (AIDS)
* Body mass index (BMI) \>40 kg/m2
* The subject has demonstrated a previous hypersensitivity reaction to GSK1322322, or to oxazolidinones
* The subject has a secondarily infected animal/human bite
* The subject has a chronic ulcerative lesion that is likely to be polymicrobial or caused by anaerobic organisms and unlikely to have Staphylococcus aureus or Streptococcus pyogenes as the causative agent
* The subject has an underlying skin disease, such as pre-existing eczematous dermatitis, with clinical evidence of secondary infection
* The subject has an infection that would normally have a high cure rate after surgical incision alone
* The subject has a bacterial skin infection which, due to the extent, depth or severity of clinical presentation, in the opinion of the investigator, cannot be appropriately treated by an oral antibiotic
* The subject has received more than one dose of treatment with a systemic and/or topical antibacterial within 7 days
* The subject is currently receiving vasopressors
* The subject is currently receiving adrenergic agents
* The subject is currently receiving serotonergic reuptake inhibitors
* The subject is currently receiving monoamine oxidase inhibitors
* The subject has a documented clinical history of pseudomembranous colitis
* The subject has known, pre-existing myelosuppression, or a history of myelosuppression with prior linezolid use, or is currently receiving a medication that produces bone marrow suppression
* The subject has a history of seizures
* The subject has a history of severe renal failure and is undergoing dialysis
* The subject has a serious underlying disease that could be imminently life-threatening
* The subject has been previously enrolled in this study
* The subject has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 30 days, 5 half-lives or twice the duration of the biological effect of the investigational product
* Subject is unable to discontinue the use of prescription drugs listed in the protocol or non-prescription drugs, including vitamins, herbal and dietary supplements prior to the first dose of study medication through the first follow up visit
* Lactating females or pregnant females as determined by positive urine pregnancy test at screening or prior to dosing