Safety and Efficacy Study of TG-873870 (Nemonoxacin) in Diabetic Foot Infections

Inclusion Criteria:

• Body weight ≥ 40 kg
• Previously known or newly diagnosed diabetes mellitus, including type 1 and type 2 (per the American Diabetes Association guidelines), which is controlled by proper lifestyle (diet, exercise) or treatment with either oral medications or insulin
• Patients' HbA1c ≦ 12% at screening
• Clinically defined diabetic foot infection of mild or moderate severity (PEDIS grade 2-3) as based on the guideline of the Infectious Diseases Society of America. It includes any inframalleolar infection of the soft-tissue, such as paronychia, cellulitis, myositis, abscesses, and tendonitis
• Evidence of necrotic tissue, purulent collections or abscess that may require excision, incision or drainage (based on investigator's judgment, and a surgeon if needed)
• Must be able to provide suitable tissue specimens (preferably obtained by biopsy or tissue curettage, or purulent fluid aspiration, rather than by swabbing) from the infected wound (after appropriate cleansing and debridement) for Gram-staining and bacterial cultures (aerobes and anaerobes)
• A confirmed Gram-positive pathogen infection by Gram-stain. The criterion to determine patient's eligibility for study recruitment is a Gram-stained smear with at least 1 Gram-positive organism seen in at least two high power fields. A solely Gram-positive pathogen infection or a polymicrobial infection including Gram-positive and Gram-negative pathogens are acceptable within the framework of the study

Exclusion Criteria:

• A co-morbid disease condition that could compromise evaluation or participation in this study, such as severe hepatic disease (e.g., active hepatitis, decompensated liver cirrhosis), renal failure (estimated creatinine clearance [CrCl] <30 ml/minute or need for hemodialysis or peritoneal dialysis), or active systemic malignancy (advanced or metastatic), unless enrollment is deemed appropriate at the discretion of the Investigator with prior consultation with the study Medical Monitor
• History of prolonged QTc interval or a medical condition requiring the use of a concomitant medication that is associated with an increased QTc interval (e.g., class I or class III anti-arrhythmic agents)
• Contact dermatitis over the infected skin area, infected third-degree burn wounds, necrotizing fascitis, extensive gangrene, pyoderma gangrenosum, deep vein thrombosis, shock, or any medical disorder that could either interfere with the evaluation of treatment or the response of the patient to therapy
• Radiological evidence of bone or joints infection within 7 days prior to or at screening, i.e. potential osteomyelitis or septic arthritis
• Clinically defined uninfected or severe infection (PEDIS grade 1 or 4) as based on the Infectious Diseases Society of America classification system
• Any known severe immunosuppressive condition, such as an active hematological malignancy, HIV infection or active treatment with any immunosuppressive drug (including corticosteroids at a dose of >20 mg/day of prednisone, or its equivalent)
• Has received or will be receiving chemotherapy or oncolytics within six months prior to entering or during the study
• History of current or active alcohol abuse (>3 drinks daily or binge drinking) or any illicit drug use
• Known or suspected critical ischemia of the affected limb (based on investigators' clinical judgments and vascular assessment)
• Wound that contains or is proximate to any prosthetic materials or devices that is/are not scheduled for removal
• Patient with a foot infection that, in the investigator's judgment, is severe enough to require hospitalization or intravenous antibiotic therapy
• Neutrophil count <1000 cells/mm3