The Safety and Efficacy of an Antibiotic Sponge in Diabetic Patients With Moderately Infected Foot Ulcers

Infected skin ulcers with diabetes can be very debilitating because they are difficult to heal. Diabetic ulcers are responsible for frequent health care visits, and are a major predictor of amputation. Diabetic ulcers can be caused by a patient's inability to sense pain or warmth as well as peripheral vascular disease, which causes diminished blood flow to the foot. Early aggressive treatment is necessary to treat infection and ultimately prevent the need for amputation.

Gentamicin is an antibiotic that is effective in treating certain kinds of infection. Collagen is a protein that is found in all mammals. The gentamicin-collagen sponge is a thin flat sponge made out of collagen that comes from cow tendons and containing gentamicin. When applied to an open ulcer, the collagen breaks down and the gentamicin is released into the ulcer, but very little is absorbed into the blood stream. The high levels of gentamicin in the open infected ulcer may help treat the infection.

In this study, all subjects will be given the necessary supplies and taught how to take care their foot ulcer. All subjects will also receive oral an antibiotic (levofloxacin). Additionally, subjects who are randomly assigned to receive the gentamicin-collagen sponge will place a gentamicin-collagen sponge on their ulcer during daily wound care.

Inclusion criteria

• Is a man or woman aged ≥ 18 and ≤ 80 years.
• Has diabetes mellitus, according to the American Diabetes Association criteria.
• Has a single infected skin ulcer below the knee, defined as "moderate" by the Infectious Disease Society of America (IDSA) Guidelines for whom, in the Investigator's opinion, intravenous (IV) or oral antimicrobial therapy is appropriate
• Has had an x ray of the infected area within the 2 days immediately preceding or at Visit 1 (Baseline/Randomization) to document the presence or absence of osteomyelitis. Patients with osteomyelitis must receive appropriate surgical intervention to remove all necrotic and infected bone and otherwise meet enrollment criteria before being enrolled in the study.
• Meets certain minimal laboratory criteria
• Has an ankle brachial index (ABI) > or = 0.7 and ≤ 1.3. (Note: Patients with ABI < 0.7 or > 1.3 may be included if they have either a transcutaneous oxygen pressure or a toe pressure > or = 40 mm Hg on limb with ulcer.)
• If female, is nonpregnant (negative pregnancy test results at the Baseline/Randomization Visit) and nonlactating.
• If female, is either not of childbearing potential (defined as postmenopausal for ≥ 1 year or surgically sterile [bilateral tubal ligation, bilateral oophorectomy or hysterectomy]) or practicing a medically acceptable methods of birth control and agrees to continue with the regimen throughout the study
• Willing to return to the study facility for the Final Study Visit.
• Must be able to fluently speak and understand English and be able to provide meaningful written informed consent for the study.

Exclusion criteria

• Has a known history of hypersensitivity to gentamicin (or other systemic aminoglycosides) or levofloxacin or drugs in the same class, or any of the test article or reference product components.
• Has a known hypersensitivity to bovine collagen.
• Has any uncontrolled illnesses that, in the opinion of the Investigator, would interfere with interpreting the results of the study.
• Has a target ulcer with a wound size > 10 × 10 cm.
• Has gangrenous tissue of the affected limb that cannot be removed with a single debridement.
• Has wound known to contain isolates resistant to levofloxacin.
• Has a wound associated with prosthetic material or device.
• Received any topical or systemic antimicrobial therapy within the 2 weeks prior to study entry (Visit 1 [Day 1]).
• If severely immunocompromised, may be excluded at the discretion of the Investigator.
• Has a history of alcohol or substance abuse in the past 12 months.
• Has serum creatinine > 3 mg/dL, is undergoing dialysis (renal or peritoneal) or has a history of kidney transplant.
• Has a history of myasthenia gravis or other neurological condition where gentamicin use is contraindicated as determined by the Investigator.
• Has a history of epilepsy
• Has a history of tendon disorders related to fluoroquinolone administration