Diabetic Foot Ulcer Infection
Diabetic foot infections (DFIs) are the leading cause of diabetes-related hospitalizations and one of the leading causes of lower limb amputation.1,2 While mild infections may be easily treated, moderate infections may be limb threatening, and severe infections may be life threatening.1 The estimated lifetime risk in a person with diabetes mellitus of developing a foot ulcer ranges from 15% to 25%. The incidence and complications related to DFIs has drastically increased due to the higher incidence of multidrug resistant (MDR) organisms, and the prevalence of MRSA involvement in DFIs in the US has increased from 11.6% to 21.9% between 2003 and 2007.4,5 It has been suggested that Gram-positive bacteria tend to predominate in acute DFIs, and Gram-negative and anaerobes tend to predominate in more persistent, chronic infections. 5,6
Studies have also demonstrated that in many chronic wounds such as DFIs, bacteria exist in biofilm communities, which are difficult to treat with systemic antimicrobial therapy (i.e. antimicrobials taken intravenously or orally) and contributes to antibiotic resistance development.7,8 In a combined analysis of chronic wound studies, biofilm was present in nearly 80% of the chronic wounds.9
Topically administered pravibismane, comprised of a suspension of pravibismane in a hydrogel formulation (named MBN-101), has the potential to provide important advantages for the treatment of DFIs, including the dual broad-spectrum antimicrobial and anti-biofilm effects of the drug and its ability to kill common antibiotic resistant species. Standard of care is frequently ineffective in treating these patients. Ineffective management of DFIs has the potential to result in: lower limb amputations; high treatment costs; additional hospitalizations; and the need for long courses of systemic antibiotics.
MBN-101-202 Diabetic Foot Infection Study
A Phase 1b/2a clinical study of topically applied pravibismane (MBN-101) with adjunct systemic antibiotic in patients with moderate to severe Diabetic Foot Infection (DFI) has been completed. The randomized, double blind, placebo-controlled trial evaluated topically applied pravibismane plus standard of care treatment, versus placebo plus standard of care treatment, in 52 patients with moderate to severe diabetic foot ulcer infection. The main objectives of the study were to evaluate the safety and tolerability of topically administered pravibismane and its effect of on resolution of infection.
Topical pravibismane (MBN-101) was well tolerated and no Treatment Emergent Adverse Events (TEAEs) or Serious Adverse Events (SAEs) occurring in the study were considered related to study drug. Although the study was not designed to demonstrate statistical efficacy, a numerical trend of greater median wound size reduction and reduced amputation rate with topical pravibismane treatment was observed compared to placebo.
- The median percent reduction in ulcer wound size from baseline was approximately 3-fold higher in the pooled topical pravibismane group (85% wound size reduction) compared to placebo (29% wound size reduction) at End of Study (defined as 4 weeks after end of treatment).
- Target ulcer-related amputation in the pooled topical pravibismane treatment groups were 2.6% vs 15.4% for placebo, an approximate 6-fold reduction.
Qualified Infectious Disease Product (QIDP) designation and Fast Track status was granted for topical pravibismane (MBN-101) by the US FDA for adjunctive treatment of moderate and severe diabetic foot ulcer infections.
Additional information about the study can be found here:
- Lipsky BA. Medical treatment of diabetic foot infections. Clin Infect Dis. 2004;39:S104-114.
- Jeffcoate WJ et al. Unresolved issues in the management of ulcers of the foot in diabetes. Diabet Med. 2008;25:1380-1389.
- Gemechu, FW et al. Diabetic foot infections. Am Fam Physician. 2013;88:177-184.
- Khoharo HK et al. Diabetic foot ulcers: Common isolated pathogens and in vitro antimicrobial activity. Prof Med J. 2009;16:53–60.
- Lipsky BA et al. Skin and soft tissue infections in hospitalised patients with diabetes: culture isolates and risk factors associated with mortality, length of stay and cost. Diabetologia. 2010;53:914-923.
- Lipsky BA et al. 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2012;54:e132-173.
- James GA et al. Biofilms in chronic wounds. Wound Repair Regen. 2008;16:37-44.
- Attinger A and Wolcott R. Clinically addressing biofilm in Chronic Wounds. Advances in Wound Care. 2012;1:127-132.
- Malone M et al. The prevalence of biofilms in chronic wounds: a systematic review and meta-analysis of published data. J Wound Care. 2017;26:20-25.