Safety, Tolerability, and Efficacy of Adjunctive Treatment with Topically Applied MBN-101 in Subjects with Moderate or Severe Diabetic Foot Infection (DFI): A Phase 1 Randomized, Double-Blind, Placebo-Controlled Study

Healing of diabetic foot ulcers is often compromised by microbial infections that are resistant to available antibiotics. New broad-spectrum topical antimicrobials may have the potential to improve clinical outcomes for these infections.

We conducted a phase 1 randomized, double-blind, placebo-controlled, multicenter study evaluating MBN-101, a topical formulation of the novel broad-spectrum, antibiofilm/ antimicrobial BisEDT, for treating infected diabetic foot ulcers. We enrolled subjects into escalating dose cohorts of MBN-101 (150, 375, 750 µg/mL BisEDT; 3, 7.5, 15 µg/cm² wound area), at a ratio of 3:1 MBN-101 to placebo. Investigators topically applied MBN-101 or placebo to the ulcers 3x/week, for 2–3 weeks as an adjunct to debridement and systemic antibiotic therapy. We evaluated subjects at end of treatment (EOT), then at test of cure (TOC) and end of study (EOS) visits two and four weeks after EOT, respectively. Assessments included adverse events, systemic exposure to BisEDT, wound area (by 3D digital photography), and clinical resolution of infection signs/symptoms.

Among 52 subjects treated, 12 received 3 µg/cm², 12 7.5 µg/cm², 15 15 µg/cm², and 13 were in the placebo group. MBN-101 was well tolerated. There was no evidence of BisEDT systemic exposure and no differences in resolution of infection signs/symptoms across treatment groups. At EOT, 42% of all MBN-101 subjects had a >50% reduction in wound size vs. 23% of placebo subjects (p=0.32). A >50% wound size reduction occurred in a greater proportion of MBN-101 subjects than placebo at TOC (59% vs. 39%, p=0.33) and EOS (61% vs. 42%, p=0.33). Target ulcer-related amputation in the pooled MBN-101 treatment groups were 2.6% vs. 15.4% for placebo (p=0.15).

These data suggest that topical MBN-101 may be beneficial in reducing wound size in diabetic persons with an infected foot ulcer.