Treatment for Diabetic Foot Infections Flunks Phase 3 Studies

Pexiganan cream is no more effective than placebo

Two phase 3 trials of pexiganan cream 0.8% (Locilex, Dipexium Pharmaceuticals) in patients with mild infections of diabetic foot ulcers (DFIs) did not meet the primary clinical endpoint of superiority compared with placebo cream plus standardized wound care. The results also did not show any meaningful differences in wound closure rates between the pexiganan arm and the vehicle arm in each study. Further, neither trial met the secondary endpoint of demonstrating a higher rate of eradication of bacteria for the pexiganan arm.

Pexiganan cream 0.8% is a chemically synthesized, 22-amino acid peptide isolated from the skin of the African clawed frog. Unlike the majority of antibiotics, which work by inhibiting the replication of bacteria (a bacteriostatic mechanism of action), pexiganan cream kills microbial targets by disrupting bacterial cell-membrane permeability (a bactericidal mechanism of action) in a broad spectrum of gram-positive, gram-negative, aerobic, and anerobic bacteria, as well as fungi, according to the product’s developer.

The OneStep-1 and OneStep-2 trials were identical, double-blind, placebo-controlled studies conducted simultaneously in a total of 389 patients in the United States. The studies’ primary objective was to establish the clinical superiority and safety of topical pexiganan cream 0.8% plus standard local wound care compared with that of placebo cream plus standard local wound care in the treatment of mild DFIs.

Patients were randomly assigned to receive either topical pexiganan cream plus standard local wound care or placebo cream plus standard local wound care for 14 days, with the final evaluation conducted at day 28. The primary endpoint of both trials was the clinical response, which was defined as infection resolved per the judgment of each treating physician using the 2012 Infectious Disease Society of America (IDSA) Clinical Practice Guideline for the Diagnosis and Treatment of Diabetic Foot Infections.

Sources: Dipexium Pharmaceuticals; October 25, 2016; and Locilex; 2016.