Native collagen matrix plus PHMB antimicrobial in hard-to-heal diabetic foot ulcers: results from the PREPARE...

PREPARE was a prospective, multicentre, randomised controlled trial evaluating purified native type 1 collagen extracellular matrix plus polyhexamethylene biguanide (PCMP) with standard of care (SoC) versus SoC alone in patients with hard-to-heal diabetic foot ulcers (DFUs).

Across 25 US sites, patients with type 1 or type 2 diabetes and hard-to-heal DFUs measuring 1-25cm² were enrolled. Patients demonstrating ≥40 percent area reduction (PAR) during four weeks of screening were excluded to restrict the study population to those with hard-to-heal wounds. SoC included sharp debridement, saline cleansing, use of moisture-balancing dressings and offloading. The primary endpoint was complete wound closure within 12 weeks, confirmed two weeks later. Secondary endpoints included time to closure, PAR and adverse events (AEs).

A total of 170 patients were randomised (PCMP+SoC, n=96; SoC alone, n=74). Complete wound closure occurred in 42% of patients receiving PCMP+SoC versus 27% of patients receiving SoC alone (absolute difference 14.6%; 95% confidence interval: 0.15%, 27.9%; p=0.047). Mean PAR was greater with PCMP+SoC than with SoC alone (75.23% versus 58.06%, respectively). No AEs or serious AEs were attributed to PCMP.

In this study, use of PCMP+SoC significantly improved 12-week closure outcomes in patients with hard-to-heal DFUs compared with SoC alone, supporting its use as an adjunctive antimicrobial barrier for these types of wounds.