The combination of cyclical pressure Topical Wound Oxygen (TWO2) therapy with optimal standard of care improves healing and can reduce recurrence of diabetic foot ulcer, according to study results published in Diabetes Care.

Oxygen has an important role in the wound-healing cascade and several studies have reported the effectiveness of topically applied oxygen for chronic wounds, while others have raised concerns regarding this treatment modality. The goal of the current study was to investigate the efficacy of cyclical pressurized TWO2 therapy in healing diabetic foot ulcers that failed to heal with standard of care.

The double-blind sham-controlled clinical trial was a multicenter study of patients with type 1 or type 2 diabetes from 17 diabetic foot centers across the United States, United Kingdom, France, Germany, and Luxembourg. All patients received optimal standard of care and were randomly assigned to receive active TWO2 therapy or sham control treatment.

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The primary outcome was the percentage of ulcers achieving 100% healing at 12-week follow-up.

Overall, 37 patients were randomly assigned to standard of care and sham therapy (mean age, 61.9±9.5 years; 84% men) and 36 to standard of care and active TWO2 therapy (mean age, 64.6±10.3 years; 89% men). Of these, 3 patients in the active therapy group and 4 patients in the control group were lost to follow-up.

At 12 weeks, the active TWO2 therapy was superior to the sham therapy, as complete healing was evident in 15 wounds (41.7%) compared with 5 wounds (13.5%), respectively (odds ratio, 4.57; 97.8% CI, 1.19-17.57; P =.010). After adjustment for ulcer grade based on the University of Texas Classification, the superiority of the active therapy was more significant (odds ratio, 6.00; 97.8% CI, 1.44-24.93; P =.004).

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The likelihood for complete healing of the ulcer over 12 weeks was significantly higher with active vs sham therapy (hazard ratio, 3.64; 97.8% CI, 1.11-11.94; P =.013). After adjustment for ulcer grade based on the University of Texas Classification, the superiority of the active therapy was again more significant (hazard ratio, 4.66; 97.8% CI, 1.36-15.98; P =.004).

At 12 months, ulcer recurrence was evident in 1 of 15 healed ulcers (6.7%) in the active TWO2 group compared with 2 of 5 healed ulcers (40%) in the control group (P =.070). At this time point, the control group had approximately one-quarter (27%) of foot ulcers closed, while most of the diabetic foot ulcers in the active TWO2 therapy (56%) were closed at 12 months after enrollment (P =.013).

The study had several limitations, including its small sample size and focus on patients with more difficult wounds to heal.

“This robust double-blinded, sham-controlled trial provides evidence to support use of this adjunctive cyclical pressurized [topical oxygen therapy] for chronic [diabetic foot ulcers],” concluded the researchers.

Disclosure: This study was sponsored by Advanced Oxygen Therapy Inc, which owns TWO2 therapy. Please see the original reference for a full list of authors’ disclosures.


Frykberg RB, Franks PJ, Edmonds M, et al. A multinational, multicenter, randomized, double-blinded, placebo-controlled trial to evaluate the efficacy of cyclical topical wound oxygen therapy (TWO2) in the treatment of chronic diabetic foot ulcers: the TWO2 study [published online October 16, 2019]. Diabetes Care. doi:10.2337/dc19-0476