Phase IIa randomized, placebo‐controlled study of antimicrobial photodynamic therapy in bacterially colonized, chronic leg ulcers and diabetic foot ulcers: a new approach to antimicrobial therapy. (18th January 2013)

• Record Type: Journal Article
• Authors: Morley, S.; Griffiths, J.; Philips, G.; Moseley, H.; O'Grady, C.; Mellish, K.; Lankester, C.L.; Faris, B.; Young, R.J.; Brown, S.B.; Rhodes, L.E.
• Is Part Of: British journal of dermatology. Volume 168:Number 3(2013:Mar.)
• Page Start: 617
• Page End: 624
• Publication Date: 2013-01-18
• Subjects: Dermatology -- Periodicals; Skin -- Diseases -- Periodicals; 616.5
• DOI: 10.1111/bjd.12098
• Languages: English
• ISSNs: 0007-0963

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Summary</title> <p> <bold>Background </bold> With increasing problems of antibiotic resistance, photodynamic therapy (PDT) is being developed as a novel antimicrobial treatment. Following light activation, cationic photosensitizer PPA904 [3, 7‐bis(<italic>N</italic>, <italic>N</italic>‐dibutylamino) phenothiazin‐5‐ium bromide] kills a broad spectrum of bacteria <italic>in vitro</italic> and this has a variety of potential clinical applications.</p> <p> <bold>Objectives </bold> To determine if PDT in bacterially colonized chronic leg ulcers and chronic diabetic foot ulcers can reduce bacterial load, and potentially lead to accelerated wound healing.</p> <p> <bold>Methods </bold> Sixteen patients with chronic leg ulcers and 16 patients with diabetic foot ulcers (each eight active treatment/eight placebo) were recruited into a blinded, randomized, placebo‐controlled, single‐treatment, Phase IIa trial. All patients had ulcer duration > 3 months, bacterially colonized with > 10<sup>4</sup> colony‐forming units cm<sup>−2</sup>. After quantitatively assessing pretreatment bacterial load via swabbing, PPA904 or placebo was applied topically to wounds for 15 min, followed immediately by 50 J cm<sup>−2</sup> of red light and the wound again sampled for quantitative microbiology. The wound area was measured for up to 3 months following treatment.</p> <p> <bold>Results </bold> Treatment was well tolerated with no reports of pain or other safety issues. In contrast to placebo, patients on active treatment showed a reduction in bacterial load immediately post‐treatment (<italic>P </italic><<italic> </italic>0·001). After 3 months, 50% (four of eight) of patients with actively treated chronic leg ulcer showed complete healing, compared with 12% (one of eight) of patients on placebo.</p> <p> <bold>Conclusions </bold> This first controlled study of PDT in chronic wounds demonstrated significant reduction in bacterial load. An apparent trend towards wound healing was observed; further study of this aspect with larger patient numbers is indicated.</p> </abstract>