This is an open-label, active-control, multicentre, parallel group, randomised and dose-finding efficacy and safety study.

Compare the efficacy and safety of BioChaperone PDGF-BB applied at 12.5 µg/cm² every two days for up to 20 weeks to becaplermin gel (Regranex® Gel 0.01%) applied daily for up to 20 weeks for the treatment of neuropathic diabetic foot ulcer.

Assess the effect of a double dose of BioChaperone PDGF-BB (25 µg/cm²) applied every two days for up to 20 weeks.

After the screening visit, the eligible patient population randomly receive one of the three following topical drugs:

• BioChaperone™ PDGF-BB 12.5 µg/cm²/application for 20 weeks,
• BioChaperone™ PDGF-BB 25 µg/cm²/application for 20 weeks, or
• BioChaperone™ PDGF-BB 4 µg/cm²/application for 20 weeks, or
• Beclapermin gel 6.25 µg/cm²/application for 20 weeks.

The assessment schedule for all the four groups is weekly once (7 day duration) till the 8th week (visit 10) and once in two weeks (14 day duration) thereafter till the end of study. The maximum number of visits expected is 16. The study data is presented at the end of 20 weeks.

Inclusion Criteria:

• Men or women aged 18 years old or older, with type 1 or 2 diabetes mellitus.
• Single full-thickness plantar ulcer of the extremity (below the malleolus) extending through the epidermis and dermis, but not involving bone, tendons, ligaments or muscles (grade IA as defined by University of Texas Diabetic Wound Classification).
• Chronic ulcer of at least six weeks despite appropriate wound care.
• Ulcer area (greatest length by greatest width), following sharp debridement, of 1 to 10 cm², both inclusive.
• Well controlled infection or cellulitis (systemic antibiotherapy).
• Peripheral neuropathy as assessed by Semmes-Weinstein monofilament test or by the bio esthesimeter (vibration perception threshold).
• Adequate arterial blood supply, to be measured by (color) doppler ultrasonography, ankle brachial pressure index > 0.60, or ankle systolic pressure > 70 mmHg or toe pressure > 30 mmHg. Ankle brachial pressure index should be lower than 1.3 (which is frequently related to medial artery calcification.
• Women surgically sterile, post-menopausal, or agree to practice adequate contraception and have a negative pregnancy test at screening. Non-nursing.
• Signed informed consent before any study procedure.

Exclusion Criteria:

• Ulcer of other cause or origin: electrical, chemical or radiation insult, bedsores, vascular ulcer or Charcot deformities ulcers.
• Active ulcer infection assessed by clinical examination and radiographic if necessary. Presence of necrosis, purulence or sinus tracts that cannot be removed by debridement.
• Active osteomyelitis affecting the area of the target ulcer.
• Poorly controlled diabetes (uncontrolled glycemia: HbA1c ≥ 12%), renal failure (serum creatinine > 3.0 mg/dL), poor nutritional status (albumin < 3.0 g/dL or total protein < 6.5 g/dL).
• Known connective tissue or malignant disease.
• Concomitant treatment with corticosteroids, immunosuppressive agents, radiation therapy, or anticancer chemotherapy.
• Use of investigational drug/device within 30 days.
• Topical application of any advance wound care on this wound (Growth Factor, antiseptics, antibiotics or debriders) within 7 days.
• Vascular reconstruction within 8 weeks. Patients expected to be noncompliant with the protocol (not available for the duration of the trial, treatment or wound care compliance), or felt to be unsuitable by the Investigator for any other reason.