The Effect of Natrox® Oxygen Wound Therapy on the Healing Rate of Chronic Diabetic Foot Ulcers

Inotec AMD

Status: Completed

Conditions: Surgical Wound; Diabetic Foot Ulcer

Treatments: Device: Natrox® Oxygen Wound Therapy

Study type: Interventional

Funder types: NETWORK; Industry

Identifiers

NCT03905863

1

Details and patient eligibility

About

A Multicentre Randomized Controlled Trial to Investigate the Effect of Natrox Topical Oxygen Wound Therapy on the Healing rates of Diabetic Foot Ulcers.

Full description

Patients with diabetic foot ulcers will be enrolled into the trial at multiple wound care centers and hospital research centers across the United States of America. After qualifying per protocol, patients will be randomized to receive standard wound care or standard wound care plus Topical Oxygen Wound Therapy for their wounds. Patients will be monitored for 12 weeks. The primary comparator between the groups will be complete wound healing at 12 weeks, but other parameters will be assessed, such as pain, wound size reduction and infection status.

Enrollment: 145 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria

1. Subjects are male or female, 18 years of age or older. At least 50% of the enrolled population must be ≥ 65 years of age.

2. Subjects with one of the following wounds:

   A. Diabetic foot ulcer present for greater than 4 weeks (documented in the medical record) but less than 12 months duration if being treated with active SOC.

   B. Minor amputation wound sites

3. Subject has clinical documentation of no visible wound improvement in the after 4 weeks of standard of care. Objectively, less than 40% healing in the past four weeks from the first treatment visit.

4. Study ulcer is a minimum of 0.5 cm2 and a maximum of 25 cm2 at first treatment visit

5. Subjects' wound score on ISDA tool is Grade 1 or 2.

6. The subject is able and willing to follow the protocol requirements

7. Subject has signed informed consent

8. Adequate circulation to the affected foot as demonstrated by a dorsum transcutaneous oxygen measurement (TCOM) or a skin perfusion pressure (SPP) measurement of ≥ 30 mmHg; an ABI between 0.7 and ≤ 1.3, or TBI of >6 within 3 months of the first Screening Visit.

9. Females of childbearing potential must be willing to use acceptable methods of contraception (birth control pills, barriers, or abstinence).

10. The target ulcer has been offloaded for at least 14 days prior to randomization.

Exclusion Criteria

1. Subject has a known life expectancy of < 1 year
2. Subject or caregiver is unable to manage the Natrox® device (charge and change batteries daily)
3. Subject has ulcers that are completely necrotic or if the clinician feels it is clinically necessary to cover the wound surface in gel or creams that would prevent the transmission of oxygen to the wound surface.
4. Subject has major uncontrolled medical disorders such as serious cardiovascular, renal, liver or pulmonary disease, lupus, palliative care or sickle cell anemia.
5. Subject currently being treated for an active malignant disease or subjects with history of malignancy within the wound.
6. The Subject has other concurrent conditions that in the opinion of the Investigator may compromise subject safety
7. Known contraindications for the Natrox system
8. Known allergies to any of the Natrox system components
9. Concurrent participation in another clinical trial that involves an investigational drug or device that would interfere with this study.
10. Index ulcer has reduced in area by 20% or more after 2 weeks of standard of care from the first screening visit (S1) to the TV1/randomization visit.
11. Subject is pregnant or breast feeding.
12. Subjects with a history of more than two weeks treatment with immunosuppressants (including systemic corticosteroids >10mg daily dose), cytotoxic chemotherapy, or application of topical steroids to the ulcer surface within one month prior to first Screening Visit, or who receive such medications during the screening period, or who are anticipated to require such medications during the course of the study.
13. Index ulcer has been previously treated with tissue engineered materials (e.g. Apligraf® or Dermagraft®) or other scaffold materials (e.g. Oasis, Matristem) within the last 30 days preceding the first treatment visit.
14. Affected extremity requiring hyperbaric oxygen during the trial or within 2 weeks of treatment visit 1.
15. Known HbA1C >12%
16. An ulcer that has visible signs of improvement in the four weeks prior to randomization defined objectively as a 40% reduction in surface area in the four weeks prior to enrollment.
17. An ulcer that has healed by more than 20% in the 2 weeks prior to screening: "historical" run-in period.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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145 participants in 2 patient groups

Standard of care arm

No Intervention group

Description:

SOC was defined to include wound cleansing with sterile water or saline solution, and gentle irrigation of the study ulcer with warm tap water; sharp debridement using a standardised protocol based on TIME principles for wound bed preparation; offloading with a TCC twice in the first week and weekly thereafter (all exceptions had to be agreed by the lead investigator; a fixed ankle walker boot or similar device was acceptable as an alternative, but shoe inserts were not deemed to provide sufficient offloading); moisture balance was provided using a hydrofibre or alginate dressing. In addition, patients were instructed on adherence to the protocol and given instructions to call their clinic if they suspected any signs of an infection.

Intervention arm

Active Comparator group

Description:

Same protocol as SOC only but were also provided with a Natrox® Oxygen Wound Therapy System, consisting of two elements: the Natrox® OG and the Natrox® ODS. The OG is a multi-use battery powered device which generates oxygen though water electrolysis at a rate of 15mL/hr. The ODS is a sterile, single use device that allows wound exudate to pass through to the secondary dressing while allowing the diffusion of oxygen across the wound bed. It connects directly to the OG via a thin flexible fine-bore tube. While the ODS can remain in situ for 7 days, it should be changed at each dressing change, based on exudate level or clinical judgement. This is a battery-operated system with a 30-hour battery life; the kit includes two interchangeable, rechargeable batteries. Each participant was advised to charge one battery while the other was in use, as the battery required changing daily. The oxygen generator is worn in a holster so that patients can remain ambulatory.

Treatment:

Device: Natrox® Oxygen Wound Therapy