(490 days)
The N-SWEAT Patch is indicated for treatment of primary axillary hyperhidrosis in adults.
The N-SWEAT Patch is composed of metallic sodium on a polyester tape. This sodium bilayer is mounted to a polyethylene medical tape (adhesive backing) and covered with a release liner which is removed prior to application. The non-sterile packaged in an impermeable, argon filled, foil pouch. The packaging protects the patch during transit and storage, preventing exposure to the environment including water and air. The device is provided non-sterile and is not intended to be sterilized. A disposal kit is provided with each N-SWEAT Patch to deactivate the patch after use. The kit includes a prefilled bottle of deactivation solution, a cover paper, and a plastic bag.
The N-SWEAT patch is a non-invasive, single-use topical patch device. The N-SWEAT patch is a thermal energy-based medical device that is activated by water released from sweat glands. When applied to a dry axilla by a clinician. the sodium bilayer in the patch interacts with the water component of sweat causing the patch to generate thermal energy as well as the byproduct sodium hydroxide (NaOH) (sodium hydroxide does not contribute to the therapeutic mechanism). The rapid exothermic reaction between sweat (water) and sodium is limited by both the amount and location of the sweat. The thermal energy temporarily inactivates sweat glands leading to a reduction in sweat production. In the absence of sweat, no thermal energy is generated.
The release liner is removed immediately prior to the treatment. The reactive material is a thin layer of sodium, which interacts with the patient's sweat to deliver the treatment. The polyethylene adhesive backing on which the sodium bilayer is mounted holds the patch in place during the treatment. The argon gas provides an inert environment in the packaging to prevent the patch from oxidizing and to increase the shelf life.
The N-SWEAT Patch is applied by a clinician to the surface of dry, unabraded, intact skin of the axilla. After the skin is cleansed and dried, the release liner is removed, and the device is applied to the skin for up to 3 minutes in a physician's office or clinic. The entire device is then removed and disposed of by medical personnel. The skin is then cleansed with water to remove any sodium hydroxide residue.
The N-SWEAT Patch is indicated for the treatment of primary axillary hyperhidrosis in adults. The acceptance criteria and the study that proves the device meets these criteria are detailed below.
1. Table of Acceptance Criteria and Reported Device Performance
According to the "Special Controls" section, clinical performance testing must demonstrate: (i) reduction in hyperhidrosis using a validated measure; (ii) all adverse events; and (iii) impact of residual chemical on the skin. Non-clinical performance testing must cover: (i) thermal reactivity; (ii) total energy and energy flux; and (iii) characterization of chemical distribution. Additionally, biocompatibility, shelf-life, and comprehensive labeling are required.
| Acceptance Criteria Category | Specific Acceptance Criterion | Reported Device Performance |
|---|---|---|
| Clinical Performance | (i) Reduction in hyperhidrosis using a validated measure (HDSS) | Primary Endpoint (HDSS 1 or 2 at 4 weeks, PP population): 63.6% (28/44) for N-SWEAT Treated vs. 44.2% (19/43) for Sham. (p=0.0332) (Met) |
| Secondary Endpoint (HDSS reduction by ≥2 points, PP population): 43.2% for N-SWEAT Treated vs. 16.3% for Sham. (Met) | ||
| (i) Reduction in hyperhidrosis using a validated measure (GSP) | Secondary Endpoint (GSP reduction by ≥50%, PP population): 60.5% of N-SWEAT treated subjects. (Met) | |
| Mean change in GSP (PP population): -57.3 mg/5min for N-SWEAT Treated vs. -18.2 mg/5min for Sham. (Met) | ||
| (ii) All adverse events | 16 N-SWEAT treated subjects had 22 AEs reported (25.4% of subjects). Most (17/22) were at the treatment site. All AEs were mild to moderate, none severe or serious, and resolved without sequalae. (Met) | |
| (iii) Impact of residual chemical on the skin (pH) | Post-procedure mean pH of 7.9 and median pH of 8.1, below the pH 11 acceptance criterion. (Met) | |
| Non-Clinical Performance | (i) Thermal reactivity of the active device component(s) | Samples with real-time aging showed average 8.5°C temperature increase, accelerated aging showed 10.5°C temperature increase, both meeting the 5-18.5°C acceptance criterion. (Met) |
| (ii) The total energy and energy flux of the device | Thermal characterization was performed by calorimetry. Specific values not provided in the summary but indicated as tested. (Met; assumed to meet internal criteria) | |
| (iii) Characterization of the distribution and homogeneity of the chemical(s) | Thermal characterization performed by characterizing the amount and distribution of sodium on the patch. Specific details not provided in the summary but indicated as tested. (Met; assumed to meet internal criteria) | |
| Biocompatibility | (3) Patient-contacting components must be demonstrated to be biocompatible | Evaluated in accordance with ISO 10993-1, including Cytotoxicity (MEM Elution Test), Sensitization (Guinea Pig Maximization), Irritation (Primary dermal irritation), and Systemic toxicity (porcine model). Results demonstrate the N-SWEAT Patch is biocompatible. (Met) |
| Shelf-Life | (4) Performance testing must support the shelf life of the device and package integrity | N-SWEAT Patch shelf-life verified to be 1 year based on sodium reactivity specifications (real-time and accelerated aging). Disposal Kit shelf-life verified to be 6 months. (Met) |
| Labeling | (5) Labeling must bear all information for safe and effective use. | Labeling is sufficient and meets requirements for prescription devices, including indications, description, contraindications, warnings, clinical data summary, IFU, potential AEs, storage, and symbols. Meets 21 CFR 801.109. (Met) |
| (6) Patient and physician labeling must include: | ||
| (i) clinical performance summary | ||
| (ii) risks | ||
| (iii) duration of effect | Labeling includes summary of clinical data, known/potential risks (local AEs, systemic effects, perspiration changes), and information about known duration of effect. (Met) | |
| (7) Physician labeling must also include: | ||
| (i) disposal instructions | ||
| (ii) shelf life | Physician labeling includes instructions for safe disposal of chemically-reactive components and a shelf life. (Met) |
2. Sample Size Used for the Test Set and Data Provenance
The primary clinical study was a randomized, double-blinded, sham-controlled, pivotal study.
- Sample Size for Test Set (Clinical Study):
- Intent-to-Treat (ITT) population: 110 randomized participants (53 N-SWEAT Treated, 57 Sham). An additional 10 participants were treated with the active device in an early safety roll-in, making the total N-SWEAT treated for safety reporting 63 (53+10).
- Per Protocol (PP) population (primary effectiveness analysis set): 89 participants (46 N-SWEAT Treated, 43 Sham). 20 participants were excluded from the PP analysis due to confounding medications.
- Data Provenance: The study involved 11 clinical trial sites. The document does not explicitly state the country of origin, but typical FDA De Novo submissions involve studies conducted in the United States or with data accepted under FDA regulations for international studies. Given the lack of specific country mention, it is reasonable to assume it aligns with typical FDA submission practices, likely within the US.
- Retrospective or Prospective: The study was a prospective randomized, double-blinded, sham-controlled clinical trial.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
For the clinical study, the primary endpoint (HDSS score) and secondary endpoints (GSP, QoL scores) were patient-reported outcomes or objective measurements.
- HDSS and QoL (Bother/Impact): These are self-reported patient questionnaires, not requiring expert consensus for ground truth.
- GSP (Gravimetric Sweat Production): This is an objective, quantitative measurement of sweat, also not requiring expert consensus for ground truth.
- AEs: Adverse events were recorded by the investigators (clinicians at the study sites). An Independent Data Safety Monitoring Board (DSMB) comprised of 3-5 clinical physicians with expertise in dermatology reviewed adverse events to monitor for safety risks. These experts primarily adjudicated safety, not the core effectiveness ground truth as it was based on quantitative and patient-reported metrics.
4. Adjudication Method for the Test Set
The effectiveness endpoints (HDSS, GSP, QoL) were objective or patient-reported measures and thus did not involve an adjudication method in the sense of expert review for ambiguous cases. The study was double-blinded, meaning neither the participants nor the staff administering the treatment and collecting initial data knew whether the active or sham device was used, minimizing bias in data collection. The DSMB reviewed safety data.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study was not performed. This device is a treatment patch, and the clinical study evaluated the direct effectiveness of the patch versus a sham, rather than comparing human readers' performance with and without AI assistance in interpreting diagnostic images or data.
6. Standalone (Algorithm Only) Performance
This question is not applicable. The N-SWEAT Patch is a physical medical device that applies thermal energy, not an algorithm, AI, or software acting in a standalone diagnostic or interpretative capacity.
7. Type of Ground Truth Used
- Clinical Study (Effectiveness):
- Patient-reported outcomes: Hyperhidrosis Disease Severity Scale (HDSS) score and Quality of Life (QoL) surveys for Bother and Impact.
- Objective quantitative measurement: Gravimetric Sweat Production (GSP).
- pH Sub-study: Objective quantitative measurement of skin pH using a Hanna H199181 skin pH meter.
- Non-Clinical/Bench Studies: Laboratory measurements and standardized test methods (e.g., thermal characterization, sodium reactivity tests, biocompatibility tests).
8. Sample Size for the Training Set
The concept of a "training set" is not relevant here as the N-SWEAT Patch is a physical medical device, not a machine learning or AI algorithm that requires a training dataset. The clinical study was designed to evaluate the safety and effectiveness of the device itself.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
N/A