Normast3 for Adults With Diabetic Polyneuropathy

This is a single-center, randomized, double-blind, placebo-controlled, parallel-group clinical trial evaluating Normast® 3 as add-on treatment in adults with diabetic polyneuropathy involving both small and large nerve fibers. The study is designed to assess whether 12 weeks of treatment with Normast® 3 improves neuropathic pain and selected clinical, psychophysical, autonomic, and morphometric markers of nociceptive and autonomic nerve fiber function compared with placebo.

Approximately 40 participants will be randomized in a 1:1 ratio to receive either Normast® 3 or matching placebo for 12 weeks, while continuing stable standard-of-care treatment. Study assessments are performed at baseline, at the end of the 12-week treatment period, and at a 24-week follow-up visit to evaluate persistence of treatment effects.

The study population includes adults with diabetic polyneuropathy characterized by symptoms and signs of distal sensory involvement and objective evidence of large- and small-fiber abnormalities. Neurological assessment includes evaluation of negative sensory signs, such as tactile, pinprick, and thermal hypoesthesia, and positive sensory signs, such as spontaneous pain, paroxysmal pain, allodynia, and pinprick hyperalgesia. Quantitative sensory testing is performed at the foot to assess thermal, mechanical, pain, pressure, paradoxical heat, and vibration-related sensory parameters.

Autonomic nervous system function is assessed using sudomotor and cardiovascular autonomic testing. Sudomotor function is evaluated through quantitative assessment of activated sweat glands at the distal leg. Cardiovascular autonomic testing includes heart-rate and blood-pressure responses at rest, during paced deep breathing, standing, the Valsalva manoeuvre, and sustained handgrip.

Skin biopsy is used to assess small-fiber and autonomic innervation. Samples are obtained from standardized distal and proximal sites and processed using immunofluorescence methods. Morphometric analyses include intraepidermal nerve fiber density, distal-to-proximal nerve fiber density ratio, sweat gland and piloerector muscle autonomic innervation density, and expression patterns of selected nociceptor-related skin biomarkers.

Normast® 3 contains palmitoylethanolamide co-micronized with rutin and hydroxytyrosol. The active product and placebo are prepared to be indistinguishable in appearance and administered twice daily. Treatment allocation is concealed from participants and study personnel until completion of the blinded phase, except when unblinding is required for safety reasons.

Safety and tolerability are assessed through clinical monitoring, vital signs, laboratory testing, and adverse-event collection during the treatment period. Compliance is assessed by return of used treatment packs at study visits. The total observation period for each participant is approximately 6 months, and the overall study duration is estimated to be approximately 18 months.