A Study to Evaluate Laser Speckle Contrast Imaging to Assess Changes in Chemical Agent-Induced Skin Blood Flow in Healthy Participants (MK-0000-420)

Phase 1

Completed

• Conditions: Healthy
• Interventions: Drug: Allyl Isothiocyanate (AITC); Drug: Capsaicin; Other: Vehicle for AITC; Other: Vehicle for Capsaicin

• Registration Number: NCT06809569
• Lead Sponsor: Merck Sharp & Dohme LLC

Brief Summary

Pain is a significant issue and there is a need for better treatments for pain management. Local changes in skin blood flow can be used as an indicator of pain in the body. Capsaicin and allyl isothiocyanate (AITC) increase blood flow and cause pain. The purpose of this study is to evaluate the use of laser speckle contrast imaging (LSCI) as a tool to assess changes in skin blood flow. Researchers want to learn about the effect size and reproducibility of using LSCI to measure the blood flow response to capsaicin and AITC.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-09-25
• Primary Completion: 2023-12-15
• Study Completion: 2023-12-15
• Status Verified: 2025-01
• Study First Submitted: 2025-01-30
• Study First Submitted QC: 2025-01-30
• Last Update Submitted: 2025-01-30
• Study First Posted: 2025-02-05
• Last Update Posted: 2025-02-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

• Is in good health based on medical history, physical examination, vital sign measurements, and electrocardiograms performed before randomization
• Has a skin surface without significant skin allergies, pigmentary disorders or active dermatological conditions that may interfere with the conduct of the laser speckle contrast imaging (LSCI) assessment

Exclusion Criteria

• Has a history of clinically significant endocrine, gastrointestinal, hematological, hepatic, immunological, renal, respiratory, or genitourinary abnormalities or diseases
• Has a history of stroke, chronic seizures, epilepsy, peripheral neuropathy or other clinically significant neurological disease or cognitive impairment that are severe enough to interfere with assessment of pain (sensory) systems

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Laser Speckle Contrast Imaging	Allyl Isothiocyanate (AITC)	Participants receive topical Allyl Isothiocyanate (AITC) application and intradermal capsaicin application sequentially along with a placebo comparator (vehicle for AITC and vehicle for capsaicin) once every 2 weeks per protocol to perform laser speckle contrast imaging.
Laser Speckle Contrast Imaging	Capsaicin	Participants receive topical Allyl Isothiocyanate (AITC) application and intradermal capsaicin application sequentially along with a placebo comparator (vehicle for AITC and vehicle for capsaicin) once every 2 weeks per protocol to perform laser speckle contrast imaging.
Laser Speckle Contrast Imaging	Vehicle for AITC	Participants receive topical Allyl Isothiocyanate (AITC) application and intradermal capsaicin application sequentially along with a placebo comparator (vehicle for AITC and vehicle for capsaicin) once every 2 weeks per protocol to perform laser speckle contrast imaging.
Laser Speckle Contrast Imaging	Vehicle for Capsaicin	Participants receive topical Allyl Isothiocyanate (AITC) application and intradermal capsaicin application sequentially along with a placebo comparator (vehicle for AITC and vehicle for capsaicin) once every 2 weeks per protocol to perform laser speckle contrast imaging.

Primary Outcome Measures

Name	Time	Method
Mean Dermal Blood Flow (DBF) in the Region of Interest (ROI)	Up to approximately 60 minutes	DBF is defined as the local changes in the skin blood flow after application of study intervention. DBF will be measured via a Laser Speckle Contrast Imager. The mean DBF in the ROI will be reported.
Area Under the Curve from Time 0 to 20 Minutes (AUC0-20) of Mean DBF in the ROI	Up to approximately 20 minutes	AUC0-20 is defined as the area under the curve from time 0-20 minutes. DBF is defined as the local changes in the skin blood flow after application of study intervention. DBF will be measured via a Laser Speckle Contrast Imager. AUC0-20 of mean DBF in ROI will be reported.
Area Under the Curve from Time 0 to 60 Minutes (AUC0-60) of Mean DBF in the ROI	Up to approximately 60 minutes	AUC0-60 is defined as the area under the curve from time 0-60 minutes. DBF is defined as the local changes in the skin blood flow after application of study intervention. DBF will be measured via a Laser Speckle Contrast Imager. AUC0-60 of mean DBF in ROI will be reported.

Secondary Outcome Measures

Name	Time	Method
Change from Baseline in the Mean Intensity of DBF (Flare-1 Mean)	Baseline, Up to 60 minutes	Flare-1 mean is defined as the mean perfusion of measurement points exceeding baseline mean DBF + 1 standard deviation. The change from baseline in the mean intensity of DBF (Flare-1 Mean) will be reported.
Change from Baseline in the Area of DBF (Flare-1 Area)	Baseline, Up to 60 minutes	Flare-1 area is defined as the total area of points with perfusion values exceeding baseline mean DBF + 1 standard deviation. The change from baseline in the area of DBF (Flare-1 Area) will be reported.
Change from Baseline in the Mean Intensity of DBF (Flare-2 Mean)	Baseline, Up to 60 minutes	Flare-2 mean is defined as the mean perfusion of points with perfusion values exceeding baseline mean DBF + 2 standard deviations. The change from baseline in the mean intensity of DBF (Flare-2 Mean) will be reported.
Change from Baseline in the Area of DBF (Flare-2 Area)	Baseline, Up to 60 minutes	Flare-2 area is defined as total area of points with perfusion values exceeding baseline mean DBF + 2 standard deviations. The change from baseline in the area of DBF (Flare-2 Area) will be reported.
Mean Change From Baseline in Pain Intensity Measured Using a Pain Numeric Rating Scale (NRS)	Baseline, Up to 60 minutes	The participant's pain intensity will be assessed on each arm utilizing a pain numeric rating scale (NRS). NRS will characterize pain on a scale of 0 to 10, with 0 being 'no pain' and 10 being the 'worst pain' imaginable. The higher score indicates worse pain intensity. The mean change from baseline in pain intensity will be reported.

Trial Locations

Locations (1)

Center for Clinical Pharmacology (CCP) (Site 0001); 🇧🇪 Leuven, Vlaams-Brabant, Belgium