Human Experimental Models of Pain (HEMP)

This pilot study will test an innovative way to establish how pain medicines provide analgesia in healthy adults. The study uses a group of short, controlled pain tests to look at different types of pain responses in the body. The main goal is to find out if this testing approach can show the pain-relieving effects of 2 medicines, pregabalin and naproxen versus placebo, and show how they provide relief of different types of pain. The study hypothesis is that this pain testing approach administered as a battery would be able to tell the difference between a medicine that works mainly in the brain and spinal cord (pregabalin) and a medicine that works mainly on inflammation in body tissues (naproxen). Up to 25 healthy adults will take part. Each participant will receive all 3 study treatments, pregabalin, naproxen, and placebo, administered in random order during separate study periods. The order will be assigned by chance. Neither the participant nor the study team will know which treatment is given at each visit. The study includes several experimental pain tests. These include:…

• Change from baseline in pain intensity after cold pressor test
• Change from baseline in pain intensity for allodynia (soft brush) after first heat/capsaicin pain model application
• Change from baseline in pain intensity for hyperalgesia (pin-prick) after first heat/capsaicin pain model application
• Change from baseline in pain intensity for mechanical hyperalgesia (pin-prick) at the UVB site

1. Study completion expected

   Dec 31, 2030

2. Primary completion expected

   Dec 31, 2029

3. Expected to start

   Nov 1, 2026

4. Last registry update

   Oct 27, 2026

5. Registered

   Apr 24, 2026