Study investigating safety, tolerability, PK and PD of KCP506

Gender: male (all parts) or female (Parts A and B only)
Age: 18 to 55 years, inclusive, at screening
Weight: 50 to 105 kg, inclusive
Body mass index: 18.0 to 30.0 kg/m2, inclusive
Status: healthy subjects

1. Previous participation in the current study, except subjects in Part C may have participated in Parts A or B,
provided they have not received a dose of KCP506 in the 3 months prior to Part C dosing.
2. Employee of PRA, CHDR or the Sponsor.
3. History of relevant drug and/or food allergies, per the Investigator’s assessment.
4. Using tobacco products within 60 days prior to first drug administration
5. History of alcohol abuse or drug addiction (including cannabis products), per the Investigator’s assessment.
6. Positive drug and/or alcohol screen (opiates, methadone, cocaine, amphetamines [including ecstasy], cannabinoids, barbiturates, benzodiazepines, tricyclic antidepressants, nicotine [cotinine – Parts A and B only]. and alcohol) at screening or first admission to the clinical research center. Tests may be repeated once at screening and once at admission in case of a suspected false positive result.
7. Average intake of more than 24 units of alcohol per week (1 unit of alcohol equals approximately 250 mL of beer, 100 mL of wine, or 35 mL of spirits).
8. Positive screen for hepatitis B surface antigen (HBsAg), antihepatitis C virus (HCV) antibodies, or antihuman immunodeficiency virus (HIV) 1 and 2 antibodies.
9. Participation in a drug study within 60 days (Parts A and B) or 90 days (Part C) or 5 drug elimination half-lives, whichever is longer) prior to the first drug administration in the current study. Participation in more than 3 other drug studies in the 10 months prior to the first drug administration in the current study.
10. Donation or loss of more than 100 mL of blood within 60 days prior to the first drug administration. Donation or loss of more than 1.5 liters of blood (for male subjects)/more than 1.0 liters of blood (for female subjects) in the 10 months prior to the first drug administration in the current study.
11. Significant and/or acute illness within 5 days prior to the first drug administration that may impact safety assessments or be consistent with COVID-19 infection, in the opinion of the Investigator.
12. Unsuitable veins for infusion or blood sampling.
13. Close contact with persons diagnosed with COVID-19 within 14 days prior to screening.
14. Positive nasopharyngeal PCR or rapid antigen test for SARS-CoV-2 on Day -1.
15. Receipt of a vaccine within 14 days prior to the first study drug administration (Parts A and B) or either study drug administration (Part C).
In addition, a subject who meets any of the following exclusion criteria will not be eligible for inclusion in Part C of the study:
16. Any confirmed significant allergic reactions (urticaria or anaphylaxis) after previous exposure to capsaicin.
17. Subject indicating intolerable pain after capsaicin administration at screening.
18. Wide-spread tattoos or scarring on the volar forearms preventing proper assessment of secondary mechanical allodynia.
19. No secondary mechanical allodynia induced in subject (area of secondary mechanical allodynia = 0 mm2) at screening.
20. Any current, clinically significant, known medical condition that would affect sensitivity to cold (such as atherosclerosis, Raynaud’s disease, urticaria, hypothyroidism) or pain (ie, disease that causes pain, hypesthesia, hyperalgesia, allodynia, paranesthesia, neuropathy).
21. Subjects who, at screening, indicate pain tests to be intolerable or who achieve tolerance at >80% of maximum input intensity for cold and electrical pain tests.