MCBE-161

This three-cohort, first-in-human, healthy participant study aims to assess the test medicine's safety and tolerability, including injection site reactions and how it is taken up by the body when given as a single dose.
For Cohort 1, up to 8 participants will be randomly assigned to receive the starting dose of the test medicine or dummy medicine (placebo) as a single intramuscular injection.
For Cohort 2, if the safety and tolerability results from Cohort 1 are satisfactory, up to 8 participants will be randomly assigned to receive double the starting dose of the test medicine or dummy medicine (placebo) as a single intramuscular injection.
For Cohort 3, if the safety and tolerability results from Cohort 1 are satisfactory, up to 8 participants will be randomly assigned to receive double the Cohort 2 dose of the test medicine or dummy medicine (placebo) as a single intramuscular injection.
Participants' blood and urine will be taken throughout the study for analysis of the test medicine and for their safety. When in the clinical unit, the injection site will be checked daily for reactions, and a diary will be provided on discharge for further recording. Participants will be discharged 6 days after dosing and return to the clinical unit an additional 9 times for for safety assessments to be performed. Participants are expected to be involved in this study for approximately 12 weeks for all study activities, from screening to the final return visit.