A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of mRNA-6231 in Healthy Adults

A Phase 1, Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of mRNA-6231, Encoding for a Human Serum Albumin - Interleukin-2 Mutein Fusion Protein (HSA-IL2m), in Healthy Adults

There are 2 parts to this study: a single ascending dose (single dose of mRNA-6231) part and a multiple ascending dose (repeat doses of mRNA-6231) part. The main goal of this study is to evaluate the safety and tolerability of escalating doses of single and repeat subcutaneous (SC) administration of mRNA-6231. Dose levels of mRNA-6231 are planned to be investigated in a dose-escalation manner.

Key Inclusion Criteria:

• Understand and agree to comply with the study procedures and provide written informed consent

Key Exclusion Criteria:

• Has received any investigational product (for example, study drug, biologic, device) within 30 days or 5 elimination half-lives, whichever is longer
• Pregnant or lactating women
• Men and women of childbearing potential without effective contraception during the study
• Has any lab abnormalities or clinically significant medical condition that could interfere with the interpretation of study results or limit the participant's enrollment