The present study in healthy participants will assess the safety, tolerability, immunogenicity, pharmacokinetics (PK) and pharmacodynamics (PD) of single ascending doses (SAD) of subcutaneously administered M5542.

Inclusion Criteria:

• Participants are overtly healthy, as determined by medical evaluation, by physical examination or laboratory evaluation and no active clinically significant disorder, condition, infection, or disease that would pose a risk to participant safety or interfere with the study evaluation, procedures, or completion at Screening and Day -1
• Participants have a body weight within the range 50 to 100 kilograms (kg) (inclusive) and body mass index (BMI) within the range 18 to 30.0 kilograms per square meter kg/m^2 (inclusive) at Screening
• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• History or presence of clinically relevant respiratory, gastrointestinal, renal, hepatic, hematological, lymphatic, neurological, cardiovascular, musculoskeletal, genitourinary, immunological, dermatological, connective tissue, psychiatric and other diseases or disorders, and epilepsy, as determined by medical evaluation at Screening and Day -1
• Any condition, including findings in the laboratory tests or other screening assessments, that in the opinion of the Investigator constitutes an inappropriate risk or a contraindication for participation in the study or that could interfere with the study's objectives, conduct, or evaluation at Screening and on Day -1
• History of any malignancy
• History of chronic or recurrent acute infection or any bacterial, viral, parasitic, or fungal infections within 30 days prior to Screening and at any time between Screening and admission, or hospitalization due to infection within 6 months prior to Screening
• Immunization with any live vaccine for 12 weeks and subunit or inactivated vaccines for 2 weeks prior to dosing on Day 1. For the herpes zoster vaccine (e.g. Shingrix), if the first dose is administered at least 2 weeks prior to Day 1, the second dose must be administered after the study treatment period has been completed
• Other protocol defined exclusion criteria could apply

IPD will not be shared for Phase I interventional or observational studies. Further information on how to request data can be found on our website bit.ly/IPD21.