A Study to Assess the Absolute Bioavailability and How Adimanebart SC Moves Through the Body in Healthy Adult Participants

Inclusion Criteria: * Is at least the local legal age of consent and aged 18 to 65 years, inclusive, when signing the ICF. * Has a body weight between 60 and 100 kg and a BMI between 18.5 and 30 kg/m2, inclusive, at screening and on day -1 for part 1 and part 3, or has a body weight \<60 kg or between 100 and 130 kg and a BMI between 18.5 and 38.0 kg/m2, inclusive, at screening and on day -1 for part 2. * Discontinues and refrains from using all medications, including nonprescription and prescription medications, for ≥2 weeks before IMP administration, except for hormonal contraceptives and hormone replacement therapy in female participants. The occasional use of acetaminophen or ibuprofen is allowed. Exclusion Criteria: * Has any current or past clinically meaningful medical or psychiatric condition, including severe hypersensitivity reactions to drugs and/or food that, in the investigator's opinion, would confound the study results or put the participant at undue risk. * Previously participated in an adimanebart clinical study and received at least 1 dose of IMP. * Is currently participating in another interventional clinical study, or has received an IMP in another clinical study within 12 weeks or 5 half-lives (whichever is longer) before screening.