The purpose of this randomized, open-label, parallel-group, placebo-controlled study is to assess pain following subcutaneous (SC) administration of gantenerumab as a high-concentration liquid formulation (HCLF) at different injection speeds. The total duration of the study for each healthy participant will be up to approximately 21 weeks.

Inclusion Criteria:

• Healthy male and female participants (healthy status is defined by the absence of evidence of any active or chronic disease following a detailed medical and surgical history, a complete physical examination including vital signs, 12-lead electrocardiogram, hematology, blood chemistry, coagulation, serology, and urinalysis)
• Body mass index between 18.0 and 30.0 kilograms per meter squared (kg/m^2), inclusive
• Female participants of childbearing potential must commit to use two acceptable forms of contraception during the study and until at least 6 months after the follow-up visit

Exclusion Criteria:

• History of any clinically significant gastrointestinal, renal, hepatic, broncho-pulmonary, neurological, psychiatric, cardiovascular, endocrinological, hematological or allergic disease, metabolic disorder, cancer, or cirrhosis
• History or suspicion of drugs of abuse or alcohol addiction
• Smokers who smoke more than 10 cigarettes per day or equivalent amount of tobacco as determined by history
• Pregnant or lactating women
• Positive result on hepatitis B virus (HBV), hepatitis C virus (HCV), or Human immunodeficiency virus (HIV)-1 and -2
• Any familial history of early onset Alzheimer's disease
• Prior administration of gantenerumab
• Participation in an investigational drug medicinal product or medical device study within 90 days before dosing or within seven times the elimination half-life, whichever is longer
• Any abnormal skin conditions or potentially obscuring tattoos, pigmentation, or lesions in the area intended for SC injection