Testing Experimental Frontotemporal Dementia Medication

Eligibility Details: Inclusion Criteria: - BMI 18.0-35.0 kg/m2 - 45-120 kg, inclusive - At screening, females must be non-pregnant and non-lactating, or of nonchildbearing potential (either surgically sterilized or physiologically incapable of becoming pregnant, or at least 1-year postmenopausal (amenorrhoea duration of 12 consecutive months); nonpregnancy will be confirmed for all females by a pregnancy test conducted at screening, (each) admission, and at follow-up. - Female participants of child-bearing potential must agree to use adequate contraception from screening until 90 days after the follow-up visit. A - In good physical health on the basis of no clinically significant findings from medical history, physical examination (PE), laboratory tests, 12 lead ECG, and vital signs, as judged by the Investigator. - Willingness and able to comply with the study protocol, in the investigator's judgement. Exclusion Criteria: - Known history of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric, human, or humanized antibodies or fusion proteins. - Positive drug or alcohol at screening and prior to first dose - History of alcohol abuse or substance abuse