This is a Phase 1, double-blind, randomized, placebo-controlled, single-dose and multiple-dose study of CRN01941 in up to 119 healthy male and female subjects. This single-center study will be conducted in 3 parts: a single-ascending dose phase (up to 8 cohorts, 8 subjects/cohort), a multiple-ascending dose phase (up to 5 cohorts, 9 subjects/cohort), and single dose phase in elderly subjects (1 cohort, 10 subjects).

Inclusion Criteria:

1. Male and female subjects 18 to 55 years of age, inclusive, at time of screening (Parts 1 and 2 only).
2. Males and females subjects 65 to 85 years of age at screening (Part 3 only).
3. Females must be non-pregnant and non-lactating, postmenopausal by history and confirmed by follicle stimulating hormone (FSH) >30 U/L at Screening, or surgically sterile.
4. Male subjects must be surgically sterile or agree to use highly effective form of contraception when sexually active with a female partner of child bearing potential.
5. Body mass index (BMI) of 18 to 32 kg/m2, inclusive at Screening.
6. Willing to provide signed informed consent.

Exclusion Criteria:

1. Any uncontrolled or active major systemic disease which makes study participation unsafe or could interfere with evaluation of the endpoints of the study.
2. History or presence of malignancy within the past 5 years, not including treated basal cell carcinomas and in situ cervical neoplasia.
3. Use of any investigational drug within the past 60 days.
4. Have a medically significant abnormality observed during screening or admission.
5. Use of any prior medication without approval of the investigator within 14 days prior to admission.
6. Subjects with human immunodeficiency virus (HIV), hepatitis B or hepatitis C infections. Subjects with previous hepatitis C infection that is now cured may be eligible.
7. History of or current alcohol or substance abuse in the past 12 months
8. Any condition that in the opinion of the investigator would jeopardize the subject's appropriate participation in this Phase 1 study.

Double-blind study