A First In Human (FIH) Study to Learn if Different Doses of ALN-ANG3 Are Safe and Well Tolerated in Healthy Adults

Key Inclusion Criteria:

1. Judged by the investigator to be in good health based on medical history, physicalexamination, vital sign measurements, and electrocardiogram's (ECG's) performed atscreening and/or prior to administration of initial dose of study drug

2. Has fasting triglyceride (TG) levels >=100 and <500 mg/dL (1.13-5.65 mmol/L) andfasting low-density lipoprotein (LDL-C) >=70 and <=300 mg/dL (1.81-7.76 mmol/L)during screening visits. Testing may be repeated once during the screening period.

3. Has a body mass index between 18 and 35 kg/m^2, inclusive, at screening visit

Key Exclusion Criteria:

1. History of clinically significant cardiovascular, respiratory, hepatic, renal,gastrointestinal, endocrine, hematological, psychiatric, neurological or otherdisease, as assessed by the investigator that may confound the results of the studyor poses an additional risk to the participant by study participation

2. Was hospitalized (ie, >24 hours) for any reason within 30 days of the screeningvisit

3. Any malignancy, except for non-melanoma skin cancer or cervical/anus in-situ thathave been resected with no evidence of metastatic disease for 3 years prior to thescreening visit

4. Has a history of significant multiple and/or severe allergies (eg, latex gloves), orhas had an anaphylactic reaction to prescription or non-prescription drugs or food

5. With the exception of stable (approximately 6 months at same dose level) statin use,any prescription medication for approximately 2 weeks or 5 half-lives, whichever islonger, prior to first administration of the study drug through the end of study (EOS). Non-prescription medications and nutritional supplements are permitted afteralignment of investigator and sponsor on their use

6. Using the Modification of Diet in Renal Disease (MDRD) or Chronic Kidney DiseaseEpidemiology (CKD-ePI) equation, has an estimated Glomerular Filtration Rate (GFR)of <60 mL/min/1.73m2 at the screening visit, as defined in the protocol

7. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) with clinicallysignificant abnormality in the opinion of investigator or ≥1.5× upper limit ofnormal (ULN) range at screening or day -1 visits

8. Is positive for human immunodeficiency virus (HIV) or hepatitis B surface antigen (HBsAg) at the screening visit. Evidence of prior hepatitis B immunization or priorresolved hepatitis B infection is not an exclusion

9. Is positive for hepatitis C antibody and positive for qualitative (ie, detected ornot detected) hepatitis C virus (HCV) ribonucleic acid (RNA) test at the screeningvisit

NOTE: Other Protocol Defined Inclusion / Exclusion Criteria Apply