The purpose of this study is to evaluate the efficacy, pharmacodynamics (PD), and safety of ALN-AGT01 RVR in participants with mild to moderate hypertension pretreated with zilebesiran.

This study will be conducted in 2 parts:

• Part A: Single dose (SD), dose-ranging part in adults with mild to moderate hypertension.
• Part B: SD in adults with mild to moderate hypertension.

Part A: Inclusion Criteria

• Is an adult participant with a mean seated office systolic blood pressure (SBP) of at least 130 mmHg and no more than than 170 mmHg
• Either not taking antihypertensive medication or on stable therapy with up to 2 antihypertensive medications

Part B: Inclusion Criteria

• Is an adult participant with a mean seated office SBP of at least 140 mmHg and no more than 170 mmHg
• Has discontinued all prior antihypertensive medication other than a calcium channel blocker (CCB) and/or thiazide/thiazide-like diuretic (if taking) for at least 3 weeks

Both Parts: Exclusion Criteria

• Has known secondary hypertension or serum potassium more than 5 mmol/L
• Has an estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73m^2

Note: other protocol defined inclusion / exclusion criteria apply

Access to Anonymized individual participant data that support these results is made available 12 months after study completion and not less than 12 months after the product and indication have been approved in the US and/or the EU.

Access to data may be declined where there is likelihood a patient could be identified or other feasibility issue, where there is a potential conflict of interest, a planned business activities or an actual or potential competitive risk. Data will be provided contingent upon the approval of a research proposal and the execution of a data sharing agreement. Timeframes for data access may vary and can take up to 6 months or more.

Requests for access to data can be submitted via the website www.vivli.org. Questions can also be directed to datasharing@alnylam.com.