The primary purpose of this study is to assess the safety and tolerability of single ascending doses of ALXN2030 in healthy participants.

Approximately 48 healthy adult participants (36 participants will be on ALXN2030 and 12 participants will be on placebo) are expected to be enrolled.

Inclusion Criteria:

• Healthy participants
• QTcF ≤ 450 msec at Screening and on admission (ie, on Day -1).
• Participants of Japanese descent are defined as: First generation (born to 2 Japanese parents and 4 Japanese grandparents).
• Participants of Japanese descent must be between 20 and 60 years of age.
• BMI within the range 18-32kg/m2 (inclusive) at Screening.

Exclusion Criteria:

• Current or recurrent disease
• Current or relevant history of physical or psychiatric illness.
• Any other significant disease or disorder that, in the opinion of the Investigator, may put the participant at risk.
• Female participants who are pregnant or breastfeeding.
• Major surgery or hospitalization within 90 days prior to dosing on Day1.
• History of allergy or hypersensitivity to an oligonucleotide or GalNAc moiety or any excipients of ALXN2030.

Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.