This will be a 2- part, phase 1, open-label, single center, single ascending dose study to investigate the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of subcutaneous (SC) and intravenous (IV) administration of CSL312 in healthy adult Japanese and Caucasian subjects.

Inclusion Criteria:

• Healthy Caucasian and Japanese male or female subjects 18 to 55 years old (inclusive) that meet the following criteria at Screening:

  • Japanese subjects defined as being born in Japan, having not lived outside of Japan for more than 10 years, and having both parents and four grandparents who are of Japanese ancestry.
  • Caucasian subjects, defined as having both parents and four grandparents descended from and of the peoples of Europe, the Middle East, or North Africa, who are body weight-matched (± 15%) 1:1 with Japanese subjects.

• Body weight in the range of ≥ 50 kg and ≤ 100 kg

• Body mass index of ≥ 18 kg/m2 and ≤ 30 kg/m2

Exclusion Criteria:

• Positive serology test for human immunodeficiency virus (HIV)-1 / 2 antibody, hepatitis B virus (HBV) surface antigen (HBsAg) or hepatitis C virus (HCV) antibody.
• Received any live viral or bacterial vaccinations within 8 weeks of Screening or is expected to receive any live virus or bacterial vaccinations during the study.
• Evidence of current active infection.
• Known malignancy or a history of malignancy in the past 5 years .
• Blood pressure or pulse rate measurements outside the normal range for the subject's age.
• Female subject of childbearing potential or fertile male subject either not using or not willing to use an acceptable method of contraception
• Pregnant, breastfeeding, or not willing to cease breastfeeding.
• Donation or loss of more than 500 mL of blood within 3 months, or donated plasma within 7 days
• History of clinically significant arterial or venous thrombosis, bleeding disorder, or any abnormal coagulation test result

CSL will consider requests to share Individual Patient Data (IPD) from systematic review groups or bona-fide researchers. For information on the process and requirements for submitting a voluntary data sharing request for IPD, please contact CSL at clinicaltrials@cslbehring.com.

Applicable country specific privacy and other laws and regulations will be considered and may prevent sharing of IPD.

If the request is approved and the researcher has executed an appropriate data sharing agreement, IPD that has been appropriately anonymized will be available.

IPD requests may be submitted to CSL no earlier than 12 months after publication of the results of this study via an article made available on a public website.

Requests may only be made by systematic review groups or bona-fide researchers whose proposed use of the IPD is non-commercial in nature and has been approved by an internal review committee.

An IPD request will not be considered by CSL unless the proposed research question seeks to answer a significant and unknown medical science or patient care question as determined by CSL's internal review committee.

The requesting party must execute an appropriate data sharing agreement before IPD will be made available.