The purpose of this study is to evaluate the safety, tolerability, pharmakokinetics and pharmacodynamics of single and repeated doses of ANX009

In this first in human, phase 1, randomized, double-blind, placebo-controlled study, single and multiple ascending doses of ANX009 or placebo will be administered to 48 healthy subjects.

Single Ascending Dose (SAD): Each SAD subject will participate for approximately 4 weeks (3 nights in-clinic confinement).

Multiple Ascending Dose: Each MAD subject will participate for approximately 6 weeks (17 nights in-clinic confinement).

All subjects will be contacted (in clinic visit or phone call) 6 months after study completion.

Inclusion Criteria:

1. Healthy male and non-pregnant, non-lactating female volunteers ≥18 to 59 years of age.
2. Females must be postmenopausal, surgically sterilized or willing and able to use highly effective methods of contraception from screening through the final study visit.
3. Males with a partner of childbearing potential must agree to use contraception from Screening through the final study visit.
4. Documented history within 5 years of screening of previous vaccination against encapsulated bacterial pathogens (MAD cohorts only).
5. Complete the full sequence of protocol-related doses, procedures and evaluations.
6. No alcohol and drugs of abuse at screening and baseline or through study completion.
7. Discontinue use of nutritional supplements and prescription and over-the-counter medications (vitamins are allowed).
8. No new tattoos/piercings or elective surgery from screening through the End of Study visit
9. Ability to understand and provide written informed consent.

Exclusion Criteria:

Subjects must not meet any of the following criteria:

1. Clinically significant, ongoing illness or medical condition that would jeopardize the safety of the subject, limit participation, or compromise the interpretation of the safety data derived from the subject.
2. Clinically significant findings on the screening or Baseline ECG or physical examination.
3. Clinically significant abnormalities on screening or Baseline laboratory assessments.
4. An ANA titer ≥ 1:160.
5. History of any autoimmune disease.
6. History of meningitis or septicemia.
7. Clinically significant infection that required medical intervention (not including antibiotic prophylaxis) within 1 month prior to study drug dosing.
8. Known genetic deficiencies of the complement cascade system or immunodeficiency.
9. Treatment with an investigational therapeutic agent within 30 days prior to study drug dosing.
10. Use of immunosuppressants or corticosteroids within 30 days prior to study drug dosing.
11. Active alcohol abuse, drug abuse or substance abuse.
12. Hypersensitivity to any of the excipients in the ANX009 drug product or active substance.
13. History of previous sensitivities or allergic or anaphylactic reactions to previous medication injections.
14. Positive for HIV Ab, Hepatitis C Ab or Hepatitis B surface antigen (HBsAg) at screening.
15. Body weight less than 50 kg or greater than 125 kg.
16. BMI less than 18 or greater than 30 (Asians greater than 27).
17. Current smoker defined as any occasional or daily smoking of tobacco products