A Phase 2a Safety, Tolerability, Pharmacokinetic (PK), and Pharmacodynamic (PD) Study of Intravenous ANX005 in Subjects With Amyotrophic Lateral Sclerosis (ALS)

Subjects must meet all of the following criteria:

1. Males or females aged 18 and above at the time of informed consent.

2. Diagnosis of ALS according to the World Federation of Neurology revised E1 Escorial
criteria.

3. Onset of weakness within 3 years prior to enrollment.

4. Slow Vital Capacity ≥ 60% of predicted normal adjusted for sex, age, and height (from
the sitting position).

5. Able to perform reproducible pulmonary function tests.

6. ALS concomitant medications stable for at least 2 months prior to Screening.

7. ALSFRS-R ≥ 30 at the Screening Visit.

8. If female, must be postmenopausal, surgically sterilized, or agree to use highly
effective methods of contraception from screening through Week 24.

9. Males with a woman partner of childbearing potential must agree to use highly
effective methods of contraception from Screening through Week 24.

10. Documented history of vaccinations within 5 years prior to screening visit against
encapsulated bacterial pathogens.

11. Complete the full sequence of protocol related procedures and evaluations, including
lumbar punctures for collection of cerebrospinal fluid.

12. 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. Subjects with body weight > 150 kg.

3. Clinically significant findings on screening laboratory testing, physical examination
or vital signs that are not specific to ALS that could interfere with the conduct of
the study, the interpretation of the data or increase subject risk.

4. An ANA titer ≥ 1:160.

5. History of previous infusion reactions, sensitivities, allergic, or anaphylactic
reactions to previous medications, environmental stimuli or other substances.

6. Receipt of an experimental agent within 60 days prior to Screening or through Week 24.

7. Prior treatment with any monoclonal antibody within 6 months of screening.

8. Hypersensitivity to any of the excipients in the ANX005 drug product.

9. Clinically significant intercurrent illness, medical condition, or medical history
that would jeopardize the safety of the subject, limit participation, or compromise
the interpretation of the data derived from the subject.

10. Any known genetic deficiencies of the complement-cascade system.

11. History of chronic systemic steroid use or immunosuppressant medication ending less
than 1 month prior to screening.

12. Active alcohol, drug abuse or substance abuse.

13. Females who are pregnant or unwilling to use highly effective methods of
contraception.

14. Contraindication to undergoing an LP.