Key Inclusion Criteria:
- Diagnosis of ALS according to the World Federation of Neurology revised EI Escorial criteria.
- Onset of weakness within 3 years prior to Day 1 visit.
- Slow Vital Capacity ≥ 50% of predicted normal adjusted for sex, age, and height (from the sitting position).
- ALS Functional Rating Scale-Revised (ALSFRS-R) ≥ 30 at the Screening visit (Week -2).
- If female, must be postmenopausal, surgically sterilized, or agree to use highly effective methods of contraception from Screening through Week 36.
- Males with a woman partner of childbearing potential must agree to use highly effective methods of contraception from Screening through Week 36.
- Documented history of vaccinations within 5 years prior to Screening visit against encapsulated bacterial pathogens or willing to undergo vaccinations.
Key Exclusion Criteria:
- Clinically significant, ongoing or intercurrent illness, medical condition, or medical history that would jeopardize the safety of the participant, limit participation, or compromise the interpretation of the safety data derived from the participant.
- Participants with body weight > 150 kilograms.
- Antinuclear antibodies (ANA) titer ≥ 1:160 (for either of the 2 ANA results a minimum of 2 weeks apart) during the Screening Period.

In this Phase 2a, multi-center, open label, proof-of-biology study, ANX005 will be administered to participants with ALS. The study consists of approximately 22 weeks of treatment and approximately 14 weeks of follow-up. All participants will be contacted by phone 6 months after study completion.

• Annexon, Inc.

NCT04569435 (First Published: 9/23/2020)