Phase 2 Study of ALXN2030 in Patients With Antibody-Mediated Rejection After Kidney Transplantation

Inclusion Criteria:

• Kidney transplant received ≥ 6 months

• Active or chronic active AMR according to Banff 2022 classification, based onScreening kidney biopsy

• Either positive C4d on Screening kidney biopsy based on the Central PathologyLaboratory report and/or positive HLA Class I and/or II antigen-specific DSA asdetermined by the local laboratory's definition of positivity using single-antigenbead based assays

• MVI score ≥ 2 (g ≥ 1 and ptc ≥ 1)

• eGFR ≥ 30 mL/min/1.73 m2

• Must be vaccinated against meningococcal infection from serogroups A, C, W, Y (and Bwhere available) at least 14 days prior to but no more than 3 years prior to Day 1

• Must be vaccinated for S pneumoniae prior to randomization

• Must be vaccinated for H influenzae type B (where available) prior to randomization

• Body weight ≥ 50 kg at Screening

Exclusion Criteria:

• Biopsy-based diagnosis of any of the following at Screening:

• TCMR, according to the Banff grade ≥ 1

• Polyoma virus nephropathy

• Severe thrombotic microangiopathy

• Glomerulonephritis

• ABO-incompatible transplant

• uACR > 2200 mg/g

• Multiorgan transplant recipient (except for previous multiple kidney transplants) orcell transplant (islet, bone marrow, stem cell) recipient

• Planned or recent treatments, < 90 days prior to the Screening Visit and duringScreening, for Acute Rejection, AMR (including plasmapheresis, plasma exchange,IVIg, B-cell depleting therapy, IL inhibitors, proteasome inhibitors, high-dosecorticosteroids [except for tapering]), HDS products with known hepatotoxicingredients, TCMR (including T-cell depleting therapy), excluding the SoCimmunosuppressant treatment which will be allowed and should be stable during theentire treatment.

• Known medical or psychological condition, including substance abuse or use disorder (including alcohol), or risk factor that may interfere with study participation,pose additional risk, or confound study outcomes