23andMe Investor Day Presentation Deck

Why Target the Receptor (CD200R1) Instead of the Ligand? • CD200R1 expression is mainly expressed on immune cells o CD200 (ligand) is broadly expressed on many cell types • An anti-CD200 monoclonal antibody, samalizumab (ALXN 6000) did not saturate cell surface CD200¹ o evaluated in patients with CD200-expressing B-cell malignancies in a Phase 1 trial¹ • 23ME'610 is expected to saturate CD200R1 and fully block binding to CD200 Target distribution Antibody affinity (KD) 1 Journal for ImmunoTherapy of Cancer 2019;7:227 CD200R1 Immune cells 23ME'610 < 0.1 nM CD200 Expressed on a wide range of cells (B cells, endothelial cells, neuronal cells, etc) samalizumab ~10 nM Copyright © 2022 23andMe, Inc. 23andMe® 41

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