Equillium Results Presentation Deck

Dose-Dependent Pharmacokinetics & Rapid Pharmacodynamics • PHARMACOKINETICS Dose-dependent increases in itolizumab exposures observed Preliminary data suggest no impact of ADA on PK* equillium Mean +/- SD itolizumab concentration (ng/mL) 10000- 100 15 43 29 Time after first dose 57 Dose (mg/kg) 0.4 0.8 1.6 2.4 3.2 % CD6 of baseline PHARMACODYNAMICS Reductions in surface levels of CD6 on CD4 cells observed** Magnitude of decrease is comparable at 1.6 mg/kg and higher 150 100- 50- 0. 0.4 Day 15 Pre 2nd dose 0.8 1.6 2.4 3.2 Dose (mg/kg) % CD6 of baseline 150 100 50- 0 "Baseline ADA only: 4/19 (21%): low titer (200) ADA observed in 3/19 (16%), at 2 (n=1) and 6 (n=2) weeks after the last dose of study drug "Some missing data points due to inadequate sample collection Day 29 14 days post-2nd dose ** in 0.4 0.8 1.6 2.4 3.2 Dose (mg/kg) Abbreviations: ADA anti-drug antibodies, PK pharmacokinetics, SD standard deviation. Interim data from 19 AUG 2021: final completion of Type A cohort Putterman et al., PO1623 ASN, 2021 ***p<0.001 ** p<0.01 *p<0.05 17

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