Equillium : Corporate Overview

Harnessing Novel Immunobiology

April 2020

www.equilliumbio.com

Safe Harbor Statement

This presentation contains forward-looking statements about Equillium, Inc. (the "Company"). In some cases, you can identify forward-looking statements by the words "will," "expect," "intend," "plan," "objective," "believe," "estimate," "potential," "continue" and "ongoing," or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements are based on Company management's current beliefs and expectations. These statements include but are not limited to statements regarding the Company's business strategy, the Company's plans to develop and commercialize its product candidates, the safety and efficacy of the Company's product candidates, the Company's plans and expected timing with respect to regulatory filings and approvals, size and growth potential of the markets for the Company's product candidates and cash runway. These statements involve substantial known and unknown risks, uncertainties and other factors that may cause the Company's actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The Company may not actually achieve the plans, intentions or expectations disclosed in its forward-looking statements, and you should not place undue reliance on the Company's forward-looking statements.

Actual results or events could differ materially from the plans, intentions and expectations disclosed or implied in the forward- looking statements the Company makes due to the risks and uncertainties inherent in the Company's business, including without limitation, risk described in the Company's filings with the Securities and Exchange Commission ("SEC"). You are cautioned not to place undue reliance on these forward-looking statements, which represent the Company's views as of the date of this presentation. The Company's anticipates that subsequent events and developments will cause the its views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company has no current intention of doing so except to the extent required by applicable law. These and other risks and uncertainties are described more fully under the caption "Risk Factors" and elsewhere in the Company's filings and reports, which may be

accessed for free by visiting EDGAR on the SEC web site at http://www.sec.gov. and on the Company's website under the

heading "Investors." All forward-looking statements are qualified in their entirety by this cautionary statement. This caution is made under the "safe harbor" provisions of Section 21E of the Private Securities Litigation Reform Act of 1995.

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Equillium Fast Facts

• Equillium was founded in 2017 - we aspire to build a world-class biotechnology company focused on dramatically improving the lives of patients with severe immuno- inflammatory diseases
• Headquartered in La Jolla, CA

• 1. office in South San Francisco
• Currently developing itolizumab (EQ001) in patients with:
• 1. acute GVHD

• 1. uncontrolled asthma o lupus nephritis
• NASDAQ: EQ

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Delivering

powerful new

treatment approaches

Our lead asset, itolizumab, is unique, modulating both the

activity and trafficking of Teff cells

Focused on	Driven by an
immuno-inflammatory	accomplished team
diseases with high	rapidly delivering key
unmet need	milestones
Initial clinical programs are targeting	Three clinical studies initiated 2019,
diseases with limited or no treatment	initial data expected 2H 2020
options

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Accomplished Management Team

Bruce Steel, CFA

Chief Executive Officer

Krishna Polu, MD

Chief Medical Officer

Steve Connelly, PhD

Chief Scientific Officer

Christine Zedelmayer

Chief Operating Officer

Jason Keyes

Chief Financial Officer

Joel Rothman

SVP of Development Operations

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Itolizumab (EQ001) First-in-class Lead Program

First-in-classanti-CD6 mAb that inhibits the activity and trafficking of

Teff cells by selectively targeting the CD6-ALCAM pathway

Broad potential 'pipeline in a product' - multiple high-value

indications applicable, three clinical studies underway

Validated therapeutic - studied in over 330 patients and approved for the treatment of psoriasis in India

Equillium acquired exclusive rights to itolizumab for the United States, Canada, Australia, and New Zealand from Biocon - partnership provides clinical & commercial product, commercial scale production at FDA regulated facility

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Itolizumab Development Strategy

Equillium is well-capitalized and staffed to execute on key programs

Indication

Phase 1

Phase 1b / 2

Phase 3

Expected Milestones

aGVHD

FDA Fast Track

Orphan Drug Designation

• EQUATE Phase 1b/2 trial underway
• Data to inform further development in GVHD, e.g. GVHD prevention, cGVHD
• Initial data expected 2H 2020

uncontrolled asthma

• EQUIP Phase 1b trial: on pause due to COVID-19

lupus nephritis

FDA Fast Track

• EQUALISE Phase 1b trial: on pause due to COVID-19

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The CD6-ALCAM Pathway

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CD6-ALCAM Pathway Central to Immuno-inflammation

APC / TISSUE	CD6 is a co-stimulatoryreceptor expressed on T cells, differentially
	expressed on subsets of innate lymphoid (ILC) and natural killer (NK)
	cells, but not on T regulatory cells (Treg)

Activated leukocyte cell adhesion molecule (ALCAM), is expressed on both antigen-presentingcells and endothelial/epithelial tissue including the blood-brain-barrier,skin, gut, lung and kidney

The binding of CD6-ALCAM is important for:

• Immune synapse formation

• Optimal co-stimulation and activation

• Trafficking into tissues

	The CD6-ALCAM pathway modulates T cell activity and trafficking
T CELL	and is central to the pathogenesis of multiple immuno-inflammatory
diseases

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Itolizumab Modulates CD6-ALCAM Pathway

APC / TISSUE

T CELL

Itolizumab

• Humanized IgG1 Kappa
• Binds to domain 1 of human CD6 with 1.3 nM affinity
• Inhibits ALCAM binding to CD6
• Non-depleting,modulatory action

Manufacturing and formulation

• Manufactured in CHO cells at commercial scale
• IV and SC formulations available

Dosing

• Half-lifeIV/SC @ 20/24 days respectively; target dosing of bi-weekly to monthly with potential for quarterly maintenance

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CD6 - Central Role in T Effector Cell Development

Highest levels of CD6 are found on activated T effector cells (Teff) and associated with amplification of the auto-reactive cascade

CD6 Low/-
	CD6 +		CD6 Hi

Th1

Th2

Th17

	CD6
Immune Regulatory	Autoreactive
"Tolerance"	"Autoimmunity"

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CD6-ALCAM Pathway Central to Immuno-inflammation

	ACTIVITY		TRAFFICKING

Increased proinflammatory

cytokine secretion

Optimal immune synapse	Increased trafficking of Teff
formation, activation
cells into target tissues
and proliferation

Suppression of regulatory

pathways	12

Itolizumab Inhibits Pathogenic T Cell Activity & Trafficking

	ACTIVITY				TRAFFICKING

Decreased proinflammatory

cytokine secretion

Inhibits optimal synapse	Decreased trafficking of Teff
formation co-stimulation,
cells into target tissues
activation and proliferation

Restoration of regulatory

pathways	13

Upstream, Disease Modifying Immuno-inflammatory Mechanism

Itolizumab acts upstream and selectively targets autoreactive effector T cells, while sparing regulatory T cells to promote immune tolerance and durable disease remission

Synergistic inhibition of multiple	Inhibition of Teff trafficking into	Restoration of immune regulation
Teff cells and cytokines*	key target organs	without immunosuppression

	Teff	Treg
Teff	Teff	Teff
Teff
	Teff

Th1 / Th2 / Th17

*including but not limited to IFN-γ,TNF-α,IL-4,IL-5,IL-6,IL-13 and IL-17	14

Clinical Strategy

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Acute graft-versus-host

disease (aGVHD)

A multisystem complication of allogeneic

hematopoietic stem cell transplants,

or allo-HSCT, caused by Teff cells, recognizing

and attacking the recipient's body

8,500

30-70%

53%

95%

0

2

1

Allo-HSCT's performed in 2016

4% procedural growth year-over-year

Allo-HSCT patients will develop aGVHD

Survival rate for steroid responders

Mortality rate for steroid non-responders

Number of approved treatments

for first-lineaGVHD

Number of products in development

for first-line aGVHD - itolizumab

Product in development that modulates both the activity and trafficking of Teff cells - itolizumab

All numbers are approximate and based on published reports

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CD6+ T Cells Drive GVHD Pathogenesis

Irradiation leads to activation of donor T cells

T cell Proliferation and secretion of proinflammatory cytokine

Activated donor T cells infiltrate tissues

GUT

SKIN

LIVER

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Itolizumab is a Differentiated aGVHD Treatment Option

Acute GVHD

0-100 days post-transplant

Prevention

First-line

ENTYVIO®

Itolizumab

Alpha-1 antitrypsin

Phase 3

Phase 2/3

Phase 1b/2

BMTCTN

DEFITELIO®

ORENCIA®

Alpha-1 antitrypsin

Phase 2

Phase 3 ready

Phase 3

Cannabidiol

Alpha-1 antitrypsin

Itacitinib

Phase 3

Phase 2

Phase 3 (failed)

Steroid-refractory

JAKAFI®

Approved

Remestemcel-L

BLA

T-Guard™

Phase 3 ready

Itolizumab

First line positioning

• Dual mode of action inhibits the activity and trafficking of Teff cells
• Potential disease-modifying therapy with durable benefit
• Immunomodulatory vs. immunosuppressive
• No cytopenia seen in Biocon Phase 3 psoriasis studies
• Positive Phase 1b data will inform lifecycle opportunity in GVHD prevention and cGVHD

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EQUATE Study for First-line Treatment in aGVHD

Study Population: First-line treatment of newly diagnosed aGVHD patients

Study Design

Phase 1b N~24 (Grade III - IV / high-risk)

• Open-label,3x3, dose escalation
• 5 doses, bi-weekly - intravenous (IV)

Primary Objectives		Secondary Objectives
• Assess the safety and tolerability of IV		• Characterize the pharmacokinetics (PK)
dosing of itolizumab		and pharmacodynamics (PD) of itolizumab

	•	Determine optimal IV dose	•	Assess the clinical activity of itolizumab:
		level(s) of itolizumab		GVHD ORR, NRM, cGVHD, durability
Phase 2 N~60 (Grade II - IV)			•	Further characterize the safety,
• Randomized, double-blind, placebo	•	Assess the clinical activity of itolizumab:
	tolerability and PD of IV dosing of
controlled		GVHD ORR, NRM, cGVHD, durability
		itolizumab
• 5 doses, bi-weekly - intravenous (IV)

Phase 1b initial data expected 2H 2020	Phase 1b informs Phase 2 study as well as lifecycle
strategy that may include GVHD prevention and cGVHD

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Uncontrolled moderate

to severe asthma

A heterogeneous disease characterized by different Teff cell subtypes and other innate immune cells driving both allergic and autoimmune mechanisms, leading to chronic airway inflammation

2.6mm	Severe asthma patients in the U.S.
1.3mm	Patients uncontrolled by standard-of-care
treatments (long-actingbeta-agonists, inhaled
	corticosteroids, oral corticosteroids)
~50%	Of uncontrolled patients do not respond
to existing biologic treatments
0	Approved products covering the full spectrum of
disease (Th2 High to Non-Th2 asthma)
2	Products in development that
target Non-Th2 asthma
1	Product in development that modulates both the
activity and trafficking of Teff cells - itolizumab
	All numbers are approximate and based on published reports	20

CD6-ALCAM Implicated Broadly in the Pathogenesis of Asthma

Type 2 Inflammation	Non-Type 2 / Th17 Inflammation
Allergens	Irritants, pollutants,
microbes, and viruses

TSLP		IL-25		IL-33		IL-6		CXCL8

CD6

Th2

cell

	IL-13		CD6
	IL-4,IL-5,IL-13	ILC2

CD6

Th17

cell

TGF-βVGM-CSF

IL-23

IFN-γ

CD6

Th1

cell

TNF

	IL-4	IL-5	IL-6,IL-17,IL-8
	Teff
		IL-3,IL-4,IL-5,IL-9
B cell	IgE
	Mast cell	Eosinophil	ALCAM	Neutrophil

Figure Legend: CD6 is expressed on Th1, Th2, Th17 and ILC2 effector cells that secrete multiple proinflammatory cytokines implicated in asthma
pathogenesis. ALCAM is expressed on antigen presentation cells that activate effector cells. ALCAM is also expressed on endothelial and	21
smooth muscle cells where it plays a role in trafficking of CD6+ effector cells. Adapted from Israel E, et al., N Engl J Med. 2017;377(10):965-976.

Upregulation of CD6 & ALCAM in Severe Asthma Patients

Examination of gene expression datasets and lung tissue support the presence of increased CD6,

CD4 T cells, and ALCAM in the lungs of severe asthma patients

6

*

*

CD6 expressionCD4 expression

(log2FPKM)(log2FPKM)

4

6.5

*

2

ALCAM expression

(log2FPKM)

6.0

0

6

***

5.5

***

4

5.0

2

4.5

l

a

o

r

m

t

n

th

0

o

s

C

A

l

a

t

a

e

e

F

y

t

r

h

a

e

t

r

v

l

e

a

e

e

d

S

H

o

M

***p<0.001, *p<0.05.

• Analysis of two different gene expression datasets support the presence of increased CD6, CD4 T cells, and ALCAM in the lungs of severe asthma patients

Fatal asthma Non-asthma

•

CD6

ALCAM

overlay

epithelium

Lamina propria

Fatal asthma patients - lung tissue staining suggests increased numbers of CD6+ cells, upregulation of ALCAM in the lamina propria (mucosa), and co-localization of CD6+ cells with ALCAM expressing tissue

Study of the Mechanisms of Asthma (MAST; NCT00595153); Bronchoscopic Exploratory Research Study of Biomarkers in Corticosteroid-refractory Asthma (BOBCAT)	22
study; Data courtesy of Reynold A. Panettieri, Jr., MD, Rutgers Institute for Translational Medicine and Science

Itolizumab May Address the Full Spectrum of Uncontrolled Asthma

Reciprocally

regulated

Th2-High	Th2-Low
Eosinophils	Low Eosinophils

Response to steroids

Current therapies target downstream

Current downstream therapies ineffective

signaling of Th2-associated inflammation

in patients with low levels of eosinophils

anti-IgE

anti-IL-5

anti-IL-4 /IL-13

anti-IL-33

anti-CD6-ALCAM

Itolizumab

NUCALA®

RG6149

DUPIXENT®

REGN3500

XOLAIR®

Marketed

Marketed

Marketed

Phase 2

Phase 2

Phase 1b

anti-TSLP

DP2 Agonist

CINQAIR®

GSK3772847

Tezepelumab

Marketed

Phase 2

GB001

Phase 3

inhaled JAK

Phase 2b

FASENRA®

Marketed

pan-JAK /TD-8236

Phase 1/2

Non-Th2

Neutrophils

No approved therapies

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EQUIP Study in Uncontrolled Asthma

Study Population: Uncontrolled moderate to severe asthma patients

	Study Design		Primary Objectives		Secondary Objectives
	Phase 1b N=32
	• Randomized, double-blind, placebo	• Assess the safety and tolerability of		• Characterize the pharmacokinetics (PK)
	controlled, dose escalation study	subcutaneous dosing of itolizumab		and pharmacodynamics (PD) of itolizumab
	• 5 doses, bi-weekly - subcutaneous	• Determine optimal subcutaneous dose		• Assess the clinical activity of itolizumab:
			level(s) of itolizumab		FEV1, ACQ, FeNO, Eos

Study on Pause Due to COVID-19

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Lupus nephritis

A heterogeneous disease that is the most

frequent and serious manifestation of systemic lupus erythematosus (SLE)

100,000

50%-75%

40%

0

9

Lupus nephritis patients in the U.S.

Of patients do not respond to

frontline treatments

Of severe, proliferative patients will progress to

end-stage renal disease

Approved treatments

Products in development

1	Product in development that modulates both the
activity and trafficking of Teff cells - itolizumab

All numbers are approximate and based on published reports

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T Cell Directed Therapies Represent a Promising Approach

Activated APC's/dendritic cells

Effector cytokines

T	reg	Teff

Activated

T cells play a central role in the immunopathogenesis of lupus, with aberrant T cell activation and function leading to defective peripheral tolerance

T cells also secrete pro-inflammatory cytokines, help B cells generate autoantibodies, and maintain disease through accumulation of autoreactive memory T cells

B cell directed and single cytokine approaches have previously failed in lupus nephritis in Phase 3 trials

Current T cell approaches have demonstrated promising efficacy (MMF, Cytoxan), but have significant toxicities and a narrow therapeutic index

effector cells

B cell

T cell

Teff

B cell	Targeted Cytokine	Complement Inhibition
		C3 Complement

Activated

B cells

KZR-616

Anifrolumab

APL2

Itolizumab

Phase 1b

Phase 2

Phase 2

Phase 2

Tissue-targeting

GAZYVA®

Narsoplimab

Complement-mediated

BI 655064

Antibodies

Phase 2

Phase 2

Phase 2

destruction

Voclosporine

BENLYSTA®

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Phase 3

Phase 3

Treating Lupus Nephritis Today - Similar Treatment for All Patients

• Standard diagnostics unable to inform biological differences between patients
• All patients treated uniformly with limited choices
• Patients may be exposed to ineffective therapies

• Payers pay for treatments that are ineffective in some patients and also pay for the associated complications

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Treating Lupus Nephritis Tomorrow - Individualized Therapy

• Biomarker driven diagnostics inform differences between patients and guide treatment

• Therapy benefit-to-risk improved for patients who may respond

• Use of ineffective treatments minimized - lower overall cost to health care system

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ALCAM is a Predictive Biomarker in Patients with Active Lupus Nephritis

Unbiased screening of >1100 urinary proteins identified urinary ALCAM as a strong predictor of disease activity

in lupus nephritis patients

Urinary ALCAM pg/mg

250000

*

200000

150000

100000

50000

0

Active

LN

Urinary ALCAM Elevated in Active

Lupus Nephritis

Distribution of ALCAM levels seen within race and disease severity

*statistical significance

	*	*
		*
	Active Non						Healthy
		Inactive SLE
	Renal				Control

Urinary Biomarker Outperforms Standard Disease Biomarkers in

Lupus Nephritis*

	AUC	P value	Sensitivity	Specificity	PPV	NPV
	(95% CI)
Urinary	0.91	< 0.0001	0.91	0.82	0.88	0.86
ALCAM	(0.86 - 0.96)
Positive anti-	NA		0.38	0.57	0.57	0.38
dsDNA
Low	NA		0.56	0.55	0.65	0.46
complement

*Performance of urinary protein markers in differentiating active lupus nephritis (N=89) from inactive lupus nephritis (N=60) in African American and Hispanic systemic lupus erythematosus patients - UT Southwestern Medical Center, TX

Stanley et al., 2016. Comprehensive Aptamer-Based Screening of 1129 Proteins Reveals Novel Urinary Biomarkers of Lupus Nephritis. ACR/ARHP Annual Meeting.	29

EQUALISE Study in Lupus / Lupus Nephritis (LN)

Study Design			Primary Objectives
Type A Cohort (SLE Patients): Phase 1b N=24
• Open-label, dose escalation in patients w/		Type A and B Cohorts
active or inactive SLE without LN	•	Assess the safety and tolerability of

• 2 doses, bi-weekly - subcutaneous	itolizumab in subjects with SLE with and
	without active proliferative lupus nephritis
	• Determine optimal subcutaneous dose
	level(s) of itolizumab

Secondary/Exploratory Objectives

Type A and B Cohorts

• Characterize the pharmacokinetics (PK) and pharmacodynamics (PD) of itolizumab
• Understand changes in disease serologies, urinary ALCAM and CD6, CD6 receptor occupancy

Type B Cohort only

Type B Cohort (active LN patients): Phase 1b N=32

• Randomized, double-blind, placebo controlled in active proliferative LN patients w/ inadequate response to existing therapy
• 7 doses, bi-weekly - subcutaneous

• Assess the clinical activity of itolizumab: proteinuria and SLEDAI-2K

Study on Pause Due to COVID-19

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Corporate

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Corporate

Exclusive rights for the United States, Canada, Australia, and New Zealand, and rights to negotiate itolizumab licensing for select additional major markets, e.g. EU / Japan

Biocon partnership provides risk-mitigatedproduct supply on attractive terms

• CMC completed and itolizumab currently manufactured at commercial scale in FDA-regulatedfacility
• Drug product supplied at no cost for 3 concurrent orphan indications until first U.S. approval; all other clinical supply at cost

Robust IP portfolio and potential for 12-yearbiologics exclusivity

Strengthened balance sheet and lean operating model expected to fund current development programs into 2H 2021

Pursuing opportunities for strategic pipeline expansion

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Summary

First-in-class: Itolizumab is the first antibody targeting the novel CD6-ALCAM pathway for the treatment of severe immuno-inflammatory disorders

Pipeline-in-a-product: Itolizumab has broad potential disease modifying therapeutic utility

Focused Development: Strong scientific rationale and translational validation supporting initial indications in areas of unmet need; multiple clinical studies launched during 2019 with initial data 2H 2020

High-valuepartnership: Biocon partnership provides clinical & commercial product, commercial scale production at FDA regulated facility

Accomplished team: Experienced in drug discovery, development and commercialization

EQ resources: Equillium is capitalized and staffed to deliver on key programs into 2H 2021

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Equillium, Inc.

2223 Avenida de la Playa / Suite 105 La Jolla, CA 92037 [e-mail]

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