Arcus Biosciences : Investor Presentation January 2021

OUR VISION: COMBINING TO CURE

WITH BEST-IN-CLASS CANCER THERAPIES

NYSE: RCUS

JANUARY 2021

Forward-looking Statements/Safe Harbor

This presentation contains forward-looking statements about Arcus Biosciences, Inc. ("we," "Arcus" or the "Company") made pursuant to the safe harbor provisions of the Private

Securities Litigation Reform Act of 1995. All statements other than statements of historical facts contained in this presentation are forward-looking statements, including statements about our upcoming milestones and associated timing, the anticipated benefits of our collaborations with Gilead and AstraZeneca, expectations regarding our cash and funding, and potential of our investigational products. These forward-looking statements are subject to a number of risks, uncertainties and assumptions that may cause actual results to differ materially from those contained in any forward-looking statements we may make, including, but not limited to: risks associated with the impact of the COVID-19 pandemic; risks associated with our collaboration arrangements including our dependence on Gilead for the successful development and commercialization of our investigational products; the inherent uncertainty associated with pharmaceutical product development and clinical trials; delays in our clinical trials due to difficulties or delays in the regulatory process, enrolling subjects or manufacturing or supplying product for such clinical trials; changes in the competitive landscape; risks associated with preliminary or interim data and the emergence of adverse events or other undesirable side effects; differences in interpretation of our clinical trial results; our limited operating history and our ability to manage our growth; and risks regarding our license agreements and our ability to obtain and maintain intellectual property protection for our product candidates.

We operate in a very competitive and rapidly changing environment. New risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially and adversely from those anticipated or implied in the forward-looking statements. Further information on these and other factors that could affect the forward-looking statements made herein are described in our most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission.

You should not rely upon forward-looking statements as predictions of future events. Except as required by law, neither we nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements. We undertake no obligation to update publicly and forward-looking statements for any reason after the date of this presentation to confirm these statements to actual results or to changes in our expectations.

The Arcus name and logo are the property of Arcus. All other trademarks used herein are the property of their respective owners and are used for reference purposes only. Such use should not be construed as an endorsement of Arcus.

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RCUS Investment Thesis

• Well-positionedto unlock the value of our pipeline
• • ~$785M cash and funding into at least 2023
  • 10-yearGilead partnership provides resources and expertise to efficiently and more fully exploit multiple unique intra- portfolio opportunities
  • Recently announced collaboration with AstraZeneca for registrational trial, PACIFIC-8, further validates the therapeutic potential of domvanalimab, Arcus's novel anti-TIGIT antibody
• Advanced pipeline of products that target 3 of the most important and highly pursued IO pathways: TIGIT, Adenosine, and PD-1

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Essential Backbones:

• AB154 (Domvanalimab): anti-TIGIT mAb - rapidly advancing in randomized combinations
• Zimberelimab: anti-PD-1 mAb with clear line-of-sight to commercialization, enables portfolio combination strategies

Adenosine Axis:

• AB928 (Etrumadenant): A2aR / A2bR antagonist - first and only dual antagonist in the clinic
• AB680: CD73 inhibitor - first small-molecule in the clinic; exceptional potency

• Initial signs of clinical activity from our early Phase 1/1b trials are being followed by randomized studies/cohorts in order to generate clear evidence of clinical activity; significant readouts from multiple studies expected in 2021

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© Arcus Biosciences 2020

Essential Backbone Agents

• PD-1/PD-L1Axis
• • Essential to fully leverage other programs and enable development and commercialization opportunities
  • Zimberelimab has profile similar to that of pembrolizumab: preclinically and clinically
  • Path to zimberelimab single-agent approval to be disclosed in 4Q 2020
• TIGIT/CD155 Axis: Arcus early investment/commitment to success

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Domvanalimab (Ph2): FcR-silent; potential advantages in solid tumors

AB308 (IND 4Q20): FcR-capable; potential advantages in hematology

• Arcus is well positioned in the TIGIT space: only company known to have both types of antibodies

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© Arcus Biosciences 2020

ATP/Adenosine Axis: One of the Most Ubiquitous Pathways Associated with Immunosuppressive Tumor Microenvironment

• Arcus's early and broad investment in modulating the pathway
• Potential best-in-class adenosine receptor antagonists designed and

optimized for oncology setting

• Etrumadenant (Ph2): first & only clinical agent that blocks A2a and A2b receptors
• • Multiple potential biological advantages relative to selective A2a receptor blockers
  • Growing evidence of A2b role in both TME immunosuppression and cancer cell-intrinsic biology
• AB680: first and most advanced small-molecule CD73 inhibitor in the clinic

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Small molecule best modality for tumor-associated enzyme inhibitor (e.g., better tumor penetration)

AB680 capable of complete inhibition of both membrane bound and soluble forms of CD73; the most advanced antibodies are not capable of fully inhibiting the enzymatic activity of CD73

• IV and oral formulations in development

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© Arcus Biosciences 2020

Approaching Multiple Randomized Data Readouts in 2021+

WT 1L

EGFRm 2L+

NSCLC

1L

PD-L1 High

Stage 3

1L

CRPC 2L+ 2L+

2L

CRC 3L

>3L

PDAC 1L

Phase 1		Phase 1b		Rand. - Phase 2		Pivotal/Phase 3

Zim ± Dom ± Etruma

Etruma + Zim + Carbo/Pem

Chemo vs. Zim vs. Zim + Dom

Durva ± Dom1	PACIFIC-8

Etruma + Zim + Enza

Etruma + Zim + Doce

Etruma + Zim ± AB680

Etruma + Zim + FOLFOX* vs.

FOLFOX*

Etruma + Zim + FOLFOX* vs. Rego

Etruma Combinations

AB680 + Zim + Gem/Nab-pac

	1Clinical collaboration with AstraZeneca; AZ will be the primary sponsor of PACIFIC-8.
	* +/- biologic	PLANNED 2021
	CRT: chemoradiotherapy; Zim: zimberelimab; Dom: domvanalimab; Etruma: Etrumadenant; Rego: regorafenib
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Gem: gemcitabine; FOLFOX: (folinic acid, fluorouracil; oxaliplatin); Nab-pac:nab-paclitaxel; Doce: docetaxel;
	Carbo: carboplatin; Pem: pemetrexed

Anticipated Upcoming Clinical Milestones

Program	Molecule	Milestone

TIGIT/CD155

Axis

Adenosine

Axis

PD-1/PD-L1

Axis

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Dom (AB154)

(TIGIT mod.IgG1)

AB308

(TIGIT wt IgG1)

Etruma (AB928)

(A2aR/A2bR)

AB680

(CD73)

Zim

(PD-1)

• ARC-7:Preliminary data in 1H21; Presentation at medical conference in 2021
• IND filing 4Q20; Initiation of Phase 1/1b in 1H21
• Randomized Phase 1b/2
• • ARC-4:Preliminary randomized data from Phase 2 portion; presentation at medical conference in 2021
  • ARC-6:Preliminary data with presentation at medical conference in 2021
  • ARC-7:Preliminary data in 1H21; Presentation at medical conference in 2021
  • ARC-9:Initiation of Phase 1b/2 platform study in 4Q20
• Phase 1/1b
• • ARC-2:Presenting preliminary data at SABCS in 4Q20 (December)
  • ARC-3:Presenting preliminary biomarker data at SITC in 4Q20 (November)
• ARC-8:Preliminary dose-escalation data at ASCO-GI in 1Q21 (January)
• ARC-7:Preliminary data in 1H21; Presentation at medical conference in 2021

© Arcus Biosciences 2020

Partnerships that Greatly Expand & Accelerate

Opportunities Inherent in Arcus's Expansive Portfolio

• 10-year"all-in" collaboration with well aligned partner
• • Gilead obtained immediate rights to zim; option to license investigational products in current and future programs
• Preserves Arcus's independence and provides strategic flexibility
• • Enables aggressive development in highly competitive areas
• Allows Arcus to maintain substantial commercial rights over pipeline with ability to accelerate and expand associated opportunities
• • 50/50 profit share on Gilead-option programs in the U.S.
• Provides mechanism for Arcus to fund its portion of co-development costs
• • Ongoing R&D support and opt-in/milestone payments

• Further validates Arcus's position at forefront of anti-TIGIT field
• • Registrational PACIFIC-8 trial for dom plus Imfinzi expected to begin in 2021
• Leverages AstraZeneca's leadership in the curative-intent Stage III NSCLC setting
• • Imfinzi is the only immunotherapy approved for patients in this setting
• Significant upside potential with optimized level of risk
• • Retained economics on respective molecules; informed cost-sharing
• Further builds on the Arcus-Gilead agreement
• • Supports combinations and settings that maximize value and bring potential benefits to broadest patient population possible

Well-positioned to unlock the value of our pipeline

~$785M1 cash and funding into at least 2023

8	1As of September 30, 2020

CLINICAL-STAGE ADENOSINE PROGRAMS

Study to Evaluate Etruma (AB928) + Zim + Chemotherapy in EGFRmut Non-Small Cell Lung Cancer

• Study design schema for dose- escalation and dose-expansion of Etruma + anti-PD-1 + Carboplatin/Pemetrexed in NSCLC patients
• Dose-expansionphase:
• • Participants must have a sensitizing EGFR mutation and failed treatment with 1 TKI (or 1-2 TKIs for tumors with T790M mutation)
  • Previous treatment with chemotherapy or PD-1/PD-L1 therapy is not allowed
  • Potential to open control arm after futility assessment
• Preliminary data presented at ESMO 2020

C/P: carboplatin/pemetrexed; RDE: recommended dose for escalation; TKI: tyrosine kinase inhibitor

A. Spira et al, ESMO (2020); presentation no.1309P; NCT03846310

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© Arcus Biosciences 2020

Platform Study to Evaluate Etruma (AB928) across Multiple Lines of Therapy in mCRPC

• Platform study in mCRPC to assess the safety and efficacy of the addition of Etruma (AB928) + Zim to standard of care Enzalutamide and Docetaxel
• • Supports early randomization and proof of concept if activity signal is seen in Stage 1
• Evaluating Etruma novel combinations for late-line patients without available standard of care
• • Opportunity for expansion of these cohorts based on initial signals

Stage 1 / Phase 1b

Etrumadenant

+ Zimberelimab R

+ Enzalutamide

Etrumadenant

+ Zimberelimab R

+ Docetaxel

Etrumadenant + Zimberelimab

R	Etrumadenant + Zimberelimab
+ AB680

Etrumadenant + AB680

Stage 2 / Phase 2

Etrumadenant + Zimberelimab

• Enzalutamide
  SOC

Etrumadenant + Zimberelimab

• Docetaxel
  SOC

Etrumadenant + Zimberelimab

Etrumadenant + Zimberelimab + AB680

Etrumadenant + AB680

Subudhi e.t al, ESMO (2020); presentation no.687TiP; NCT04381832

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© Arcus Biosciences 2020

Phase 1/1b Evaluation of AB680 + Chemotherapy + Zim in 1L mPDAC

• Evaluation of AB680 (CD73 small molecule inhibitor) in combination with zimberelimab (anti-PD-1) + gemcitabine/nab-paclitaxel in first line metastatic pancreatic cancer
• • Phase 1 dose-escalation of AB680 to define a recommended dose for expansion (RDE) is ongoing
  • Phase 1b expansion anticipated to start in 2H2020 with potential to include a randomized control arm

Previously	AB680 +
Gem/Nab-
Untreated
Paclitaxel +
mPDAC
Zim

R

Control Arm	Endpoints:
Safety,
	PK/PD,
AB680 + Gem/Nab-	Clinical
Paclitaxel + Zim	Activity

Ph1 Dose-escalation of	Expansion Phase
AB680 to Establish RDE	(Potential to also randomize to a control arm)

• Plans underway to evaluate AB680 in multiple combinations and indications once RDE achieved (e.g., mCRPC)

Bendell et al, GI ASCO (2020); presentation no. TPS788; NCT04104672

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© Arcus Biosciences 2020

CLINICAL-STAGE TIGIT PROGRAMS

Domvanalimab - Phase 1 Clinical Summary

• Domvanalimab (Dom) is well tolerated in combination with zimberelimab (Zim) at all doses and regimens assessed thus far.
• To-date,no evidence of ADAs in any of the Ph1 samples for domvanalimab, nor has there been any evidence of ADAs in our clinical studies for zimberelimab.
• 100% TIGIT occupancy on blood lymphocytes achieved at all timepoints at 0.5 mg/kg q2w and higher. Similar TIGIT occupancy has been seen with q3w and q4w regimens.
• Increased proliferation (Ki-67) of blood CD8 T cells, of a magnitude similar to what has been described for anti-PD-1 mAbs, observed in Ph1 subjects, both with domvanalimab single agent and in combination with zimberelimab.
• Ongoing evaluations of various dose-schedule combinations of domvanalimab and zimberelimab in our Ph1 study, which will be presented at an upcoming medical conference once complete.

Ph1 Patient Example: Prolonged Confirmed Partial Response in a Late-line,Post-Checkpoint Inhibitor, Esophageal Cancer Patient

• 68 y.o. male with late-line metastatic esophageal cancer (CPS2)
• Patient remains on therapy with continued tumor shrinkage (cPR) at Cycle 9

Baseline

Cycle 6

Prior therapies:

• FOLFOX
• Carbo/Pac
• Pembrolizumab

Baseline: very large metastatic right liver lobe lesion with right massive liver enlargement and compression of right kidney/renal vein

CSP: COMBINED POSITIVE SCORE (PD-L1 CELLS; PEMBRO APPROVAL IS IN CSP≥10 FOR ESOPHAGEAL CANCER; cPR: CONFIRMED

15 PARTIAL RESPONSE

Cycle 6: significant tumor shrinkage and relief of liver enlargement & right kidney/vein compression

REPRESENTATIVE IMAGES COURTESY OF DR. AMITA PATNAIK (CO-DIRECTOR OF CLINICAL RESEARCH, THE START CENTER FOR CANCER CARE, SAN ANTONIO)

Dom (TIGIT) + Zim (PD-1) + Etruma (A2a/A2b) vs.

Dom + Zim vs. Zim in 1L NSCLC (PD-L1 ≥ 50%)

		Arm 1 (N=50)
		Zimberelimab Monotherapy
1L NSCLC		(crossover to triplet allowed)
PDL1 ≥ 50%		Arm 2 (N=50)	PFS & ORR
excluding	R	co-primary
Zim + Dom
	endpoints
EGFR/ALK
mutations		Arm 3 (N=50)
		Zim + Dom + Etruma

• ARC-7is the first study to investigate the triple combination of anti-PD-1,anti-TIGIT, and adenosine receptor antagonism including in patients who have progressed on PD-1 monotherapy for whom there is a high unmet need
• Ongoing enrollment in the US and Asia

Chaudhry et al, ESMO (2020); presentation no.1419TiP; NCT04262856

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10	Phase 3 Study Design
	Enables potential approval of BOTHZim mono and Zim + Dom Combination

1L NSCLC

PD-L1 TPS ≥ 50%

(excludingR actionable mutations

such as: EGFR/ALK/ BRAF/ROS/NTRK)

Arm A (N=125)
Investigators Choice Chemotherapy
(cross-over to Arm B allowed)	OS
Arm B (N=250)
Zim Monotherapy	PFS and OS

co-primary

Arm C (N=250)endpoints

Zim + Dom

• Reviewed and aligned with the US and EU health authorities
• ARC-7is ongoing in the US and Asia; intended to provide data supportive of ARC-10

NCT#: pending

Two New INDs Expected in 2H21

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© Arcus Biosciences 2020