Arcus Biosciences : Investor Presentation October 2020

OUR VISION: COMBINING TO CURE

WITH BEST-IN-CLASS CANCER THERAPIES

NYSE: RCUS

NOVEMBER 2020

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 vision, strategy, advantages, benefits associated with our Gilead collaboration, potential of our product candidates and development strategies, anticipated milestones and timelines and expectations regarding our available cash and investments. 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 arrangement with Gilead 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 and collaboration 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 U.S. 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 any forward-looking statements for any reason after the date of this presentation to conform these statements to actual results or to changes in our expectations.

The Arcus name and logo are the property of Arcus. All other trademarks included 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.

2

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

‒

‒

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

3

© 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

‒

‒

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

4

© 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

‒

‒

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

5

© Arcus Biosciences 2020

Expanding on ProvenClinical Roles of These Pathways: Combinations Address Major Areas of Medical Need and Are Uniquely Enabled by Arcus Pipeline

-- Illustrative Major Tumor Types Associated with Each Pathway -

	NSCLC	CRC	PDAC	CRPC	TNBC
Adenosine	✓	✓	✓	✓	✓
TIGIT	✓	✓	✓		✓
PD-1	✓	✓	✓	✓	✓

Zim + Carbo/Pem ± Etruma	Etruma Combo		Etruma + Zim ± SOC
Zim ± Dom ± Etruma		Etruma + Rego + Atezo	Etruma + PLD
✓ Strong scientific rationale; current RCUS study				AB680 + Zim + Gem/Nab-pac
✓ Strong scientific rationale; potential future RCUS study				Etruma + Atezo + Gem/Nab-pac
6

© Arcus Biosciences 2020

Broad Clinical Program to Compete Aggressively in Settings with Significant Therapeutic and Commercial Potential

Phase 1

Phase 1b

Randomized Phase 2

NSCLC

WT 1L

Zim ± Dom ± Etruma

EGFRm 2L+

Etruma + Zim + Carbo/Pem

1L

Etruma + Zim + Enza

mCRPC

2L+

Etruma + Zim + Doce

2L+

Etruma + Zim ± AB680

3L

Etruma + Atezo + Rego

CRC

1-3L+

Etruma + FOLFOX

2L+

Etruma Combination

PDAC

1L

Etruma + Atezo + Gem/Nab-pac

1L

AB680 + Zim + Gem/Nab-pac

TNBC

2L+

Etruma + PLD ± eganelisib

Abbreviations

Abbreviations

Zim: zimberelimab

Carbo/Pem: carboplatin/pemetrexed

Zimberelimab: PD-1mAb

Domvanalimab (AB154): TIGIT mAb

Dom: domvanalimab

Bev: bevacizumab

ONGOING

Etruma: etrumadenant

Gem/Nab-pac:gemcitabine/nab-paclitaxel

PLANNED

Etrumadenant (AB928): Dual A2aR/A2bR antagonist

AB680: CD73 inhibitor

Enza: enzalutamide

PLD: pegylated liposomal doxorubicin

Doce: docetaxel

7

Atezo: atezolizumab

© Arcus Biosciences 2020

Rego: regorafenib

Anticipated Upcoming Clinical Milestones

Program	Molecule	Milestone

TIGIT/CD155

Axis

Adenosine

Axis

PD-1/PD-L1

Axis

8

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

Gilead Collaboration Positions Arcus to Unlock the Value of Arcus's Pipeline

• 10-year"all-in" collaboration brings a well-aligned partner with the financial and operational resources, scientific expertise and long-term vision required to capitalize on the promise of the Arcus pipeline
• • Immediate rights to co-develop and co-commercialize zim; option to exclusively license investigational products from each of Arcus's other current and future programs over the 10-year collaboration term
  • For each program, Arcus's achievement of a designated development milestone will trigger an option window, and Gilead may exercise its option at any time up until the end of the option window
  • Partnership provides additional opportunities to maximize value and bring potential benefits to broadest patient population possible (e.g., AstraZeneca PACIFIC-8 study)
• Preserves Arcus's independence and provides strategic flexibility, while accelerating its path towards becoming a fully-integrated commercial biopharmaceutical company
• • Maintains Arcus's ability to quickly generate and advance molecules into and through early clinical development
• Allows Arcus to maintain substantial commercial rights over its entire pipeline while also accelerating the associated opportunities
• • 50/50 profit share on Gilead-optioned programs in the U.S.
• Provides a mechanism for Arcus to fund its portion of co-development costs through

ongoing R&D support and opt-in/milestone payments

9

© Arcus Biosciences 2020

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

10

© 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

11

© Arcus Biosciences 2020

Phase 2 Study to Evaluate: Dom (AB154) + Zim and Dom + Etruma (AB928) + Zim vs Zim Mono in 1L NSCLC

Randomized Phase 2 Study of Combinations with Zim, Dom, and Etruma in 1L NSCLC

	Arm 1 (n=50)
	Zimberelimab Monotherapy
1L NSCLC	(crossover to triplet allowed)

PDL1 ≥ 50%	R	Arm 2 (n=50)	PFS & ORR
co-primary
excluding	1:1:1	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

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

12

© 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

13

© Arcus Biosciences 2020

Two New INDs Expected in 2H21

14

© Arcus Biosciences 2020