March 2017

Forward-looking statements

This presentation contains forward-looking statements. These forward-looking statements

are subject to risks and uncertainties, including the factors described under the Risk

Factors section of our most recent Annual Report on form 10-K or Quarterly Report on

Form 10-Q filed with the Securities and Exchange Commission and made available on our

website at www.agenusbio.com. When evaluating Agenus’ business and prospects, careful

consideration should be given to these risks and uncertainties. These statements speak

only as of the date of this presentation, and Agenus undertakes no obligation to update or

revise these statements. This presentation and the information contained herein do not

constitute an offer or solicitation of an offer for sale of any securities.

2

Broad I-O portfolio: enabling optimal combos

3

4

Agenus Five Year Growth Plan: balancing low & high risk initiatives

• Advance on most rapid path to BLA

• Develop, register, and launch anti-PD-1/CTLA-4 mAb combinations in validated

indications

• Pursue novel breakthrough indications to expedite market entry

• Leverage novel targets for market expansion

• Pursue optimal I-O mAb and vaccine combinations with anti-CTLA-4 +/- anti-PD-1

• Progress partnered programs (GITR, OX40, TIM-3, LAG-3) towards registration

• Advance Ab programs against innovative undisclosed targets to the clinic

• Engage in strategic partnerships

5

Current partnerships

• 1 undisclosed target

• Lead selection completed

• Up to $100 million in milestones

• Pre-clinical: LAG-3, TIM-3, TIGIT, 2 undisclosed• Royalty rates are generally 6-12%*

• Clinical: GITR, OX40 • Royalty rate 15%

• Up to $510 million in milestones across all programs

• QS-21 Stimulon®: adjuvant for Shingrix®

• GSK filed for registration in U.S., Canada and Europe

• Royalties and milestones partly monetized

* *Incyte eligible for 15% royalty for TIGIT

Clinical Strategy

7

New clinical development paradigm compressed

Conventional time to BLA

Ris

k

AGEN1884 /

AGEN2034

Solid Tumors

Efficacy proven

AGEN1884 /

AGEN2034

Solid Tumors

Efficacy

unknown

AGEN1884 /

AGEN2034

+

Vaccine

AGEN1884 /

AGEN2034

+

Novel CPM

(A, B, C)

10 years

AGEN1884 = anti-CTLA-4 mAb

AGEN2034 = anti-PD-1 mAb

CPM = checkpoint modulator

8

anti-CTLA-4 + anti-PD-1:

first clinically validated I-O mAb combo

*Anti-CTLA-4 antibody AGEN1884 is partnered with Recepta for certain South American territories

• anti-CTLA-4 (low dose) combined with anti-PD-1/PD-L1 is the only

validated mAb combination with improved efficacy and safety profile

• Near doubling of clinical response - from 25% to ~57% in NSCLC(1)

• Control of CTLA-4 + PD-1/PD-L1 targeted therapies could offer a pricing advantage

• Provides a foundation for mAbs against novel checkpoints that are yet to show

efficacy in the absence of CTLA-4 antagonism

1. Hellmann et al. Lancet Oncol 2017

1. Hellmann et al. Lancet Oncol 2017

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Targeting PD-1 has clinical benefit but

combining with CTLA-4 antagonism works better

*Anti-CTLA-4 antibody AGEN1884 is partnered with Recepta for certain South American territories

• anti-CTLA-4 (low dose) combination with anti-PD-1/PD-L1

reduces development risk and expands markets

• anti-CTLA-4 and anti-PD-1 mAb combination is already approved in

metastatic melanoma & almost doubles clinical benefit in 1L NSCLC(1)

• CTLA-4 + PD-1/PD-L1 antagonists +/- mAbs targeting novel checkpoints have

shown compelling data in preclinical models

• Clinical development:

• SOC marginally changed after the approval of Avastin in combination with chemo in 1L

• No effective treatment options in 2L; unmet medical need

• Clinical activity of other anti PD-X in virally induced and HPV driven malignancy (HNSCC HPV+)

suggests that AGEN1884 administration could lead to an ORR 15% in all comers, > 20% in PD-L1+

•Regulatory:

• US: Possibility of applying for Breakthrough Designation, assuming hypotheses are backed up by

clinical data, Accelerated Approval possible

• EU: Possibility of applying for conditional marketing authorization

• Commercial:

• Potential niche opportunity with most of the patients from Japan and South Korea where premium

prices for unmet medical needs are commonly given and where there is no off-label use reimbursed

10

Metastatic virally induced malignancies*:

appealing target for Agenus

* Anticipated in cervical cancer

11

*

2017 2018 2019 2020 2021

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

First patient for 2034 dose

escalation

Dose is established

Virally-induced Cancer

PD-1 vs PD-1 + CTLA-4 vs SOC

Phase 1

2L Virally-induced Cancer

n = 30

*

*

* Anticipated in cervical cancer

** Projections

AGEN2034 (anti-PD-1) and AGEN1884 (anti-CTLA-4): projected clinical

inflection points

Phase 1b n = 30

First patient for dose

escalation 2034 + 1884

*US filing US approval

*Top line

data** **

**

Preclinical data

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Sculpting the immune response to maximize clinical benefit

Vaccine Platforms

Prophage™

AutoSynVax™ (ASV™)

PhosphoSynVax™ (PSV™)

Checkpoint mAbs

Anti-CTLA-4*

Anti-PD-1*

Anti-TIGIT

Anti-TIM-3**

Anti-LAG-3**

Checkpoint mAbs

Anti-4-1BB

Anti-OX40**

Anti-GITR**

Neoantigen vaccines: ASV™, PSV™

Adjuvant: QS-21 Stimulon®

Anti-CTLA-4*

Anti-PD-1*

* Partnered with Recepta for certain South American territories

** Partnered with Incyte

14

Integrated antibody discovery technologies, combined with

immunology expertise

Agenus anti-CTLA-4 mAb improves primate

vaccine response

-7 1 5 2 9 4 3 5 9 6 9

0

5 0 0 ,0 0 0

1 ,0 0 0 ,0 0 0

1 ,5 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

An

ti-H

Bs

Ag

Ig

G (

U/m

L)

C o n tr o l (N = 6 )

A G E N 1 8 8 4 (N = 6 )

D a y s A fte r In itia l D o s in g

A d m in is tra tio n s o f an tib o d y

o r v e h ic le (c o n tro l)

p lu s H B s A g v a c c in e

Anti-CTLA-4 antibody AGEN1884

+

Hepatitis B surface antigen (HBsAg) vaccine

Internal data (unpublished)

VaccineAntibody

-4 0 8 1 5 2 2 2 9 3 6 4 3 5 0 5 7 6 7

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

SF

U/1

x1

06

PB

MC

Is o ty p e c o n tro l

A G E N 1 8 8 4

Humoral Response Cellular Response

15

AGEN2034: Anti-PD-1 antagonist antibody

AGEN2034 enhances T cell responsiveness to

suboptimal TCR activation

AGEN2034 binds to PD-1 with high affinity (nM)

and potently inhibits PD-1 binding to PD-L1/2

-5 -4 -3 -2 -1 0 1 2

0

5 0

1 0 0

A n t ib o d y ( lo g g /m L )

PD

-L1

or

PD

-L2

bin

din

g (

%)

A G E N 2 0 34

is o ty p e

A G E N 2 0 34

is o ty p ePD -L1

PD -L2

-7 -6 -5 -4 -3 -2 -1 0 1 2

0

1 0 0

2 0 0

3 0 0

A n t ib o d y ( lo g g /m L )IL

-2 (

pg

/ml) Is o ty p e

A G E N 2 0 34

PD-1 inhibits TCR-induced signaling to impair

T cell effector function

Response rates observed with an PD-1 antagonist in a range of

solid and hematological tumor settings

Internal data (unpublished) 16

17

AGEN1884 combines in primary T cell assays with PD-1:PD-L1

blockade (as well as LAG-3)

Internal data (unpublished)

Isotype

Pembrolizumab

Business

2016 2017 2018

Accomplishments

• Three CPM mAbs in clinic

• CTLA-4 antagonist (AGEN1884)*

• GITR agonist (INCAGN1876)**

• OX40 agonist (INCAGN1949)**

• Clinical Development team with I-O

development success on board

• QS-21 Stimulon® containing

Shingles vaccine filed for regulatory

approval

Clinical Deliverables

• Clinical trials

• Initiate Ph 1 for PD-1 antagonist

(AGEN2034)* monotherapy

• Initiate virally-induced cancer trial (2L)

• Initiate Ph 1b with AGEN1884* with

AGEN2034*

• Initiate Ph 1 with AutoSynVax™

• Clinical results

• Optimal monotherapy dose for

AGEN2034*

• Optimal combination dose of AGEN2034*

+ AGEN1884*

• Clinical responses

• Data from 30 patients

• Initial immune biomarker data from 6-

patient Ph 1 ASV proof-of-mechanism trial

Clinical Activity & Readouts

• Complete enrollment for 2nd line

virally-induced cancer cohort

• Top line data for the virally-

induced cancer cohort:

• Response rate

• Duration of response

• Safety and tolerability

Projected milestones

19

* Partnered with Recepta for certain South American rights

** Partnered with INCY Anticipated in cervical cancer

20

Management Team• Garo Armen, PhD, Chairman & CEO

Elan Corporation, plc, Protagenic Therapeutics, Founder - Children of Armenia Fund (COAF)

• Robert Stein, MD, PhD, President, R&D

Incyte Pharmaceuticals, Ligand Pharmaceuticals, Dupont/Merck, Roche, KineMed, Merck, Sharp & Dohme

• Jennifer Buell, PhD, VP R&D and External Affairs

Harvard Clinical Research, Bristol-Myers Squibb

• Christian Cortis, PhD, VP Business Development

Synta Pharmaceuticals, Advanced Technology Ventures, Columbia University

• Jean-Marie Cuillerot, MD, Chief Medical Officer

EMD Serono, Bristol-Myers Squibb, University Louis Pasteur

• Alex Duncan, PhD, Chief Technology Officer

Actigen, Affitech A/S, Astra Zeneca, Cambridge Antibody Technology

• Christine Klaskin, VP Finance

Arthur Andersen, George Washington University

• Michelle Linn, VP Corporate Communications

Linnden Communications, Ogilvy PR/Feinstein Kean, Chair of Women In Bio Boston Chapter

• Karen Valentine, JD, Chief Legal Officer & General Counsel

Palmer and Dodge LLP