EpiVax Non-Confidential Overview of the Tregitope Technology. June 2013 www.

1. Tregitope Overview
Non-confidential
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Annie De Groot M.D. CEO/CSO
Bill Martin, COO/CIO

2. EpiVax Corporate Summary
• Founded 1998 – cash positive since inception
• Privately Held (De Groot, Martin Principals)
• Better Vaccine and Protein Design – Services
• Development of Immunomodulatory Products (Vaccines,
Tregitope)
• Successful mix of services and grant-funded research:
14% growth, year over year, without venture funding.
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3. Management Team
http://www.epivax.com/about/management-team/
• Dr. Anne De Groot, CEO/CSO
• William Martin, Chief Information Officer
• Dr. Leslie Cousens, Director of Protein Therapeutics
• Dr. Lenny Moise, Director of Vaccine Research
• Anthony Marcello, Business Development Associate
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4. EpiVax: Four Core Strengths
www.epivax.com
Epitope Services
Epitope Mapping
HLA Binding
T cell assays
In vivo assays (HLA Tg mice)
Fee for Service
Vaccines
Grant funded R & D
Excellent proof of principle
Grant Funded
2nd Generation
Therapeutics
Select targets
Funded Res. Or Joint Devt
Develop molecule and license
Sponsored Research /
Joint Development
Immuno-
modulation
Tregitopes
In preclinical development- may be large
market - allergy, autoimmunity
Options available for
selected “Field of Use”
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5. Discovery of Tregitopes
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Tregitopes, discovered by Anne De Groot and Bill Martin at EpiVax, are linear
sequences of amino acids contained within the framework of monoclonal
antibodies and immunoglobulin G; the original finding was published in the journal
Blood in 2008. Since their discovery, EpiVax has compiled substantial evidence
linking Tregitopes to the activation of natural regulatory T cells. By selectively
activating these natural regulatory T cells, Tregitopes can dampen unwanted
immune responses.
Preliminary studies carried out by EpiVax and collaborators indicate that
Tregitopes may be useful for inducing tolerance to transplants, protein drugs, and
blood replacement therapies, as well as for the treatment of allergies. EpiVax
believes Tregitopes may explain the effectiveness of intravenous immunoglobulin
G (IVIG), widely utilized as an autoimmune treatment.
NIH SBIR grants coupled with private foundation funds have brought total pre-
clinical funding for Tregitopes to more than $3.4M in the past 4 years.
Tregitopes – Quick Summary

6. Discovery of Tregitopes
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EpiVax Screens mAbs
For immunogenicity
Found Epitopes that are
Highly conserved
Tolerated or ignored?
(David W. Scott connection)
Tregs?
. . . Test hypothesis
APC Tregitope peptide
derived from IgG
Discovery of Tregitopes

7. Published in Blood, 25 July 2008
Reprints available on request
Original Publication
http://www.epivax.com/publications/tregitope-publications/

8. Previous Evidence of Treg
Epitope in Fc domain
Constantin Baxevanis, et al.:
– 1986 hFc could induce tolerance in mice
– CH3 could not induce tolerance
– “Tolerogenic epitopes may exist in CH2 domain”
Eur. J. Immunol. 1986.16: 1013-1016
= No Tolerance
= Tolerance
hFc
CH3
CH2
CH3
CH3

9. Fc Fusion Studies (David Scott Lab)
– 1996 Ag-IgG fusion could induce tolerance
– 2000 MHC CII essential in tolerance induction
– 2004 GAD-IgG induces CD4+CD25+ Tregs
–Also see work by Habib Zaghouani et al.
Evidence of Tregitopes in IgG
= ToleranceCH2
CH3
Ag
CH1

10. What’s the Evidence?
(1) HLA Binding
(4) Bystander Suppression
. . . and antigen-specific
tolerance induction
(2) nTreg induction
(3) aTreg induction
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(5) Modify APC Phenotype

11. Are there other examples in the literature?
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12. Edratide - TGF-beta and
FoxP3 expression (Human)

13. Edratide – HLA Restriction
Frame Frame DRB1*0101 DRB1*0301 DRB1*0401 DRB1*0701 DRB1*0801 DRB1*1101 DRB1*1301 DRB1*1501
Start Stop Z-Score Z-Score Z-Score Z-Score Z-Score Z-Score Z-Score Z-Score
1 GYYWSWIRQ 9 -1.01 -1.63 -1.79 0.16 0.07 -1.37 -0.74 -0.79 -0.42 0
2 YYWSWIRQP 10 -1.14 -0.15 0.31 0.37 1.11 -0.10 1.06 -0.48 -0.70 0
3 YWSWIRQPP 11 -1.18 0.14 0.52 0.68 0.89 0.80 1.16 0.31 0.40 0
4 WSWIRQPPG 12 -1.08 1.48 -0.31 1.05 0.05 1.19 1.77 0.14 0.15 1
5 SWIRQPPGK 13 -1.41 -0.08 -0.92 -0.50 -0.96 0.55 0.26 0.26 -0.01 0
6 WIRQPPGKG 14 -1.37 2.29 1.27 1.97 1.28 2.62 2.35 0.88 1.26 4
7 IRQPPGKGE 15 -1.66 0.12 0.10 0.08 0.18 0.63 -0.59 0.97 0.03 0
8 RQPPGKGEE 16 -2.54 -2.45 0.29 -2.38 -2.31 -0.21 -1.45 -0.13 -0.65 0
9 QPPGKGEEW 17 -2.14 -1.47 -1.99 -1.62 -1.00 -2.67 -2.50 -2.86 -2.21 0
10 PPGKGEEWI 18 -1.26 -2.63 -1.56 -3.15 -1.36 -1.52 -2.36 -1.54 -2.89 0
11 PGKGEEWIG 19 -1.12 -1.50 -1.15 -1.61 -1.87 -1.80 -0.76 -2.12 -0.89 0
DRB1*0101 DRB1*0301 DRB1*0401 DRB1*0701 DRB1*0801 DRB1*1101 DRB1*1301 DRB1*1501 Total
2.29 1.27 1.97 1.28 2.62 2.35 0.97 1.26 --
2.29 0.00 1.97 0.00 2.62 4.12 0.00 0.00 11.00
1.00 0.00 1.00 0.00 1.00 2.00 0.00 0.00 5.00
Top 10%*
Top 5% Top 1%
Hydrophobic amino acid sequences scoring above 2.0 can be difficult to synthesize as peptides. Mutated amino acids are indicated in red typeface.
EpiMatrix Cluster Detail Report
File: MOZES_HCDR1 Sequence: HCRD1 Cluster: 1
March 29, 2012 (Epx Ver. 1.2)
Z score indicates the potential of a 9-mer frame to bind to a given HLA allele; the strength of the score is indicated by the blue shading.
All scores in the Top 5% (Z-Score >= 1.64) are considered "Hits". *
Scores in the top 10% (shown but not highlighted) are considered elevated, other scores are grayed out for simplicity.
Frames containing four or more alleles scoring above 1.64 are referred to as Epi-Bars and are highlighted in yellow. These frames have an increased likelihood of binding to HLA.
Frames conserved in IgG antibodies and believed to be either passively tolerated or actively regulatory are highlighted in green.
Flanking amino acids, added to stabilize the cluster during in-vitro testing, are presented in blue type face and underlined.
Total Assessments Performed: 88 Hydrophobicity: -1.09 EpiMatrix Score: 1.93 EpiMatrix Score (w/o flanks): 1.93
Scores Adjusted for Tregitope: -- EpiMatrix Score: -7.30 EpiMatrix Score (w/o flanks): -7.30
Hits
Summarized Results (29-MAR-2012)
Maximum Single Z score
Sum of Significant Z scores
Count of Significant Z Scores
AASequence &nbspHydro- &nbspphobicity
The hCDR1 peptide: GYYWSWIRQPPGKGEEWIG
The pCDR1 peptide: TGYYMQWVKQSPEKSLEWIG
The pCDR3 peptide: YYCARFLWEPYAMDYWGQGS

14. 14
DiaPep 277
Also somewhat HLA-restricted

15. Tregitope Collaberator Checklist - Relevant to
Autoimmunity?
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 Tregitopes induce adaptive tolerance in C57Bl/6, D011.10, OTII
 Tregitopes suppress/treat diabetes in NOD model (Scott/EpiVax)
 Tregitopes suppress transplant rejection in CD28 KO mice (Scott)
 Tregitopes suppression = IVIG in OVA/Allergy Model (Mazer)
 Tregitopes suppress immune responses to AAV capsid (Mingozzi)
Tregitopes cause expansion of Tregs – iTreg or nTreg?.
Details (and slides) for the above are available under CDA.
Contact: amarcello@epivax.com

16. Anticipated Applications
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 Antigen specific tolerance induction (De-immunization of
biotherapeutics).
 Treatment of Autoimmune Disease (MS, T1D, others yet to be
studied)
 Treatment of Allergy

17. How Tregitopes are used in our Web Based
Immunogenicity Screening Platform - ISPRI
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18. 18
Correlation of antibody immunogenicity without
Tregitope adjusted EPX Scores
Correlation to observed Immunogenicity before accounting for Tregitopes
R2=0.17

19. Factoring in Tregitopes. . .
T cell response depends on:
T cell epitope content – Tregitope content + HLA of subject
Protein Immunogenicity can be Ranked
epitope
Protein Therapeutic
1 + 1 - Regulatory T cell epitope* = Response
epitopeepitope
Immunogenicity Scale for Monoclonals
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6/13/2013 Confidential

20. 20
Correlation of antibody immunogenicity with
Tregitope adjusted EPX Scores
Accounting for Tregitopes results in more accurate predictions.
Correlation to observed immunogenicity after accounting for Tregitopes
R2=0.76

21. Antibodies: A Special Case
- 80 -
- 70 -
- 60 -
- 50 -
- 40 -
- 30 -
- 20 -
- 10 -
- 00 -
- -10 -
- -20 -
- -30 -
- -40 -
- -50 -
- -60 -
- -70 -
- -80 -
IgG FC Region
Nuvion (0%)
Avastin (0%)
AB01 (EPX Adjusted Score: -46.98)
AB02 (EPX Adjusted Score: -44.48)
AB03 (EPX Adjusted Score: -44.81)
AB04 (EPX Adjusted Score: -45.81)
AB05 (EPX Adjusted Score: -45.88)
AB06 (EPX Adjusted Score: -47.85)
AB07 (EPX Adjusted Score: -46.99)
AB08 (EPX Adjusted Score: -46.30)
AB09 (EPX Adjusted Score: -47.40)
AB10 (EPX Adjusted Score: -45.88)
AB11 (EPX Adjusted Score: -47.40)
Synagis (1%)
Simulect (1.4%)
Humira (12%)
Bivatuzumab (6.7%)
Remicade (26%)
Rituxan (27%)
Campath (45%)
Humicade (7%)
Reopro (5.8%)
Tysabri (7%)
LeukArrest (0%)
Herceptin (0.1%)
New drug
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6/13/2013 Confidential
Due to the presence of Tregitopes, antibodies tend to fall lower
on the immunogenicity scale.
We have developed a refined method using regression
analysis to predict the immunogenicity of antibody sequences
based on observed clinical responses.
We have found that a balance in favor of Tregitope (regulatory)
content over neo-epitope (effector) content is correlated with
reduced clinical immunogenicity.
NeoEpitopeContent
Tregitope Content
High Low
Low
Avastin (0%)
Herceptin (0%)
Mylotarg (3%)
Simulect (1%)
Synagis (1%)
High
Campath (45%)
Remicade (26%)
Rituxan (27%)

22. Leslie Cousens and Annie De Groot
EpiVax, Inc.
Mechanism of Tregitope Action:
In Vitro Studies
226/13/2013 Confidential EpiVax

23. APC
CD4
Teff
CD4+
CD25+
Treg
Notch
MHC
Class
II
TCR
CD28/
CTLA4
CD80/
CD86
IL-10
Identifying Tregitope Mechanisms of
Action at the Immunological Synapse
ILT3
236/13/2013 Confidential EpiVax

24. Thanking our Collaborators
EpiVax, Inc.
William Martin
Lenny Moise
Leslie Cousens
Tim Musset
Matt Ardito
Ryan Tassone
McGill
University
Bruce Mazur
Ciro Piccirillo
Amir Massoud
Dartmouth
College
Chris Bailey-Kellogg
Partial funding by
the NIH
Uniformed
Services
University of the
Health Sciences
David Scott
Yan Su
Xin Li
University of
Maryland
Achsah Keegan
Preeta Desgupta
Children’s
Hospital of
Philadelphia
Katherine High
Federico Mingozzi
Daniel Hui
9/28/2012
Harvard Brigham &
Women’s Hospital
Mo Sayegh
Nadar Najafian
Francesca D’Addio
Ciara Magee
Samia Khoury
Wassim Elyaman
Institute for
Immunology and
Informatics
Anne De Groot
Loren Fast
Alan Rothman
Denice Spero
Duke University
Priya Kishnani
Dwight Koeberl

25. EpiVax: Four Core Strengths
Confidential
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