1. XBiotech Harnessing Natural Immunity to Transform Medicine
A platform overview and review of recent findings in dermatology

2. FORWARD LOOKING STATEMENT
This presentation contains forward-looking statements, including declarations regarding management's beliefs and expectations that involve substantial risks and uncertainties. In some cases, you can identify forward-looking statements by terminology such as "may," "will," "should," "would," "could," "expects," "plans," "contemplate," "anticipates," "believes," "estimates," "predicts," "projects," "intend" or "continue" or the negative of such terms or other comparable terminology, although not all forward- looking statements contain these identifying words. Forward-looking statements are subject to inherent risks and uncertainties in predicting future results and conditions that could cause the actual results to differ materially from those projected in these forward-looking statements. These risks and uncertainties are subject to the disclosures set forth in the "Risk Factors" section of certain of our SEC filings. Forward-looking statements are not guarantees of future performance, and our actual results of operations, financial condition and liquidity, and the development of the industry in which we operate, may differ materially from the forward-looking statements contained in this presentation. Any forward-looking statements that we make in this presentation speak only as of the date of this presentation. We assume no obligation to update our forward-looking statements whether as a result of new information, future events or otherwise, after the date of this presentation.

3. XBiotech Manufacturing & R&D Center

4. Mine the Human Antibody Repertoire
Healthy Human Volunteers with Natural Immunity to Disease
…And We Develop the Best that the Human Antibody Repertoire has to Offer 4

5. Opportunities Skin Disease (ie. Inflammatory disease)
Cardiovascular Disease
Infectious Disease
Cancer
Acute Infectious Outbreaks 5

6. Innovations for Antibody Discovery
Precision High Throughput Screen of Antibody Drug Candidates in Human Blood
Flow Cytometry Based, Epitope Driven Antibody Identification
Rapidly Identify Rare Antibody Genes from Blood
Comprehensive Repertoire and Inclusive Variable Region Cloning
Innovations for Antibody Discovery 6

7. Simplicity—Reduced Plant & Equipment Infrastructure
Flexibility—modular, scalable
Capital Sparing
Compliant—disposable
Reducing the Cost Barrier for Commercialization: Manufacturing Innovation

8. XBiotech designed and engineered manufacturing technology8

9. 250 Issued and Pending Patents World-Wide

10. Pipeline Treatment Area Indication Discovery/Pre-Clinical Phase I
Phase II
Phase III
Dermatology
Atopic Dermatitis
Hidradenitis Suppurativa
Acne Vulgaris
Plaque Psoriasis
Pyoderma Gangrenosum
Systemic Scleroderma
Oncology
Pancreatic Cancer
Symptomatic / Advanced Colorectal Cancer
Palliative Care
Endocrine
Type II Diabetes
Anti-Infective
Staphylococcus Aureus (514G3)
Clostridium Difficile (CDX-1)
Varicella Zoster (VZX)
Influenza (HAN-X)
Bermekimab

11. Targeting a Master Regulator of Inflammation
Interleukin-1a

12. Bermekimab: a new kind of antibody
First-In-Class (only antibody therapy derived from human)
Derived from a Natural Human Response—NOT animal derived or so called “fully human”
No engineering of antibody binding
Naturally neutralizes Interleukin-1a—the master regulator of inflammation

13. Bermekimab Clinical Studies in Dermatology
Indications
Hidradenitis Suppurativa (DBPCRS intravenous)
Hidradenitis Suppurativa (POC s.c.)
Plaque Psoriasis (POC s.c.)
Acne Vulgaris (POC s.c.)
Atopic Dermatitis (POC s.c.)
DBPCRS = Double blind placebo controlled randomized study
POC = Proof of concept clinical study
s.c. = subcutaneous

14. XBiotech’s Published Primary Clinical Research for Bermekimab in Dermatology
Bermekimab Targeting Interleukin-1Alpha for Moderate to Severe Hidradenitis Suppurativa not Eligible for Adalimumab: A Randomized Study
Kanni T, Argyropoulou M, Spyridopoulos T, Pistiki A, Stecher M, Dinarello CA, Simard J, Giamarellos-Bourboulis EJ. J Invest Dermatol Apr;138(4):
Open-label trial of Bermekimab, a true human monoclonal antibody targeting interleukin 1α, for the treatment of psoriasis
Coleman KM, Gudjonsson JE, Stecher M.
JAMA Dermatol May;151(5):555-6.
An open label, phase 2 study of Bermekimab monotherapy for the treatment of acne vulgaris and psychiatric comorbidity
Carrasco D, Stecher M, Lefebvre GC, Logan AC, Moy R.
J Drugs Dermatol Jun;14(6):560-4.

15. Recent Reviews for Bermekimab in Dermatology
Investigational Drugs in Clinical Trials for Hidradenitis Suppurativa
Peter Theut Riis, Linnea R. Thorlacius & Gregor B. Jemec. Expert Opinion on Investigational Drugs Jan;27(1):43-53.
The Role of Interleukin‐1 in Inflammatory and Malignant Human Skin Diseases and the Rationale for Targeting Interleukin‐1 Alpha
Mayassa J. Bou-Dargham et al., Med Res Rev Jan;37(1):

16. Hidradenitis Suppurativa
Bermekimab, an Anti-IL-1α Monoclonal Antibody, Shows Efficacy for Treating Hidradenitis Suppurativa (HS) with Breakthrough Reduction in Pain
Hidradenitis Suppurativa
Data Presented at the American Academy of Dermatology, March 2019
Alice Bendix Gottlieb MD, PhD
Clinical Professor of Dermatology
Icahn School of Medicine at Mount Sinai
New York, NY 16

17. Phase II Open Label, Study of Bermekimab in Patients with Moderate to Severe Hidradenitis Suppurativa
Week 0
Week 12
Patients who have previously failed
anti-TNF Therapy (“Failures”)
400mg Every Week (n=24)
Baseline Data
1st Injection
Endpoint Data
After 12 injections
Week 0
Week 12
Patients with no prior treatment
with anti-TNF Therapy (”Naïve”)
400mg Every Week (n=18)
Baseline Data
1st Injection
Endpoint Data
After 12 injections

18. Bermekimab vs Humira Positive HiSCR at week 12
Subjects Achieved %
p=0.003
p<0.001
PIONEER I * *
Humira
Humira +
Oral antibiotics
N=24
N=18
*Source: N Engl J Med Aug 4;375(5): doi: /NEJMoa
Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa. 18

19. Bermekimab vs Humira Patients with total abscess and inflammatory-nodule count of 0, 1, or 2 at week 12
Subjects Achieved % * *
Humira +
Oral antibiotics
Humira
N=24
N=18
p=0.961
p=0.010
*Source: N Engl J Med Aug 4;375(5): doi: /NEJMoa
Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa.

20. Bermekimab vs Humira: Pain Patients with 30% reduction and ≥1 unit reduction in pain Score
Subjects Achieving % * *
Humira
Humira +
Oral antibiotics
N=24
N=18
*Source: N Engl J Med Aug 4;375(5): doi: /NEJMoa
Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa. 20

21. Double-Blind, Placebo Controlled, Phase II Study of Bermekimab in Patients with Hidradenitis Suppurativa Refractory to Adalimumab
Kanni T, Argyropoulou M, Spyridopoulos T, Pistiki A, Stecher M, Dinarello CA, Simard J, Giamarellos-Bourboulis EJ. J Invest Dermatol Apr;138(4):

22. Primary study endpoint
*Fisher’s exact test
**Mantel-Haenszel’s statistics
CIs: confidence intervals
OR: odds ratio
ORHiSCR(+) MABp1: 13.50**
(95%CIs: , p: 0.035)

23. HiSCR to 24 Weeks
2° endpoint
*Fisher’s exact test

24. Abscesses & Inflammatory Nodule Total Counts
2° endpoint
* Comparison of AUCs by the Students “t-test”

25. ATOPIC DERMATITIS
Bermekimab An Anti-IL-1α Monoclonal Antibody Shows Efficacy for Treating Atopic Dermatitis (AD) with Breakthrough Reduction in Itch
Data Presented at the American Academy of Dermatology, March 2019

26. Treatment Regimens Week 0 Week 4 200mg Every Week Baseline Data
1st Injection
Endpoint Data
After 4 rounds
n=10
Week 0
Week 4
Week 8
400mg
Every Week
Baseline Data
1st Injection
Midpoint Data
After 4 rounds
Endpoint Data
After 8 rounds
n=28

27. Subjects Achieving EASI-75
Mean % reduction
% Change from Baseline
% Subjects Achieving
P<0.001
200mg
(N=10)
400mg
(N=28) 27
Any missing patient data imputed using LOCF

28. Bermekimab vs Dupilumab EASI-75
Week 8
Week 16
Patients achieving EASI 75 % *
Bermekimab
Dupilumab
(400mg Group, N = 28)
* N Engl J Med Dec 15;375(24): Epub 2016 Sep 30.
Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis.

29. SCORAD Bermekimab vs Dupilumab
Week 8
Week 16
Improvement %

30. Bermekimab vs Dupilumab HADS Combined Score Improvement
Week 7
Week 16
Point Reduction
SOLO1
SOLO2
Bermekimab
Dupilumab
(400mg Group, N = 28)

31. Patients achieving ≥ 4 improvement
Patients achieving ≥ 4 points improvement in worst itch NRS week 4
Patients achieving ≥ 4 improvement %
(400mg Group, N = 28)
Dupilumab

32. Subjects Achieving ≥4 NRS Score
NRS Pain
Mean % Reduction
Subjects Achieving ≥4 NRS Score
Reduction in Pain
Mean Reduction %
% Subjects Achieving
(400mg Group, N = 28)
(400mg group, Subjects having ≥ 4 at baseline N = 20)
Any missing patient data imputed using LOCF

33. A shining star on the dermatology horizon: Bermekimab
Time Period
8 Weeks*
16 Weeks
Therapy
Bermekimab
400mg qw
Lebrikizumab
250mg q2w
Dupilumab*
300mg q2w
Upadacitinib#
30mg daily
15mg daily
EASI-75
75%*
61%
44-51%
69%
52%
Pruritus NRS %
improvement
78%*
Not
reported
41%
48%
Pain NRS ≥4 Decrease
80%*
Reported/Studied %
* N Engl J Med Dec 15;375(24): Epub 2016 Sep 30. Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis. #

34. HS Data Echo the Story for AD
% Achieving Positive HISCR
%Decrease in Abscess & Lesion Count
% Achieving Decrease in Pain
Bermekimab Ph2
IV weekly x 12 60 42 --
400mg SQ weekly x 12
TNF Naive 61 46 67
TNF Failure 63 72
Adalimumab Ph3
40mg SQ weekly x 12
PIONEER I* 29 28
*Source: N Engl J Med Aug 4;375(5): doi: /NEJMoa
Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa.

35. Thank you