OBI-999 is an antibody-drug conjugate targeting Globo H that is being developed by OBI Pharma. Preclinical studies show that OBI-999 selectively binds and is internalized by Globo H positive cancer cells, exhibits bystander killing of neighboring Globo H negative cells, and accumulates in tumors through target-mediated uptake. In animal models, OBI-999 demonstrated strong and dose-dependent antitumor activity against breast, gastric, pancreatic, and lung cancer xenografts, with some models achieving complete responses. A phase 1/2 clinical trial is ongoing to evaluate the safety, pharmacokinetics, and activity of OBI-999 in patients with advanced solid tumors

1. A Novel Globo H-targeting
Antibody-drug Conjugate:
OBI-999
World ADC Digital
Ming-Tain Lai, Ph.D.
Chief Scientific Officer
OBI Pharma, Inc.
16 Sept, 2020

2. Acknowledgement
2
❖ Ming-Chen Yang,1 Ph.D.
❖ Yu-Jung Chen1
❖ Chi-Sheng Shia,2 Ph.D.
❖ Hui-Wen Chang2
❖ Wan-Fen Li,2 Ph.D.
❖ Cheng-Der Tony Yu,3 Pharm. D., Ph. D.
❖ I-Ju Chen,1 Ph.D.
1 Translational Biology of R&D ; 2 Pharmacology, PharmacoKinetics and Toxicology of R&D; 3 R&D Advisor

3. Presentation Outline
3
1. Introduction of Globo Series
2. Potential role of GH in tumor development
3. Pre-clinical study of OBI-999
4. Anti-tumor efficacy of OBI-999 in animal model
5. Safety data from GLP toxicity study in monkey

4. Globo Series: A Unique Class of Glycosphingolipids
(GSLs) Involved in Tumor Development and Survival
4
Zhang et al. Frontiers in Immunology 2019;10
GSL roles in molecular signaling, cellular cross-talk, and cell adhesion
Cer
β3
SSEA-3
β3
Cer
Gb4Cer
Cer
ββ4α4
Gb3Cer
Fuc GalNAcGalGlc
FUT-1 or 2
β3GalT5
Globo H Ceramide
α2
Cer
β3GalT3

5. Pancreatic Esophageal Gastric Breast Lung Colon Liver
0
50
100
150
200
250
300
Globo H IHC H-score of various tumor tissues
Hscore
High Globo H Expression in Common Cancers
5
Resections + TMAs + 822-001 Samples. TMA: tissue microarray. Red bar: median score. OBI Data on File.
Cancer
#
Evaluable
Specimens
#
H-score
≥100
Prevalence
at H-score
≥100
Pancreatic 72 36 50.0%
Esophageal 64 11 17.2%
Gastric 73 18 24.7%
Breast 131 17 13.0%
Lung 77 8 10.4%
Colon 75 12 16.0%
OBI’s Globo H Expression Assay (NeoGenomics)
IDE-Approved by FDA

6. Potential Roles of Globo H in Immunosuppression,
Angiogenesis and Cancer Cell Survival Signaling
6
1Tsai YC, et al. J Cancer Sci Ther 2013;5:264-270
2Cheng JY, et al. Cancer Res 2014;74:6856-6686
3Chuang PK, et al. PNAS 2019;116:3518-3523
Promotes
Immunosuppression1
Tumor Shedding
of Globo H
Ceramide
TRAX
Ca2+ 
Endothelial Cells
Notch1
Ub
Ub
Degradation
Tumor Cells
Lymphocytes
Kinase
e
Tumor Survival
Kinase
Kinase
Promotes
Angiogenesis2
Promotes Tumor
Survival Signaling3

7. The OBI Pharma Novel and Diverse Cancer Pipelines
7ALL, acute lymphoblastic leukemia; CRPC, castration-resistant prostate cancer; HCC, hepatocellular carcinoma; TNBC, triple-negative breast cancer.
TARGET CANCER DISCOVERY PRE-CLINICALPRODUCT P1 P2 P3
OBI-833
OBI-888
OBI-999
OBI-866
OBI-898
Globo H
Breast (TNBC)
Ovarian
Globo H
Globo H
Globo H
SSEA-4
SSEA-4
Multiple
Cancers
Multiple
Cancers
Multiple
Cancers
Multiple
Cancers
Breast
OBI-3424 AKR1C3
Liver (HCC)
Prostate (CRPC)
T-ALL
Adagloxad
Simolenin
Vaccine
Vaccine
mAb
ADC
mAb
Vaccine
Prodrug
TYPE
OBI-998 ADC SSEA-4
Multiple
Cancers

8. OBI-999 Improved Homogeneity Compared to Adcetris
8
OBI data on file.
0
20
40
60
80
100
0 1 2 3 4 5 6 7 8
%
DAR Species
OBI-999
0
20
40
60
80
100
0 1 2 3 4 5 6 7 8
%
DAR Species
Adcetris
Worldwide exclusive license to use the ThioBridge®
technology for ADCs targeting the Globo series (Globo H
Ab / Thiobrige / vc-PAB-MMAE)
Unique linker technology maintains the stability of the
antibody and a consistent drug-to-antibody ratio (DAR)

9. Binding Specificity OBI-999 by Confocal Microscopy
9
OBI-999AdcetrisHu-IgG
MDA-MB-231
(GH 11%)
SKBR-3
(GH 0.1%)
NCI-N87
(GH 94%)
DAPIa-Hu-IgG
HCC-1428
(GH 99%)
Globo H
Negative
Low
High
0.1 1 10 100 1000
0
10000
20000
30000
OBI-999 binding specificity
mAb or ADC (g/mL)
GeoMFI
Ctrl ADC (HCC-1428)
OBI-999 (HCC-1428)
Ctrl ADC (MDA-MB-231)
OBI-999 (MDA-MB-231)
Ctrl ADC (SKBR-3)
OBI-999 (SKBR-3)

10. EEA-1: Endosome markerHCC-1428 (GH 99%)
OBI-999 Internalization in Globo H Positive Cancer
Cells (HCC-1428)
10

11. 11
MCF7 (GH high) and ES-2 (GH low) cells were co-cultured in the presence of OBI-999. The viability of ES-2 cells is much lower than the cells alone treated
with OBI-999. CD30 was used as a control antigen.
OBI-999 Bystander Effect
Tumor killing for surrounding Globo H low or negative expressing tumor cells
OBI data on file.
OBI-999 (nM)

12. OBI-999 Exhibited Target-mediated Tumor Accumulation
12Yang, MC et al. AACR 2019. Abstract No. 4814.
OBI data on file.
Tum
or
Liver
Lung
Spleen
H
eart
K
idney0
2
4
6
OBI-999 (ADC)
ConcentrationofOBI-999(µg/g)
1h
4h
8h
24h
72h
168h
336h
Tum
or
Liver
Lung
Spleen
H
eart
K
idney
Serum
0.00
0.01
0.02
0.03
0.04
0.05
0.00
0.01
0.02
0.03
0.04
0.05
free MMAE
ConcentrationoffreeMMAE(µg/g)
ConcentrationoffreeMMAE(µg/mL)
1h
4h
8h
24
72
16
33
Tumor/tissue distribution of OBI-999 Tumor/tissue distribution of payload
Tumor:NCI-N87 gastric cancer (94%) Free MMAE in serum maintains at very low level!

13. OBI-999 Strong Anti-Tumor Effects in 4 Cancer Models
13
PDX, patient-derived xenograft; TGI, tumor growth inhibition; QW, every week; Q3W, every 3 weeks.
Yang, MC et al. AACR 2019. Abstract No. 4814.
OBI Data on File.
CANCER
TYPE
TUMOR
MODEL**
DOSES
(mg/kg)
TREATMENT
DURATION
RESPONSE OR TGI AT
HIGHEST DOSE, %
Breast MCF7 1, 3 QW x 6 or Q3W x 2 Complete Response
Gastric* NCI-N87 1, 3,10 QW x 4
Complete Response
(CR achieved at both 3 and 10 mg/kg)
Pancreatic* HPAC 10 QW x 4 Complete Response
Lung PDX LU-01-0266 1, 3, 10 QW x 4 Complete Response
Complete
Response
=
Tumor Free
* Received FDA orphan drug designation
** GH prevalence: MCF7 (91%); NCI-N87 (94%); HPAC (88%); LU-01-0266 (27%)

14. HPAC xenograft (OBI-20180927)
Days
500
1000
1500
2000
2500
1 5 8 12 15 19 22 26 29 33 36-7
Tumorvolume(mm3
)
Vehicle
3000
Days
100
200
1 6 9 12 16-7T
Vehicle
OBI-999 1mpk, IV, QWKx4
OBI-999 3mpk, IV, QWKx4
OBI-999 10mpk, IV, QWKx4
QWK x4
Latent day: 7 days
Day 0: Start treatment day.
Cell inoculation 3x106
Tumor
Free
OBI-999 at 3 mg/kg:
TGI 36.1% on Day
36
OBI-999 Strong Tumor Growth Inhibition in
HPAC Pancreatic Cancer Xenograft Model
14OBI data on file. Female BALB/c nude mice (n = 8 per group) were implanted subcutaneously with HPAC pancreatic cancer cells. Complete response defined
as tumor free. Globo H expression: 97.2%.
HPAC
88 %

15. Day 0 : Cell inoculation
2.5x106 with matrigel (1:1)
all test
compounds/
once per week
Latent
day: 1
day
8 1 5 2 2 2 9 3 6 4 3 5 0 5 7 6 4
0
5 0 0
1 0 0 0
1 5 0 0
2 0 0 0
N C I-N 8 7 x e n o g ra ft (A B 6 7 8 3 5 )
Tumorvolumn(mm
3
)
O B I-9 9 9 , 1 0 m g /k g (Q W x 4 , IV )
D a y s
V e h ic le (Q W X 4 ,IP + IV )
O B I-9 9 9 , 1 m g /k g (Q W x 4 , IV )
O B I-9 9 9 , 3 m g /k g (Q W x 4 , IV )
OBI-999 at
3 and 10 mg/kg:
Tumor Free
OBI-999 at 1 mg/mL:
TGI% = 83% on Day 53
OBI-999 Strong Tumor Growth Inhibition in
NCI-N87 Gastric Carcinoma Xenograft Model
15OBI data on file. Female nude mice (n = 8 per group) bearing NCI-N87 gastric tumors were given as indicated. Dose-dependent anti-tumor activity was
observed in animals receiving OBI-999, with complete response noted in the groups of 3 and 10 mg/kg. Globo H expression: 56.6%.
94 %
GloboH

16. Safety Study in Cynomolgus Monkeys
16
A single-dose toxicity study in cynomolgus monkeys showed that OBI-999 at 30 mg/kg caused animal death due to severe hematologic toxicity and bone
marrow suppression whereas OBI-999 was tolerated at levels of 3 and 10 mg/kg. A dose range from 2 to 10 mg/kg was therefore selected for the GLP repeat-
dose toxicity study. OBI data on file.
Study Type Repeated-dose
Species Cynomolgus Monkey
Number/Sex/Group 5/sex/group
Dose Level (mg/kg) 0, 2, 5, 10
Frequency of Dosing/Recovery Q3W x 2; 3-week recovery
Route of Administration IV infusion
Dose Volume 1.97 mL/kg
Key Study Findings • No mortality
• No OBI-999 related body weight changes and clinical signs
• No remarkable observations in safety pharmacology exam
• Dose-dependent, reversible effects on hematopoiesis, suggesting a cycle of bone marrow
suppression 5-7 days post-dose, followed by a regenerative hematopoietic effort 2-3 weeks post-
dose
• Bone marrow smears showed a minimal-mild decrease of M:E at 10 mg/kg
• Reversible effects on clinical chemistry at 10 mg/kg including mild decrease of albumin and
minimal increase of AST and creatine kinase; no microscopic correlates
HNSTD 10 mg/kg
The first-in-human dose was determined using the FDA-recommended approach—1/6th of the monkey
HNSTD after consideration of allometric scaling. The proposed FIH is 0.4 mg/kg/dose.

17. OBI 999 Poster presentation at 2020 ASCO
Apostolia Maria Tsimberidou et al. A Phase 1/2, Open-Label, Dose-Escalation, and Cohort-Expansion Study Evaluating the Safety, Pharmacokinetics, and
Therapeutic Activity of OBI-999 in Patients with Advanced Solid Tumors. Poster # 387 ASCO20 Virtual Annual Meeting June 2020
17

18. OBI 999 (Anti-Global H ADC) Conclusions
18
• Globo H (GH) may play an important role in tumor development and survival
• OBI-999 with thiobridge linker provides uniform drug-antibody ratio
• MMAE showed persistence in tumor once released from OBI-999
• OBI-999 has demonstrated scientifically to date ……
✓ Targeted accumulation and persistence in tumor
✓ High specificity to GH positive cancer cells
✓ Internalized GH positive cancer cells within 2.5 h
✓ Bystander effects in co-culturing cell model
✓ Excellent efficacy in suppressing tumor growth in various animal models
✓ Acceptable safety margin in animal model
• Phase 1/2 study ongoing at MD Anderson Cancer Center in multiple cancer types

19. THANK YOU
Please visit our website:
www.obipharma.com

20. OBI-888 is Highly Tumor Specific
20Chen, YC et al. AACR 2019. Abstract No. 4814.
OBI Data on File.
MCF7-TUMOR BEARING MICENORMAL MICE
Distribution of
labeled Globo H
mAb (OBI-888) in
the tumor of the
MCF7 mouse
Eppendorf tubes for
reference purposes

21. 21
Globo H expression is low in most Normal Human Tissues
Tissue Adrenal
gland
Bladder,
urinary
Bone
marrow
Salivary
gland
Eye Breast
Cerebellu
m
Cerebral
cortex
Fallopian
tube
Esophagus Stomach
Small
intestine
Colon Rectum Heart
Kidney,
cortex
Kidney,
medulla
Peripheral
nerve
Ureter
Median 0 0 37.5 140 0 10 0 0 60 60 0 5 0 0 0 5 30.5 0 12.5
Tissue Liver Lung Ovary Pancreas Parathyroid
Pituitary
gland
Placenta Prostate Skin Spinal cord Spleen
Skeletal
muscle
Testis Thymus Thyroid Tonsil Uterus, cervix Uterus, endometrium
Median 0 2 0 200 50 65 0 1 0 0 0 0 0 2 0 1 100 0
A
drenalgland
B
ladder,urnary
B
one
m
arrow
Salivary
gland
EyeB
reast
C
erebellum
C
erebralcortex
Fallopian
tube
Esophagus
Stom
ach
Sm
allintestineC
olon
R
ectumH
eart
K
idney,cortex
K
idney,m
edulla
PeripheralnerveU
reterLiverLungO
vary
Pancreas
Parathyroid
Pituitary
gland
Placenta
ProstateSkin
SpinalcordSpleen
Skeletalm
uscleTestis
Thym
us
ThyroidTonsil
U
terus,cervix
U
terus,endom
etrium
0
100
200
300
Globo H expression in Human Normal TMA
H-score n=2~3, Median
OBI Data on File.

22. 22
0 1 2 5 23
0
20
40
60
80
100
Time (hr)
Internalization(%)
OBI-999
Tratuzumab
hIgG
OBI-999 internalization in Globo H positive cancer cells
(HCC-1428)

23. Treatment started
when tumor volume
reaches to 150-200
mm3. / once per week
Latent
day: 25
days 0 5 10 15 20 25 30
0
500
1000
1500
2000
2500
3000
3500
D a y s a ft e r t h e s ta r t o f t r e a t m e n t
TumorVolume(Mean㊣SEM;mm3)
G ro u p 1 V e h ic le IV , D a y 1 , 8 , 1 5 , 2 2 , n = 8
G ro u p 2 O B I-9 9 9 , 1 m g /k g , IV , D a y 1 , 8 , 1 5 , 2 2 , n = 8
G ro u p 3 O B I-9 9 9 , 3 m g /k g , IV , D a y 1 , 8 , 1 5 , 2 2 , n = 8
G ro u p 4 O B I-9 9 9 , 1 0 m g /k g , IV , D a y 1 , 8 , 1 5 , 2 2 , n = 8
OBI-999 at
10 mg/kg:
Tumor Free
TGI%
41%
78%
OBI data on file. Globo H expression: 27% in live cells; 32.8% in dead cells.
OBI-999 Tumor Growth Inhibition in LU-01-0266 Lung
Cancer PDX model
23

24. 68%
27%
77%
123%
TGI%
Day 0 :
Cell inoculation
2x107
Ab injection
8 1 5 2 2 2 9 3 6 4 3 5 0 5 7 6 4 7 1 7 8
0
2 0 0
4 0 0
6 0 0
8 0 0
1 0 0 0
Tumorvolumn(mm
3
)
D a y s
v e h ic le ,(Q W x 6 , IV )
O B I-9 9 9 , 1 m g /k g (Q W x 6 , IV )
O B I-9 9 9 , 3 m g /k g (Q W x 6 , IV )
O B I-8 8 8 , 3 m g /k g , (Q W x 6 , IV )
P a y lo a d 0 .0 5 7 m g /k g (Q W x 6 , IV )
OBI-999 at 3mpk:
Tumor Free
OBI-999 Strong Tumor Growth Inhibition in MCF-7
Breast Xenograft Tumor Model
OBI data on file. Female nude mice (n = 8 per group) bearing MCF-7 breast tumors were used. No significant body weight loss or overt toxicities were noticed.
Payload alone showed much less anti-tumor activity compare to OBI-999. Globo H expression: 90.72%.
91 %
GloboH
24

25. 0
2 0 0
4 0 0
6 0 0
8 0 0
1 0 0 0
1 2 0 0
1 4 0 0
1 6 0 0
M C F 7 x e n o g ra ft (A B 6 7 8 3 7 )
O B I-9 9 9 (3 m p k , Q 3 W K x 2 , IV )
D a y s1 3 7 10 14 17 21 24 28 31 35
V e h ic le (Q W K x 4 , IV )
O B I-9 9 9 (3 m p k , Q W K x 4 , IV )
38 42
Tumorvolume(mm3)
45 49 52 56 59 64
once per for
four weeks
Latent
day: 7
day
once per 3 weeks
for two doses
Cell inoculation
2x107 with
matrigel (1:1)
OBI-999 TGI%: QWK 100%, Q3WK 85%
OBI-999 Anti-tumor Effects Remained Strong with
Longer Dosing Interval in MCF7 Breast Cancer Model
OBI data on file. Female nude mice (n = 8 per group) were bearing MCF-7 breast cancer cells were dosed as indicated. Globo H expression: 80.92%.
25

26. OBI-999-001 Study Design
26
OBI Data on File.
⚫ Subject number: 3+3 design, up to 36 (sequential enrollment);
⚫ Cohorts: 6 cohorts of escalating dose levels of 0.4, 0.8, 1.2, 1.8, 2.4 and 3.2 mg/kg;
⚫ Treatment cycle: 21-day cycle up to 35 cycles (approximately 2 years);
⚫ SRC: review safety and PK data after each cohort completes the 1st cycle.
3+3 Dose-Escalation Phase 1
MDACC (Dr Tsimberidou) &
West Clinic (Dr Grothey)
0.4 mg/kg
OBI-999
0.8 mg/kg
OBI-999
1.2 mg/kg
OBI-999
3.2 mg/kg
OBI-999
1.8 mg/kg
OBI-999
2.4 mg/kg
OBI-999
SRC
SRC
SRC
SRC
SRC
SRC
Identify
MTD &
RP2D
Simon 2-Stage Phase 2
Roll-over successful 888 sites
Cohort 1:
Pancreatic ca.
Cohort 2:
Gastric ca.
Cohort 3:
Esophageal ca.
Cohort 4:
Colorectal ca.
Cohort 5:
Basket
⚫ Primary objectives:
- Safety and tolerability of OBI-
999
- MTD and PR2D
⚫ Exploratory objectives:
- Tumor Tissue Samples: Globo H testing
- CTC counts: CTC counts, CTC Globo H
expression
⚫ Secondary objectives:
- ORR, CBR, DOR, PFS
- ADAs
- PK
H0 5%; H1 25%;
Alpha 0.5%; Power 90%;
Stage I ORR ≥1/9;
Stage II ORR ≥4/30