1. a new class of non-opioid analgesic in Phase 3
WEX Pharmaceuticals Inc.
Bin Huang, President & CEO April 2010

2. Forward looking Statement
This presentation contains forward-looking statements which involve
known and unknown risks, uncertainties and other facts which may
cause the actual results, performance or achievements of the Company, or
industry results, to be materially different from any future results,
performance or achievements expressed or implied by such forward-
looking statements. The Company does not expect to update forward-
looking statements continually as conditions change. Investors are referred
to the full discussion of risk factors associated with the Company’s
business contained in the Company’s Annual Information Form filed with
securities regulatory authorities dated February 15, 2010.
2

3. $7B opioids*
the Gold Standard for
moderate to severe pain relief
*2005 global sales
3

4. But opioids have limitations
• Side effects
– Respiratory
– GI
RISKS
with prescribing, administering
– CNS
– Others
& taking opioids: • Ineffective
• Tolerance
• Addiction
4

5. Cancer pain is a vivid example
1 in
of all cancer patients
require opioids to
manage pain 1
in
4 fail opioid therapy
4 5

6. there is no good alternative to
opioids!
6

7. Reformulation is not the answer
• MS Contin®
• OxyContin®
• DURAGESIC® All the same concerns remain:
• Remoxy®
• FENTORA®
a reformulated opioid is
• AVINZA® still an opioid!
• Actiq®
7

8. Tetrodotoxin:
a NEW class of NON opioid analgesic
8

9. Tetrodotoxin (TTX)
• >80 issued and pending • No opioid-like side effects
patents – Non addictive
– No tolerance
• Blocks VGSC (voltage gated
sodium channels) on • Long duration of action
neurons associated with – 2-3 weeks
persistent pain
• Rapid onset of pain relief
• 2000x more potent than – 20 minutes
morphine
• Significant activity in
• Highly specific to pain fibers neuropathic pain
• Safe and well-tolerated
9

10. TTX is safe
• >200 patients treated to date in Canadian trials
• 5 trials completed
• Well-tolerated in single and multiple doses
(up to 4X per day, 4-7 days of treatment)
• Mild, short lasting side effects (numbness, tingling)
• Intramuscular administration comparable
to subcutaneous
10

11. TTX efficacy signals in cancer pain
Phase IIa Phase IIb
• Open label, dose escalation, • Randomized, double-blind placebo
multicentre trial controlled, multicentre trial
• 24 patients • 77 patients
• Severe cancer pain inadequately • Moderate to severe unrelieved cancer
controlled with opioids pain despite best available treatment
• Primary endpoint: proportion of patients
achieving >30% pain intensity reduction
55% of treatments resulted in pain reduction Trial terminated at interim analysis
8-15 day duration 42% treated vs. 31% placebo
(not statistically significant)
11

12. Phase IIb Phase IIb
CTA Submitted IMMPACT paper Interim Results
2004 2005 2006
“Physical and emotional functioning
and participant reports of global
improvements should also be included
among the six core domains”
- IMMPACT paper
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13. Strong efficacy signal using IMMPACT guidelines
Original Endpoint TTX=38 42%
>30% decrease in pain intensity Placebo=39 31% p=0.425
Non statistically significant trend
Composite Endpoint
based on IMMPACT guidelines TTX=38 45%
>30% decrease in pain intensity
OR Placebo=39 21% p=0.043
>50% decrease in opioid use
AND Robust analgesic effect
>30% increase in quality of life
13

14. Ongoing Phase III trial
• Multicentre, randomized, double-blind, placebo-controlled trial
• Moderate to severe inadequately controlled cancer-related pain
• 120 patients planned
• Primary endpoint: Composite endpoint based on IMMPACT guidelines
• Interim results expected Q3 2010
Screening Follow up/
Randomization Baseline Treatment Follow up Open label
-28 to -7 days -7 to 0 days 1 to 4 days 5, 8, 15 days >15 days
14

15. Strong efficacy signals in neuropathic pain
Composite Endpoint
Robust analgesic effect
based on IMMPACT guidelines
TTX=22 44%
Neuropathic pain subset analysis
Placebo=28 18%
15

16. Phase II trial in planning
• Chemotherapy-induced
neuropathic pain
• Common following combined
What is
treatment with a platinum and neuropathic pain?
a taxane
• Shooting, burning pain
• Health Canada – no objection
letter March 2009
• Limits dosing of
chemotherapy
• File U.S. protocol Q4 2010
16

17. Multiple data events
Clarity Events Data Events
Phase III
Cancer-related Q3 10 H2 11
pain Interim Final results
analysis
Phase II
Chemotherapy- Q4 10 Q3 11 Q2 12
induced Submit U.S. Interim Final results
neuropathic pain protocol analysis
17

18. TTX in the cancer pain landscape
18

19. Tetrodotoxin manufacturing
• API manufactured
by wholly-owned
Chinese subsidiary
• Finished product
manufactured by
Sandoz Canada
Source: Pufferfish
19

20. Financial Highlight
Symbol WXI
Cash (January 2010) $39M
Monthly burn rate $800,000
Shares o/s 442 million
Major shareholder (89%) CK Life Sciences Int’l., Inc.
20

21. CK Life Sciences International
Hong Kong Stock
Exchange Stock Code: 00775
$20M Private Placement, October 2007
Investment in WEX
$34M as part of Rights Offering, January 2010
Business areas Pharmaceutical / Nutraceutical / Agriculture
Revenue USD350M (2009)
TTX is the most advanced drug candidate
in CKLS’ pipeline of pharmaceutical products
21

22. Management and Clinical Investigators
Bin Huang, PhD, MBA Neil Hagen MD, FRCPC
President and CEO Lead Investigator
Former CEO of GeneHarbor (HK) and Cytovax, Division Chief, Division of Palliative Medicine,
VP BD Monsanto Canada Calgary; Professor, Faculty of Medicine,
University of Calgary
Kwong Choo, CGA
CFO, VP Finance & Admin Bernard Lapointe, MD, FRCPC
20 years international experience in finance and Co-lead Investigator
accounting Associate Professor, Oncology, McGill
(Jewish General Hospital); 2007 Canadian Hospice
Larry Gontovnick, PhD Palliative Care Award of Excellence
Vice President, R&D
Over 20 years experience in drug development; Patrick du Souich, MD, PhD
Former Sr. Director clinical development, GSK Medical Monitor
Professor and Chairman, Dept of Pharmacology,
Anh Ho Ngoc, PhD Faculty of Medicine, University of Montreal;
Director, Regulatory Affairs Chairman, Division of Clinical Pharmacology of
Over 20 years pharma industry IUPHAR
experience; 3 years at Health Canada
22

23. No narcotic
How large
side effects?
would the
$7B opioid market
be with… Less risk of
tolerance or
addiction?
23

24. 700,000
chemo-induced
1,420,000 neuropathic pain
cancer pain
(700,000*)
(350,000*)
368,000
painful diabetic
neuropathy
130,000
post herpetic neuralgia
Tetrodotoxin *WEX’s target market
Initial indication prevalence in North America
24
Follow on indication prevalence in North America

25. a new class of non-opioid analgesic in Phase 3
WEX Pharmaceuticals Inc.
Corporate Presentation April 2010