Rule 425

Filed by Discovery Partners International, Inc. Pursuant to Rule 425

Under the Securities Act of 1933

and Deemed Filed Pursuant to Rule 14a-12

Under the Securities Exchange Act of 1934

Subject Company: Infinity Pharmaceuticals, Inc.

Commission File No. 333-134438

Additional Information about the Merger and Where to Find It

In connection with the proposed merger transaction between Infinity Pharmaceuticals, Inc. (“Infinity”) and Discovery Partners International, Inc. (“Discovery Partners”), on July 11, 2006, Discovery Partners filed with the Securities and Exchange Commission (the “SEC”) an amended registration statement that contains a proxy statement/prospectus. Investors and securityholders of Discovery Partners and Infinity are urged to read the proxy statement/prospectus (including any amendments or supplements to the proxy statement/prospectus) regarding the proposed transaction because it contains important information about Discovery Partners, Infinity and the proposed transaction. Discovery Partners’ stockholders can obtain a free copy of the proxy statement/prospectus, as well as other filings containing information about Discovery Partners and Infinity, without charge, at the SEC’s Internet site (http://www.sec.gov). Copies of the proxy statement/prospectus can also be obtained, without charge, by directing a request to Discovery Partners International, Inc., 9640 Towne Centre Drive, San Diego, CA 92121, Attention: Investor Relations, Telephone: (858) 455-8600.

Participants in the Solicitation

Discovery Partners and its directors and executive officers and Infinity and its directors and executive officers may be deemed to be participants in the solicitation of proxies from the stockholders of Discovery Partners in connection with the proposed transaction. Information regarding the special interests of these directors and executive officers in the merger transaction is included in the proxy statement/prospectus referred to above. Additional information regarding the directors and executive officers of Discovery Partners is also included in Discovery Partners’ proxy statement for its 2006 Annual Meeting of Stockholders, which was filed with the SEC on April 6, 2006. This document is available free of charge at the SEC’s web site (http://www.sec.gov) and from Discovery Partners’ Investor Relations at the address listed above.

On August 2, 2006, Infinity made the presentation set forth below at the Robert W. Baird Focus on Oncology Conference.


RW Baird
Focus on Oncology Conference
August 2, 2006


2
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*
*
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*
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3
Forward-Looking Statements
Various
statements
in
this
presentation
concerning
our
future
expectations,
plans
and
prospects
constitute
forward-looking
statements
for
the
purposes
of
the
safe
harbor
provisions
under
The
Private
Securities
Litigation
Reform
Act
of
1995.
Such
forward-looking
statements
include
statements
regarding
the
proposed
transaction
with
Discovery
Partner
International
(DPI),
DPI
and
the
combined
company's
net
cash
at
closing,
the
trading
of
the
combined
company's
shares
on
the
NASDAQ
National
Market,
the
potential
value
created
by
the
proposed
merger
for
DPI's
and
Infinity's
stockholders,
the
efficacy,
safety,
and
intended
utilization
of
Infinity's
product
candidates,
the
results
of
discovery
efforts
and
clinical
trials,
and
plans
regarding
regulatory
filings,
future
research
and
clinical
trials
and
current
and
future
collaborative
activities.
Actual
results
may
differ
materially
from
those
indicated
by
such
forward-looking
statement
as
a
result
of
various
important
factors,
including
risks
related
to:
the
ability
of
DPI
and
Infinity
to
complete
the
proposed
transaction;
the
amount
of
DPI's
net
cash
at
closing;
the
availability
of
funds
to
continue
research
and
development
activities;
the
results
of
future
clinical
trials
with
respect
to
Infinity's
product
candidates
and
compounds
and
Infinity's
ability
to
successfully
develop
and
commercialize
product
candidates;
the
success
of
Infinity's
collaborations
and
its
ability
to
enter
into
additional
collaborations;;
the
timing
and
success
of
regulatory
filings;;
the
scope
of
Infinity's
patents
and
the
patents
of
others;
competitive
factors
and
other
risks
and
uncertainties
more
fully
described
in
DPI's
filings
with
the
Securities
and
Exchange
Commission,
including
its
Registration
Statement
on
Form
S-4,
as
filed
on
May
24,
2006
and
subsequently
amended.
The
proposed
transaction
is
subject
to
customary
closing
conditions,
including
approval
of
DPI's
and
Infinity's
stockholders.
Any
forward-looking
statements
speak
only
as
of
the
date
made.
Infinity
undertakes
no
obligation
to
publicly
update
any
forward-looking
statements,
whether
as
a
result
of
new
information,
future
events
or
otherwise.


4
Mission
To develop targeted therapies for the treatment
of cancer and related conditions discovered
through the use of our innovative small
molecule drug technologies


5
Strategy
Drugs
Internally discovered novel small molecules
Targets
“Well-credentialed, but not well-trodden”
Products
Opportunity for first-in class or fast follower best-in-class


6
Leadership team
Mr. Steven Holtzman, CEO
Millennium, DNX
Dr. Julian Adams, President & CSO
Millennium, ProScript
Boehringer
Ingelheim, Merck
Ms. Adelene Perkins, CBO
Transform, Genetics Institute,
Bain, GE
Dr. Christine Bellon, Sr
Patent Counsel
Wyeth, Fish & Richardson
Dr. Michael Foley, VP Chemistry
Harvard ICCB, Glaxo, BMS
Dr. Christian Fritz, Sr
Dir Cancer Biology
Millennium, Chemgenix
Dr. David Grayzel, VP Clinical Development
& Medical Affairs
Dyax,  Mass General Hospital
Dr. Vito Palombella, VP Biology
Syntonix, Millennium, ProScript
Dr. Margaret Read, Sr
Dir Cancer Biology
Millennium, ProScript
Dr. Jeffrey Tong, VP Corp Prod Dev
McKinsey & Co, Harvard Center for
Genomics Research
Dr. Jim Wright, VP Pharm
Dev
Millennium, Alkermes, Boehringer
Ingelheim, Syntex, U. of Wisconsin


7
Product Pipeline: IPI-504 (Hsp90)
Discovery
Preclinical
IND Filing
Hsp90
(IPI-504)
Clinical Trials
Bcl-2/Bcl-xL &
Additional
Targets
2005
2007/2008 forward
Phase I ongoing
Phase II expected by
early 2007
Hedgehog 
Pathway
Phase I expected by
early 2007
On-going studies
TBD based on data/results


8
Product Pipeline: IPI-504 (Hsp90)
Discovery
Preclinical
IND Filing
Hsp90
(IPI-504)
Clinical Trials
Bcl-2/Bcl-xL &
Additional
Targets
2005
2007/2008 forward
Phase I ongoing
Phase II expected by
early 2007
Hedgehog 
Pathway
Phase I expected by
early 2007
On-going studies
TBD based on data/results


9
Broad activity, multiple cancers
Single agent activity
Synergy in combination
Activity in resistant settings
Large therapeutic window
2
nd
generation oral formulation
under development
Lead Clinical Product: IPI-504
IPI-504
OH
N
H
N
OH
O
OH
Me
O
O
O
O
NH
2
H
H
+
Cl
-


10
IPI-504: Broad Market Potential
Indications
Multiple Myeloma (MM)
Chronic Myelogenous
Leukemia (CML)
Acute Myelogenous
Leukemia (AML)
Non-Hodgkin’s Lymphoma (NHL)
Gastrointestinal Stromal Tumors (GIST)
Breast cancer (HER2+)
Non-small cell lung cancer (NSCLC)
Renal cell carcinoma
Malignant Melanoma
Hormone Refractory Prostate cancer (HRPC)
Hematologic
malignancies
Solid
tumors


11
Stabilizes proteins in
functional conformations
Two roles in cancer
Generally: Maintaining
protein homeostasis in
cancer cells
Specifically: Stabilization
of key oncoproteins,
including drug-resistant
ones
Heat Shock Protein 90 (Hsp90)


12
Velcade
Gleevec / AMN107
Investigational
Gleevec / Sutent
Herceptin
Tarceva
/ Erbitux
Sorafenib
/ Sutent
Sorafenib
Investigational
Targeted therapy
The emerging world of targeted cancer therapies
Indication
Myeloma
CML
AML
GIST
Breast (HER2+)
NSCLC
Renal cell
Melanoma
Prostate (PTEN -/-)
NF-
B
Bcr-Abl
Flt3
c-Kit
HER2
EGFR
VEGFR / HIF-1a
b-Raf
p-Akt
Molecular Target


13
The emerging world of targeted cancer therapies
NF-
B
Bcr-Abl
Flt3
c-Kit
HER2
EGFR
VEGFR / HIF-1a
b-Raf
p-Akt
Molecular Target
All are clients of Hsp90
Inhibiting Hsp90 affects the
stability of these targets


14
Highly
responsive to
Hsp90
inhibition
Alternative to
chasing
mutations
T315I
T790M
T670I
Hsp90: Potential Universal Salvage Therapy
BCR-ABL
EGFR
KIT
Hsp90 Client
Disease
Drug
CML
NSCLC
GIST
Gleevec,
Dasatinib
Tarceva,
Iressa
Gleevec,
Sutent
Kinase
Inhibitor
Resistance
Mutation


15
Placebo
Gleevec
IPI-504
Collaboration:
Shauguang
Li, Jackson Labs
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
15
17
19
21
23
25
27
29
31
33
Days
Oral IPI-504: survival benefit in Gleevec-resistant T315I
CML transplantation model
Gleevec: 100 mpk
/ b.i.d.
IPI-504: 50 mpk
/ q.o.d.


16
Placebo
Gleevec
IPI-504
Collaboration:
Shauguang
Li, Jackson Labs
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
15
17
19
21
23
25
27
29
31
33
Days
Oral IPI-504: survival benefit in Gleevec-resistant T315I
CML transplantation model
Gleevec: 100 mpk
/ b.i.d.
IPI-504: 50 mpk
/ q.o.d.


17
Collaboration:
Shauguang
Li, Jackson Labs
Placebo
Gleevec
IPI-504
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
15
17
19
21
23
25
27
29
31
33
Days
Oral IPI-504: survival benefit in Gleevec-resistant T315I
CML transplantation model
Gleevec: 100 mpk
/ b.i.d.
IPI-504: 50 mpk
/ q.o.d.


18
Phase I MM trial: complete
Phase I GIST trial: complete
Phase II MM and/or GIST trial: initiate
Additional potential indications and milestone events
Phase
I
combination
studies
(e.g.
Taxotere,
Velcade,
Gleevec)
Additional
Phase
II
studies
(e.g.
NSCLC,
CML,
CLL)
IPI-504: Clinical Goals for Remainder 2006 / Early 2007


19
On-going trial
Phase II –
additional
indication or combination
2005
2006
2007
2008
Multiple myeloma
Phase I
Multiple myeloma
GIST
Combinations
GIST
Phase II
GIST / MM
Other indications
Phase II–
MM or GIST
TBD based on data/results
IPI-504: Clinical Plan
Phase Ib
combinations


20
Product Pipeline: IPI-504 (Hsp90)
Discovery
Preclinical
IND Filing
Hsp90
(IPI-504)
Clinical Trials
Bcl-2/Bcl-xL &
Additional
Targets
2005
2007/2008 forward
Phase I ongoing
Phase II expected by
early 2007
Hedgehog 
Pathway
Phase I expected by
early 2007
On-going studies
TBD based on data/results


21
Hedgehog program summary
Potential for first-in-class systemic hedgehog inhibitor
Proprietary NCE’s
Systemic (sub-cu and oral) products
Lead molecule in advanced preclinical development
First in man by 2007
Broad anti-cancer potential
Strong
data
supporting
pancreatic,
metastatic
prostate,
SCLC, others
Single agent activity
Potential for synergy with standards of care


22
1
Hahn
et
al.,
1996,
Cell
85:
841
2
Bale
&
Yu,
2001,
Human
Molec.
Genetic.
10:
757
(review)
3
Berman
et
al.,
2002
Science
297:
1559
4
Berman
et
al.,
2003
Nature
425:
846
5
Kayed
et
al.,
2004
Int.
J.
Cancer
110:
668
6
Thayer
et
al.,
2003
Nature
425:
851
7
Karhadkar
et
al.,
2004
Nature,
431:
707
8
Fan
et
al.,
2004
Endocrinology
145:
3961
9
Watkins
et
al.,
2003,
Nature
422:
313
10
Sicklick
2005
ASCO;
Mohini,
2005
AACR
11
Kubo
et
al.,
2004
Cancer
Res.
64
:6071
State
Normal
Basal cell carcinoma
1,2
Medulloblastoma³
Pancreatic cancer
4,5,6
Prostate cancer
7,8
Small cell lung cancer
9
Hepatocellular
cancer
10
Breast Cancer
11
Pathway activation
OFF
ON
ON
ON
ON
ON
ON
ON
Hedgehog Pathway: Broad Rationale in Solid Tumors


23
0
200
400
600
800
1000
1200
1400
1600
31
36
41
46
51
56
61
Days
Vehicle
IPI-609 10 mpk/day
IPI-609 efficacious in PC-3 prostate xenograft


24
F
I
L
E
I
N
D
2005
2006
2007
2008
IND-enabling studies
Clinical development
Pharmacology
GLP toxicology
Manufacturing
Phase I
Pancreatic
SCLC
Met Prostate, etc.
Heme malignancies
Phase II
Single or combo
Phase II or III
Registration trial
IPI-609 clinical plan
On-going studies
TBD based on data


25
Product Pipeline: IPI-504 (Hsp90)
Discovery
Preclinical
IND Filing
Hsp90
(IPI-504)
Clinical Trials
Bcl-2/Bcl-xL &
Additional
Targets
2005
2007/2008 forward
Phase I ongoing
Phase II expected by
early 2007
Hedgehog 
Pathway
Phase I expected by
early 2007
On-going studies
TBD based on data/results


26
Bcl
family of proteins: key anti-apoptotic factors
Up-regulated in many cancers
Up-regulated in response to chemotherapy in many cancers
Highly attractive but historically “intractable”
Protein-protein interaction targets
Prospective products
Combination with chemotherapy: general chemo-sensitizing agent
Single agent: in cancers dependent on Bcl
family members for survival
Types of products:
Bcl-2 selective
Bcl-2 and Bcl-xL
dual selective
Bcl-2 / Bcl-xL
Antagonists: Opportunities


27
Total payments         >$400M
Bcl-2 alliance with Novartis
Joint discovery of novel Bcl-2
targeted cancer drugs
Infinity participation in clinical
development (at NVS expense)
COLLABORATION
Infinity participation in US sales
effort (at NVS expense)
$30M
Upfront &
committed funds
FINANCIALS
Royalties on WW sales


28
Diversity Oriented Synthesis (DOS)
2004 –
2006:  > $60 million upfront/committed cash
Additional milestone and royalty potential
No license of proprietary Infinity product rights
Small Molecule Drug Technologies & Technology Access
Alliances
N
O
O
H
R²
R³
N
O
R³
H
H
H
O
O
N
R
4
O
R
R2
R1
N
O
NR
4
O
R1
O
SR2
R3


29
Discovery
Preclinical
Start Clinical
Trials
IPI-504
(Hsp90)
Bcl2/Bcl-xL
2005
2007/2008
100% owned
100% owned
Novartis
Non-exclusive
Amgen
Novartis
J&J
Small molecule drug technologies
Alliance and financing strategy: value retention
Hedgehog 
Pathway
(e.g., IPI-609)
By early
2007


30
Reverse Merger
with
Discovery Partners International, Inc.
(Nasdaq: DPII)
*
*
*
*
*


31
Discovery Partners International (DPII) rationale
Response to dramatic changes in discovery business
Outsourcing to India, China
Price pressures
Better upside for investors in near-term product opportunities with
significant potential
Therefore: divest and invest


32
Why DPI chose Infinity
Top-tier private company
Multiple near-term value driving events
Ongoing clinical trials
Pipeline
Partnerships
Management that has discovered drugs and built companies
Invest in/create a security with market-recognized value


33
Infinity’s rationale for merger
Efficient, timely access to capital
Clinical trial / preclinical pipeline funding
Generate efficacy data on lead product candidate, IPI-504
Accelerate and expand Infinity pipeline


34
A financing event
DPI “invests”
cash and divests operating units
7/7/06: Sale of all DPI operating assets to Galapagos
If DPI cash between $70M and $75M, ownership:
DPII shareholders = 31%
Infinity shareholders = 69%
If cash above $75M or below $70M, adjustment applied
The reverse merger: a creative financing and access to
public markets


35
Lead clinical product in two ongoing Phase I cancer studies
Phase II expected by early 2007
Pipeline of preclinical cancer drug candidates
Internally discovered and developed, chemistry platform
4 Pharma/Biotech corporate alliances
Amgen, J & J and Novartis (2)
Proven biotech leadership team
Estimated approximately $ 90 million cash
Projected cash runway into 2008 through key value driving events
before any additional alliances or financing
Snapshot of Post-Merger Infinity (NASDAQ: INFI)


36
Status of Reverse Merger
File Initial S4
Respond to 1
st
Round of SEC Comments
Respond to 2
nd
Round of SEC Comments
S-4 is Declared Effective
Mail S-4 to DPI and IPI Shareholders
Hold Shareholder Meeting / vote
Following Successful Vote, Deal Closes,
INFI publicly traded
May 24, 2006
July 11, 2006
Early August
Early August
September 12, 2006
September 13, 2006
* Projected: requires SEC approval


37
Product Pipeline
IPI-504: Complete Phase I trials
IPI-504: Expect to initiate Phase II by early 2007
Hedgehog Pathway: Expect to initiate
Phase I by early 2007
Pipeline: New INDs
/ programs for 2007+
Successful alliance execution (Novartis, J&J, Amgen)
At least one new corporate alliance
Financing event
Year-end cash runway:  =
12-24 months
NVS -
Bcl
2006 Goals, Achievements and Anticipated News Flow
Pending
DPII merger
AMGN
extension