8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): January 8, 2007

Infinity Pharmaceuticals, Inc.

(Exact name of registrant as specified in charter)

Delaware	000-31141	33-0655706
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

780 Memorial Drive, Cambridge, MA	02139
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (617) 453-1000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 7.01. Regulation FD Disclosure.

From time to time, we intend to conduct meetings with third parties in which our current corporate slide presentation is presented. A copy of this slide presentation, dated January 8, 2007, is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

The information responsive to Item 7.01 of this Form 8-K and Exhibit 99.1 hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 8.01. Other Events.

On January 8, 2007, we issued a press release announcing our corporate goals for 2007. The full text of this press release is filed as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) The following exhibits are included in this report:

Exhibit No.	Description
99.1	Slide presentation of Infinity Pharmaceuticals, Inc. dated January 8, 2007
99.2	Press release of Infinity Pharmaceuticals, Inc. dated January 8, 2007

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	INFINITY PHARMACEUTICALS, INC.
Date: January 8, 2007	By:	/s/ Adelene Q. Perkins
		Adelene Q. Perkins
		Chief Financial Officer & Treasurer

EX-99.1

Infinity Pharmaceuticals (NASDAQ: INFI)

Overview for investor presentations

January 2007

Exhibit 99.1

2

Forward-Looking Statements

•

This presentation contains forward-looking statements within the meaning of The Private Securities Litigation

Reform Act of 1995.  These statements involve risks and uncertainties that could cause actual results to be

materially different from historical results or from any future results expressed or implied by such forward-

looking statements. 

•

Such forward-looking statements include statements regarding future clinical trial activity for IPI-504 in both

intravenous and oral form; the collection of additional clinical

information on IPI-504; the intended utilization

and commercial potential of IPI-504; the ability to name clinical candidates in the company’s research programs;

estimates of 2007 financial performance and year-end cash balance; and the expectation that Infinity will have

cash to support its current operating plan through at least December 31, 2009. 

•

Such statements are subject to numerous factors, risks and uncertainties that may cause actual events or

results to differ materially from the company's current expectations.  For example, there can be no guarantee

that any product candidate Infinity is developing will successfully complete necessary preclinical and clinical

development phases, be approved for sale in any market or that, if approved, revenue from sales of such

product will reach any specific level. In particular, management's expectations could be affected by risks and

uncertainties relating to: results of clinical trials and preclinical studies, including subsequent analysis of

existing data and new data received from ongoing and future studies; the content and timing of decisions made

by the U.S. Food and Drug Administration and other regulatory authorities and investigational review boards at

clinical trial sites; Infinity’s ability to enroll patients in its clinical trials; Infinity's dependence on its

collaborations with MedImmune and Novartis; Infinity's ability to obtain additional funding required to conduct

its research, development and commercialization activities; unplanned cash requirements and expenditures;

and Infinity's ability to obtain, maintain and enforce patent and other intellectual property protection for any

products it is developing. 

•

These and other risks which may impact management's expectations

are described in greater detail under the

caption "Risk Factors" included Infinity's quarterly report on Form 10-Q for the quarter ended September 30,

2006, as filed with the Securities and Exchange Commission on November 9, 2006. 

•

Further, any forward-looking statements contained in this presentation speak only as of the date hereof, and

Infinity expressly disclaims any obligation to update any forward-looking statements, whether as a result of new

information, future events or otherwise.

•

All trademarks used in this presentation are the property of their respective owners.

3

•

Focus on emerging targets in oncology

•

Lead clinical product: IPI-504, a novel Hsp90 inhibitor

–

Biologically active, well-tolerated in disease-focused Phase I trial (GIST)

–

Expansion of clinical development expected in 2007

•

Pipeline of internally-discovered cancer drug candidates

–

Hedgehog pathway, Bcl-2/Bcl-xL, additional programs

•

5 Pharma/Biotech corporate alliances

–

MedImmune, Novartis (2), Amgen, and J & J

•

Significant cash position

–

Projected cash runway through at least the end of 2009

•

Proven biotech leadership team

Profile of Infinity Pharmaceuticals (NASDAQ: INFI)

4

IPI-504 (Combinations)

IPI-504 (Oral)

Additional tumors

(solid & hem.)

IPI-504 (IV)

NSCLC

IPI-504 (IV)

GIST

IPI-504 (IV)

Early discovery

Hsp90

Bcl-2/Bcl-xL

Hedgehog pathway

Phase II

Phase I

Preclinical

Discovery

Programs

Product pipeline

Current

Planned for next 12

months, pending data

Phase I/II

5

Lead clinical program

IPI-504 –

a novel Hsp90 inhibitor

*

*

*

*

*

*

6

Lead clinical product: IPI-504 (Hsp90 inhibitor)

•

Novel chemical entity with strong intellectual property position

•

Preclinical evidence of broad therapeutic potential

•

Biologically active and well-tolerated in Phase I (patients with

metastatic

Gleevec

®

-refractory

GIST)

•

Clinical expansion expected in 2007

–

Phase I/II trial in non-small cell lung cancer (NSCLC)

–

Phase II trial(s)

–

Combination with standards of care

•

Clinical trial for oral IPI-504 planned for 2007

7

Phase I trial in refractory GIST

Principal Investigator:

•

Dr. George Demetri, Dana-Farber Cancer Institute

Objectives:

•

Safety, PK, dose-ranging

•

Establish Phase II dose

Surrogate marker of

response:

•

PET scans

Schedule A:

•

Days 1, 4, 8, 11 of 21 day cycle, with a 10-day-off

period, or “drug holiday”

Schedule B:

•

Twice weekly in a 3-week cycle (i.e., no drug

holiday)

Trial description:

•

Phase I trial in patients with Gleevec-refractory

metastatic gastrointestinal stromal

tumors (GIST)

8

Preliminary results from GIST trial (November 2006)

•

20 GIST patients treated with IPI-504

–

20/20

prior Gleevec

®

therapy

–

19/20

prior Sutent

®

therapy

•

IPI-504

well-tolerated

up

to

400

mg/m

2

–

MTD not reached

•

Biological activity observed via qualitative assessment of PET

images (“PET response”) in 7 of 17 evaluated patients (41%)

•

6

of

15

evaluated

patients

(40%)

received

5

or

more

cycles

of

therapy

9

Background on PET imaging

•

Positron

emission

tomography

(PET)

is

an

imaging

technology

–

Labelled

glucose is visible on PET scan

–

Glucose concentrates in most metabolically-active tissues

–

Cancer cells appear as bright spots on PET images

•

PET

used

as

a

surrogate

marker

of

response

in

oncology

trials

–

PET responses also seen in Gleevec

and Sutent

GIST trials

•

PET

response

correlated

with

enhanced

survival

in

many

cancers,

including

GIST

1

1

Kelloff

GJ,

et

al.

Clin

Cancer

Res

2005;11(8)

April

15,

2005:

2785.

10

Initial

PET

response

predicts

long-term

survival

(Gleevec)

1

Kaplan Meier Estimate of Overall Survival

1

Stroobants

S,

et

al.

Eur

J

Cancer

2003;39:2012-20.

PET responders

PET

non-responders

11

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Weeks Post First Dose

0

12

24

36

48

60

72

84

96

108

120

132

144

156

168

180

192

204

216

228

240

252

264

PROGRESSION

On Imatinib

Median 36 wks

Overall Survival by Best Response Achieved

(Kaplan Meier Estimate)

STABLE DISEASE

Median not reached

PARTIAL RESPONSE

GIST Patients Benefit Regardless of Tumor Shrinkage (Gleevec)

1

Blanke,

CD,

et

al.

J

Clin

Onc

2006

(ASCO

Proceedings)

Part

I,

Vol

24;

No.

18S:

9528.

1

12

IPI-504 PET response (at 150 mg/m

2

)

Baseline

Cycle 1, Day 21

After 10 days

off treatment

Cycle 1, Day 11

72 hours post

2

nd

dose of IPI-504

Cycle 3, Day 12

After additional

cycles of

treatment

Courtesy

of

Van

den

Abbeele

&

Demetri:

Dana-Farber Cancer Institute

Harvard Medical School

13

IPI-504 PET response (at 400 mg/m

2

)

Baseline

Cycle 1 Day 12

24 hours after 4

th

dose of IPI-504

Courtesy of Van den Abbeele, Wagner & Demetri:

Dana-Farber Cancer Institute

Harvard Medical School

(Other spots are

anatomical

features: kidney,

bladder, etc.)

Tumor

14

PET images suggest biological activity and inform

schedule

•

Modulation of PET signal in response to drug administration and

holiday suggests a pharmacological effect of IPI-504

–

Similar pattern of response seen with Sutent

on a 4-weeks on, 2-weeks

off schedule¹

•

New schedule to evaluate removal of drug holiday

Days 1, 4, 8, 11 of 21-day

cycle (with drug holiday)

90 mg/m

2

400 mg/m

2

No MTD reached

Twice-weekly,

no drug holiday

150 mg/m

2

Dose-escalate through

MTD and/or Phase II

dose

1  Van den Abbeele

AD, et al. Abstract 714, ECCO 13, 2005

15

Next Indication: Phase I/II NSCLC trial

•

Patient population

–

Stage IIIb/IV NSCLC patients

•

Rationale from preclinical data

–

Mutant EGFR is highly sensitive to treatment with IPI-504

–

Kinase

inhibitor (Tarceva, Iressa) resistance mutations are equally sensitive to

treatment with IPI-504

•

Trial design

–

Dose escalate to determine MTD followed by expansion

–

Assess response by RECIST, correlate with EGFR mutation status (+/-)

–

Additional assessment with PET

•

Lead investigator

–

Dr. Thomas Lynch, Massachusetts General Hospital

•

Expect to treat first patient in 1H07

16

0

500

1000

1500

2000

2500

3000

3500

4000

12

15

19

22

26

27

32

Days Post-Implant

IPI-504 Vehicle

Gefitinib Vehicle

100mpk Gefitinib, oral (daily for 3 weeks)

100mpk IPI-504, IP (2x weekly)

69%

difference

in tumor

volume

(p=0.009)

IPI-504 is active preclinically

against Tarceva/Iressa-

resistant NSCLC

17

Heat shock protein 90 (Hsp90) is an emerging cancer

target

Function of Hsp90

•

“Chaperone”

protein responsible for proper

folding and function of some proteins

Function of Hsp90 in cancer cells

•

Many oncogenic

proteins rely on Hsp90 to

function

•

Inhibiting Hsp90 is another way to inhibit

the oncogenic

proteins themselves

18

Apoptosis

Tyrosine kinase

inhibitor

(e.g., Gleevec, Tarceva)

Normal

protein

Oncogenic

protein

drives cancer cell

survival & growth

Resistance mutations

evade TKI therapy

IPI-504

IPI-504: an alternative to direct inhibition of oncogenic

proteins

IPI-504

Dependent on

Hsp90 for function

Still dependent on

Hsp90 for function

19

Potential advantages of IPI-504

1.

Equally potent to targeted

therapies (e.g., Gleevec)

2.

Overcome resistance to kinase

inhibitors in refractory settings

3.

Active against multiple

resistance mutations

4.

Synergistic in combination with

kinase

inhibitors

Front-line use

Refractory settings where TKI

has failed

Fast path to market due to high

unmet medical need

Less reliant on genotyping or

patient subpopulations

Earlier lines of therapy

Expanded market potential

Potential opportunity

Preclinical evidence

20

0%

20%

40%

60%

80%

100%

15

35

55

75

95

Days post BMT

Placebo

Gleevec

IPI-504 (50 mpk/d)

IPI-504 (100 mpk/d)

Overcomes resistance to kinase

inhibitors in preclinical

models of refractory settings

Oral

IPI-504

prolongs

survival

in

Bcr-Abl

T315I

mice

(Gleevec-resistant)

Collaboration:

Shauguang

Li, Jackson Labs

21

0%

20%

40%

60%

80%

100%

15

35

55

75

95

Days post BMT

Overcomes resistance to kinase

inhibitors in preclinical

models of refractory settings

Placebo

Gleevec

IPI-504 (50 mpk/d)

IPI-504 (100 mpk/d)

Oral

IPI-504

prolongs

survival

in

Bcr-Abl

T315I

mice

(Gleevec-resistant)

Collaboration:

Shauguang

Li, Jackson Labs

22

0%

20%

40%

60%

80%

100%

15

35

55

75

95

Days post BMT

Overcomes resistance to kinase

inhibitors in preclinical

models of refractory settings

Placebo

Gleevec

IPI-504 (50 mpk/d)

IPI-504 (100 mpk/d)

Oral

IPI-504

prolongs

survival

in

Bcr-Abl

T315I

mice

(Gleevec-resistant)

Collaboration:

Shauguang

Li, Jackson Labs

23

Collaboration:

Shauguang

Li, Jackson Labs

0%

20%

40%

60%

80%

100%

15

35

55

75

95

Days post BMT

Overcomes resistance to kinase

inhibitors in preclinical

models of refractory settings

Placebo

Gleevec

IPI-504 (50 mpk/d)

IPI-504 (100 mpk/d)

Oral

IPI-504

prolongs

survival

in

Bcr-Abl

T315I

mice

(Gleevec-resistant)

24

Active against multiple resistant mutations

0

20

40

60

80

100

15

20

25

30

35

40

45

50

55

60

65

70

Days post BMT

Placebo

IPI-504

T315I

0

20

40

60

80

100

20

30

40

50

60

70

80

90

Days post BMT

Placebo

IPI-504

E225K

0

20

40

60

80

100

12

16

20

24

28

32

36

40

44

48

Days post BMT

Placebo

IPI-504

M351T

0

20

40

60

80

100

13

17

21

25

29

33

Days post BMT

Placebo

IPI-504

Y253F

IPI-504 at 50 mpk/d

Collaboration:

Shauguang

Li, Jackson Labs

Oral IPI-504 in Bcr-Abl

mice with various resistance mutations

25

0

20

40

60

80

100

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Days post BMT

Placebo

Gleevec

IPI-504

Gleevec+IPI-504

Oral IPI-504 in Bcr-Abl

mice with mixed-population tumors (both “wild-type”-and

T315I Bcr-Abl

tumor cells)

Synergistic in combination with kinase

inhibitors in

preclinical studies

IPI-504 at 50 mpk/d

Collaboration:

Shauguang

Li, Jackson Labs

26

Long list of oncogenic

proteins depend on Hsp90…

Indication

CML

AML

CLL

GIST

Breast (HER2+)

NSCLC

Renal cell

Prostate (PTEN-/-)

Bcr-Abl

Flt3

Zap70

c-Kit

HER2

EGFR

VEGFR / HIF-1a

p-Akt

Hsp90

client proteins

Broad clinical

potential for

Hsp90

inhibition

27

Gleevec

®

/Sprycel

®

Investigational

Investigational

Gleevec

®

/Sutent

®

Herceptin

®

/Tykerb

®

Tarceva

®

/Erbitux

®

Nexavar

®

/Sutent

®

Investigational

Targeted therapy

…with well-validated commercial potential

Indication

CML

AML

CLL

GIST

Breast (HER2+)

NSCLC

Renal cell

Prostate (PTEN-/-)

Bcr-Abl

Flt3

Zap70

c-Kit

HER2

EGFR

VEGFR / HIF-1a

p-Akt

Broad clinical

and commercial

potential for

Hsp90

inhibition

Hsp90

client proteins

28

•

Focus on most rapid path to registration

–

Single-agent activity in refractory setting (potential for accelerated

approval)

•

In parallel, initiate additional trials for broader indications

–

Additional solid and hematological tumors in refractory settings

–

Combination therapy with standards of care to expand market

potential

IPI-504 clinical development strategy

29

Preclinical programs

Hedgehog,

Bcl-2

*

*

*

*

*

30

Overview of Hedgehog program

•

Role of Hedgehog pathway in cancer (emerging rationale)

–

Aberrantly up-regulated in a variety of lethal cancers

–

May be implicated in cancer stem cell signaling

•

Cancer stem cells suspected to be progenitor cells primarily responsible for tumor

growth, survival, and metastasis

•

Infinity’s program

–

Highly potent, systemic inhibitors of Hedgehog pathway

–

Clinical candidate to be selected in 2007

–

MedImmune alliance

–

Opportunity for best-in-class product

31

Overview of Bcl-2 program

•

Role of Bcl-2 in cancer

–

Central molecule in the apoptosis pathway (along with XIAP)

–

Promotes cancer cell survival, including drug resistance, by inhibiting

apoptosis

•

Infinity’s program

–

Novel, highly-potent and on-target inhibitors of Bcl-2 and Bcl-2/Bcl-xL

–

Lead optimization; potential for clinical candidate selection in

2007

–

Novartis alliance

–

Opportunity for best-in-class product

32

Corporate Alliances and Financials

Strong validation, significant value retention

*

*

*

*

*

33

Chemistry platform

2004-2006

Core technology

Non-exclusive access to DOS

chemistry libraries

•

$60M upfront & committed

•

Potential royalties

•

No downstream rights

Chemistry platform

2004-2006

Core technology

Non-exclusive access to DOS

chemistry libraries

•

$60M upfront & committed

•

Potential royalties

•

No downstream rights

1

st

and 2

nd

generation alliances

Build the company

Traditional product-based license

Bcl-2/Bcl-xL

March 2006

Discovery

•

$30M upfront & committed

•

>$370M milestones

•

Significant WW royalty

•

Co-promotion right in US

34

3

rd

generation alliance

Ensure near-term financial strength and long-term value

Multi-program partnership;

R&D and commercial jointly led

Hsp90/Hedgehog

August 2006

Preclinical/Phase I

•

$70M upfront

•

$430M milestones

•

50/50 R&D cost share

•

50/50 WW profit split

•

Co-promotion right in US

•

Leverage Infinity’s

strengths in chemistry

and oncology

•

Add MedImmune’s

worldwide registration

and commercialization

reach

•

Align with MedImmune’s

strategic expansion in

oncology

35

Strong balance sheet and cash runway

•

January 2007 cash and equivalents (unaudited) : ~$135M

–

Includes $35M payment from MedImmune received on January 5, 2007

(second half of upfront fee from collaboration)

•

Burn rate well-controlled via alliances

–

50%

cost-sharing of Hsp90, Hedgehog programs with MedImmune

–

100%

of Bcl-2 program funded by Novartis

•

January 2008 cash and equivalents (projected) : >$100M

•

Cash runway through at least the end of 2009

–

Based on current projected operating plan

36

Corporate Summary

Proven team, track record of success

*

*

*

*

*

37

Leadership

Steven Holtzman, CEO

Millennium, DNX

Julian Adams, Ph.D., President &

CSO

Millennium, ProScript,

Boehringer

Ingelheim, Merck

Adelene Perkins, EVP & CBO

Transform, Genetics Institute,

Bain, GE

David Grayzel, M.D., VP Clinical

Development & Medical Affairs

Dyax,  Mass General Hospital

Steven Kafka, Ph.D., VP Strategic Product

Planning & Finance

Millennium, Strategic Decisions Group

Vito Palombella, Ph.D., VP Drug Discovery

Syntonix, Millennium, ProScript

Gerald Quirk, Esq., VP & General Counsel

Genzyme, Palmer & Dodge

Jeffrey Tong, Ph.D., VP Corporate & Product

Development

McKinsey & Co, Harvard Center for Genomics

Research

Jim Wright, Ph.D., VP Pharmaceutical

Development

Millennium, Alkermes, Boehringer

Ingelheim,

Syntex, U. of Wisconsin

38

•

Advance product pipeline

2006 Infinity goals and achievements

AMGN extension

Novartis on track

J&J complete

NVS (Bcl)

Reverse merger

with DPI

(3+ years of cash)

+

+

MEDI (Hsp90, HH)

IPI-504:

Well-tolerated in Phase I

Biological activity in

resistant GIST

+

•

Successful execution of

technology access alliances

•

At least one new corporate alliance

•

Financing event

–

Year-end cash runway:

12-24 months

39

2007 Infinity goals and milestones: R&D

•

Initiate Phase I/II trial of IPI-504 in NSCLC (1H07)

•

Complete Phase I trial of IPI-504 in GIST (2H07)

•

Progress IPI-504 to one or more Phase II trials (2H07)

•

Initiate IPI-504 combination study (2H07)

•

Enter clinic with oral formulation of IPI-504 (2H07)

•

Select clinical candidate for Hedgehog program

•

Continue progress with Novartis-on Bcl-2 program

•

Advance early discovery programs

40

2007 Infinity goals and milestones: Business

•

Maintain a strong balance sheet

–

End 2007 with >$100M

cash and runway through at least the end of 2009

(based on current operating plan)

•

Sustain excellence in strategic alliances with MedImmune and

Novartis

•

Employ position of strength to strategically to create shareholder

value

–

Evaluate business development and other value-adding opportunities

Infinity Pharmaceuticals (NASDAQ: INFI)

Overview for investor presentations

January 2007

EX-99.2

Exhibit 99.2

FOR IMMEDIATE RELEASE

INFINITY REVIEWS 2006 ACHIEVEMENTS AND ANNOUNCES PRODUCT AND

BUSINESS GOALS FOR 2007

— Aims to Build on Strong 2006 With Expansion of Clinical Studies for IPI-504, Infinity’s

Lead Oncology Candidate —

CAMBRIDGE, Mass. – January 08, 2007 – Infinity Pharmaceuticals, Inc. (NASDAQ: INFI), an innovative cancer drug discovery and development company, today announced its product and business goals for 2007, including cash guidance. Infinity’s goals build upon its scientific and commercial successes of 2006.

Key Highlights from 2006:

• Published evidence of biological activity of IPI-504, Infinity’s lead anticancer agent, in a Phase I clinical trial in patients with gastrointestinal stromal tumors (GIST)

• Completed a reverse merger with Discovery Partners International, Inc. providing approximately $78 million in net cash and a public listing on NASDAQ

• Initiated a worldwide collaboration with MedImmune, Inc. around Infinity’s two lead programs, inhibitors of heat shock protein 90 (Hsp90) and the Hedgehog cell-signaling pathway

• Established a global strategic alliance with Novartis to discover, develop and commercialize drugs targeting Bcl-2 protein family members

• Generated a strong balance sheet with over three years of cash to fund projected operating expenses.

“2006 was an extraordinary year for Infinity – one in which we exceeded the goals we set for ourselves in terms of the evolution of the company and the growth of our therapeutic programs,” said Steven Holtzman, Chief Executive Officer of Infinity. “We are excited to announce our goals for 2007, which feature numerous product-based events, continuing financial strength, and additional progress and value for patients in the coming year.”

2007 Product Goals

• Initiate Phase I/II trial of IPI-504 in non-small cell lung cancer (NSCLC): In collaboration with its partner MedImmune, Infinity anticipates expanding its ongoing clinical trials of IPI-504 to include a second solid tumor indication, non-small cell lung cancer (NSCLC). The trial will focus on Stage III/IV patients with known EGFR status, and will be led by Thomas J. Lynch, M.D., Director, Center for Thoracic Cancers at Massachusetts General Hospital. Additional details regarding this trial will be announced once the first patient enters the trial, expected in the first half of 2007.

• Complete Phase I trial of IPI-504 in GIST: Based on the positive preliminary data for IPI-504 in 20 patients with Gleevec^®-refractory GIST (published in November 2006), Infinity has added a second schedule of treatment for patients. The new schedule provides a more intensive twice-weekly regimen, without a drug holiday. Data from this trial extension will be collected in 2007 and will be evaluated for safety, tolerability, and biological activity as assessed by positron emission tomography (PET) imaging.

Infinity Pharmaceuticals, Inc.     780 Memorial Drive     Cambridge, MA 02139

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• Progress IPI-504 to one or more Phase II trials: In the second half of 2007, IPI-504 is expected to enter Phase II development. Infinity and MedImmune will be data-driven in choosing indications for Phase II development.

• Initiate IPI-504 combination study: Infinity anticipates beginning development of IPI-504 in combination with existing approved therapies, which could further expand the commercial potential of IPI-504.

• Enter clinic with oral formulation of IPI-504: Infinity expects the oral formulation of IPI-504, currently in IND-enabling studies, to enter the clinic by the end of 2007.

• Select clinical candidate for Hedgehog program: A clinical candidate for the Hedgehog program will be selected in 2007. Infinity’s line of Hedgehog pathway antagonists, also partnered with MedImmune, are highly potent and feature attractive pharmacological properties in preclinical models.

• Advance early pipeline: Infinity expects to make substantial progress toward naming clinical candidates in its discovery-stage programs, including the Bcl-2 program partnered with Novartis.

2007 Business Goals

• Maintain financial strength and cash position: Based on unaudited financial results for 2006 and a payment from MedImmune of $35 million (the second half of the collaboration license fee received January 5, 2007), Infinity currently has approximately $135 million in cash, cash equivalents, and available-for-sale securities. Based on its current operating plan and assuming no additional financings or business development activity, Infinity expects to end 2007 with over $100 million in cash and equivalents and has sufficient funds to operate the company at least until the end of 2009.

• Sustain excellence in alliances: Infinity expects to continue its focus on execution and alignment in its product alliances with MedImmune and Novartis, building on the strong track record in both collaborations to date.

• Employ position of strength to create shareholder value: Infinity will consider strategic opportunities that allow it to capitalize on its financial strength and create additional long-term value for shareholders.

About IPI-504

IPI-504 is Infinity’s proprietary small molecule drug candidate that, in preclinical studies, potently and selectively inhibits Hsp90, thereby killing cancer cells. IPI-504 has been well-tolerated in its ongoing Phase I studies and has shown promising biological activity in a Phase I clinical trial in patients with GIST. In preclinical studies, IPI-504 has demonstrated broad potential to treat certain cancers as both a single agent as well as in combination with existing anti-cancer drugs. The water-based formulation of IPI-504 is delivered as an intravenous infusion; an oral formulation of IPI-504 is currently in preclinical development and is expected to enter clinical trials by the end of 2007.

About Hsp90

Hsp90 is an emerging therapeutic target of interest for the treatment of cancer. Proteins are the mainstay of structural and signaling elements of all cells. Hsp90 is a molecule that maintains the conformation and activity of specific proteins in the cell, also called “client proteins” of Hsp90. Many cancers result from specific mutations in such client proteins; Hsp90 enables those cancers’ survival by maintaining the function of their mutated client proteins. Therefore, inhibition of Hsp90 has broad therapeutic potential for the treatment of patients with solid tumors and hematological cancers, including cancers that are resistant to other drugs.

About Infinity – MedImmune Collaboration

In August 2006, Infinity and MedImmune announced that they had entered into an agreement to jointly develop and commercialize novel small molecule cancer drugs targeting heat shock protein 90 (Hsp90) and the Hedgehog cell-signaling pathway. The collaboration is focusing on IPI-504, Infinity’s lead Hsp90 inhibitor in Phase I clinical trials, as well as next-generation oral versions of IPI-504 and a series of preclinical molecules targeting the Hedgehog pathway.

About Infinity Pharmaceuticals, Inc.

Infinity is an innovative cancer drug discovery and development company that is seeking to leverage its strength in small molecule drug technologies to discover, develop, and deliver to patients best-in-class medicines for the treatment of cancer and related conditions. For more information on Infinity, please refer to the company’s website at http://www.ipi.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. These statements involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Such forward-looking statements include statements regarding future clinical trial activity for IPI-504 in both intravenous and oral form; the collection of additional clinical information on IPI-504; the intended utilization and commercial potential of IPI-504; the ability to name clinical candidates in the company’s research programs; estimates of 2007 financial performance and year-end cash balance; and the expectation that Infinity will have cash to support its current operating plan through at least December 31, 2009. Such statements are subject to numerous factors, risks and uncertainties that may cause actual events or results to differ materially from the company’s current expectations. For example, there can be no guarantee that any product candidate Infinity is developing will successfully complete necessary preclinical and clinical development phases, be approved for sale in any market or that, if approved, revenue from sales of such product will reach any specific level. In particular, management’s expectations could be affected by risks and uncertainties relating to: results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by the U.S. Food and Drug Administration and other regulatory authorities and investigational review boards at clinical trial sites; Infinity’s ability to enroll patients in its clinical trials; Infinity’s dependence on its collaborations with MedImmune and Novartis; Infinity’s ability to obtain additional funding required to conduct its research, development and commercialization activities; unplanned cash requirements and expenditures; and Infinity’s ability to obtain, maintain and enforce patent and other intellectual property protection for any products it is developing. These and other risks which may impact management’s expectations are described in greater detail under the caption “Risk Factors” included Infinity’s quarterly report on Form 10-Q for the quarter ended September 30, 2006, as filed with the Securities and Exchange Commission on November 9, 2006. Further, any forward-looking statements contained in this press release speak only as of the date hereof, and Infinity expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

Investors: John Evans 617.453.1254 John.Evans@ipi.com Media: Monique Allaire 617.453.1105 Monique.Allaire@ipi.com