NASDAQ: INFI

December 2009

Infinity

Innovative. Independent. Inspired.

Exhibit 99.1

Innovative. Independent. Inspired.

2

Safe Harbor Statement

•

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 and IPI-493; the presentation of

clinical data for IPI-504 and IPI-493; the filing of an IND for IPI-940; estimates of 2009 financial performance; the continuation of the

Purdue/Mundipharma

alliance

and

the

exercise

of

warrants

held

by

Purdue,

and

the

expectation

that

Infinity

will

have

capital

to

support its current operating plan into 2013.

•

Such forward-looking 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 Infinity’s strategic alliance

with

Purdue/Mundipharma

will

continue

for

its

expected

term

or

that

these

entities

will

fund

Infinity’s

programs

as

agreed,

or

that

any

product candidate Infinity is developing will successfully complete necessary preclinical and clinical development phases. In addition,

Infinity’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, investigational review boards at clinical

trial sites, and publication review bodies; Infinity's ability to enroll patients in its clinical trials; unplanned cash requirements and

expenditures; market acceptance of any products Infinity or its partners may successfully develop; and Infinity's ability to obtain,

maintain and enforce patent and other intellectual property protection for any product candidate it is developing.

•

These

and

other

risks

which

may

impact

management's

expectations

are

described

in

greater

detail

under

the

caption

"Risk

Factors"

included in Infinity's quarterly report on Form 10-Q filed with the U.S. Securities and Exchange Commission in November 2009.

•

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.

•

Our

Internet

website

is

http://www.infi.com.

We

regularly

use

our

website

to

post

information

regarding

our

business,

product

development programs and governance.  We encourage investors to use www.infi.com, particularly the information in the section

entitled

“Investors/Media,”

as

a

source

of

information

about

Infinity.

References

to

www.infi.com

in

this

presentation

are

not

intended

to,

nor

shall

they

be

deemed

to,

incorporate

information

on

www.infi.com

into

this

presentation

by

reference.

2

2

Infinity: Uniquely positioned for success

Full ownership of industry-leading Hsp90 chaperone inhibitors

U.S. commercialization rights to all oncology programs

Worldwide royalties up to 20% on neuropathic pain program

3

Financial strength

Value-creating

asset ownership

Innovative

pipeline

Cash and funding to aggressively invest in programs to key

clinical inflection points

Phase 2: Hsp90 chaperone inhibition

Phase 1: Hedgehog pathway inhibition

Near IND: Fatty acid amide hydrolase

(FAAH) inhibition

World-class discovery organization

Innovative. Independent. Inspired.

Innovative. Independent. Inspired.

Financial strength

today to aggressively invest

in pipeline 

•

$140 million in cash & equivalents as of September 30, 2009

•

Purdue / Mundipharma

collaboration

–

Access to $50 million line of credit (interest at prime; payment due 2019)

–

Up to $162.5 million in committed R&D funding through 2011 ($12.5M in

4Q2009, up to $65M in 2010, up to $85M in 2011); options to extend

through 2013

•

~ 26 million shares outstanding

–

Up to $200 million in potential proceeds from Purdue exercisable

warrants

(6 million shares at exercise price of $15 to $40 per share)

4

Innovative. Independent. Inspired.

5

Financial Strength:

Runway to Clinical Inflection Points

2009

Key objectives

•

Advance Hsp90 trials

•

Advance Hedgehog trial

•

IND for FAAH inhibitor program

Total investment

$80

–

90M

$157M

2009 starting

cash*

2009 ending cash

$127 –

137M

*$127M on 12/31/08, plus $30M Purdue equity investment 1/7/09

** After $12.5M residual funding from AstraZeneca

Net cash burn

(Purdue funds non-Hsp90)

($20

-

30M)**

5

2010-2012

•

Advance late-stage Hsp90 program

•

Initiate addt’l

Hh

and FAAH  studies

•

Strategically enhance pipeline

$375

–

425M

($140

–

170M)

Additional sources of cash

$50M Purdue line of credit

•

Up to $200M Purdue warrants

•

Partner Hsp90 ex-U.S.

Innovative. Independent. Inspired.

6

6

Infinity: Developing Breakthrough Therapeutics

6

Discovery

Preclinical

Phase 1

Phase 2

Phase 3

Hsp90 Chaperone Inhibitors

Hsp90

IV:

IPI-504

(retaspimycin

hydrochloride)

NSCLC

HER2+ mBC

Solid Tumors

Liposarcoma

Hsp90 oral: IPI-493 

Solid Tumors

Hedgehog

Pathway:

IPI-926

Solid Tumors

FAAH: IPI-940

Bcl-2/Bcl-xL*

Discovery Programs

*Transitioned to Novartis

Pipeline at November 2009 

Herceptin®

Combination

Taxotere®

Combination

Expected to Begin Early 2010

Innovative. Independent. Inspired.

7

Hsp90 Chaperone Inhibition Program:

New angle of attacking oncoproteins

Innovative. Independent. Inspired.

8

8

Hsp90 chaperone inhibition:

A new

angle

for targeting oncoproteins

8

•

Hsp90 chaperone

stabilizes

oncoprotein,

enabling growth

signaling and tumor

cell proliferation

•

Inhibit Hsp90 and

oncoproteins become

unstable, unfolded, and

unable to signal

•

Unfolded oncoproteins

will then be degraded

rapidly, arresting tumor

cell growth

•

Currently, targeted

therapies inhibit

oncoproteins in

distinctly different ways

that do not affect the

critical function of

Hsp90

Hsp90 Chaperone Inhibition: Broad medical &

commercial potential

9

Breast cancer

Additional tumors

Address substantial

oncology market with a new

treatment approach

Combine Hsp90 chaperone

therapy with existing

standards of care to delay

recurrence

Serve as late-line therapy

where tumors have become

refractory to other drugs

Lung cancer

Innovative. Independent. Inspired.

IPI-504 IV

(retaspimycin

hydrochloride)

IPI-493 oral

Innovative. Independent. Inspired.

10

10

Infinity’s Hsp90 chaperone inhibition program

Broad medical & commercial potential

10

Lung cancer

Non-small cell

180,000 US

incidence

•

IPI-504 Ph 2 in NSCLC (ASCO 2009)

14% ORR in wtEGFR

patients

•

IPI-504 Ph 1b combo with Taxotere

®

(ASCO 2009)

Generally well-tolerated; combinable

•

Molecular

characterization ongoing

•

Ph 2 data and further

clinical development

expected 2010

INDICATION

TRIALS & DATA

CATALYTS

Innovative. Independent. Inspired.

11

11

Infinity’s Hsp90 chaperone inhibition program

Broad medical & commercial potential

11

Lung cancer

Non-small cell

180,000 US

incidence

•

IPI-504 Ph 2 in NSCLC (ASCO 2009)

14% ORR in wtEGFR patients

•

IPI-504 Ph 1b combo with Taxotere

®

(ASCO 2009)

Generally well-tolerated; combinable

•

Molecular

characterization ongoing

•

Ph 2 data and further

clinical development

expected 2010

Breast cancer

HER2+

45,000 US

incidence

•

IPI-504 Ph 2 in HER2+ mBC combination

with Herceptin

®

Demonstrated potency and tumor growth

inhibition in preclinical models

•

Clinical data expected

2010

INDICATION

TRIALS & DATA

CATALYTS

Innovative. Independent. Inspired.

12

12

Infinity’s Hsp90 chaperone inhibition program

Broad medical & commercial potential  

12

Lung cancer

Non-small cell

180,000 US

incidence

•

IPI-504 Ph 2 in NSCLC (ASCO 2009)

14% ORR in wtEGFR

patients

•

IPI-504 Ph 1b combo with Taxotere

®

(ASCO 2009)

Generally well-tolerated; combinable

•

Molecular

characterization ongoing

•

Ph 2 data and further

clinical development

expected 2010

Breast cancer

HER2+

45,000 US

incidence

•

IPI-504 Ph 2 in HER2+ mBC

combination

with Herceptin

®

Demonstrated potency and tumor growth

inhibition in preclinical models

•

Clinical data expected

2010

Additional

tumors

•

IPI-493 oral Ph 1 study in solid tumors

•

IPI-504 Ph 2 in dedifferentiated

liposarcoma

expected to begin early 2010

•

Ph 1 data and further

IPI-493 clinical

development expected

2010

•

RING data to be

presented at ASCO GI

INDICATION

TRIALS & DATA

CATALYTS

Innovative. Independent. Inspired.

13

Hedgehog Program

Innovative. Independent. Inspired.

14

The Hedgehog

pathway:

A promising new focus for targeted drug therapy

14

14

•

The Hedgehog (Hh) pathway is

not active in most adult cells

•

Smoothened (Smo)  --

which

can promote growth of certain

cancers –

is held in an inactive

state by Patched (Ptc)

•

Gli

transcription factors do not

enter the nucleus to promote

transcription

Malignant activation of the Hedgehog pathway may be implicated in many

insidious cancers including pancreatic, ovarian, small cell lung, breast, brain,

and basal cell (skin) cancers

Innovative. Independent. Inspired.

15

The role of Smoothened in malignant activation

of the Hedgehog pathway

15

15

•

Tumor

derived

Hh

ligands

act

through

Smo

to

initiate

a

signaling cascade through Gli

•

Gli

dependent transcription of

genes can now promote tumor

survival and growth

•

Tumor

derived

Hh

ligands

act

through

Smo

on

stromal

cells

in the tumor microenvironment

•

Stromal

cells in the

microenvironment provide

support for growth and survival

of tumor cells

•

Hh

signaling activated by

genetic mutation

•

Loss-of-function mutations in

Ptc

allow

Smo

to

initiate

a

signaling cascade in the

absence

of

Hh

ligand,

leading

to tumor survival and growth

Ligand-Dependent Signaling

Ligand-Independent

Signaling

Innovative. Independent. Inspired.

16

Infinity’s IPI-926

inhibits Smoothened

16

16

•

IPI-926 inhibits Smo,

preventing the signaling

cascade that otherwise

leads to tumor cell

growth and survival

IPI-926

IPI-926 in ongoing

Ph 1 clinical trial

Innovative. Independent. Inspired.

17

17

Significant anti-tumor activity with IPI-926

in

small cell lung cancer model

Days Post Implant

5 weeks total of IPI-926 follow-up

treatment; 40 mg/kg, PO QD

Travaglione

et al., 2008 AACR

Innovative. Independent. Inspired.

18

IPI-926

+ Gemcitabine

provides a survival

benefit in

pancreatic

cancer

model

IPI-926 depletes tumor stroma

through down-regulation of Hh

signaling, resulting in increased

drug delivery to the tumor

Olive et al., 2009 Science

0

15

30

45

60

75

90

0

20

40

60

80

100

Days of Treatment

Vehicle

Gem

IPI-926

IPI-926/Gem

Model resembling human

pancreatic cancer responds

poorly to gemcitabine

due to

lack of tumor perfusion

Innovative. Independent. Inspired.

Compelling potential path forward for Phase 2

development in 2010 

•

Recent Science

article highlights promising role of IPI-926 in

chemo-resistant pancreatic cancer model

•

Evidence for Hh

inhibition as maintenance therapy in

chemo-responsive tumor models, including SCLC and ovarian

•

IPI-926 advancing through Phase 1 study

19

Innovative. Independent. Inspired.

20

Early Pipeline:

Fatty Acid Amide Hydrolase

(FAAH)  

Innovative. Independent. Inspired.

Fatty acid amide hydrolase

(FAAH):

21

21

Next Generation Innovation: IPI-940 for

neuropathic pain

21

Advance IPI-940 to IND

by year-end 2009 

FAAH inhibition increases the duration of anandamide’s

analgesic effect, prolonging pain relief at the site of release

CB1

Anandamide

Innovative. Independent. Inspired.

22

22

Infinity: Developing Breakthrough Therapeutics

22

Discovery

Preclinical

Phase 1

Phase 2

Phase 3

Hsp90 Chaperone Inhibitors

Hsp90

IV:

IPI-504

(retaspimycin

hydrochloride)

NSCLC

HER2+ mBC

Solid Tumors

Liposarcoma

Hsp90 oral: IPI-493

Solid Tumors

Hedgehog

Pathway:

IPI-926

Solid Tumors

FAAH: IPI-940

Bcl-2/Bcl-xL*

Discovery Programs

*Transitioned to Novartis

Pipeline at November 2009 

Herceptin®

Combination

Taxotere®

Combination

Expected to Begin Early 2010

Innovative. Independent. Inspired.

23

23

•

Report IPI-504 NSCLC Ph 2 data, mid-2009

•

Report

IPI-504

Ph

1b

Taxotere®

combo

data,

mid-2009

•

Advance oral IPI-493 Ph 1

•

Initiate additional trials (including HER2+ mBC)

23

2009 R&D Milestones

Hsp90: IPI-504 and IPI-493 oral

•

Advance IPI-940 to IND

FAAH: IPI-940

•

Report IPI-926 preclinical data, multiple tumor models, mid-2009

Hedgehog: IPI-926

Innovative. Independent. Inspired.

24

24

Business and Commercial Objectives

24

•

Build market presence

–

Infinity to commercialize all oncology products in U.S.

–

Potential to partner Hsp90 for ex-U.S. marketing

–

Purdue/Mundipharma ex-U.S. marketing

•

Identify strategic opportunities to enhance profile

•

Maintain strong financial profile

–

Opportunities for additional capital including

Purdue warrants, Hsp90 partnering

Innovative. Independent. Inspired.

Infinity: Uniquely positioned for success

Full ownership of industry-leading Hsp90 chaperone inhibitors

U.S. commercialization rights to all oncology programs

Worldwide royalties up to 20% on neuropathic pain program

25

Financial strength

Value-creating

asset ownership

Innovative

pipeline

Cash and funding to aggressively invest in programs to key

clinical inflection points

Phase 2: Hsp90 chaperone inhibition

Phase 1: Hedgehog pathway inhibition

Near IND: Fatty acid amide hydrolase

(FAAH) inhibition

World-class discovery organization

Innovative. Independent. Inspired.

26

26

Infinity

Innovative. Independent. Inspired.

26