Presentation dated January 9, 2012

Exhibit 99.1

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:

the

therapeutic

potential

Infinity’s

Hedgehog

pathway,

Hsp90

and

PI3K

inhibitors;

the

potential

saridegib

and

Hedgehog

pathway

inhibition

addressing

chondrosarcoma,

pancreatic

cancer

and

myelofibrosis;

the

potential

IPI-145

and

PI3K

inhibition

addressing hematologic malignancies and inflammation; the potential of combination therapy based on retaspimycin HCl in addressing non-small cell lung cancer

and the expectation that Infinity: will provide an update on the

Phase 1b portion of the trial of saridegib in combination with gemcitabine in patients with pancreatic

cancer at ASCO GI in January 2012; will report data in the second half of 2012 from the Phase 2 portion of the trial of saridegib in combination with gemcitabine

in patients with pancreatic cancer, the Phase 2 trial of saridegib in patients with myelofibrosis, the dose-escalation portion of the Phase 1b/2 trial of retaspimycin

HCl

combination

with

everolimus

patients

with

NSCLC,

and

each

the

Phase

trials

IPI-145;

and

will

complete

enrollment

the

second

half

2012

the Phase 2 trial of saridegib in patients with chondrosarcoma and the Phase 2 trial of retaspimycin HCl in combination with docetaxel in patients with NSCLC.

Such forward-looking statements also include estimates of 2012 financial performance (including revenue, net operating cash burn, and year-end cash and

investments balance) and the expectation that Infinity will have

a cash runway to support its current operating plan through key

inflection points.

•

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 Infinity’s strategic alliance with Mundipharma will continue for its expected term or that it will fund

Infinity’s programs as agreed, that any product candidate Infinity is developing will successfully complete necessary preclinical and clinical development phases,

or that development of any of Infinity’s product candidates will continue. Further, there can be no guarantee that any positive developments in Infinity’s product

portfolio

will

result

stock

price

appreciation.

Management’s

expectations

could

also

affected

risks

and

uncertainties

relating

to:

Infinity’s

results

clinical

trials

and

preclinical

studies,

including

subsequent

analysis

existing

data

and

new

data

received

from

ongoing

and

future

studies;

the

content

and

timing

decisions

made

the

U.S.

Food

and

Drug

Administration

and

other

regulatory

authorities,

investigational

review

boards

clinical

trial

sites

and

publication

review bodies; Infinity’s ability to enroll patients in its clinical trials; unplanned cash requirements and expenditures, including in connection with business

development activities; development of agents by Infinity’s competitors for diseases in which Infinity is currently developing its product candidates; and Infinity’s

ability to obtain, maintain and enforce patent and other intellectual property protection for any product candidates it is developing.

•

These

and

other

risks

which

may

impact

management's

expectations

are

described

greater

detail

under

the

caption

"Risk

Factors"

included

Infinity's

quarterly report on Form 10-Q for the quarter ended September 30, 2011 filed with the U.S. Securities and Exchange Commission on November 8, 2011.

•

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.

encourage

investors

use

www.infi.com,

particularly

the

information

the

section

entitled

“Investors/Media,”

source

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.

Average survival for newly diagnosed,

metastatic pancreatic cancer:

Less than six months.

Standard treatment for

unresectable chondrosarcoma:

None.

Historical response rate to docetaxel for

second-line NSCLC:

8%.

The urgency is real.

The time is NOW.

Sustainable model

for value creation

Building a Fully Integrated

Biopharmaceutical Company

Breakthrough

Science

Deep,

Diverse

Pipeline

High-value,

Enabling

Partnerships

Full U.S.

Commercial

Rights

Promising Pipeline Based on Breakthrough

Science

1H’12

1H’13

2H’13

2H’12

Phase 2

Phase 1

Phase 2

Phase

Phase 2

Hedgehog: Saridegib

Hsp90: Retaspimycin HCl

PI3K: IPI-145

Pancreatic Cancer

Chondrosarcoma

NSCLC (Heavy Smokers)

Myelofibrosis

NSCLC (mKRAS)

Inflammation

Hematologic Malignancies

2012

2013

Data

Randomized, double-blind, placebo-controlled trial.

Data

Phase 1b/2

Data

Saridegib

Clinical

Development

Market

Potential

•

Key features:

–

Potent, oral Smoothened inhibitor

–

Clinically active

–

Well-tolerated as single agent and in combination

•

Lead development program with three Phase 2 trials

–

Key data anticipated in 2012

–

Clear registration paths

•

Robust biomarker strategy

•

First-in-class potential in multiple indications*

–

Pancreatic cancer: ~100,000 patients

–

Myelofibrosis: ~30,000 patients

–

Chondrosarcoma: Ultra-orphan

Saridegib: Establishing a Leadership Position in

Underserved, Life-Threatening Diseases

*Estimates based upon G7 countries (US, UK, IT, DE, ES, FR, JP)

Saridegib in Pancreatic Cancer: Enables

Chemotherapy to Reach Tumor

Vehicle

Gemcitabine alone

Saridegib +

gemcitabine

Current standard of care

in pancreatic cancer

Tumor cell nuclei

Fluorescent contrast agent

Saridegib

gemcitabine

doubles

median

survival

mouse

model

pancreatic

cancer

(Olive et al. 2009, Science 324: 1457-61.)

New Scientific Insights: Saridegib’s Effect on

Tumor Vasculature Enhances Tumor Access

Control

Bevacizumab

Saridegib

Campbell et al., AACR Tumor Microenvironment Complexity Conference, 2011.

Saridegib increases microvessel density, vessel volume

and vessel function to enhance tumor access

Saridegib: Rigorous Phase 2 Trial in

Metastatic Pancreatic Cancer

•

Randomized, double-blind, placebo-controlled trial

–

Primary endpoint: Overall survival

–

Dose: 160 mg saridegib (QD) and 1000 mg/m

gemcitabine (Q3W)

•

Enrollment complete; Data anticipated 2H’12

–

Phase 1b data to be updated at ASCO GI in January 2012

Dose

Escalation

MTD

1:1

Randomization

Saridegib + gemcitabine

(n = 60)

Placebo + gemcitabine

(n = 60)

Phase 1b

Phase 2

Saridegib: Encouraging Activity and

Tolerability in Phase 1b

•

Saridegib + gemcitabine led

to a 31% response rate

–

Overall response rate to

gemcitabine is historically

<10%*

•

Favorable PK and safety

profile

–

No interaction between

saridegib and gemcitabine

–

Most common AEs were

fatigue and nausea

–

Combination did not reveal

unique or more severe AEs

Stephenson et al., ASCO 2011.

*Moore, et al. J Clin Oncol 25:1960-6.; Seitz et al. Oncology 18:43-7.

Saridegib: Evidence of Activity in

Pancreatic Cancer

Pre-treatment

After 4 months of treatment

Pancreatic mass and liver metastases

Reduction in primary mass and metastases

Liver

metastasis

Pancreas

•

Blood cancer characterized by bone

marrow failure and enlarged spleen due

to pathogenic fibrosis

•

In myelofibrosis, Hedgehog ligand

expressed in bone marrow

•

Current treatments target symptoms,

not underlying fibrosis

Saridegib in Primary Myelofibrosis: Hedgehog Pathway

Plays Key Role in Pathogenic Fibrosis

Tkachuk and Hirshmann, Wintrobe’s Atlas of Clinical Hematology, 2007.

Saridegib 160 mg (QD)

(N = up to 45)

Saridegib 160 mg (QD)

(N = up to 45)

Saridegib 160 mg (QD)

(N = 12)

Saridegib: Phase 2 Trial in Myelofibrosis

•

Open-label, exploratory trial with option for expansion

–

Primary endpoint: Response rate according to International Working Group

Criteria

–

No spontaneous remissions in this disease

•

Data anticipated in 2H’12

Expansion

Saridegib: Global, Randomized Phase 2 Trial in

Chondrosarcoma

•

Randomized, double-blind, placebo-controlled trial

–

Enrolling patients with metastatic or locally advanced, unresectable

chondrosarcoma

–

Primary endpoint: Progression-free survival

•

Strong preclinical rationale: Saridegib inactivates Hedgehog signaling in

chondrosarcoma, killing tumor cells*

•

Enrollment completion anticipated 2H’12

~140 Patients

Saridegib 160 mg

(QD)

(N = ~94)

Placebo

(N = ~46)

Progression -

crossover to saridegib

2:1

Randomization

*Read, AACR 2011.

Retaspimycin HCl (IPI-504)

Targeting Non-Small Cell Lung Cancer Through

Hsp90 Inhibition

•

Key features:

–

Selective and potent Hsp90 inhibitor in Phase 2 development

–

Well-defined and manageable safety profile with QW dosing

–

Clinical activity in combination with docetaxel in NSCLC

•

Two trials ongoing in NSCLC

–

In combination with docetaxel in heavy smokers

–

In combination with everolimus in mKRAS

•

Robust biomarker strategy

Retaspimycin HCl: Leading the Field in Hsp90

*Estimates based upon G7 countries (US, UK, IT, DE, ES, FR, JP)

•

Targeting unmet need in NSCLC patient subpopulations*

Heavy smokers: ~180,000 patients

Squamous cell carcinoma: ~145,000 patients

mKRAS: ~125,000 patients

Retaspimycin

HCl

Clinical

Development

Market

Potential

Retaspimycin HCl: Phase 2 Trial in NSCLC

Patients with a Smoking History

•

Randomized, double-blind, placebo-controlled trial

~200 smokers w/

or 3

-line

NSCLC

(docetaxel naïve)

Follow-up for OS

Docetaxel +

Retaspimycin HCl

(N = ~100)

Docetaxel +

placebo

(N = ~100)

Primary endpoint: Overall survival

Secondary endpoints: Predictive biomarkers, progression free survival,

overall response rate

Dose: 450 mg/m

retaspimycin HCl (QW) and 75 mg/m

docetaxel (Q3W)

•

Enrollment completion anticipated 2H’12

Retaspimycin HCl Phase 1b Trial: Clinically

Active in Combination with Docetaxel

Encouraging Phase 1b data

•

Partial response in 6 patients

(ORR = 26%)

•

Stable disease in 7 patients

•

Well-tolerated

–

No unexpected or overlapping

toxicities

–

No dose reductions or

discontinuations due to liver

function tests

Riely et al., ASCO 2011.

Retaspimycin HCl: Responses Observed in

Patients with Historically Poor Prognoses

*Hanna et al, J Clin Oncol, 22:1589-97.

Retaspimycin HCl: Phase 1b/2 Trial in

NSCLC Patients with mKRAS

Retaspimycin HCl

+ everolimus

(N = 12)

Determine

recommended

Phase 2 dose in

mKRAS NSCLC

•

Small, open-label exploratory trial with option for expansion

–

Primary efficacy endpoint: Response rate

–

Neither drug active as single agent in these patients

•

Strong preclinical rationale: Evidence of substantial tumor regression in a

NSCLC model*

•

Data anticipated 2H’12

Retaspimycin HCl

+ everolimus

(N = up to 45)

Expansion

Phase 1b

Phase 2

*De Raedt et al., 2011; Cancer Cell 13;20(3):400-13.

IPI-145

Clinical

Development

Market

Potential

•

Key features:

–

Oral

–

Potent PI3K-

inhibitor

–

Active in preclinical models of inflammation

•

Dual development path:

–

Inflammation

–

Hematologic malignancies

•

Robust biomarker strategy

IPI-145: Only PI3K-

Inhibitor in the Clinic

*Estimates based upon G7 countries (US, UK, IT, DE, ES, FR, JP)

The Power of PI3K-

Inhibition

IPI-145: Dual Clinical Development Paths in

Inflammation and Hematological Malignancies

IPI-145

Phase 1 in Hematologic

Malignancies

•

Dose Escalation

•Expansion Cohorts

Phase 1 in

Healthy Subjects

•

Single Ascending Dose

•

Multi Ascending Dose

Phase 2 in

Inflammation

Phase 2 in

Hematologic

Malignancies