Presentation materials

(NASDAQ: AUXL)

September 2008

Exhibit 99.1

(NASDAQ: AUXL)

Safe Harbor Statement

We will make various remarks during this presentation that constitute “forward-looking statements” for purposes of the safe harbor provisions under The

Private Securities Litigation Reform Act of 1995, including statements regarding the pricing, time to market, size of market, growth potential and therapeutic

benefits of the Company’s product candidates, including those for the treatment of Dupuytren’s contracture, Peyronie’s disease, and Frozen Shoulder

syndrome; interpretation of market research data; competition within certain markets relevant to the Company’s product candidates; interpretation of clinical

results, including the efficacy and tolerability of the Company’s product candidates; the timing of the commencement and completion of clinical trials and the

timing of reporting of results therefrom; the timing of manufacturing scale up for the Company’s product candidates; the Company’s ability to manufacture

XIAFLEX™ (clostridial collagenase for injection – formerly referred to as AA4500) at the Company’s Horsham facility; the timing of the filing of the Biologics

License Application for approval of XIAFLEX for the treatment of Dupuytren’s contracture and the approval thereof; the timing of the phase IIb trials for

XIAFLEX for the treatment of Peyronie’s disease; competitive developments affecting the Company’s products and product candidates, including generic

competition; the success of the Company’s development activities; future Testim market share, prescriptions and sales growth and factors that may drive

such growth; size and growth potential of the testosterone replacement therapy market and the gel segment thereof and factors that may drive such growth;

the protection for Testim afforded by U.S. Patent No. 7,320,968, and its listing in the Orange Book, the value of extending patent protection for Testim

through January 2025, the value and likelihood that patents will be granted from the continuation and divisional applications filed by CPEX Pharmaceuticals,

Inc.; the absence of an ANDA for the generic to Testim; the Company’s development and operational goals and strategic priorities for fiscal 2008; the ability

to fund future operations; and the Company’s expected financial performance during 2008 and financial milestones that it may achieve for 2008, including

2008 net revenues, research and development spending, selling, general and administrative expenses, stock-based compensation expenses, and net loss.

All remarks other than statements of historical facts made during this presentation, including but not limited to, statements regarding future expectations,

plans and prospects for the Company, statements regarding forward-looking financial information and other statements containing the words “believe,” “may,”

“could,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “expect,” and similar expressions, as they relate to the Company, constitute

forward-looking statements. Actual results may differ materially from those reflected in these forward-looking statements due to various factors, including

general financial, economic, regulatory and political conditions affecting the biotechnology and pharmaceutical industries and those discussed in the

Company’s Annual Report on Form 10-K for the year ended December 31, 2007 under the heading “Risk Factors”, which is on file with the Securities and

Exchange Commission (the “SEC”) and may be accessed electronically by means of the SEC’s home page on the Internet at http://www.sec.gov or by

means of the Company’s home page on the Internet at http://www.auxilium.com under the heading “Investor Relations - SEC Filings.” There may be

additional risks that the Company does not presently know or that the Company currently believes are immaterial which could also cause actual results to

differ from those contained in the forward-looking statements. Given these risks and uncertainties, any or all of these forward-looking statements may prove

to be incorrect. Therefore, you should not rely on any such factors or forward-looking statements.

In addition, forward-looking statements provide the Company’s expectations, plans or forecasts of future events and views as of the date of this presentation.

The Company anticipates that subsequent events and developments will cause the Company’s assessments to change. However, while the Company may

elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so. These forward-

looking statements should not be relied upon as representing the Company’s assessments as of any date subsequent to the date of this presentation.

Poised for Growth

Fastest Growing

TRT product in

the U.S.

Late Stage

Blockbuster

Product

Opportunity

(NASDAQ: AUXL)

Auxilium Pharmaceuticals, Inc. (NASDAQ: AUXL)

•

Specialty biopharmaceutical company focused on Urologists,

Endocrinologists, Orthopedists and certain PCPs

•

Founded in 1999

•

Headquarters in Malvern, Pa.

–

Manufacturing in Horsham, Pa.

–

Approximately 330 employees (~190 commercial)

•

I.P.O in July 2004

–

Currently approximately 41.4 million shares issued & outstanding

–

Additional 6.6 million shares subject to issuance from stock

options & warrants

•

A component of the NASDAQ BIOTECH INDEX

(NASDAQ: AUXL)

Broad Maturing Pipeline

Note: Worldwide rights for all products available, except Testim where ex -U.S. rights have been licensed.

XIAFLEX™

(clostridial collagenase for injection) was formally referred to as AA4500

Product

Testim®

gel

Approved in U.S.

Europe & Canada

XIAFLEX™

Transmucosal Film

AA4010

Transmucosal Film

Market

Phase III

Phase II

Phase I

Pre-clinical

Late Research

Hypogonadism

Dupuytren’s Contracture

Peyronie’s Disease

Frozen Shoulder Syndrome

Overactive Bladder

Hormones and Urology

Pain

(NASDAQ: AUXL)

Anticipated News Flow Events

Q308:

•

XIAFLEX

Initiate Peyronie's

Phase IIb Study

H109:

•

XIAFLEX

Open Label Safety

Data

Early 2009:

•

XIAFLEX

File BLA for

Dupuytren's Contracture

Early 2010

•

XIAFLEX

FDA

Approval In

Dupuytren’s

Contracture

Q409

Q309

Q209

Q109

Q408

Q308

2010

XIAFLEX™

(clostridial collagenase for injection)

Unique, Late-Stage Opportunity with Blockbuster

Potential

(NASDAQ: AUXL)

XIAFLEX-

Unique, Late-Stage, Blockbuster

Opportunity

•

Potential to be first effective non-surgical treatment for two

high unmet needs

–

Late-Stage Phase III data for the treatment of Dupuytren’s

contracture -expect to file U.S. BLA in early 2009

–

We believe promising Phase II data in Peyronie’s disease

•

Well-characterized mode of action

•

Worldwide rights offer options to build company or

generate cash –

exploring EU partnering opportunities

now

•

We believe there are at least 450,000 potential patients

annually in U.S. and EU for Dupuytren’s & Peyronie’s

indications -

> $1 Billion opportunity, based on market

research and analysis

(NASDAQ: AUXL)

Dupuytren’s Contracture—a Debilitating Condition

•

Excessive collagen deposition

•

Nodules represent early, active

form

•

Cords develop over time, are

palpable, and result in

contractures

•

Debilitating effect on quality of life

•

Surgery may be reserved for

advanced disease due to

unpredictable results,

complications, long recovery and

recurrence/additional surgeries

(NASDAQ: AUXL)

Current Treatment Options Are Invasive or

Ineffective

•

Surgery

•

Non-surgical options

–

Splinting

–

Physical therapy

–

Corticosteroids

•

Needle

fasciotomy/

aponeurotomy

•

Amputation

(NASDAQ: AUXL)

Dupuytren’s

Contracture—Unmet Medical Need

•

Disease prevalence is estimated at 3%-6% among adult

Caucasians,

but occurs in all populations

•

Higher

prevalence

patients

northern-European

descent

•

Hereditary

component

approximately

40%

patients

•

On average, patients have 2.2 affected joints at the time of

diagnosis,

and

about

half

patients

have

bilateral

disease

•

Recurrence

rate

surgical

patients

–

30% in 2 years

–

55% in 10 years

•

We believe Dupuytren’s

contracture is under-diagnosed and

under-treated

Tubiana

2006.

Hueston

1963

Skoog

1948

Mikkelsen

1976

(NASDAQ: AUXL)

XIAFLEX—Potential to Revolutionize Treatment

for Dupuytren’s Contracture

(NASDAQ: AUXL)

XIAFLEX—Potential to Revolutionize

Treatment for Dupuytren’s Contracture

(NASDAQ: AUXL)

91%

86%

100%

85%

20%

40%

60%

80%

100%

Pivotal Phase III Study (DUPY-303): Results*

•

54/62 (87%) joints achieved 0°-5°

contracture in the study

and its open-label extension

•

Recurrence rates

–

3 of 54 joints followed for 12 months

–

5 of 27 joints followed for 24 months

•

Mean number of injections for success was 1.4

•

Injections well tolerated with only local AEs

*The Journal of Hand Surgery.

2007;32(6).

* After up to three injections. Success rate was 70% after a single injection.

21/23

12/14

9/9

33/39

Primary joint

P<.001

MP joint

P<.001

PIP joint

P<.001

Non-Primary joints

0/12

0/7

0/5

XIAFLEX

Placebo

(NASDAQ: AUXL)

Most Patients Achieved Full Extension,

Regardless of Joint Affected or Severity

92%

78%

86%

61%

47%

53%

79%

60%

70%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

PIP

Combined

10,000 units, approximately 0.58 mg.

Joint Type

Response

rate

joint

type

and

baseline

joint

severity

Studies 202-303-404 combined

Low severity

High severity

Total

(NASDAQ: AUXL)

CORD I Design

•

Largest ever double-blind, placebo-controlled

trial in Dupuytren’s Contracture

–

randomized in 2:1 ratio of active to placebo

–

enrolled a 2:1 ratio of MP:PIP

–

enrolled 1:1 ratio of less severe to more severe joints

•

Primary endpoint is reduction in contracture to

within 0 -

5°

of normal

•

Secondary endpoints to measure clinical

improvement and time to success

–

50% improvement in contracture

–

change in primary joint degree of contracture

•

3 month and 12 month safety profile

(NASDAQ: AUXL)

Primary Endpoint Outcome Compares Favorably

To Surgery

(NASDAQ: AUXL)

4 Out Of 5 Dupuytren’s Contracture Patients

Improved By 50%

(NASDAQ: AUXL)

Contracture Reduction By Degrees Indicates Average

XIAFLEX Patient Achieves ~10°

Of Contracture

(NASDAQ: AUXL)

XIAFLEX Phase III AE and SAE Rates Should

Compare Favorably To Surgical Complications

Serious Adverse Events

Number

Rate/Inj.

Tendon / Ligament*:

Confirmed Tendon Rupture

0.14%

Ligament Injury

0.05%

Total Tendon / Ligament

0.20%

Deep Vein Thrombosis

0.05%

Complex Regional Pain Syndrome

0.05%

Total

0.30%

Note: > 2,000 injections in approximately 850 patients from CORD,

JOINT and PK studies as of July 31, 2008.

*one unconfirmed tendon injury was changed to confirmed tendonitis

•

Common adverse events and rates were consistent with prior

XIAFLEX trials

(NASDAQ: AUXL)

CORD I Key Takeaways

•

Primary endpoint of 5°

reached in 64% of patients

(p<0.001)

–

25 of 26 endpoints met with statistical significance

of <0.001, 1 of 26 was met with a p-value = 0.002

–

Of the 73 patients who didn’t respond, 44 received

less than 3 injections and 25 had no palpable cord

•

Primary joint contractures improved 50% in 4 out of 5

patients

•

82.2% of patients receiving XIAFLEX completed the

study with contractures 25°

•

Less severe contractures responded better than more

severe contractures

•

MP joints responded better than PIP joints

•

Safety profile compares favorably to surgery

–

No systemic exposure and no allergic reactions

(NASDAQ: AUXL)

We believe:

•

There is a pent-up demand for non-surgical therapy

•

Surgeons and patients prefer non-invasive treatment

•

Each patient on average has 2.2 joints which will require

treatment; about half have contractures in both hands

•

Early data indicates on average 1.4 vials of XIAFLEX required

per joint

2.2

joints

per

patient

1.4

vials

per

joint

3.1

vials

per

patient

average

•

We believe XIAFLEX treatment can be priced competitively to

cost

surgery

(~$5,000

the

U.S.

–

equates

$1,600

per

vial)

Dupuytren’s Commercial Opportunity

(NASDAQ: AUXL)

Market Research Performed –

Dupuytren’s

•

Multiple prevalence data sets proved to be highly variable in

numbers of patients

•

Two rounds of quantitative primary research have been

commissioned by Auxilium on XIAFLEX for Dupuytren’s

contracture

•

A combined 571 Orthopedic Surgeons have been interviewed to

estimate

market

size

(401

U.S.;

170

Europe)

and

391

have

given feedback on potential usage of XIAFLEX (221 U.S.; 170

Europe)

•

Second study (n=444 total & 340 in depth) was designed to

provide 95% confidence level and 7.5% margin of error

(NASDAQ: AUXL)

Patients

Seeking

Treatment

~1,030,000

No Prior

Surgery

~540,000

Had Surgery

Previously

~490,000

Watchful

Waiting

~270,000

Medical/

Surgical

Treatment

~270,000

Medical/

Surgical

Treatment

~125,000

Watchful Wait/

In Follow Up

~365,000

XIAFLEX

Potential

Candidates

~240,000 or 60%

of the

Medical/Surgical

Candidates

At least 240,000 Dupuytren’s Candidates In U.S. & Europe

Annually

Source: 2006 Auxilium research and analysis

~150,000 in U.S.

~ 90,000 in Europe

Prevalence

3 –

6% of

Population

~13,500,000 to

27,000,000

(NASDAQ: AUXL)

Expected Pathway to BLA Filing in Early 2009

•

Complete 12 month open-label safety follow up from

>100 CORD I patients originally randomized to

XIAFLEX

•

Complete open-label CORD II and JOINT I/II trials to

attain 1,000 patient exposure data

•

Finalize BLA filing (CMC, etc.)

(NASDAQ: AUXL)

XIAFLEX I.P. Position for Dupuytren’s

Contracture

•U.S. Orphan Drug Exclusivity granted on May 23, 1996

for 7 years post approval

•Market Exclusivity expected in EU for 10 years post-

approval

–Data protection granted for 8 years

•Method of Use Patent in U.S. through 2014

•Use Patent in France, UK, Sweden through 2018

–Pending in Germany and Denmark

•Highly Purified Collagenase API and manufacturing

patent filed (if issued, expected expiry 2027)

(NASDAQ: AUXL)

1. Smith BH. Am J Clin Pathol. 1966;45:670-678.

2. Somers KD, Dawson DM. J Urol. 1997;157:311-315.

Peyronie’s Disease—a Devastating Disorder

•

Scarring phenomenon affecting the

tunica

albuginea

•

Plaques show excessive collagen

deposition

•

Potential Symptoms

–

Pain with erection, penile

curvature/deviation, penile

shortening, indentations, and/or

erectile dysfunction

–

May experience difficulty with sexual

intercourse, loss of self-esteem, and

depression

•

There are no approved therapies

for the treatment of Peyronie’s

disease

(NASDAQ: AUXL)

•

Prevalence of Peyronie’s disease is estimated at 1 in 20

adult

men

–

Actual

prevalence

higher

based

autopsies

•

Prevalence rate increases with age

–

The

average

age

disease

onset

years

•

High association with other diseases such as:

–

Diabetes, erectile dysfunction (ED), Dupuytren’s

contracture, plantar fascial contracture,

tympanosclerosis,

gout,

and

Paget’s

disease

•

We believe Peyronie’s disease is under-diagnosed and

under-treated

Epidemiology—Peyronie’s Disease

1. Schwarzer U, The prevalence of Peyronie’s disease: Results of a large survey.

BJU

Int

2001;88:727–30;

Mulhall

al:

Urology

2004:171:

2350

–

2353;Rhoden

et al: Int J. Impot Res 2001 :13 : 291 –

293; La Pera et al : EUR Urology 2001: 40

:525 –

530.

2. Smith BH. Am J Clin Pathol. 1966;45:670-678.

3. Lindsay MB, J Urol.

1991;146:1007–1009.

4. Nyberg L, J Urol.128: 48, 1982

(NASDAQ: AUXL)

Current Treatment—Surgical

•

The goal of surgery is simply to make the two sides of the

penis equal in size

•

Graft or prosthetic may be required

•

Cost of surgery in U.S. is ~$10-12K

(NASDAQ: AUXL)

Peyronie’s Disease—Unapproved Treatments

Have Been Used With Little Reported Success

•

Verapamil

•

Vitamin E

•

Colchicine

•

Potassium aminobenzoate (Potaba)

•

Tamoxifen

•

Interferon alpha-2a

•

Corticosteroids

•

Energy transfer treatment including

extracorporeal shock wave therapy (ESWT),

laser and ultrasound therapy, and

orthovoltage radiation

(NASDAQ: AUXL)

Promising Phase II Results: Patients With

25%

Reduction in the Angle of Deviation

Study 1030

58%

53%

35%

20%

40%

60%

80%

100%

Month 3

Month 6

Month 9

Study 1035

50%

100%

89%

20%

40%

60%

80%

100%

Week 6

Month 3

Month 6

Month 9

(NASDAQ: AUXL)

Market Research Performed –

Peyronie’s

•

Two rounds of quantitative primary research have

been commissioned by Auxilium on XIAFLEX for

Peyronie’s disease

•

A combined 575 Urologists have been interviewed to

estimate market size (415 in U.S.; 160 in Europe) and

383 have given feedback on potential usage of

XIAFLEX (223 U.S.; 160 Europe)

•

Second study (n=472 total & 333 in depth) was

designed to provide 95% confidence level and 7.5%

margin of error

(NASDAQ: AUXL)

Patients

Seeking

Treatment

~475,000

Surgery Not

Recommended

~365,000

Watchful

Waiting

~160,000

Medical or

Intralesional

Therapy

~205,000

Surgery

Recommended

~110,000

XIAFLEX

Potential

Candidates or

67% of

Medical/

Surgical

candidates

~210,000

At least 210,000 Peyronie’s Candidates In U.S. and Europe

Annually

Source: 2006 Auxilium research and analysis

~135,000 in U.S.

~ 75,000 in Europe

Prevalence

1 in 20 Adult

Males

(NASDAQ: AUXL)

Peyronie’s Clinical Plan

•

Phase IIb dose ranging study expected to begin in

Q3 2008

•

A proprietary Patient Reported Outcome (PRO)

questionnaire has been developed

–

To be validated in Phase IIb and likely to be used as a

primary efficacy endpoint in Phase III clinical trials

•

File as a Supplemental BLA for Peyronie’s

indication

–

Will not be filed before Dupuytren’s BLA approved

(NASDAQ: AUXL)

XIAFLEX I.P. Position for Peyronie’s

Disease

•U.S. Orphan Drug Exclusivity granted on March 12, 1996

for 7 years post approval

•Market Exclusivity in EU could be extended to 11 years on

approval of additional indication

–Biosimilars would need to generate extensive regulatory, safety,

and efficacy data

•Method of Use Patent in U.S. through 2019

•Use Patent Granted in France, UK, and Ireland (expiry 2020)

–Pending in Germany, Denmark, and Norway

•Highly Purified Collagenase API and manufacturing patent

filed (if issued, expected expiry 2027)

Testim

1% Testosterone Gel:

Near-Term Growth Driver

Executing on Opportunities

(NASDAQ: AUXL)

Testim®

is the Fastest Growing Testosterone

Replacement Therapy Gel

•

Proprietary, topical

1% testosterone gel

–

Once-a-day application

–

Favorable clinical and commercial profile

•

Recent study indicates 39% of U.S. males over 45 yrs

are hypogonadal*

–

We estimate that less than 10% of affected population

receives treatment

•

We believe diagnosis is increasing through education

and awareness

*Mulligan T. et al. Int J. Clin Pract

2006

(NASDAQ: AUXL)

Patient Benefits are Clinically Proven

Total Testosterone

2,000

3,000

4,000

5,000

6,000

Mean AUC

0-24

(ng*h/dL)

Testim

AndroGel

Free Testosterone

100

150

200

250

Mean AUC

0-24

(ng*h/dL)

Testim

AndroGel

•

clinical

studies

involving

approx.

1,800

patients

–

largest

placebo-controlled

study

ever

conducted

•

Clinical

trial

Testim

vs.

AndroGel

–

Testim provides 30% higher testosterone absorption (p<0.001)

Note:

Adjusted

geometric

means

(CV

single-dose

(50

testosterone),

randomized,

complete

crossover

study

hypogonadal

men.

(NASDAQ: AUXL)

Gels Fastest Growing TRT Segment

Source: IMS data

($ in millions)

Gel

Patch

Oral

Injectables

$35

$117

$200

$287

$340

$383

$449

100

200

300

400

500

600

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

$459

$399

$302

$210

$77

$59

$49

$499

$118

$568

Gel Segment Growth ($)

Jun 2008 L12M:

Gel Segment Growth ($)

Jun 2008 L12M:

2007

700

$685

$563

22.8+%

(NASDAQ: AUXL)

Testim

quarterly net revenues and scripts

($ in millions)

Established Track Record of Consistent Growth

Q2 2008 Net

Revenues

Y/Y Growth:

Q2 2008 Net

Revenues

Y/Y Growth:

Q2 2008 TRX

YY Growth:

Q2 2008 TRX

YY Growth:

Source: Auxilium and IMS data

+24.2%

+32.4%

(NASDAQ: AUXL)

We Believe Testim Is Driving Growth in

Overall Gel Market

Source: IMS data

Testim Share of TRx of Gel Market

22.2%

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

Mar-03

July-08

Strong market share with high-prescribing urologists & PCP’s;

41.9% gel market share of decile 8-10 Urologists and 29.9% share with

decile 8 –

10 PCP’s in July 2008

(NASDAQ: AUXL)

•

U.S. Patent # 7,320,968 covering method of use claims for Testim

issued January 22, 2008; expires 2025

•

We believe no Paragraph III ANDA was filed prior to issuance of the

’968 patent, since five months have passed since listing in the

Orange Book

•

Divisional application and continuations filed with U.S. PTO in late

2007 with a plan to protect additional inventions and seek additional

claims

•

New patent issued in Canada; expires 2023

•

New patent issued in Europe; expires 2023

•

Patents granted and applications pending in numerous countries

worldwide

Testim Patent Coverage

Note: The referenced Testim patents are owned by CPEX Pharmaceuticals, Inc.

Financials / Strategic Priorities

(NASDAQ: AUXL)

2008

Q2 ’08

1H’08

Guidance

Revenues

$30.9

$58.0

$120-125

R&D Expense

$13.4

$26.6

$52-56

SG&A Expense

$22.2

$43.2

$88-92

Net

Loss

($11.7)

($24.0)

($44-

48)

Stock –

Based

Comp Expense

$2.8

$4.9

$9-11

Cash & cash equivalents

$48.8

2Q08 Financial Results and 2008 Guidance

($ Millions)

(NASDAQ: AUXL)

Strategic Priorities

•

Continue Development of XIAFLEX with a plan to:

–

File Dupuytren’s BLA in early 2009

–

Initiate Phase IIb in Peyronie’s Disease in Q3 2008

–

Continue market research activities; prepare commercial

team

–

Continue development of XIAFLEX in Peyronie’s Disease

and Frozen Shoulder Syndrome indications

•

Continue Driving Testim Growth

(NASDAQ: AUXL)

Poised for Growth

Fastest Growing

TRT product in

the U.S.

Late Stage

Blockbuster

Product

Opportunity