1. EMBARGOED FOR RELEASE UNTIL MONDAY, MAY 16, 2011 AT 10:00 A.M.
Contact: Wendy Waldsachs Isett, AUA
410-977-4770, wisett@AUAnet.org
ABIRATERONE DEMONSTRATES EFFECTIVE RESULTS WITH FAVORABLE SAFETY PROFILE IN MEN WITH
CASTRATION-RESISTANT ADVANCED PROSTATE CANCER
WASHINGTON, DC, May 16, 2011—Abiraterone acetate (AA) with low-dose prednisone (P) extended overall
survival with favorable PSA and radiographic responses in patients with castration-resistant prostate cancer
progressing after docetaxel-based chemotherapy, according to updated data from COU-AA-301, a multi-
institutional, randomized, double-blind, placebo-controlled, phase III study from researchers at 147
institutions across 13 countries. AA is a selective androgen biosynthesis inhibitor that blocks the action of the
CYP17 gene, which plays a vital role in androgen and estrogen biosynthesis.
Data will be presented to the media during a special press conference on Monday, May 16, 2011 at 10:00 a.m.
at the Walter E. Washington Convention Center in Washington, DC, during the 2011 Annual Meeting of the
American Urological Association (AUA). The session will be moderated by Christopher Amling, MD.
The study included 1,195 patients with castration-resistant prostate cancer who had previously undergone
chemotherapy with docetaxel. Patients were randomized 2:1 to receive 1,000 mg AA plus 5 mg P twice daily,
or placebo. Patients were assessed using prostate-specific antigen (PSA) scores and radiographic tests.
The study, of which the primary endpoint was overall survival, demonstrated:
An increase in overall survival by a median of 14.8 months, compared to 10.9 with placebo.
An improved time to PSA progression of 10.2 months
That AA+P reduced the risk of death by 35 percent (HR=0.65) compared with placebo.
AA+P demonstrated a favorable safety profile compared to placebo, with patients experiencing less fatigue (8
percent vs. 10 percent), back pain (6 percent vs. 10 percent) and spinal cord compression (3 percent vs. 5
percent). The most common grade 3/4 adverse events were decreased lymphocyte levels (21 percent vs. 23
percent), fluid retention (2.3 percent vs. 1 percent), hypokalemia (3.9 percent vs. 0.8 percent), liver function
test abnormalities (3.5 percent vs. 3.0 percent), hypertension (1.3 percent vs. 0.3 percent) and cardiac
disorders (4.1 percent vs. 2.3 percent).
“In men with metastatic prostate cancer, hormone therapy typically slows disease progression for a
substantial time. Chemotherapy becomes an option when the disease no longer responds to standard
hormone therapy,” Dr. Amling said. “But what happens when prostate cancer progresses after chemotherapy?

2. By targeting persistent androgen synthesis, these data suggest that abiraterone, combined with low-dose
prednisone, may be an option.”
NOTE TO REPORTERS: Experts are available to discuss this study outside normal briefing times. To arrange
an interview with an expert, please contact the AUA Communications Office at the number above or e-mail
wisett@AUAnet.org.
About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the
American Urological Association is the pre-eminent professional organization for urologists, with more than 17,000
members throughout the world. An educational nonprofit organization, the AUA pursues its mission of fostering the
highest standards of urologic care by carrying out a wide variety of programs for members and their patients.
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3. 705
ABIRATERONE ACETATE PLUS LOW-DOSE PREDNISONE HAS A FAVORABLE SAFETY PROFILE, IMPROVES
SURVIVAL AND PRODUCES PSA AND RADIOGRAPHIC RESPONSES IN METASTATIC CASTRATION-RESISTANT
PROSTATE CANCER PROGRESSING AFTER DOCETAXEL-BASED CHEMOTHERAPY: RESULTS FROM COU-AA-301,
A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE III STUDY
Fred Saad, Johann S. de Bono, Christopher M. Haqq, Christopher J. Logothetis, Karim Fizazi, Robert J. Jones,
Kim N. Chi, Thian Kheoh, Howard I. Scher, Arturo Molina, Montreal, Canada
INTRODUCTION AND OBJECTIVES: Abiraterone acetate (AA) is a selective androgen biosynthesis inhibitor
that blocks the action of CYP17 and potently inhibits persistent androgen synthesis (PAS) from adrenal and
intratumoral sources. Early studies suggested that some castration-resistant prostate cancers (CRPCs) remain
dependent on androgen receptor (AR) signaling. We recently reported that AA + prednisone (P) improves
overall survival in mCRPC progressing after docetaxel (De Bono et al, ESMO 2010). Herein we provide updated
safety outcomes and radiographic and PSA response data from this study.
METHODS: In COU-AA-301 (NCT00638690), pts with docetaxel-treated mCRPC were randomized 2:1 to AA
(1000 mg) + P (5 mg BID) (n=797) or placebo + P (n=398) at 147 centers in 13 countries. Safety assessments
were standard; the primary endpoint was overall survival (OS). PSA and radiographic assessments were
adapted from the PCWG2 criteria (Scher, JCO, 2008).
RESULTS: 1195 patients were enrolled. Based
Efficacy Endpoints for Abiraterone Acetate vs. Placebo
on a pre-specified interim analysis, the IDMC
recommended that the study be unblinded. Endpoint AA (n=797)Placebo (n=398) (95% P Value
HR CI) Efficacy
results are presented in the table below. Grade
OS, median
3/4 adverse events (AEs) occurred in 55% of 14.8 mos 10.9 mos 0.65 (0.54, 0.77)
<0.0001 pts with
AA vs 58% with placebo. Frequently
TTPP, median 10.2 mos 6.6 mos 0.58 (0.46, 0.73)
<0.0001
occurring (> 5%) AEs with AA vs placebo were:
fatigue (8% vs 10%), anemia (7.5% vsrPFS, median
7.4%), 5.6 mos 3.6 mos 0.67 (0.58, 0.78)
<0.0001 back
pain (6% vs 10%), and spinal cord
PSA response
compression (3% vs 5%); the most common 38% 10% - <0.0001 grade
3/4 AEs were decreased lymphocytes (21% responsea 14% (n=55/392) (n=5/181) b (2.1, 12.5)
Objective 2.8% 5.1 <0.0001
vs 23%)
and increased ALP (18% vs 13%). Grade 3/4 AEs of
a
special interest (AA vs placebo) were:RECIST in subjects with measurable disease at baseline; brelative risk.
fluid
retention (2.3% vs 1%), hypokalemia (3.8% vs
0.8%), LFT abnormalities (3.5% vs 3.0%), hypertension (1.3% vs 0.3%), and cardiac disorders (4.1% vs 2.3%).
CONCLUSIONS: AA + P significantly improves OS, TTPP, rPFS, PSA response rate, and radiologic response rate
by RECIST criteria with a favorable safety profile in pts with mCRPC post docetaxel. This trial confirms that AA
provides clinical benefit by targeting PAS and AR signaling following medical/surgical castration and docetaxel
in pts with mCRPC.

4. Source of Funding: Cougar Biotechnology