First Oral Treatment for Metastatic Prostate Cancer that Inhibits Androgen Production at All Three Sources
Toronto, ON, July 28, 2011- Janssen Inc. announced today that after a
priority review, Health Canada has approved ZYTIGA™ (abiraterone
acetate), an oral medication for the treatment of men with metastatic
prostate cancer. ZYTIGA™ is indicated with prednisone for the treatment
of men with metastatic prostate cancer (castration-resistant prostate
cancer) who have received prior chemotherapy containing docetaxel.1
“This approval is an important advancement in the treatment of
metastatic prostate cancer,” said Dr. Scott North, Medical Oncologist,
Cross Cancer Institute, University of Alberta. “For these patients, the
efficacy and safety of ZYTIGA™ will fill an important unmet medical need
for additional treatment options. Most importantly, clinical trial
results demonstrate extended overall survival and improved pain relief. I
believe these benefits provide improved quality of life for many
patients.”
ZYTIGA™: Unique Mechanism of Action
Androgens are hormones that
promote the development and maintenance of male sex characteristics;
however, in prostate cancer, androgens can help fuel tumour growth.
Androgen production primarily occurs in the testes and adrenal glands;
in men with prostate cancer, the tumour itself is an additional source
of androgen. ZYTIGA™ is an androgen biosynthesis inhibitor that inhibits
the CYP17 enzyme complex, which is required for the production of
androgens. It is the first oral treatment for metastatic prostate cancer
that inhibits androgen production at all three sources.
Results of the pivotal Phase 3 study (N=1,195) showed that at the
pre-specified interim analysis, treatment with ZYTIGA™ plus prednisone
resulted in a 35 per cent reduction in the risk of death (14.8 months
vs. 10.9 months [hazard ratio (HR) = 0.646; 95 per cent CI: 0.543,
0.768; p<0.0001]) and a 3.9 month difference in median survival
compared to placebo plus prednisone. In an updated analysis, results
were consistent with those from the interim analysis with a 4.6 month
difference between the two arms in median survival (15.8 months vs. 11.2
months [HR = 0.74]). The study was conducted in 147 centres in 13
countries, including 12 centres in Canada; 154 Canadian men participated
in the study, which represents approximately 13 per cent of the study
population.
“This new treatment is important to me because the oral dosage is
very manageable and convenient and I spend less time in treatment,” said
Richard Pokorny, who has been living with prostate cancer for 11 years.
“I also feel stronger and have more energy, allowing me to do
day-to-day tasks and enjoy quality time with my loved ones as we face
this disease together.”
About Metastatic Prostate Cancer
Metastatic prostate cancer
occurs when cancer has spread beyond the prostate and disease progresses
despite serum testosterone below castrate levels.2
Prostate cancer is the most common cancer to afflict men in Canada,
excluding non-melanoma skin cancer. Approximately 25,500 men are
expected to be diagnosed with prostate cancer in Canada in 2011, and one
in seven Canadian men will develop prostate cancer during his
lifetime.3 The incidence rate of prostate cancer has been increasing
since 1980, likely due to an increased rate of early detection and the
aging population since the chances of developing prostate cancer
increases with age.3 However, according to Prostate Cancer Canada,
prostate cancer is turning up in men in their 40s.4
Ninety per cent of prostate cancer cases are curable if detected and
treated early.4 However, an estimated 4,100 Canadian men will still die
of the disease in 2011.sup>3 On average, 80 Canadian men will die of
prostate cancer every week.3 Fortunately, death rates have been
declining since the mid-1990s, likely due to early detection, better
treatment or both.4
Pivotal Study
ZYTIGA™ with prednisone was evaluated in a Phase
3, randomized, placebo-controlled, multi-centre clinical study in
patients who had received prior chemotherapy containing docetaxel (N =
1,195). Patients were randomized 2:1 to receive ZYTIGA™ 1 gram daily
plus prednisone 10 milligrams (mg) daily or placebo in combination with
prednisone 10 mg daily (control arm).
The most common adverse reactions observed with ZYTIGA™ were
myopathy, joint pain or discomfort, peripheral edema, hot flush,
diarrhea, hypokalemia (low serum potassium), urinary tract infection and
cough. Serious adverse reactions with ZYTIGA™ included urinary tract
infections, bone fracture and hypokalemia.1
About Janssen Inc.
As a member of the Janssen Pharmaceutical
Companies, Janssen Inc. is dedicated to addressing and solving the most
important unmet medical needs in pain management, psychiatry, oncology,
immunology, psoriasis, virology, anemia, attention deficit hyperactivity
disorder, gastroenterology and women’s health. Driven by our commitment
to the passionate pursuit of science for the benefit of patients, we
work together to bring innovative ideas, products and services to
patients around the world.
