UK-based drugmaker AstraZeneca and Janssen Pharmaceuticals K.K have entered into a co-promotion agreement for a new oral therapy called abiraterone acetate, a CYP17-inhibitor, to treat prostate cancer patients.
Medical castration is the main treatment option currently available to patients in Japan, but prostate cancer can still progress in many patients due to the production of androgens, hormones which stimulate prostate cancer cells to grow, in other tissues.
Abiraterone acetate marketed as Zytiga in the US and the EU offers an effective alternate option as it slows down the key enzyme which modulates the production of androgens from all sources in the body, reducing the level of androgens available to the prostate cancer cells.
In July, Janssen submitted a marketing approval application for abiraterone acetate to the Japanese Ministry of Health, Labour and Welfare for the treatment of prostate cancer.
Janssen also secured FDA and European Commission approval for abiraterone acetate in April 2011 and September 2011 respectively, to treat patients with metastatic castration-resistant prostate cancer (mCRPC).
AstraZeneca executive vice-president of global products and portfolio strategy Marc Dunoyer said abiraterone acetate being added to the company’s existing portfolio of leading cancer treatments, with real potential will help in addressing an important and growing patient need.
"This deal is a strong strategic fit for AstraZeneca, reinforcing both our focus on oncology as a core therapy area and Japan as one of our key growth drivers," Dunoyer said.
In the US and the EU, abiraterone acetate is used in combination with prednisone (steroid) before and after treatment with docetaxel (chemotherapy) for patients with mCRPC.
In May 2013, Janssen also received Health Canada approval for the once-daily, oral medication Zytiga for use in combination with prednisone for the treatment of mCRPC in patients who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy.
However, it is contraindicated in patients with hypersensitivity to any ingredients of the drug and severe hepatic impairment and in women who are pregnant or may potentially be.
Abiraterone acetate is an androgen biosynthesis inhibitor that inhibits CYP17, an enzyme expressed in testicular, adrenal, and prostatic tumour tissues and is required for androgen biosynthesis.
Image: Micrograph of prostatic adenocarcinoma, conventional (acinar) type. Photo: courtesy of Nephron.