Zytiga - abiraterone acetate

What is Zytiga - abiraterone acetate?

Zytiga is a medicine containing the active substance abiraterone acetate. It is available as tablets (250 mg).

What is Zytiga used for - abiraterone acetate?

Zytiga is indicated for the treatment of prostate cancer (a gland of the male reproductive system) in adult men.

It is used when the carcinoma is metastatic (it has spread to other parts of the body) and when the medical castration (the interruption of the production of male hormones in the body) or the anti-cancer therapies based on docetaxel do not give or cease to give results satisfactory.

Zytiga is given together with prednisone or prednisolone medicines.

The medicine can only be obtained with a prescription.

How is Zytiga used - abiraterone acetate?

Zytiga tablets should be swallowed whole with water at least two hours after a meal. Food cannot be consumed for at least an hour after taking the tablets. The recommended dose is four tablets once a day. In patients who develop liver problems the treatment must be stopped. Treatment can be resumed with a reduced dose of the medicine if the liver function returns to normal, but it must be stopped again if the liver disorders recur.

How does Zytiga - abiraterone acetate work?

The active ingredient in Zytiga, abiraterone acetate, stops the production of testosterone (a male hormone) by the body. Abiraterone acts in this way by blocking an enzyme (a type of protein) called CYP17, which is found in the testicles and other parts of the body. Because the tumor needs a certain amount of testosterone to survive and develop, stopping the production of this abiraterone acetate hormone can slow the growth of prostate cancer.

What studies have been carried out on Zytiga - abiraterone acetate?

The effects of Zytiga were first tested in experimental models before being studied in humans.

Zytiga was compared with placebo (a substance without effects on the body) in a main study involving 1, 195 men with prostate cancer in which the disease worsened despite medical castration or docetaxel-based chemotherapy. Patients were treated with prednisone or prednisolone in combination with Zytiga or placebo. The main measure of effectiveness was overall survival (how long the patients lived).

What benefit has Zytiga - abiraterone acetate shown during the studies?

Patients treated with Zytiga survived for almost 15 months from the start of therapy, while subjects treated with placebo survived for just under 11 months.

What is the risk associated with Zytiga - abiraterone acetate?

The most common side effects of Zytiga (seen in more than 1 patient in 10) were urinary tract infection, hypokalemia (lack of potassium in the blood), hypertension (high blood pressure) and peripheral edema (swelling of the limbs due to retention) of liquids). For the full list of all side effects reported with Zytiga, see the Package Leaflet.

Zytiga should not be used in people who may be hypersensitive (allergic) to the active substance or any of the other substances. The medicine is not intended for use in women and its use is prohibited in fertile or pregnant women.

Why has Zytiga - abiraterone acetate been approved?

The CHMP noted that Zytiga, given in combination with prednisone or prednisolone, improved the survival of patients compared to placebo. The committee is also aware that there are very few alternative therapies for metastatic prostate cancer, which has progressed despite medical castration or docetaxel-based chemotherapy. The committee considered that the way in which Zytiga is administered orally could be an additional benefit of the medicine. Finally, he noted that although the consequences of Zytiga in the liver are still not entirely clear, the main risks are known and manageable. Therefore, the CHMP decided that Zytiga's benefits are greater than its risks and recommended that it be given marketing authorization.