NewsResearch
FDA Approval: Abiraterone (Zytiga) for Prostate Cancer
In April 2011 the FDA approved abiraterone acetate (Zytiga) with prednisone for metastatic castration-resistant prostate cancer after docetaxel chemotherapy. The trial showed people lived longer. Here is what was approved and what it means.
Original commentary from the Cancer Explained editorial team.
Historical context: this page explains an event dated 2011. It was published as an explainer on July 12, 2026 and is not breaking news.
Please note: this page is educational only — it is not medical advice, and it does not speculate about anyone’s health beyond reliable public reporting. For questions about your own health, talk with your healthcare team.
The problem this drug was built for
Prostate cancer usually needs testosterone to grow. The first treatment for advanced disease is to shut that supply down. Doctors call this castration, whether it is done with drugs or surgery.
It works, and then it stops working. When the cancer grows again despite very low testosterone, it is called castration-resistant. For years the assumption was that such tumors had stopped caring about hormones altogether.
They had not. They were making their own.
What FDA approved in April 2011
The 2011 label states the indication in one sentence. Zytiga, in combination with prednisone, is indicated for patients with metastatic castration-resistant prostate cancer who have received prior chemotherapy containing docetaxel.
That is a narrow group. These were men whose cancer had spread, whose hormone treatment had failed, and who had already been through chemotherapy.
The dose is 1,000 mg by mouth once a day, with prednisone 5 mg twice daily. It has to be taken on an empty stomach, with no food for two hours before and one hour after. Those are label figures. The prescription written for you is the one to follow, and the empty-stomach rule is part of it.
Both parts of that pairing come from the label. Take the amounts on your own prescription, and never stop the steroid on your own.
How it works, and why prednisone comes with it
Abiraterone blocks an enzyme called CYP17. That enzyme is a step on the assembly line that makes androgens, the hormone family that includes testosterone. Blocking it cuts off production in the testicles, the adrenal glands, and in the tumor itself.
Cutting that line has a side effect. The adrenal glands respond by making more of a different class of hormone, which drives up blood pressure, holds onto fluid, and lowers potassium. Prednisone is given to damp that response down. It is not an optional add-on. Our overview of prostate cancer explains where hormone treatment fits overall.
The trial
The evidence was a randomized, placebo-controlled phase 3 trial in 1,195 men. They were assigned 2 to 1: 797 received abiraterone with prednisone, and 398 received placebo with prednisone.
The men were typical of this setting. Median age 69. Ninety percent had cancer in their bones, and 30 percent had it in internal organs. Seventy percent had already had one chemotherapy regimen and 30 percent had had two.
The planned interim analysis was done after 552 deaths. Median overall survival was 14.8 months with abiraterone against 10.9 months with placebo. The hazard ratio was 0.646, and the p-value was below 0.0001. An updated analysis after 775 deaths showed 15.8 months against 11.2 months.
Roughly four extra months at the midpoint, in men who had run out of standard options. That was enough for approval, and it changed the sequence of treatment for this disease.
What taking it involves
Side effects follow from the mechanism. The label's warnings cover low potassium, fluid retention, and cardiovascular effects from that hormone shift, along with adrenal insufficiency and liver enzyme rises.
Practically, that means blood tests on a schedule, especially in the first three months, and blood pressure checks. It also means the empty-stomach rule is not a suggestion, since food sharply changes how much drug is absorbed.
The label is also explicit that Zytiga is contraindicated in women who are or may become pregnant, and is not indicated for use in women or children.
Where the drug is now
The label has widened. The current FDA prescribing information lists Zytiga with prednisone for metastatic castration-resistant prostate cancer, and also for metastatic high-risk castration-sensitive prostate cancer, meaning disease still responding to hormone treatment.
The drug moved earlier in the course of the illness, which is the same path many cancer drugs take after an initial approval in late-stage disease.
Prostate cancer, in context
The American Cancer Society projects about 333,830 new prostate cancer cases and 36,320 deaths in the United States in 2026. Five-year relative survival across all stages is 98.2 percent for people diagnosed from 2016 to 2022.
That figure conceals the gap this drug addresses. About 69 percent of cases are found while local and 14 percent regional, both with five-year relative survival of 100.0 percent. About 9 percent are distant at diagnosis, where five-year relative survival is 40.1 percent. Every one of those stage figures rests on the same 2016 to 2022 cohort. These are group averages and do not describe any individual.
When to raise prostate concerns
Screening is a discussion, not a default. The U.S. Preventive Services Task Force says that for men aged 55 to 69, the decision to have periodic PSA testing should be an individual one, made after talking through the benefits and harms with a clinician.
Symptoms are a separate matter. NCI lists trouble starting the flow of urine, frequent urination especially at night, trouble emptying the bladder fully, and a weak or stop-and-go stream. For advanced disease it lists pain in the back, hips, or pelvis that does not go away, along with shortness of breath, tiredness, fast heartbeat, dizziness, or pale skin from anemia. The bone pain matters because this cancer spreads to bone. Our page on prostate cancer symptoms covers what happens next.
What this approval cannot tell you
- Median survival is a midpoint for a group. Half of the men did better than 14.8 months and half did worse.
- Everyone in the trial had already had docetaxel. The result does not transfer to untreated disease on its own.
- Four months at the midpoint is a real gain and a limited one. It is not a cure, and the label makes no such claim.
- The 2011 indication is not the current one. Check the current label rather than this page.
Sources
- FDA approval package, NDA 202379 (ZYTIGA), April 2011
- FDA prescribing information, ZYTIGA, 2011
- FDA prescribing information, ZYTIGA, current label
- NCI drug information: Abiraterone Acetate
- NCI: Prostate Cancer Treatment (PDQ) — Patient Version
- USPSTF: Prostate Cancer Screening recommendation
- SEER Cancer Stat Facts: Prostate Cancer
How this page was made
An AI-assisted editorial system helped prepare this page. This article has not been reviewed by a healthcare professional unless a named reviewer is specifically shown. Cancer Explained is published by the National Cancer Information Foundation as a nonprofit-oriented public-interest education project. It is not a diagnostic service, does not recommend treatments, and is not for emergencies.
Found an error, a broken source link, outdated information, or wording that feels insensitive? Report it here — we log and act on material corrections.
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Put the story in context
Prevention, possible warning signs, screening, and diagnosis
This story relates to Prostate cancer. The information below is general: it does not reveal anything else about a public person’s health, and not every point applies to every cancer. Personal advice depends on age, symptoms, family history, exposures, and medical history.
Prevention and risk reduction
Not every cancer can be prevented. Avoiding tobacco, protecting skin from ultraviolet radiation, limiting alcohol, staying active, and receiving recommended HPV or hepatitis B vaccination can lower the risk of certain cancers. A risk factor is not a prediction or a cause in one individual.
Symptoms and possible early signs
Possible signs vary and are often caused by conditions other than cancer. Changes worth discussing include a new lump, unexplained bleeding or weight loss, a persistent cough, lasting bowel or bladder changes, a changing skin spot, or symptoms that persist or worsen. Some early cancers cause no symptoms.
Screening and early detection
Screening looks for certain cancers before symptoms begin. Recommended tests exist only for some cancers and depend on age and risk. Screening can have benefits and harms; it is not the same as evaluating a new symptom, and there is no single routine scan or blood test that reliably screens for every cancer.
How cancer is diagnosed
Diagnosis may involve a history and exam, imaging, laboratory tests, and often a biopsy. Pathology can identify the cancer type and may test biomarkers that guide treatment. Symptoms, screening results, tumor markers, or online stories alone cannot confirm cancer.
Learn about this story’s cancer topic
A public story may encourage questions, but it should not be used to estimate your risk or choose testing. Contact a healthcare professional about a persistent or concerning change. Seek urgent care for severe or rapidly worsening symptoms.