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Abiraterone & Prostate cancer |
The results of a trial of new drug called abiraterone have been published involving men with advanced metastatic advanced prostate cancer. This was a phase 3 study to comparing the clinical benefit of abiraterone acetate plus prednisone with placebo plus prednisone in patients with metastatic castration-resistant prostate cancer. It was published in the Journal of Clinical Oncology and involved men with prostate cancer (CRPC) who have already received hormones for their disease failed one or two chemotherapy regimens. At least one of the previous chemotherapies must have contained docetaxel
How does abiraterone work? It blocks the formation of the male hormone testosterone by inhibiting an enzyme called CYP450c17, also known as 17α-hydroxylase/17,20 lyase. This enzyme is involved in the formation of DHEA, which ultimately is metabolized into testosterone.
The Primary Outcome Measure of the trial was overall survival and the secondary outcome measures was the proportion of patients achieving a PSA decline ≥ 50% according to Prostate Specific Antigen Working Group (PSAWG) criteria. Men in this and another similar study were given 1000mg of abiraterone daily.
The results showed that in this category of disease abiraterone lowered PSA, it shrank the size of tumours and doubled their rate of survival. (in effect about by about 3 months).
These are promising results but further tests are necessary. Only through well conducted research will we be able to truly know the full benefit of this drug. Cougar Biotechnology Inc. of Los Angeles, the company which owns abiraterone, expects the drug to reach the market in 2011. In the mean time it is only available in a trial setting. (About clinical trails)
Information
on the latest UK Abiraterone trial
(starting august 2008).
A number of UK research centres are involved in a new trial of abiraterone, including Addenbrookes Hospital Cambridge and the Royal Marsden Hospital London. This is a Double blind placebo controlled (2:1 in favour of abiraterone) trial of placebo plus prednisone versus abiraterone acetate plus prednisone.
Eligibility
Histologically/cytologocally proven adenocarcinoma of the prostate without neuroendocrine differentiation or small cell histology.
At least 1 but not more than 2 chemotherapy regimes for metastatic castration-resistant prostate cancer. 1 regime must have contained docetaxel. (Docetaxel plus docetaxel retreatment is considered as a single chemotherapy regime).
PSA progression and/or progressive soft tissue metastases and/or 2 or more new lesions on a bone scan.
On-going androgen deprivation.
ECOG 0, 1, 2.
Hb>=9.0, Plt >= 100, Alb>=30g/L, creatinine<1.5xULN, K+>=3.5mmol/L
Able to swallow tablet whole.
Main exclusion
Serious comorbidity
Elevated LFT’s: bilirubin>=1.5xULN, ALT/AST>=2.5xULN
Uncontrolled HT.
Brain mets.
Prior treatment with abiraterone.
Prior treatment with ketoconazole.
Radiotherapy, chemotherapy or immunotherapy within 30 days of prospective first dose abiraterone. Single fraction RT within 14 days first dose.
4 tablets daily throughout 28 day cycles. See day 1 and 15 first cycle and then day 1 each subsequent cycle. Rescan every 12 weeks. Treatment is ongoing until study end-point is reached.
Other comments – if you have been randomised to placebo, it is not possible to then crossover to abiraterone.
More about Prostate cancer:
Presenting
symptoms: Possible symptoms of prostate cancer include blood in the urine or
semen, pain and trouble passing urine, frequent urination (find out
more).
UK incidence: The risk of this condition increases with the age, generally men over the age of 50 are affected. In the UK nearly 32,000 men are diagnosed every year with prostate cancer which causes more than 10,000 deaths every year. Overall, one men in fourteen will get prostate cancer at some point in his life.
Types: Although there are several cell types in the prostate, nearly all prostate cancers start in the gland cells. This kind of malignancy is known as adenocarcinoma (find out more).
Risks factors: Most cases of this condition are diagnosed in men over the age of 65. There are usually no predisposing risk factors but there is some evidence of associations with a previous poor diet (high in fat, low in fruits and vegetables), being a black male, men who have a strong family history of the disease are at greater risk. (find out more)
Tests to determine a diagnosis and help decide on treatment options: Prostate-Specific Antigen (PSA) blood test, Digital Rectal Examination (DRE), transrectal ultrasound (TRUS), biopsy (find out more)
What determines the treatment options and prognosis:
Treatment options (find out more): Prostate cancer can often grow very slowly and most men with this diagnosis live their lives without it causing any problems to them. Therefore there is a lot to consider when deciding the best way to treat prostate cancer. It may take more than one visit to your doctor to discuss all your concerns and you may want to consider getting a second opinion. Make sure all your concerns and questions have been answered before you decide on a treatment. Your treatment plan may involve one or a combination of treatments:
Click for prostate cancer UK clinical guidelines
Further information: Your doctors and specialist nurses are in an ideal position to give information relevant to your situation. Macmillan has a help line and a prize winning video available in English UK ethnic languages explaining Radiotherapy & Chemotherapy. Cancernet.co.uk is a complete cancer information resource written by an experienced team of doctors, health professionals and patients. It will help you make informed decisions and guide you through the cancer journey including information about: Optimum treatment of specific cancers: e.g.Breast | Prostate | Bowel. Common treatments: Chemotherapy | Radiotherapy | Hormones | Biological agents | Complementary. Lifestyle and cancer: Books based on the facts | Exercise | Diet | Smoking | Sunbathing | Alcohol. Tip to help with the symptoms of cancer and side effects of treatments. Financial issues: Traveling and cancer | Travel insurance | Links to support groups | Books | Videos | Glossary | About us | Disclaimer | Tests for cancer | Clinical trials | What is cancer | How to avoid cancer