Xtandi (enzalutamide) is a hormone therapy used for the treatment of advanced prostate cancer. It is used to treat prostate cancer that has not spread, but which no longer responds to therapies designed to lower testosterone. It is also used to treat metastatic prostate cancer or prostate cancer that has spread to other parts of the body.
Five-year survival rates are nearly 100% for men with prostate cancer that has not spread or has only spread locally. However, in cases where prostate cancer has spread to distant sites around the body, the five-year survival rate is 31%.
Xtandi is used to improve overall survival in men with advanced prostate cancer and delay the progression of the cancer.
Xtandi length of treatment - how long can you take it for?
Xtandi comes in the form of a capsule or a tablet, which is taken once a day alongside a gonadotropin-releasing hormone (GnRH) analog or bilateral orchiectomy.
Xtandi is typically taken until prostate cancer starts to progress or spread (metastasize), or until the patient can no longer tolerate therapy because of the side effects or adverse events it causes.
See the table below for details from various clinical trials about the length of time it took patients to show signs of disease progression when treated with Xtandi.
How long is Xtandi effective?
In clinical trials, Xtandi was effective at delaying the time to disease progression in men with advanced prostate cancer. In men who had not received prior treatment with chemotherapy, Xtandi was also effective at delaying the need for treatment with a cytotoxic chemotherapy agent.
During clinical trials radiographic imaging was performed regularly to pick up disease progression. PSA (prostate-specific antigen) levels were also measured.
| Study name | Results |
| PROSPER trial - Xtandi vs placebo in men with non-metastatic castration-resistant prostate cancer (nmCRP) |
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| AFFRIM trial - Xtandi vs placebo in men with metastatic castration resistant prostate cancer (mCRPC) after chemotherapy |
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| PREVAIL trial - Xtandi vs placebo in men with mCRPC who have not have chemotherapy |
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| TERRAIN trial - Xtandi vs Casodex (bicalutamide) in men with mCRPC |
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| ARCHES trial - Xtandi vs placebo in metastatic castration-sensitive prostate cancer (mCSPC) |
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How long does Xtandi extend life?
In the AFFIRM trial, treatment with Xtandi extended life by almost 5 months. Treatment with Xtandi resulted in a median overall survival time of 18.4 months (95% CI 17.3 to not yet reached) compared with 13.6 months (95% CI 11.3 to 15.8) in the placebo recipients (p<0.001). The trial was conducted in men with mCRPC who had previously received chemotherapy.
In the PREVAIL trial, 72% of Xtandi recipients were alive at 12 months compared with 63% of those started on placebo (CI 95% 0.60 to 8.84; p<0.001). The trial was conducted in men with mCRPC who had not received chemotherapy and was stopped at 12 months, by which point Xtandi was shown to be better than placebo.