How many years has XTANDI been used in prostate cancer patients and how effective is it?

Question

I had surgery for prostate cancer in 2007. I was given radiation therapy in 2008. The cancer recurred in 2017. I have been given ELIGARD injections since that time, which lowered my PSA from 17 to 1. The cancer recurred again in early 2019, the PSA was 7.66. I have been on XTANDI for a year, which has lowered the PSA to 2.36. I am wondering about the median time of effectiveness of the drug? I asked my doctor about this. He said, "We'll see. Can the PSA continue to go down, stay stable, go up slowly, go up suddenly? Thank you for your attention.

Alexandre Marineau · Accepted Answer

Hello, Many studies have been done in relation to the effectiveness of Xtandi based on different factors, including the type of cancer and treatments attempted prior to Xtandi initiation. It is a treatment with which we have a lot of experience and excellent results; it was marketed in 2012 in the United States and has been available in Canada since 2015. The PROSPER study was conducted in patients with non-metastatic prostate cancer that has progressed despite treatment with antihormonal drugs (such as Eligard). The use of enzalutamide (Xtandi) prolongs the median time to metastasis to 36.6 months compared to 14.7 months without treatment. Of note, after the 36.6 months, half of the patients continue to receive treatment. In this same study, the median time to PSA progression from drug use was 37.2 months. PSA variation, on the other hand, is a less good marker of treatment efficacy and monitoring of cancer progression, since its presence and variation are not specific to prostate cancer. Thus, any variation in PSA is possible and its control is not the sole purpose of prostate cancer treatment. Bref, it's hard to predict anything and each case may be different, but I hope this gives you a good idea. :) Happy day!" Jean-Paul Duong, pharmacy student Reviewed by Alexandre Marineau, pharmacist