Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Prostate cancer drug reduces testosterone levels in as little as three days without initial hormone surge

03.12.2008
More than 95 per cent of men who took degarelix for prostate cancer saw their testosterone levels fall dramatically as early as three days after they started treatment, according to a paper in the December issue of BJU International.

They also experienced much greater falls in their prostate-specific antigen (PSA) levels at 14 and 28 days than men taking leuprolide.

Researchers from Canada, the USA, France, Denmark and the Netherlands studied 610 men as part of the Phase Three trial, randomly assigning them to one of three study groups.

“Androgen deprivation hormone therapy is an effective response to prostate cancer, but the drugs that are most widely used cause an initial rise in testosterone - the hormone we are trying to reduce - when the patient first takes them” explains lead author Dr Laurence Klotz from the Division of Urology at the University of Toronto, Canada.

“We prefer to avoid this biochemical surge as it can stimulate the prostate cancer cells and exacerbate a number of clinical symptoms, such as spinal cord compression and bone pain. It could also result in more rapid growth of microscopic disease that is present in the patient but is too small to be detected.

“Degarelix is a new gonadotrophin-releasing hormone (GnRH) antagonist. It works by binding to, and blocking, the GnRH receptors in the pituitary gland, reducing the amount of LH and FSH hormones that are released. This leads directly to a rapid fall in testosterone.”

Group one (207 patients) received an injection of 240mg of degarelix in month one, followed by a maintenance dose of 80mg every month for eleven months and group two (202 patients) received 240mg of degarelix in month one followed by a maintenance dose of 160mg for eleven months.

The third group (201 patients) received a monthly 7.5mg dose of leuprolide, which is a GnRH agonist.

At the start of the trial the study participants had a median testosterone level of 3.93 ng/mL. The aim was to reduce this to 0.5ng/mL or less at all monthly measurements from day 28 to day 364.

Eight out of ten study participants completed the trial (504 patients) between February 2006 and October 2007, with similar drop-out and exclusion rates in all three groups.

The key findings were impressive:

•Three days after starting their treatment regimes, 96.1 per cent of the patients on 240/80mg degarelix and 95.5 per cent of the patients on 240/160mg degarelix had achieved a testosterone level of 0.5ng/mL or less. In contrast, median testosterone levels in the leuprolide group had increased by 65 per cent by day three, but had reduced by day 28.

•At the end of the study period, 98.3 per cent of the 240/160mg degarelix group and 97.2 per cent of the 240/80mg degarelix group had achieved a testosterone level of 0.5ng/mL or less. The figure for the leuprolide group was 96.4 per cent.

•PSA levels fell much faster in the degarelix groups when measured at 14 and 28 days – by 64 per cent and 85 per cent in the degarelix 240/80mg group, 65 per cent and 83 per cent in the 240/160mg degarelix group and 18 per cent and 68 per cent in the leuprolide group.

The hormonal side-effects experienced by the three treatment groups were similar to previously reported effects for androgen deprivation hormone therapy.

Patients receiving degarelix were much more likely to experience injection-site reactions than those receiving leuprolide (40 per cent compared to one per cent).

However degarelix patients suffered fewer urinary tract infections than those in the leuprolide group (three per cent versus nine per cent) together with fewer joint pains and chills (four per cent versus nine per cent).

“More than 2,000 patients have now taken part in clinical trials for degarelix and there have been no signs of immediate or late-onset systemic allergic reactions, in contrast to other reported trials of other GnRH antagonists” points out Dr Klotz.

“The aim of the study was to show that degarelix was not inferior to leuprolide when it came to maintaining low testosterone levels over a one-year treatment period. We have conclusively shown that this is the case.

“However, we have also demonstrated that degarelix - which is an antagonist - offers an advantage, in that it reduces testosterone and PSA levels very quickly. It doesn’t cause the initial surge of testosterone seen with agonist drugs like leuprolide - the other drug featured in this study.

“This is relevant as biochemical surges in testosterone can stimulate the prostate cancer cells and cause unpleasant side effects for patients. They may also require further drug therapy to counteract the effects of agonist drugs like leuprolide.”

Annette Whibley | alfa
Further information:
http://www.bjui.org

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>