Degarelix

Degarelix is a synthetic decapeptide that blocks the GnRH receptor instead of stimulating it (Firmagon). Because it is an antagonist, testosterone falls from the first dose - there is no flare - which matters in prostate cancer with spinal metastases. It is a prescription medicine given as a monthly subcutaneous injection.

1. 1

   Competitively blocks pituitary GnRH receptors.

2. 2

   LH and FSH release falls within hours rather than weeks.

3. 3

   Testosterone reaches castrate levels within a few days, with no initial surge.

4. 4

   No receptor desensitisation is required, unlike agonists.

5. 5

   Blocks the trophic signal to prostate cancer cells, which depend on androgen receptor signalling.

• Castrate testosterone within about three days, faster than agonists
• Sustained suppression to castrate level over 12 months in trials
• PSA reduction comparable to leuprolide
• Injection-site reactions are the most common adverse effect

1. 01Klotz et al., The efficacy and safety of degarelix: a 12-month comparative study versus leuprolide in patients with prostate cancer, BJU International 2008
2. 02European Medicines Agency - Firmagon product information

References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.