Prostate cancer is cancer of the prostate gland (a small organ in a man’s pelvis) and is the second most common cancer in the UK. There are three stages: localised, locally‐advanced and advanced (or metastatic) prostate cancer. The symptoms may vary depending on the stage of cancer but can include pain, tiredness, problems emptying the bladder and the bowels. About half of men diagnosed with locally‐advanced prostate cancer will see their cancer spread to other body organs (i.e. becoming metastatic). Prostate cancer growth and spread depends on the hormone, testosterone. Cancer that do not respond to hormonal treatment to reduce the level of testosterone are known as castrationresistant prostate cancer.
Darolutamide is a hormonal drug under development for castration resistant prostate cancer that has not spread (non‐metastatic). It acts by blocking testosterone receptors from getting activated on the cancer cells and consequently reducing the size of the cancer. Darolutamide is taken orally twice a day. If licenced, darolutamide will provide an additional treatment option for men with non‐metastatic castration‐resistant prostate cancer that are at high risk of their cancer spreading to other parts of the body.
Triptorelin is being developed as an injection under the skin (subcutaneous) for the treatment of locally advanced or metastatic prostate cancer. It is already marketed for this condition but is given by injection deep into the muscles (intramuscular). Triptorelin is an artificial analogue of natural gonadotropin‐releasing hormone that acts to slowly reduce the level of testosterone in the body. The first administration of triptorelin stimulates an increase in testosterone levels but prolonged administration leads to a fall in plasma testosterone or oestradiol to castrate levels which is maintained for as long as the product is administered. Triptorelin as a subcutaneous injection formulation has the potential advantage of improved safety and local tolerability when compared to intramuscular injection formulation.