Inclusion Criteria:

- Patient has given written informed consent before any trial-related activity is
performed.

- Patient is 18 years or older.

- Histologically confirmed prostate cancer.

- Patient has received GnRH receptor agonist therapy for a duration of at least 12
months (the first dose of GnRH-antagonist is to be administered when the next dose of
the GnRH-agonist would have been due).

- Patient has experienced rising PSA levels although receiving GnRH agonist therapy,
defined as two consecutive rises of PSA at least two weeks apart in two 50% increases
over the nadir, and at least one PSA value of >2.5 ng/mL within the last six months.

- Testosterone on castrate level (defined as ≤ 0.5 ng/mL) (cohort 1); Testosterone ≥0.2
ng/mL at inclusion (cohort 2)

- Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2.

- Estimated life expectancy at least 12 months.

Exclusion Criteria:

- Previous history or presence of another malignancy, other than prostate cancer or
treated squamous / basal cell carcinoma of the skin, within the last five years.

- Ongoing GnRH agonist therapy (last dose of previous GnRH agonist must have been
received before Visit 1).

- Any pre-trial secondary hormonal manipulation (including antiandrogens) after PSA
increase as described as above and before trial entry. Antiandrogens as part of
complete androgen blockade must have been discontinued at least three months before
first dose of trial medication.

- Previous or current treatment with chemotherapy (e.g. estramustine) for prostate
cancer.

- Known hypersensitivity towards any component of the investigational medical product.

- History of severe uncontrolled asthma, anaphylactic reactions, or severe urticaria
and/or angioedema.

- Known or suspected clinically significant liver and/or biliary disease.

- Any clinically significant laboratory abnormalities, disorders, or other condition,
including alcohol or drug abuse, which may affect the patient's health or the outcome
of the trial as judged by the Investigator.

- Patient has a clinically significant disorder (other than prostate cancer) including,
but not limited to, renal, hematological, gastrointestinal, endocrine, cardiac,
neurological, or psychiatric disease, and alcohol or drug abuse or any other
condition, which may affect the patient's health or the outcome of the trial as
judged by the Investigator.

- Patient has a mental incapacity or language barriers precluding adequate
understanding or co-operation.

- Patient has received an investigational drug within the last 28 days preceding
screening visit. Or longer if considered to possibly influencing the outcome of the
current trial.

- Previous participation in any degarelix trial.