Safety and Pharmacokinetics of ODM-209

MAIN INCLUSION CRITERIA:

* Written informed consent (IC) obtained.
* Age ≥ 18 years.
* ECOG performance status 0-1.
* Adequate marrow, liver and kidney function.
* Able to swallow study treatment.

Main Prostate cancer specific inclusion criteria:

* Histologically confirmed adenocarcinoma of the prostate.
* Castration resistant prostate cancer with serum testosterone \< 50 ng/dl.
* Metastatic disease.
* Ongoing androgen deprivation therapy with GnRH analogue, or have had bilateral orchiectomy.
* Have had treatment with at least one line of second generation androgen receptor targeting therapy and one line of chemotherapy.

Main Breast cancer specific inclusion criteria:

* Histologically confirmed breast carcinoma
* ER positive, HER2-negative advanced breast cancer
* Postmenopausal or pre/perimenopausal if amendable to be treated with GnRH agonist or antagonist.
* Documented disease progression after treatment with at least 2 lines of systemic treatment for advanced breast cancer. Of these, at least one line must have been endocrine treatment in combination with a cdk4/6 inhibitor.

MAIN EXCLUSION CRITERIA

* History of pituitary dysfunction.
* Known brain metastases or active leptomeningeal disease.
* Active infection or other medical condition that would make corticosteroids contraindicated.
* Hypotension or uncontrolled hypertension.
* Clinically significant cardiovascular disease, e.g. myocardial infarction, arterial thrombotic events, or pulmonary embolism in the past six months, unstable angina, or congestive heart failure (New York Heart Association \[NYHA\] class II-IV).
* Prolonged QTcF interval.
* Use of any investigational drug 4 weeks prior to the start of the study treatment.