A Study to Determine Enzalutamide Long-term Safety and Efficacy After Anti-androgen Therapy for CRPC

A Study to Determine Enzalutamide Long-term Safety and Efficacy After Anti-androgen Therapy for CRPC

This is a prospective observational study to evaluate effectiveness and safety of Enzalutamide for Castration Resistant Prostate Cancer (CRPC) patients who decided to administer Enzalutamide after anti-androgen therapy.

CRPC Patients who are observed PSA or disease progression after anti-androgen therapy and decided to administrate Enzalutamide will dose the Enzalutamide 160 mg orally once daily and observed the practical treatment. Total research term is for 4 years, consists of 2-year case registration terms and 2-year observational terms.

Inclusion Criteria:

1. Patients with histologically or cytologically confirmed prostate cancer.

2. Patients who are receiving or received continuous androgen deprivation therapy using both gonadotropin-releasing hormone (GnRH) agonist and antagonist (medical castration), or both testicles removal by surgery (surgical castration).

3. Castration resistant prostate cancer (CRPC) patients who are observed disease progression after castration treatment and implied the treatment resistant.

4. CRPC patients who conducted anti-androgen alternating therapy as shown below 1) and are observed one or more of disease progression shown as below 2) during or after the therapy and decided to administer enzalutamide.

   Note 1) anti-androgen alternating therapy is defined as the therapy of flutamide administration after bicalutamide.

   Note 2) Disease progression criteria during or after anti-androgen alternating therapy

   ① PSA progression during or after anti-androgen alternating therapy: PSA increased more than 25% compare to the lowest test results after initial dose of anti-androgen alternating therapy (flutamide) and the increasing is more than 2ng/ml.

   ②Confirmed disease progression of soft tissue lesion defined as RECIST v1.1.

   ③Confirmed disease progression of bone lesion defined as 2 or more of new appearance of bone lesion on bone scintigraphy.

5. Patients with the Eastern Cooperative Oncology Group (ECOG) performance status 0-2

6. Patients who have signed written informed consent to participate in this study

Exclusion Criteria:

1. Patients who is administering or have administration history of enzalutamide, abiraterone, docetaxel or cabazitaxel
2. Patients with history of seizure or predisposing disease of seizure
3. Patients with severe liver dysfunction
4. Patients with a previous history of hypersensitivity to any component of drugs which will be administered in this study
5. Patients who considered to be inappropriate for the study participation by the investigator