AD ASTRA (Androgen Deprivation with Apalutamide and STereotactic RAdiotherapy)

Prior treatment

• Prior treatment with systemic glucocorticoids ≤4 weeks prior to enrollment or subject expected to require long-term use of corticosteroids during the study.
• Use of first-generation antiandrogen (e.g., bicalutamide) ≤4 weeks prior to enrollment.
• Use of 5-α reductase inhibitors (e.g., dutasteride, finasteride) ≤4 weeks prior to enrollment.
• History of seizure or any condition that may predispose to seizure (including, but not limited to prior stroke, transient ischemic attack or loss of consciousness ≤1 year prior to enrollment; brain arteriovenous malformation; or intracranial masses such as schwannomas and meningiomas that are causing edema or mass effect).
• Current or prior treatment with anti-epileptic medications for the treatment of seizures.
• Use of any investigational agent ≤4 weeks prior to enrollment.
• Major surgery ≤4 weeks prior to enrollment.
• Prior treatment with LHRH agonist/antagonist analogue or anti-androgen or both for >3 months prior to enrollment.
• Prior systemic (e.g., chemotherapy) or local (e.g., radical prostatectomy, cryotherapy) treatment for prostate cancer.
• Prior treatment with enzalutamide, abiraterone acetate, orteronel, galeterone, ketoconazole, aminoglutethimide, estrogens, megestrol acetate, and progestational agents (including cyproterone acetate) for prostate cancer.

Other illness

• Presence of distant metastasis on conventional imaging or 68Ga PSMA/PET (clinical stage M1). Isolated pelvic nodal disease below the iliac vessels bifurcation (clinical stage N1) is not an exclusion.
• Gastrointestinal conditions affecting absorption.
• Known or suspected contraindications or hypersensitivity to apalutamide or LHRH agonists/antagonist or any of the components of the formulations.
• Any condition for which, in the opinion of the investigator, participation would not be in the best interest of the subject.
• History of pelvic radiation.

Other

• Current chronic use of opioid analgesics, for ≥3 weeks for oral or ≥7 days for non-oral formulations.
• Bilateral orchiectomy.

• Subject must be a man in the age of 18 – 79 years.
• Each subject must sign an informed consent form (ICF) indicating that he understands the purpose and procedures required for the study and is willing to participate in the study. Subjects must be willing and able to adhere to the prohibitions and restrictions specified in this protocol.
• Indicated and planned to receive primary RT for prostate cancer.
• Histologically confirmed adenocarcinoma of an intact prostate and one of the following risk factors for EUA high-risk localized or locally prostate cancer at diagnosis: • Localized high-risk prostate cancer: PSA >20 ng/mL or GS >7 (ISUP grade 4/5) or cT2c, • Locally advanced high-risk prostate cancer: cT3 – 4 or cN+, any PSA, any ISUP grade; Note: Documentation of clinical T stage (cT2c, cT3, cT4) may be obtained from any clinical assessment acceptable for clinical T staging including digital rectal examination (DRE) and MR. Documentation of N and M stage may be obtained from conventional imaging (technetium bone scan, and prostate MR or abdominopelvic CT) or molecular imaging (68Ga PSMA PET/CT).
• Modified Charlson comorbidity index (CCI) ≤4.
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) grade 0 or 1.
• Adequate organ function determined by the following local laboratory values: • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5x upper limit of normal (ULN); total bilirubin ≤1.5x ULN, • Serum creatinine ≤2x ULN, • Thrombocytes ≥140x10^9/L, • Hemoglobin ≥120 g/L (no transfusion is allowed within 3 months prior to enrollment).
• To avoid risk of drug exposure through the ejaculate (even men with vasectomies), subjects must use a condom during sexual activity while on study drug and for 3 months following the last dose of study drug. Donation of sperm is not allowed during the Treatment Phase and for 3 months following the last dose of study drug.
• Be able to swallow whole study drug tablets, undergo prostate MR, prostate seeds implantation and prostate radiotherapy in supine position.