| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated | 
| Metastatic Hormone-sensitive Prostate Cancer (mHSPC) |  | 
| E.1.1.1 | Medical condition in easily understood language |  | 
| E.1.1.2 | Therapeutic area | Diseases [C] - Cancer [C04] | 
| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| 
| E.1.2 | Version | 21.1 |  
| E.1.2 | Level | PT |  
| E.1.2 | Classification code | 10036909 |  
| E.1.2 | Term | Prostate cancer metastatic |  
| E.1.2 | System Organ Class | 10029104 - Neoplasms benign, malignant and unspecified (incl cysts and polyps) |  | 
| E.1.3 | Condition being studied is a rare disease | No | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| The primary objective is to determine if the addition of apalutamide to ADT provides superior efficacy in improving radiographic progression-free survival (rPFS) or overall survival (OS) for subjects with mHSPC. |  | 
| E.2.2 | Secondary objectives of the trial | 
| *To evaluate clinically relevant improvements with addition of apalutamide to ADT including delays in pain progression and opioid use for prostate cancer,  skeletal-related events, and the need for cytotoxic chemotherapy *To characterize the safety of adding apalutamide to ADT in subjects with low-volume mHSPC
 *To characterize the population pharmacokinetics (PK) and pharmacodynamics  (PD) of apalutamide
 *To evaluate the concentration of leuprolide and assess the PD effect of leuprolide on testosterone concentrations when used alone or in combination with apalutamide
 *To evaluate the treatment effectiveness with the addition of
 Apalutamide to ADT for the subpopulations of subjects with mHSPC
 |  | 
| E.2.3 | Trial contains a sub-study | Yes | 
| E.2.3.1 | Full title, date and version of each sub-study and their related objectives | 
| Title of sub-study: Leuprolide PK Sub-study (Please refer to Attachment 5 in the protocol) Objective of sub-study: To collect pharmacokinetic samples from at least 60 subjects who received or will receive leuprolide acetate as the GnRHa at the time of randomization for analysis of leuprolide and testosterone concentrations
 |  | 
| E.3 | Principal inclusion criteria | 
| - Diagnosis of prostate adenocarcinoma as confirmed by the investigator - Metastatic disease documented by greater than or equal to (>=) 1
 bone lesions on 99mTc bone scan. Participants with a single bone lesion must have confirmation of bone metastasis by computed tomography (CT) or magnetic resonance imaging (MRI)
 - Eastern Cooperative Oncology Group Performance Status (ECOG PS) grade of 0 or 1
 - Participants who received docetaxel treatment must meet the following criteria:
 a) Received a maximum of 6 cycles of docetaxel therapy for mHSPC;
 b) Received the last dose of docetaxel <=2 months prior to
 randomization;
 c) Maintained a response to docetaxel of stable disease or better, by investigator assessment of imaging and PSA, prior to randomization
 - Other allowed prior treatment for mHSPC:
 a) Maximum of 1 course of radiation or surgical intervention; radiation therapy for metastatic lesions must be completed prior to
 randomization;
 b) Less than or equal to (<=) 6 months of ADT prior to randomization
 - Allowed prior treatments for localized prostate cancer (all treatments must have been completed >= 1 year prior to randomization)
 a) <= 3 years total of ADT;
 b) All other forms of prior therapies including radiation therapy,
 prostatectomy, lymph node dissection and systemic therapies
 |  | 
| E.4 | Principal exclusion criteria | 
| - Pathological finding consistent with small cell, ductal or neuroendocrine carcinoma of the prostate - Known brain metastases
 - Lymph nodes as only sites of metastases
 - Visceral (ie, liver or lung) metastases as only sites of metastases
 - Other prior malignancy less than or equal to 5 years prior to
 randomization with the exception of squamous or basal cell skin
 carcinoma or noninvasive superficial bladder cancer
 - Prior treatment with other next generation anti-androgens or other CYP17 inhibitors, immunotherapy or radiopharmaceutical agents for prostate cancer
 - History of seizures or medications known to lower seizure threshold
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| - Radiographic Progression-Free Survival (rPFS) - Overall Survival (OS)
 |  | 
| E.5.1.1 | Timepoint(s) of evaluation of this end point | 
| - Up to 54 Months - Up to 54 Months
 |  | 
| E.5.2 | Secondary end point(s) | 
| - Time to Pain Progression - Time to Skeletal-Related Event (SRE)
 - Time to Chronic Opioid Use
 - Time to Initiation of Cytotoxic Chemotherapy
 |  | 
| E.5.2.1 | Timepoint(s) of evaluation of this end point | 
| - Up to 54 Months - Up to 54 Months
 - Up to 54 Months
 - Up to 54 Months
 |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | No | 
| E.6.4 | Safety | Yes | 
| E.6.5 | Efficacy | Yes | 
| E.6.6 | Pharmacokinetic | Yes | 
| E.6.7 | Pharmacodynamic | Yes | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | No | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | No | 
| E.6.13 | Others | Yes | 
| E.6.13.1 | Other scope of the trial description | 
| Biomarkers and tumour response assessments |  | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | No | 
| E.7.1.2 | Bioequivalence study | No | 
| E.7.1.3 | Other | No | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | No | 
| E.7.3 | Therapeutic confirmatory (Phase III) | Yes | 
| E.7.4 | Therapeutic use (Phase IV) | No | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | Yes | 
| E.8.1.1 | Randomised | Yes | 
| E.8.1.2 | Open | No | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | Yes | 
| E.8.1.5 | Parallel group | No | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | No | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | Yes | 
| E.8.2.3 | Other | No | 
| E.8.2.4 | Number of treatment arms in the trial | 2 | 
| E.8.3 | The trial involves single site in the Member State concerned | No | 
| E.8.4 | The trial involves multiple sites in the Member State concerned | Yes | 
| E.8.4.1 | Number of sites anticipated in Member State concerned | 12 | 
| E.8.5 | The trial involves multiple Member States | Yes | 
| E.8.5.1 | Number of sites anticipated in the EEA | 100 | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA | Yes | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | No | 
| E.8.6.3 | If E.8.6.1 or E.8.6.2 are Yes, specify the regions in which trial sites are planned | 
| Argentina |  
| Australia |  
| Brazil |  
| China |  
| Czechia |  
| France |  
| Germany |  
| Hungary |  
| Israel |  
| Italy |  
| Japan |  
| Korea, Republic of |  
| Mexico |  
| Poland |  
| Romania |  
| Russian Federation |  
| Spain |  
| Sweden |  
| Turkey |  
| Ukraine |  
| United States |  | 
| E.8.7 | Trial has a data monitoring committee | Yes | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial | 
| EoT Visit is within 30 days after the last dose of study drug for all subjects. |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 6 | 
| E.8.9.1 | In the Member State concerned months | 7 | 
| E.8.9.1 | In the Member State concerned days | 27 | 
| E.8.9.2 | In all countries concerned by the trial years | 6 | 
| E.8.9.2 | In all countries concerned by the trial months | 7 | 
| E.8.9.2 | In all countries concerned by the trial days | 27 |