Clinical Trials List
Protocol Number5541-CL-0201
Active
2025-06-30 - 2032-05-01
Phase II
Recruiting6
A phase 2, open-label, multi-population trial evaluating the efficacy and safety of ASP5541 in participants with advanced prostate cancer.
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Trial Applicant
Astellas Pharma Inc.
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Sponsor
Taiwan Astellas Pharmaceutical Co., Ltd.
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Trial scale
Multi-Regional Multi-Center
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Update
2026/07/24
Investigators and Locations
Co-Principal Investigator
- Chuan-Shu Chen 無
- Cheng-Kuang Yang 無
- Cheng-Che Chen 無
- 裘坤元 無
- Chia-Yen Lin 無
- 洪晟鈞 無
- 梅承恩 無
- 林雁婷 無
- 蔡世傳 無
- Jian-Ri Li 無
- 張瓈文 無
- JU-CHUAN HU 無
- 賴谷順 無
- 張家程 無
- 楊涵中 無
- 楊哲瑞 無
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
- - - 無
- Yu-Chieh Tsai 無
- 闕士傑 無
- CHUNG-HSIN CHEN 無
- JHE-CYUAN GUO 無
- YU-CHUAN LU 無
- CHING-CHU LU 無
- FU-JEN HSUEH 無
- YEN-HENG LIN 無
- PO-MING CHOW 無
- 王中傑 無
- JIAN-HUA HONG 無
- 吳婉禎 無
- 曾啟新 無
- 莊建淮 無
- 邱士庭 無
- 董牧喬 無
The Actual Total Number of Participants Enrolled
0 Recruiting
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
- Chao-Hsiang Chang 無
- Chi-Ping Huang 無
- Wei-Ching Lin 無
- Yi-Huei Chang 無
- Han Chang 無
- Chi-Rei Yang 無
- Po-Fan Hsieh 無
- 謝德鈞 無
- 蔡禮賢 無
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
- 李明儒 無
- Wen-Jeng Wu 無
- Hsiang Ying Lee 無
- Ching-Chia Li 無
- 阮雍順 無
- Hsin-Chih Yeh 無
- 張顥瀚 無
The Actual Total Number of Participants Enrolled
0 Recruiting
Principal Investigator
See-Tong Pang
Co-Principal Investigator
The Actual Total Number of Participants Enrolled
0 Recruiting
Condition/Disease
* Percentage of mCRPC participants who have not used ARPI and whose PSA has decreased by ≥90% from baseline.* Incidence of no mineral corticosteroid toxicity (defined as no ≥ Grade 1 hypokalemia and no ≥ Grade 2 hypertension).* Percentage of mHSPC participants with PSA ≤ 0.2 ng/mL at 8 months.* DLT, AE, SAE, laboratory test results (including chemistry, hematology, and urinalysis), ECG, vital signs, physical examination, and ECOG performance status score.
Objectives
*Primary Objectives:
• Evaluate the efficacy of ASP5541 + pred compared to AA + pred in ARPI-naïve mCRPC participants (Group 1).
• Evaluate the safety of ASP5541 without steroids (Group 2 safety assessment) in ARPI-naïve mHSPC participants.
• Evaluate the efficacy of ASP5541 without steroids compared to AA + pred in ARPI-naïve mHSPC participants (Group 2).
• Evaluate the safety of ASP5541 + pred in Japanese mCRPC or mHSPC participants (Group 3).
*Secondary Objectives:
• Further evaluate the efficacy of ASP5541 with and without pred compared to AA + pred.
• Evaluate the safety of ASP5541 with and without pred compared to AA + pred.
• Evaluate the safety of ASP5541 with and without pred. Pharmacodynamic properties of ASP5541 with and without pred compared to AA + pred
• Evaluate pain exacerbation after ASP5541 administration compared to AA + pred
*Exploratory objectives:
• Further evaluate other efficacy endpoints of ASP5541 administration compared to AA + pred with and without pred
• Evaluate the pharmacokinetic properties of ASP5541 and AA
• Evaluate disease-related symptoms and HRQoL based on PRO
• Evaluate the overall side effect impact of the trial treatment using the EORTC tolerability program
• Further evaluate the pharmacodynamic properties of ASP5541 administration compared to AA + pred with and without pred
• Evaluate the effect of ASP5541 administration compared to AA + pred
Biologically relevant potential blood or tumor biomarkers that may be correlated with treatment outcomes
• Analysis or assessment of genes associated with clinical response, pharmacokinetics and/or toxicity/safety and/or disease (related to selective pharmacogenomics trials)
• Assessment of participants' past or future achievable health status using real-world data sources in the United States
Test Drug
"Chengda" Prednisone Tablets 5 mg (Penisol)
"Boli" Concentrate Tablets 5 mg (Penisol)
Abiraterone acetate
ASP5541 (Abiraterone decanoate)
Cosyntropin
Prednisone
Abiraterone Tablets 250 mg
Prednisone Tablets
Erezhi Film-Coated Tablets 250 mg
Lerdan Tablets
"Boli" Concentrate Tablets 5 mg (Penisol)
Abiraterone acetate
ASP5541 (Abiraterone decanoate)
Cosyntropin
Prednisone
Abiraterone Tablets 250 mg
Prednisone Tablets
Erezhi Film-Coated Tablets 250 mg
Lerdan Tablets
Active Ingredient
PREDNISOLONE
PREDNISOLONE
Abiraterone Acetate
Abiraterone Acetate
tetracosactide
PREDNISONE
Abiraterone Acetate
PREDNISOLONE
Abiraterone Acetate
PREDNISOLONE
PREDNISOLONE
Abiraterone Acetate
Abiraterone Acetate
tetracosactide
PREDNISONE
Abiraterone Acetate
PREDNISOLONE
Abiraterone Acetate
PREDNISOLONE
Dosage Form
Tablets
Tablets
Tablets
Injection Solution
Frozen Crystal Powder for Injection
Tablets
Tablets
Tablets
Tablets
Tablets
Tablets
Injection Solution
Frozen Crystal Powder for Injection
Tablets
Tablets
Tablets
Tablets
Dosage
5 MG
5 MG
250 MG
900 mg in 5 mL of solution in 10 mL vial
250 ug
5 MG
250 MG
5 MG
250 MG
5 MG
5 MG
250 MG
900 mg in 5 mL of solution in 10 mL vial
250 ug
5 MG
250 MG
5 MG
250 MG
5 MG
Endpoints
* Proportion of mCRPC participants who have not used ARPI and whose PSA has decreased by ≥90% from baseline
* Incidence of no mineral corticosteroid toxicity (defined as no ≥ Grade 1 hypokalemia and no ≥ Grade 2 hypertension)
* Proportion of mHSPC participants with PSA ≤ 0.2 ng/mL at 8 months
* DLT, AE, SAE, laboratory test results (including chemistry, hematology, and urinalysis), ECG, vital signs, physical examination, and ECOG performance status score
* Incidence of no mineral corticosteroid toxicity (defined as no ≥ Grade 1 hypokalemia and no ≥ Grade 2 hypertension)
* Proportion of mHSPC participants with PSA ≤ 0.2 ng/mL at 8 months
* DLT, AE, SAE, laboratory test results (including chemistry, hematology, and urinalysis), ECG, vital signs, physical examination, and ECOG performance status score
Inclution Criteria
Age
1. Male, and at least 18 years old at the time of consent.
Participant Type and Disease Characteristics
2. You have been diagnosed with histologically or cytologically confirmed prostate cancer without neuroendocrine differentiation or small cell characteristics.
3. Your East Coast Cancer Clinical Research Partnership (ECOG) performance status is 0 or 1, or 2 due to bone pain.
4. If you have metastatic hormone-sensitive prostate cancer (mHSPC), your estimated life expectancy must be ≥ 12 months, or if you have metastatic castration-resistant prostate cancer (mCRPC), it must be > 6 months.
5. Based on the trial administrator's assessment, you are able to understand and follow all trial requirements and procedures, including completing the Patient Reported Outcomes (PRO) questionnaire.
Gender and Contraception Requirements
6. Male Participants:
● Must agree to use a clearly defined form of contraception with a female partner of childbearing potential (including breastfeeding partners) throughout the treatment period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention.
● Must agree to maintain abstinence or condom use throughout the trial period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention, during the pregnancy of a pregnant partner.
● Must not donate sperm during the treatment period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention.
Informed Consent
7. You have provided informed consent, including compliance with the requirements and restrictions listed in the Participant Consent Form (ICF) and the trial plan.
Other Inclusion Criteria
8. You have adequate gluteal muscle mass for intramuscular injection.
9. You agree not to participate in another study trial while receiving ASP5541 in this trial.
10. If not supplemented at screening, your serum potassium should be normal (3.5 to 5.5 mEq/L, or within the normal range at your local laboratory).
Inclusion criteria for Group 1: mCRPC participants who have not previously used androgen receptor pathway inhibitors (ARPIs) and received ASP5541 + pred + ADT or AA + pred + ADT.
11. You have been diagnosed with mCRPC, confirmed by a record of metastatic lesions on a bone scan, computed tomography (CT), magnetic resonance imaging (MRI), or prostate-specific cell membrane antigen positron emission tomography (PSMA-PET).
12. You have evidence of disease exacerbation, defined as meeting at least one of the following criteria at the time of participation in the trial.
● Evidence of disease progression on radiographic imaging prior to the first dose and most recent prostate cancer treatment is defined as disease progression (PD) on CT/MRI scans assessed by the trial administrator according to the Solid Tumor Response Assessment Criteria, version 1.1 (RECIST v1.1), or on bone scans assessed according to the Prostate Cancer Working Group 3 (PCWG3).
● Prostate-specific antigen (PSA) progression is defined as an increase in PSA of at least 25% from the lowest value and ≥ 1 ng/cc, confirmed by a second measurement at least 1 week later, with at least one measurement obtained within 90 days prior to screening. The lowest PSA value is defined as the lowest PSA level during or after the most recent treatment period.
13. You are currently receiving ongoing ADT using a gonadotropin-releasing hormone (GnRH) analogue, or have previously undergone bilateral orchiectomy (i.e., surgical or medical castration).
Note: If you have not undergone bilateral orchiectomy, you must plan to maintain effective GnRH analog therapy throughout the trial.
14. At the screening follow-up, your serum testosterone concentration is < 1.73 nmol/L (< 50 ng/dL).
15. You are able to swallow AA.
Inclusion criteria for Group 2: mHSPC participants who have not used ARPIs and are receiving ASP5541 + ADT or AA + pred + ADT.
16. You have been diagnosed with mHSPC, confirmed by a record of metastatic lesions on a bone scan, CT, MRI, or PSMA-PET.
17. You must have started castration therapy (i.e., medical or surgical) at least 14 days prior to Day 1 of Cycle 1.
Note: If you have not undergone bilateral orchiectomy, you must plan to maintain effective GnRH analog therapy throughout the trial.
18. Your baseline morning serum cortisol level should be ≥ 14 mcg/dL.
19. You are able to swallow AA.
20. For groups B and C, you have available primary (preferably) or metastatic (excluding bone) tumor tissue, the source and availability of which have been confirmed prior to trial treatment.
1. Male, and at least 18 years old at the time of consent.
Participant Type and Disease Characteristics
2. You have been diagnosed with histologically or cytologically confirmed prostate cancer without neuroendocrine differentiation or small cell characteristics.
3. Your East Coast Cancer Clinical Research Partnership (ECOG) performance status is 0 or 1, or 2 due to bone pain.
4. If you have metastatic hormone-sensitive prostate cancer (mHSPC), your estimated life expectancy must be ≥ 12 months, or if you have metastatic castration-resistant prostate cancer (mCRPC), it must be > 6 months.
5. Based on the trial administrator's assessment, you are able to understand and follow all trial requirements and procedures, including completing the Patient Reported Outcomes (PRO) questionnaire.
Gender and Contraception Requirements
6. Male Participants:
● Must agree to use a clearly defined form of contraception with a female partner of childbearing potential (including breastfeeding partners) throughout the treatment period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention.
● Must agree to maintain abstinence or condom use throughout the trial period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention, during the pregnancy of a pregnant partner.
● Must not donate sperm during the treatment period, and for 7 months after the last dose of ASP5541 or 3 months after the AA trial intervention.
Informed Consent
7. You have provided informed consent, including compliance with the requirements and restrictions listed in the Participant Consent Form (ICF) and the trial plan.
Other Inclusion Criteria
8. You have adequate gluteal muscle mass for intramuscular injection.
9. You agree not to participate in another study trial while receiving ASP5541 in this trial.
10. If not supplemented at screening, your serum potassium should be normal (3.5 to 5.5 mEq/L, or within the normal range at your local laboratory).
Inclusion criteria for Group 1: mCRPC participants who have not previously used androgen receptor pathway inhibitors (ARPIs) and received ASP5541 + pred + ADT or AA + pred + ADT.
11. You have been diagnosed with mCRPC, confirmed by a record of metastatic lesions on a bone scan, computed tomography (CT), magnetic resonance imaging (MRI), or prostate-specific cell membrane antigen positron emission tomography (PSMA-PET).
12. You have evidence of disease exacerbation, defined as meeting at least one of the following criteria at the time of participation in the trial.
● Evidence of disease progression on radiographic imaging prior to the first dose and most recent prostate cancer treatment is defined as disease progression (PD) on CT/MRI scans assessed by the trial administrator according to the Solid Tumor Response Assessment Criteria, version 1.1 (RECIST v1.1), or on bone scans assessed according to the Prostate Cancer Working Group 3 (PCWG3).
● Prostate-specific antigen (PSA) progression is defined as an increase in PSA of at least 25% from the lowest value and ≥ 1 ng/cc, confirmed by a second measurement at least 1 week later, with at least one measurement obtained within 90 days prior to screening. The lowest PSA value is defined as the lowest PSA level during or after the most recent treatment period.
13. You are currently receiving ongoing ADT using a gonadotropin-releasing hormone (GnRH) analogue, or have previously undergone bilateral orchiectomy (i.e., surgical or medical castration).
Note: If you have not undergone bilateral orchiectomy, you must plan to maintain effective GnRH analog therapy throughout the trial.
14. At the screening follow-up, your serum testosterone concentration is < 1.73 nmol/L (< 50 ng/dL).
15. You are able to swallow AA.
Inclusion criteria for Group 2: mHSPC participants who have not used ARPIs and are receiving ASP5541 + ADT or AA + pred + ADT.
16. You have been diagnosed with mHSPC, confirmed by a record of metastatic lesions on a bone scan, CT, MRI, or PSMA-PET.
17. You must have started castration therapy (i.e., medical or surgical) at least 14 days prior to Day 1 of Cycle 1.
Note: If you have not undergone bilateral orchiectomy, you must plan to maintain effective GnRH analog therapy throughout the trial.
18. Your baseline morning serum cortisol level should be ≥ 14 mcg/dL.
19. You are able to swallow AA.
20. For groups B and C, you have available primary (preferably) or metastatic (excluding bone) tumor tissue, the source and availability of which have been confirmed prior to trial treatment.
Exclusion Criteria
Medical Conditions
1. You have any coexisting diseases, infections, or comorbidities that, according to the trial administrator, would interfere with your ability to participate in the trial, expose you to undue risk, or complicate data interpretation.
2. You have known active central nervous system (CNS) metastases.
Note: You are eligible if your CNS metastases have been treated with surgery and/or radiation therapy, you are no longer receiving pharmacological doses of glucocorticoids, and you are neurologically stable.
3. You have a known malignancy other than prostate cancer that requires active treatment, except for any of the following:
● Appropriately treated basal cell carcinoma, squamous cell carcinoma of the skin, or any type of carcinoma in situ.
● Your stage I cancer, which has been in remission for ≥ 2 years, is currently in remission after appropriate treatment.
● You have been cancer-free for ≥ 5 years.
If you have any questions regarding this exclusion criterion, please contact your medical monitor.
4. At your screening follow-up visit, you have any unexcluded toxicities classified as Grade 2 or higher according to the National Cancer Institute Common Adverse Event Evaluation Criteria (NCI-CTCAE) (version 5.0).
Note: You will not be excluded if you are currently receiving ongoing hormone replacement therapy for endocrine-immune related adverse events (AEs) without clinical symptoms.
5. You have undergone major surgery (e.g., requiring general anesthesia) within 90 days prior to screening, or have not fully recovered from surgery, or are scheduled to undergo major surgery during your expected participation in the trial.
6. You have had/have had a febrile illness or symptomatic viral, bacterial (including upper respiratory tract infections), or fungal (non-skin) infection within 28 days prior to Day 1 of Cycle 1.
7. You have received a blood transfusion within one month prior to Day 1 of Cycle 1.
8. You have a history of pituitary or adrenal dysfunction (e.g., Addison's disease, Cushing's syndrome).
9. Your glycated hemoglobin (HbA1c) is >10% and you have a previous diagnosis of diabetes. Your HbA1c is >8% and you have not been previously diagnosed with diabetes (you may be rescreened after referral and if there is evidence of improvement in your condition).
10. You have jaundice of any cause or a known active liver disease, including hepatitis A (positive hepatitis A virus IgM, but hepatitis A testing is not required at screening), hepatitis B (positive HBsAg, or HBV DNA positive when HBsAg negative/anti-HBc positive), or hepatitis C (positive HCV antibody and confirmed by HCV RNA).
11. You have moderate or severe hepatic impairment (Child-Pugh B or C).
12. You have a known history of human immunodeficiency virus (HIV) infection. HIV testing is not required unless mandated by your local health authority.
13. Your body mass index (BMI) is > 40 kg/m².
14. You have a history of drug or alcohol abuse according to DSM-5 criteria within the 2 years prior to screening.
Previous/Concomitant Therapies
15. You received a dose of glucocorticoids greater than 10 mg pred daily equivalent within 4 weeks prior to Day 1 of Cycle 1. Topical, intraocular, inhaled, intranasal, or intra-articular glucocorticoids are permitted.
16. You received herbal medicine treatment (e.g., saw palmetto) within 4 weeks prior to Day 1 of Cycle 1. You must agree not to use herbal products during your participation in the trial.
17. You are currently receiving systemic ketoconazole or any other CYP17 inhibitor. You must discontinue systemic ketoconazole or any other CYP17 inhibitor at least 4 weeks before Day 1 of Cycle 1.
18. You are receiving a CYP2D6 receptor with a narrow treatment index (for Groups 1 and 2 only). See the table at the end of this section for examples of listed medications.
19. You have received systemic potent CYP3A4 inducer or inhibitor within 4 weeks prior to Day 1 of Cycle 1. Concomitant use of potent CYP3A4 inducers or inhibitors is not permitted during the trial. See the table at the end of this section for examples of listed medications.
20. You need to use biotin (i.e., vitamin B7) or a biotin-containing supplement at a dose exceeding the appropriate daily intake of 30 micrograms.
Note: You are eligible to participate in the trial if you switch from a high dose to 30 micrograms or less daily before Day 1 of Cycle 1.
21. You received a live attenuated vaccine within 30 days prior to the scheduled start of the trial treatment. Examples of live attenuated vaccines include, but are not limited to, the following: measles, mumps, rubella, varicella/shingles, yellow fever, rabies, BCG, and typhoid vaccines. Injectable seasonal influenza vaccines are usually inactivated virus vaccines and are permitted; however, intranasal influenza vaccines (e.g., FluMist®) are live attenuated vaccines and are not permitted.
22. You need to use any of the prohibited medications listed in the exclusions and concomitant medications list at the end of this section.
Previous/Concurrent Clinical Trial Experience
23. You received any investigational therapy within 4 weeks or 5 half-lives (whichever is longer) prior to Day 1 of Cycle 1.
24. You previously received ASP5541 (PRL-02).
Diagnostic Assessment
25. At screening, your absolute neutrophil count < 1500/μL, platelet count < 100,000/μL, hemoglobin < 9 g/dL (6.2 mmol/L), or international normalized ratio (INR) ≥ 1.5 (INR ≤ 2.0 is permissible unless the participant is taking oral anticoagulants).
Note: You must not have received any growth factors within 7 days prior to obtaining hematological values at screening, and you must not have received a blood transfusion within the previous 28 days.
26. At screening, your serum total bilirubin (TBL) > 1.5 times the upper limit of normal (ULN) (except for participants with a medical record of Gilbert’s disease) or serum alanine transaminase (ALT) or aspartate transaminase (AST) > 2.5 times the ULN.
27. You do not have adequate renal function at screening, defined as a creatinine clearance < 30 c.c./min calculated using the validated formula for calculating creatinine clearance.
28. Your serum albumin < 3.0 g/dL (30 g/L) at screening.
Other exclusion criteria
29. You have a known or suspected allergy to ASP5541, AA (for groups 1 and 2 only), pred, or any component of the formulation used in the trial.
30. You have a gastrointestinal disorder that affects absorption.
Exclusion criteria for group 1: mCRPC participants who have not previously used androgen receptor pathway inhibitors (ARPIs) and are receiving ASP5541 + pred + ADT or AA + pred + ADT.
31. You have previously received treatment with a second-generation ARPI (e.g., AA, enzalutamide, apalutamide, or darolutamide).
Note: Limited use of second-generation ARPIs is permitted in cases of neoadjuvant therapy, adjuvant therapy, or non-metastatic biochemical recurrence, provided there is no evidence of disease progression at least 6 months after the last dose.
32. Prostate cancer treated with any of the following within the specified timeframe prior to inclusion:
● Hormone therapy (e.g., androgen receptor [AR] antagonists, 5-alpha reductase inhibitors, estrogens, cyproterone acetate) within 4 weeks prior to day 1 of cycle 1.
Note: Bicalutamide treatment within 6 weeks prior to inclusion is not permitted. GnRH agonists or antagonists are permitted.
● You received chemotherapy within 2 weeks or 5 half-lives (whichever is longer) before Day 1 of Cycle 1.
● You received biologic therapy within 4 weeks before Day 1 of Cycle 1.
● You received immunotherapy within 4 weeks before Day 1 of Cycle 1.
● You received radiation therapy (including radioligand therapy) within 4 weeks before Day 1 of Cycle 1.
33. If you have a known BRCA mutation, you should be excluded from the trial unless you have previously received a polyadenylate ribose diphosphate polymerase inhibitor (PARPi), are ineligible for PARPi, or are unable to obtain PARPi.
34. You have clinically significant heart disease, defined as any of the following:
● Clinically significant and poorly controlled arrhythmia, including bradycardia. Controlled atrial fibrillation is permissible.
● Congenital QT prolongation syndrome.
●QTcF ≥ 450 ms at screening. If your QTc is prolonged and you have a pacemaker or bundle branch block, you may be included in the trial if confirmed by a medical monitor.
●A history of clinically significant heart disease or congestive heart failure (NYHA Class II or higher), or a left ventricular ejection fraction (LVEF) < 50% at baseline. You must not have experienced unstable angina (symptoms at rest) or new-onset angina within the past 3 months, or a myocardial infarction within the past 6 months.
●Potency poorly controlled with optimal medical treatment, defined as two consecutive confirmed systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
● You have experienced an arterial or venous thrombotic or embolic event, such as a cerebrovascular accident (including transient ischemic attack), deep vein thrombosis, or pulmonary embolism (excluding catheter-related venous thrombosis that occurred > 1 month before Day 1 of Cycle 1 and was treated appropriately).
Exclusion criteria for Group 2: mHSPC participants who have not previously used ARPIs and are receiving ASP5541 + ADT or AA + pred + ADT
35. You have previously received second-generation ARPI therapy (e.g., AA, enzalutamide, apalutamide, or darolutamide). Note: Limited use of second-generation ARPI therapy is permitted in cases of neoadjuvant therapy, adjuvant therapy, or non-metastatic biochemical recurrence, provided there is no evidence of disease progression at least 6 months after the last dose.
36. You have previously received any medical treatment, radiation therapy, or surgery for metastatic prostate cancer. The following exceptions are permitted:
● If, prior to Day 1 of Cycle 1, you have undergone up to 4 months of ADT (within 4 months prior to Day 1 of Cycle 1) with a GnRH agonist or antagonist or orchiectomy, with or without concurrent antiandrogen therapy, and there is no radiographic evidence of disease progression and PSA levels are not elevated.
● You may have received one cycle of palliative radiation therapy or surgery to treat symptoms caused by metastatic disease, provided it was performed at least 4 weeks prior to Day 1 of Cycle 1. Radiation therapy to your prostate is also permitted if you have low-volume metastatic disease and received radiation therapy at least 4 weeks prior to Day 1 of Cycle 1.
● Up to 6 cycles of docetaxel therapy, with the last dose of docetaxel administered ≤ 2 months prior to Day 1 of Cycle 1. If you have previously received docetaxel, you should be assessed by angiography and PSA by the trial administrator before Day 1 of Cycle 1 to maintain a stable or better response to docetaxel.
● If you have previously received docetaxel treatment, before Day 1 of Cycle 1, you should have undergone up to 6 months of ADT with or without concurrent ordrug therapy using a GnRH agonist or antagonist, and before Day 1 of Cycle 1, you should have no radiographic evidence of disease progression and no elevated PSA levels.
37. You have clinically significant heart disease defined as any of the following:
• Clinically significant and poorly controlled arrhythmias, including bradycardia. Controlled atrial fibrillation is permissible.
• Congenital QT prolongation syndrome.
• QTcF ≥ 450 ms at screening. If you have a prolonged QTc and a pacemaker or bundle branch block, you may be included in the trial if confirmed by a medical monitor.
● A history of clinically significant heart disease or congestive heart failure (NYHA Class II or higher), or a left ventricular ejection fraction (LVEF) < 50% at baseline. You must not have experienced symptomatic heart failure, unstable or new-onset angina, or myocardial infarction within the past 12 months.
● Poorly controlled hypertension despite optimal medical treatment, defined as two consecutive confirmed systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg. You may be on up to two antihypertensive medications started at least 3 months prior to Day 1 of Cycle 1.
● An arterial thrombotic or embolic event, such as a cerebrovascular accident (including transient ischemic attack), within the past 12 months.
● A venous thromboembolic event (deep vein thrombosis or pulmonary embolism) has occurred within 3 months prior to the start of the investigational drug (excluding catheter-related venous thrombosis that occurred more than 1 month before day 1 of cycle 1 and was treated appropriately).
1. You have any coexisting diseases, infections, or comorbidities that, according to the trial administrator, would interfere with your ability to participate in the trial, expose you to undue risk, or complicate data interpretation.
2. You have known active central nervous system (CNS) metastases.
Note: You are eligible if your CNS metastases have been treated with surgery and/or radiation therapy, you are no longer receiving pharmacological doses of glucocorticoids, and you are neurologically stable.
3. You have a known malignancy other than prostate cancer that requires active treatment, except for any of the following:
● Appropriately treated basal cell carcinoma, squamous cell carcinoma of the skin, or any type of carcinoma in situ.
● Your stage I cancer, which has been in remission for ≥ 2 years, is currently in remission after appropriate treatment.
● You have been cancer-free for ≥ 5 years.
If you have any questions regarding this exclusion criterion, please contact your medical monitor.
4. At your screening follow-up visit, you have any unexcluded toxicities classified as Grade 2 or higher according to the National Cancer Institute Common Adverse Event Evaluation Criteria (NCI-CTCAE) (version 5.0).
Note: You will not be excluded if you are currently receiving ongoing hormone replacement therapy for endocrine-immune related adverse events (AEs) without clinical symptoms.
5. You have undergone major surgery (e.g., requiring general anesthesia) within 90 days prior to screening, or have not fully recovered from surgery, or are scheduled to undergo major surgery during your expected participation in the trial.
6. You have had/have had a febrile illness or symptomatic viral, bacterial (including upper respiratory tract infections), or fungal (non-skin) infection within 28 days prior to Day 1 of Cycle 1.
7. You have received a blood transfusion within one month prior to Day 1 of Cycle 1.
8. You have a history of pituitary or adrenal dysfunction (e.g., Addison's disease, Cushing's syndrome).
9. Your glycated hemoglobin (HbA1c) is >10% and you have a previous diagnosis of diabetes. Your HbA1c is >8% and you have not been previously diagnosed with diabetes (you may be rescreened after referral and if there is evidence of improvement in your condition).
10. You have jaundice of any cause or a known active liver disease, including hepatitis A (positive hepatitis A virus IgM, but hepatitis A testing is not required at screening), hepatitis B (positive HBsAg, or HBV DNA positive when HBsAg negative/anti-HBc positive), or hepatitis C (positive HCV antibody and confirmed by HCV RNA).
11. You have moderate or severe hepatic impairment (Child-Pugh B or C).
12. You have a known history of human immunodeficiency virus (HIV) infection. HIV testing is not required unless mandated by your local health authority.
13. Your body mass index (BMI) is > 40 kg/m².
14. You have a history of drug or alcohol abuse according to DSM-5 criteria within the 2 years prior to screening.
Previous/Concomitant Therapies
15. You received a dose of glucocorticoids greater than 10 mg pred daily equivalent within 4 weeks prior to Day 1 of Cycle 1. Topical, intraocular, inhaled, intranasal, or intra-articular glucocorticoids are permitted.
16. You received herbal medicine treatment (e.g., saw palmetto) within 4 weeks prior to Day 1 of Cycle 1. You must agree not to use herbal products during your participation in the trial.
17. You are currently receiving systemic ketoconazole or any other CYP17 inhibitor. You must discontinue systemic ketoconazole or any other CYP17 inhibitor at least 4 weeks before Day 1 of Cycle 1.
18. You are receiving a CYP2D6 receptor with a narrow treatment index (for Groups 1 and 2 only). See the table at the end of this section for examples of listed medications.
19. You have received systemic potent CYP3A4 inducer or inhibitor within 4 weeks prior to Day 1 of Cycle 1. Concomitant use of potent CYP3A4 inducers or inhibitors is not permitted during the trial. See the table at the end of this section for examples of listed medications.
20. You need to use biotin (i.e., vitamin B7) or a biotin-containing supplement at a dose exceeding the appropriate daily intake of 30 micrograms.
Note: You are eligible to participate in the trial if you switch from a high dose to 30 micrograms or less daily before Day 1 of Cycle 1.
21. You received a live attenuated vaccine within 30 days prior to the scheduled start of the trial treatment. Examples of live attenuated vaccines include, but are not limited to, the following: measles, mumps, rubella, varicella/shingles, yellow fever, rabies, BCG, and typhoid vaccines. Injectable seasonal influenza vaccines are usually inactivated virus vaccines and are permitted; however, intranasal influenza vaccines (e.g., FluMist®) are live attenuated vaccines and are not permitted.
22. You need to use any of the prohibited medications listed in the exclusions and concomitant medications list at the end of this section.
Previous/Concurrent Clinical Trial Experience
23. You received any investigational therapy within 4 weeks or 5 half-lives (whichever is longer) prior to Day 1 of Cycle 1.
24. You previously received ASP5541 (PRL-02).
Diagnostic Assessment
25. At screening, your absolute neutrophil count < 1500/μL, platelet count < 100,000/μL, hemoglobin < 9 g/dL (6.2 mmol/L), or international normalized ratio (INR) ≥ 1.5 (INR ≤ 2.0 is permissible unless the participant is taking oral anticoagulants).
Note: You must not have received any growth factors within 7 days prior to obtaining hematological values at screening, and you must not have received a blood transfusion within the previous 28 days.
26. At screening, your serum total bilirubin (TBL) > 1.5 times the upper limit of normal (ULN) (except for participants with a medical record of Gilbert’s disease) or serum alanine transaminase (ALT) or aspartate transaminase (AST) > 2.5 times the ULN.
27. You do not have adequate renal function at screening, defined as a creatinine clearance < 30 c.c./min calculated using the validated formula for calculating creatinine clearance.
28. Your serum albumin < 3.0 g/dL (30 g/L) at screening.
Other exclusion criteria
29. You have a known or suspected allergy to ASP5541, AA (for groups 1 and 2 only), pred, or any component of the formulation used in the trial.
30. You have a gastrointestinal disorder that affects absorption.
Exclusion criteria for group 1: mCRPC participants who have not previously used androgen receptor pathway inhibitors (ARPIs) and are receiving ASP5541 + pred + ADT or AA + pred + ADT.
31. You have previously received treatment with a second-generation ARPI (e.g., AA, enzalutamide, apalutamide, or darolutamide).
Note: Limited use of second-generation ARPIs is permitted in cases of neoadjuvant therapy, adjuvant therapy, or non-metastatic biochemical recurrence, provided there is no evidence of disease progression at least 6 months after the last dose.
32. Prostate cancer treated with any of the following within the specified timeframe prior to inclusion:
● Hormone therapy (e.g., androgen receptor [AR] antagonists, 5-alpha reductase inhibitors, estrogens, cyproterone acetate) within 4 weeks prior to day 1 of cycle 1.
Note: Bicalutamide treatment within 6 weeks prior to inclusion is not permitted. GnRH agonists or antagonists are permitted.
● You received chemotherapy within 2 weeks or 5 half-lives (whichever is longer) before Day 1 of Cycle 1.
● You received biologic therapy within 4 weeks before Day 1 of Cycle 1.
● You received immunotherapy within 4 weeks before Day 1 of Cycle 1.
● You received radiation therapy (including radioligand therapy) within 4 weeks before Day 1 of Cycle 1.
33. If you have a known BRCA mutation, you should be excluded from the trial unless you have previously received a polyadenylate ribose diphosphate polymerase inhibitor (PARPi), are ineligible for PARPi, or are unable to obtain PARPi.
34. You have clinically significant heart disease, defined as any of the following:
● Clinically significant and poorly controlled arrhythmia, including bradycardia. Controlled atrial fibrillation is permissible.
● Congenital QT prolongation syndrome.
●QTcF ≥ 450 ms at screening. If your QTc is prolonged and you have a pacemaker or bundle branch block, you may be included in the trial if confirmed by a medical monitor.
●A history of clinically significant heart disease or congestive heart failure (NYHA Class II or higher), or a left ventricular ejection fraction (LVEF) < 50% at baseline. You must not have experienced unstable angina (symptoms at rest) or new-onset angina within the past 3 months, or a myocardial infarction within the past 6 months.
●Potency poorly controlled with optimal medical treatment, defined as two consecutive confirmed systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
● You have experienced an arterial or venous thrombotic or embolic event, such as a cerebrovascular accident (including transient ischemic attack), deep vein thrombosis, or pulmonary embolism (excluding catheter-related venous thrombosis that occurred > 1 month before Day 1 of Cycle 1 and was treated appropriately).
Exclusion criteria for Group 2: mHSPC participants who have not previously used ARPIs and are receiving ASP5541 + ADT or AA + pred + ADT
35. You have previously received second-generation ARPI therapy (e.g., AA, enzalutamide, apalutamide, or darolutamide). Note: Limited use of second-generation ARPI therapy is permitted in cases of neoadjuvant therapy, adjuvant therapy, or non-metastatic biochemical recurrence, provided there is no evidence of disease progression at least 6 months after the last dose.
36. You have previously received any medical treatment, radiation therapy, or surgery for metastatic prostate cancer. The following exceptions are permitted:
● If, prior to Day 1 of Cycle 1, you have undergone up to 4 months of ADT (within 4 months prior to Day 1 of Cycle 1) with a GnRH agonist or antagonist or orchiectomy, with or without concurrent antiandrogen therapy, and there is no radiographic evidence of disease progression and PSA levels are not elevated.
● You may have received one cycle of palliative radiation therapy or surgery to treat symptoms caused by metastatic disease, provided it was performed at least 4 weeks prior to Day 1 of Cycle 1. Radiation therapy to your prostate is also permitted if you have low-volume metastatic disease and received radiation therapy at least 4 weeks prior to Day 1 of Cycle 1.
● Up to 6 cycles of docetaxel therapy, with the last dose of docetaxel administered ≤ 2 months prior to Day 1 of Cycle 1. If you have previously received docetaxel, you should be assessed by angiography and PSA by the trial administrator before Day 1 of Cycle 1 to maintain a stable or better response to docetaxel.
● If you have previously received docetaxel treatment, before Day 1 of Cycle 1, you should have undergone up to 6 months of ADT with or without concurrent ordrug therapy using a GnRH agonist or antagonist, and before Day 1 of Cycle 1, you should have no radiographic evidence of disease progression and no elevated PSA levels.
37. You have clinically significant heart disease defined as any of the following:
• Clinically significant and poorly controlled arrhythmias, including bradycardia. Controlled atrial fibrillation is permissible.
• Congenital QT prolongation syndrome.
• QTcF ≥ 450 ms at screening. If you have a prolonged QTc and a pacemaker or bundle branch block, you may be included in the trial if confirmed by a medical monitor.
● A history of clinically significant heart disease or congestive heart failure (NYHA Class II or higher), or a left ventricular ejection fraction (LVEF) < 50% at baseline. You must not have experienced symptomatic heart failure, unstable or new-onset angina, or myocardial infarction within the past 12 months.
● Poorly controlled hypertension despite optimal medical treatment, defined as two consecutive confirmed systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg. You may be on up to two antihypertensive medications started at least 3 months prior to Day 1 of Cycle 1.
● An arterial thrombotic or embolic event, such as a cerebrovascular accident (including transient ischemic attack), within the past 12 months.
● A venous thromboembolic event (deep vein thrombosis or pulmonary embolism) has occurred within 3 months prior to the start of the investigational drug (excluding catheter-related venous thrombosis that occurred more than 1 month before day 1 of cycle 1 and was treated appropriately).
The Estimated Number of Participants
-
Taiwan
19 participants
-
Global
218 participants
