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A Phase 2, Open-label, Multi-cohort Study to Assess the Efficacy and Safety of ASP5541 in Participants with Advanced Prostate Cancer

Status
Not yet recruiting
Phases
Phase 2
Study type
Interventional
Source
EU CTIS
Registry ID
CTIS2024-517653-27-00
Acronym
5541-CL-0201
Enrollment
89
Registered
2025-10-22
Start date
Unknown
Completion date
Unknown
Last updated
2026-01-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer

Brief summary

• Proportion of ARPI-naïve mCRPC participants with PSA decline ≥ 90% from baseline (Cohort 1), • Rates of no mineralocorticoid toxicity, defined as experiencing neither Grade ≥ 1 hypokalemia nor Grade ≥ 2 hypertension (Cohort 2 safety-run in), • Proportion of mHSPC participants with PSA ≤ 0.2 ng/mL at 8 months (Cohort 2), • dose-limiting toxicities (DLTs), AEs, serious Adverse Events (SAEs), laboratory results (including chemistry, hematology and urinalysis), electrocardiograms (ECGs), vital signs, physical examinations and ECOG performance status scores (Cohort 3)

Detailed description

• Radiographic progression-free survival (rPFS), defined as the time from date of randomization/first dose date until the date of radiological progressive disease (PD) per RECIST v1.1 and PCWG3 as determined by investigator or death from any cause • Prostate-specific antigen (PSA) decline ≥ 50% from baseline • PSA decline ≥ 90% from baseline (Cohorts 2 and 3 only), • PSA undetectable rate (≤ 0.2 ng/mL) (Cohorts 1 and 3 only) • PSA undetectable rate (≤ 0.02 ng/mL) • Time to PSA progression per PCWG3 criteria • Objective response rate per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease • Duration of response per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease, • Best overall response per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease, • AEs, SAEs, laboratory results (including chemistry, hematology, urinalysis • spot urine potassium and creatinine (Cohort 2 only) • ECGs, vital signs, physical examinations and ECOG performance status scores (Cohorts 1 + 2 only), • Testosterone suppression to ≤ 1 ng/dL, or achieves a ≥ 90% reduction from baseline level • Mean testosterone values by time point, Time to pain progression defined using pain scores from the BPI-SF and opiate analgesic use.

Interventions

DRUGABIRATERONE ACETATE
DRUGPREDNISOLONE
DRUGPREDNISONE

Sponsors

Astellas Pharma Global Development Inc.
Lead SponsorINDUSTRY

Eligibility

Sex/Gender
Male
Age
18 Years to No maximum

Design outcomes

Primary

MeasureTime frame
• Proportion of ARPI-naïve mCRPC participants with PSA decline ≥ 90% from baseline (Cohort 1), • Rates of no mineralocorticoid toxicity, defined as experiencing neither Grade ≥ 1 hypokalemia nor Grade ≥ 2 hypertension (Cohort 2 safety-run in), • Proportion of mHSPC participants with PSA ≤ 0.2 ng/mL at 8 months (Cohort 2), • dose-limiting toxicities (DLTs), AEs, serious Adverse Events (SAEs), laboratory results (including chemistry, hematology and urinalysis), electrocardiograms (ECGs), vital signs, physical examinations and ECOG performance status scores (Cohort 3)

Secondary

MeasureTime frame
• Radiographic progression-free survival (rPFS), defined as the time from date of randomization/first dose date until the date of radiological progressive disease (PD) per RECIST v1.1 and PCWG3 as determined by investigator or death from any cause • Prostate-specific antigen (PSA) decline ≥ 50% from baseline • PSA decline ≥ 90% from baseline (Cohorts 2 and 3 only), • PSA undetectable rate (≤ 0.2 ng/mL) (Cohorts 1 and 3 only) • PSA undetectable rate (≤ 0.02 ng/mL) • Time to PSA progression per PCWG3 criteria • Objective response rate per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease • Duration of response per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease, • Best overall response per RECIST v1.1 for soft tissue disease and PCWG3 for bone disease, • AEs, SAEs, laboratory results (including chemistry, hematology, urinalysis • spot urine potassium and creatinine (Cohort 2 only) • ECGs, vital signs, physical examinations and ECOG performance status scores (C

Countries

France, Germany, Italy, Poland, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026