A Comparative Dose-finding Study of RS-113 in Patients With Metastatic Castration-resistant Prostate Cancer

NCT07553988 | Active Not Recruiting Phase 2

• 1 other identifier: CL01069052
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 16

Brief Summary

The primary objective of the study is to determine the therapeutic dose of RS-113 in patients with metastatic castration-resistant prostate cancer based on efficacy, safety, and pharmacokinetic parameters. The secondary objectives are to assess a pilot efficacy and safety of different doses of RS-113 versus abiraterone, as well as to investigate pharmacokinetics profile and to perform a pilot evaluation of pharmacokinetics parameters of RS-113 in patients with metastatic castration-resistant prostate cancer

Conditions

Metastatic Castration-resistant Prostate Cancer

Keywords

Metastatic Castration-resistant Prostate Cancer; RS-113

Outcome Measures

Primary Outcomes (1)

• Median Progression-free survival (PFS) at 1 year in RS-113 treatment arms

  Progression-free survival (PFS) expressed as the median PFS for a period of up to 1 year of treatment inclusive in RS-113 treatment arms (per RECIST 1.1 and PCWG3 criteria) PFS is defined as the time from randomization to disease progression per RECIST 1.1 (an ≥ 20% increase in the sum of diameters of target lesions taking as reference the smallest sum recorded during the study (with an absolute increase of sum at least 5 mm), or the appearance of ≥ 1 new lesions), or death due to any cause According to PCWG3, progression is defined as: * two or more new lesions detected on the first post-baseline scan with at least 2 additional lesions on a subsequent scan * two or more new lesions detected on a subsequent scan (if one or no new lesions were seen at the first post-baseline scan) and confirmed by a follow-up scan

  Up to day 337 (visit 16)

Secondary Outcomes (19)

• Progression-free survival (PFS) rate (%) at 1 year in RS-113 treatment arms

  Up to day 337 (visit 16)

• Prostate-specific antigen (PSA) response rate (%) in RS-113 treatment arms

  at Week 9, 21, 33, 45, 57, 69, 81, 93, 101 and FU visit

• Number (%) of patients achieved ≥50% prostate-specific antigen (PSA) decline in RS-113 treatment arms

  once at screening, on days 29 (visit 3), 57 (visit 5), 85-701 (visits 7-29) and FU visit

• Number (%) of patients achieved ≥90% prostate-specific antigen (PSA) decline in RS-113 treatment arm

  once at screening, on days 29 (visit 3), 57 (visit 5), 85-701 (visits 7-29) and FU visit

• Objective response rate (ORR)(%) at 1 year in RS-113 treatment arms

  once at screening, on days 57 (visit 5), 113 (visit 8), 169 (visit 10), 253 (visit 13), 337 (visit 16) and FU visit

Other Outcomes (34)

• Median progression-free survival (PFS) at 1 year (comparative assesment)

  Up to day 337 (visit 16)

• Progression-free survival (PFS) rate (%) at 1 year (comparative assessment)

  Up to day 337 (visit 16)

• Median progression-free survival (PFS) at 2 years (comparative assesment)

  Up to day 701 (visit 29)

Study Arms (4)

RS-113, 160 mg + androgen deprivation therapy (ADT)

EXPERIMENTAL

RS-113 is taken once daily (QD) orally, 2 capsules at a time (160 mg), 1 hour after a meal in the morning Androgen deprivation therapy (ADT) will be administered using analogues of luteinizing hormone-releasing hormone (aLHRH): * goserelin (at a dose of 3.6mg every 28 days or 10.8 mg every 84 days, subcutaneously, into the anterior abdominal wall), or * leuprorelin (7.5 mg every 28 days or 22.5 mg every 3 months, subcutaneously, into the anterior abdominal wall), or * triptorelin (3.75 mg every 28 days intramuscularly), or * buserelin (3.75 mg every 28 days, intramuscularly)

Drug: RS-113, 160 mg; Drug: Androgen deprivation therapy (ADT)

RS-113, 240 mg + androgen deprivation therapy (ADT)

EXPERIMENTAL

RS-113 is taken orally QD, 3 capsules at a time (240 mg), 1 hour after a meal in the morning Androgen deprivation therapy (ADT) will be administered using analogues of luteinizing hormone-releasing hormone (aLHRH): * goserelin (at a dose of 3.6mg every 28 days or 10.8 mg every 84 days, subcutaneously, into the anterior abdominal wall), or * leuprorelin (7.5 mg every 28 days or 22.5 mg every 3 months, subcutaneously, into the anterior abdominal wall), or * triptorelin (3.75 mg every 28 days intramuscularly), or * buserelin (3.75 mg every 28 days, intramuscularly)

Drug: RS-113, 240 mg; Drug: Androgen deprivation therapy (ADT)

RS-113, 320 mg + androgen-deprivation therapy (ADT)

EXPERIMENTAL

RS-113 is taken orally QD, 4 capsules at a time (320 mg), 1 hour after a meal in the morning Androgen deprivation therapy (ADT) will be administered using analogues of luteinizing hormone-releasing hormone (aLHRH): * goserelin (at a dose of 3.6mg every 28 days or 10.8 mg every 84 days, subcutaneously, into the anterior abdominal wall), or * leuprorelin (7.5 mg every 28 days or 22.5 mg every 3 months, subcutaneously, into the anterior abdominal wall), or * triptorelin (3.75 mg every 28 days intramuscularly), or * buserelin (3.75 mg every 28 days, intramuscularly)

Drug: RS-113, 320 mg; Drug: Androgen deprivation therapy (ADT)

Abiraterone + prednisolone + androgen deprivation therapy (ADT)

ACTIVE COMPARATOR

Abiraterone is taken at a dose of 1000 mg (4 tablets of 250 mg) QD, 1 hour before a meal or 2 hours after a meal in combination with prednisolone at a dose of 10 mg (2 tablets of 5 mg) QD Androgen deprivation therapy (ADT) will be administered using analogues of luteinizing hormone-releasing hormone (aLHRH): * goserelin (at a dose of 3.6mg every 28 days or 10.8 mg every 84 days, subcutaneously, into the anterior abdominal wall), or * leuprorelin (7.5 mg every 28 days or 22.5 mg every 3 months, subcutaneously, into the anterior abdominal wall), or * triptorelin (3.75 mg every 28 days intramuscularly), or * buserelin (3.75 mg every 28 days, intramuscularly)

Drug: Abiraterone; Drug: Prednisolone; Drug: Androgen deprivation therapy (ADT)

Interventions

RS-113, 160 mg DRUG

Hard gelatin capsules, 80 mg

Also known as: L01069

RS-113, 160 mg + androgen deprivation therapy (ADT)

RS-113, 240 mg DRUG

Hard gelatin capsules, 80 mg

Also known as: L01069

RS-113, 240 mg + androgen deprivation therapy (ADT)

RS-113, 320 mg DRUG

Hard gelatin capsules, 80 mg

Also known as: L01069

RS-113, 320 mg + androgen-deprivation therapy (ADT)

Abiraterone DRUG

Tablets, 250 mg

Abiraterone + prednisolone + androgen deprivation therapy (ADT)

Prednisolone DRUG

Tablets, 5 mg

Abiraterone + prednisolone + androgen deprivation therapy (ADT)

Androgen deprivation therapy (ADT) DRUG

* Goserelin: subcutaneous implant, 3.6 mg or 10.8 mg, or * Leuprorelin: lyophilisate for solution for subcutaneous injection, 7.5 mg or 22.5 mg, or * Triptorelin: lyophilisate for solution for intramuscular injection, 3.75 mg, or * Buserelin: lyophilisate for solution for intramuscular injection, 3.75 mg

Abiraterone + prednisolone + androgen deprivation therapy (ADT); RS-113, 160 mg + androgen deprivation therapy (ADT); RS-113, 240 mg + androgen deprivation therapy (ADT); RS-113, 320 mg + androgen-deprivation therapy (ADT)

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Voluntarily signed and dated Informed Consent Form (ICF) of the patient agreed to take part in this Study
• Histologically confirmed diagnosis of prostate adenocarcinoma showing no neuroendocrine, signet-ring cell, small cell, or ductal differentiation
• Ongoing androgen deprivation therapy for prostate cancer aimed at testosterone suppression with a luteinizing hormone-releasing hormone (LHRH) agonist or antagonist at a stable dose and schedule for at least 4 weeks immediately prior to Day 1, or a history of bilateral orchiectomy (i.e., medical or surgical castration). Patients who have not undergone bilateral orchiectomy must agree to continue effective continuous LHRH analogue therapy throughout the study
• Serum testosterone level ≤ 50 ng/dL (1.73 nmol/L)
• Prostate-specific antigen (PSA) level \> 2 ng/mL
• Evidence of progressive disease at the time of randomization, defined by one or more of the following criteria:
• PSA progression, defined as at least two consecutive increases in PSA levels occurring ≥ 2 weeks apart, with at least one increase documented during screening; the PSA level at screening must be ≥ 2 ng/mL
• Soft tissue disease progression based on computed tomography (CT) or magnetic resonance imaging (MRI) assessment per RECIST v1.1
• Bone disease progression based on bone scintigraphy findings
• Disease progression occurring during androgen deprivation therapy or during or after docetaxel chemotherapy administered as first-line treatment for metastatic hormone-sensitive prostate cancer
• Asymptomatic or mildly symptomatic prostate cancer, defined as a score \< 4 on Question 3 of the Brief Pain Inventory-Short Form (BPI-SF)
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Life expectancy ≥ 24 weeks
• Major organ function must meet the following criteria:
• Absolute neutrophil count (ANC) ≥ 1,500/mm\^3 (1.5 × 10\^9 cells/L)

You may not qualify if:

• Prior antitumor therapy:
• Radiotherapy (except palliative irradiation of bone lesions for pain control) within 4 weeks prior to the planned date of randomization
• Prior treatment with first-generation antiandrogens (flutamide, bicalutamide, nilutamide) within 4 weeks prior to the planned date of randomization
• Prior treatment with second-generation antiandrogens (enzalutamide, apalutamide, darolutamide)
• Use of bisphosphonates or denosumab is permitted only if treatment was initiated prior to the planned date of randomization
• Clinically significant cardiovascular disease, including:
• Myocardial infarction within 6 months prior to the planned date of randomization
• Unstable angina within 3 months prior to the planned date of randomization
• Chronic heart failure NYHA class III or IV
• Clinically significant ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation)
• QTc interval \> 460 ms on ECG (calculated using Fridericia formula), or long QT syndrome identified at screening
• Left ventricular ejection fraction ≤ 50% by echocardiography
• Hypotension (systolic blood pressure \< 80 mmHg) or bradycardia (heart rate \< 50 bpm), except when drug-induced (e.g., beta-blockers), at the time of the planned randomization
• Uncontrolled arterial hypertension (systolic blood pressure \> 180 mmHg or diastolic blood pressure \> 105 mmHg) at the time of the planned randomization
• Clinically significant CNS disorders, including:

Sponsors & Collaborators

• R-Pharm International, LLC: lead

Study Sites (16)

State Budgetary Healthcare Institution of the Arkhangelsk Region "Arkhangelsk Oncology Dispensary"

Arkhangelsk, 163045, Russia

Location

Moscow City Clinical Oncology Hospital No. 62 of the Moscow Department of Healthcare

Istra, 143515, Russia

Location

Ivanovo Regional Oncology Dispensary

Ivanovo, 153040, Russia

Location

Kaluga Regional Clinical Oncology Dispensary

Kaluga, 248007, Russia

Location

State Budgetary Healthcare Institution "Leningrad Regional Clinical Hospital"

Kuz'molovskiy, 191104, Russia

Location

Oncology Center No. 1 of the City Clinical Hospital named after S.S. Yudin of the Moscow Healthcare Department

Moscow, 117152, Russia

Location

National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation

Moscow, 125284, Russia

Location

Federal State Autonomous Institution "National Medical Research Center 'Medical and Rehabilitation Center'" of the Ministry of Health of the Russian Federation

Moscow, 125367, Russia

Location

Research Lab LLC

Moscow, 127521, Russia

Location

Joint-Stock Company "Medsi Group of Companies"

Moscow, 143442, Russia

Location

LLC MSCh "Klinitsist-Klinika Pretor"

Novosibirsk, 630091, Russia

Location

Private Healthcare Institution "Clinical Hospital "RZD-Medicine" of Saint-Petersburg"

Saint Petersburg, 195271, Russia

Location

City Clinical Oncology Dispensary (Saint Petersburg)

Saint Petersburg, 198255, Russia

Location

Siberian State Medical University

Tomsk, 634063, Russia

Location

Multidisciplinary Clinical Medical Center "Medical City"

Tyumen, 625041, Russia

Location

State Institution of Healthcare of Yaroslavl Region "Regional Oncology Hospital"

Yaroslavl, 150054, Russia

Location

MeSH Terms

Interventions

abiraterone; Prednisolone; Androgen Antagonists

Intervention Hierarchy (Ancestors)

Pregnadienetriols; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Hormone Antagonists; Hormones, Hormone Substitutes, and Hormone Antagonists; Physiological Effects of Drugs; Pharmacologic Actions; Chemical Actions and Uses

Study Officials

• Mikhail Samsonov

  R-Pharm

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Open label
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 21, 2026
• First Posted: April 28, 2026
• Study Start: October 24, 2024
• Primary Completion (Estimated): May 14, 2026
• Study Completion (Estimated): May 9, 2027
• Last Updated: April 28, 2026

Record last verified: 2026-04

Locations

RU (16)