MedPath

TulmiSTAR-02: A Phase I/II Open-label Study of Tulmimetostat in Combination With Darolutamide vs. Darolutamide, and Tulmimetostat With Abiraterone in Patients With Metastatic Hormone-sensitive Prostate Cancer (mHSPC)

Not Applicable
Not yet recruiting
Conditions
Metastatic Hormone-Sensitive Prostate Cancer (mHSPC)
Interventions
Registration Number
NCT07190300
Lead Sponsor
Novartis Pharmaceuticals
Brief Summary

The purpose of the study is to evaluate the safety, tolerability, and efficacy of the two different treatment combinations of tulmimetostat in participants with de novo or recurrent Metastatic Hormone-Sensitive Prostate Cancer (mHSPC).

Detailed Description

The study consists of two phases:

1. The Phase I part includes two groups: Part 1 will assess the combination of tulmimetostat with darolutamide (Group A), and Part 2 will assess tulmimetostat with abiraterone (Group B). The primary objective of Phase I is to determine the Recommended Dose Escalations (RDEs) for each combination, with enrollment using a staggered approach between the groups. Participants in both Group A and Group B will continue androgen deprivation therapy (ADT) to maintain castrate testosterone levels (\< 50 ng/dL or \< 1.7 nmol/L), with the ADT modality determined by the investigator based on local guidelines. In Group B, abiraterone will be co-administered with an oral corticosteroid (prednisone or prednisolone) as per local prescribing information.

2. The Phase II part is a randomized, open-label, multicenter dose-expansion study designed to further evaluate the recommended dose(s) of tulmimetostat in combination with darolutamide and provide proof-of-concept for its efficacy and safety. Participants in Phase II will be randomized to receive either tulmimetostat plus darolutamide or darolutamide alone. Eligible participants include those with de novo or recurrent mHSPC who have not previously received prior radioligand therapy but may have prior exposure to taxane-based chemotherapy and/or androgen receptor pathway inhibitors (ARPI, excluding darolutamide). This study aims to explore tulmimetostat-based combinations as potential therapeutic options for men with mHSPC.

The study for each participant consists of a screening period, a study treatment period followed by a post treatment long-term follow-up.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
Male
Target Recruitment
203
Inclusion Criteria
  • Adult men ≥ 18 years old with de novo or recurrent mHSPC (without neuroendocrine or small cell features), with at least one documented metastatic lesion. This lesion may be located in the bone, soft tissue/visceral region, or both.

  • Participants must have castrate levels of testosterone, i.e., ≤ 50 ng/dL (≤ 1.7 nM).

  • Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2

  • Adequate bone marrow and organ function

  • Prior ADT: Participants must have started ADT at least 1 month but no more than 24 months before study entry and be willing to continue ADT during treatment

  • Prior taxane use for mHSPC:

    ~ Phase I and II: Participants may have received, but not progressed on, one prior taxane-based therapy.

  • Prior ARPI (abiraterone, enzalutamide, darolutamide, or apalutamide) is allowed in both Phase I and Phase II:

    1. Prior ARPI use in biochemical recurrence (BCR) or curative treatment is allowed for any duration, provided therapy was discontinued and participant had no evidence of conventional imaging positive metastatic disease at that time

    2. Prior ARPI use in mHSPC

      • Phase I: Allowed for any duration.
      • Phase II: Allowed prior exposure to ARPI is ≤6 months. Participants with ongoing use of darolutamide are not eligible.
  • Other permitted prior local therapy for mHSPC:

    • Phase I and II: Prior prostate-directed radiation or surgical intervention. Radiation must be completed before study entry; surgery at least 2 weeks prior.

Key

Exclusion Criteria
  • Participants with evidence of mCRPC or biochemical recurrence / PSA only disease or asymptomatic prostate cancer without known metastatic disease and with no requirement for therapy and with normal PSA for ≥ 1 year prior to the start of study treatment.
  • Participants with PSA levels of ≤ 0.2 ng/mL at the start of study treatment.
  • Participants with a history of central nervous system (CNS) metastases who are neurologically unstable, symptomatic, or receiving corticosteroids for the purpose of maintaining neurologic integrity. Participants with CNS metastases are eligible if received therapy (surgery, radiotherapy, gamma knife), are asymptomatic and neurologically stable without corticosteroids. Baseline and subsequent radiological imaging for them must include evaluation of the brain.
  • Concurrent use of first-generation anti-androgens (like bicalutamide). Prior use of a first-generation anti-androgen drug in the context of ADT initiation with a GNRH analog is allowed, provided it was administered for ≤14 days and the last dose was administered ≥7 days from the study entry.
  • Systemic ketoconazole is used as antineoplastic treatment for prostate cancer.
  • Previous exposure to radioligand therapy.
  • Treatment with any investigational agent within 28 days (or 5 half-lives, whichever is longer) prior to study entry.
  • Previous treatment with any Polycomb Repressive Complex 2 (PRC2) inhibitor, including but not limited to Enhancer of Zeste Homolog 2 (EZH2) inhibitors, EZH2/1 inhibitors, or embryonic ectoderm development (EED) inhibitors.
  • Herbal products that may decrease PSA levels within 4 weeks prior to the start of study drug treatment and while on study
  • Participants taking prohibited medication(s) prior to study treatment and for the duration of the study treatment or prohibited herbal product(s) that cannot be stopped 7 days prior to study treatment.

Other inclusion/exclusion criteria may apply

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Phase I: Group A (part 1)TulmimetostatTulmimetostat oral (PO) once a day (QD) escalating doses + Darolutamide 600 mg twice a day (BID)
Phase I: Group A (part 1)DarolutamideTulmimetostat oral (PO) once a day (QD) escalating doses + Darolutamide 600 mg twice a day (BID)
Phase I: Group B (part 2)TulmimetostatTulmimetostat PO QD escalating doses + Abiraterone 1000 mg PO QD
Phase I: Group B (part 2)AbirateroneTulmimetostat PO QD escalating doses + Abiraterone 1000 mg PO QD
Phase II: Arm 1TulmimetostatTulmimetostat dose 1 PO + Darolutamide 600 mg PO BID
Phase II: Arm 1DarolutamideTulmimetostat dose 1 PO + Darolutamide 600 mg PO BID
Phase II: Arm 2TulmimetostatTulmimetostat dose 2 PO + Darolutamide 600 mg PO BID
Phase II: Arm 2DarolutamideTulmimetostat dose 2 PO + Darolutamide 600 mg PO BID
Phase II: Arm 3DarolutamideDarolutamide 600 mg PO BID
Primary Outcome Measures
NameTimeMethod
Phase I (Group A and Group B): Dose-limiting toxicities (DLTs)Up to 28 days

A dose-limiting toxicity is defined as an adverse event or abnormal laboratory value, not clearly due to underlying disease or extraneous causes, that occurs within the first 28 days of treatment with tulmimetostat and meets any of the criteria specified in the protocol. The National Cancer Institute Common Terminology Criteria for Adverse events (NCI CTCAE) version 5.0 will be used for all grading. For the purpose of dose-escalation decisions, DLTs will be considered and included in the Bayesian Logistic Regression Model (BLRM).

Phase I (Group A and Group B): Incidence rate of Adverse Events (AEs) and Serious Adverse Events (SAEs)From date of randomization till 30 days safety fup, assessed up to approximately 79 months

The analysis of adverse events will include categorization by type, frequency, and severity, as graded by the NCI CTCAE version 5.0.

Phase I (Group A and Group B): Number of Participants with dose adjustmentsFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

The number of participants with dose adjustments (reductions, interruption, or permanent discontinuation) will be summarized by treatment arm.

Phase I (Group A and Group B): Dose IntensityFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

Dose intensity (computed as the ratio of actual cumulative dose received and actual duration of exposure) and the relative dose intensity (computed as the ratio of dose intensity and planned dose intensity) will be summarized by means of descriptive statistics

Phase I (Group A and Group B): Duration of exposure to each study drugFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

Duration of exposure to each study drug will be summarized by means of descriptive statistics

Phase II (Group A): Biochemical Response Rate (BCR)From date of randomization till 30 days safety fup, assessed up to approximately 79 months

Biochemical Response Rate (BCR) is defined as prostate-specific antigen (PSA) decline to \< 0.2 ng/mL at 6 months, confirmed by a second PSA measurement ≥ 3 weeks later.

Secondary Outcome Measures
NameTimeMethod
Phase I (Group A): Plasma concentrations of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Tulmimetostat and Darolutamide pharmacokinetic (PK) samples will be obtained and evaluated in all participants at all dose levels by treatment arms

Phase I (Group A): AUC of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Area under the concentration-time curve from time zero to the time of last quantifiable concentration (AUClast), Area under the concentration-time curve from time zero (pre-dose) extrapolated to infinite time (AUCinf) and Area under the concentration-time curve calculated to the end of a dosing interval (tau) at steady-state (AUCtau) will be listed and summarized using descriptive statistics.

Phase I (Group A): Cmax of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmax will be listed and summarized using descriptive statistics.

Phase I (Group B): Plasma concentrations of Tulmimetostat and AbirateroneCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours), Day 2 (0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Tulmimetostat and Abiraterone pharmacokinetic (PK) samples will be obtained and evaluated in all participants at all dose levels by treatment arms

Phase I (Group B): AUC of Tulmimetostat and AbirateroneCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours), Day 2 (0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Area under the concentration-time curve from time zero to the time of last quantifiable concentration (AUClast), Area under the concentration-time curve from time zero (pre-dose) extrapolated to infinite time (AUCinf) and Area under the concentration-time curve calculated to the end of a dosing interval (tau) at steady-state (AUCtau) will be listed and summarized using descriptive statistics.

Phase I (Group B): Cmax of Tulmimetostat and AbirateroneCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours), Day 2 (0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmax will be listed and summarized using descriptive statistics.

Phase II (Group A): Radiographic progression free survival (rPFS)From date of randomization until date of radiographic progression or date of death from any cause, whichever comes first, assessed up to approximately 79 months

Radiographic progression free survival (rPFS) is defined as the time between randomization and the first occurrence of disease progression as per PCWG3-modified RECIST v1.1 or death due to any cause

Phase II (Group A):Overall survival (OS)From date of randomization until date of death from any cause, assessed up to approximately 79 months

Overall survival (OS) is defined as the time between randomization to date of death due to any cause

Phase II (Group A): Objective response (OR)From date of randomization until date of confirmed Complete Response (CR) or Partial Response (PR), assessed up to approximately 79 months

Objective response (OR) is defined as a confirmed Complete Response (CR) or Partial Response (PR) per Prostate Cancer Working Group 3 (PCWG3)-modified RECIST 1.1 as assessed by the Investigator

Phase II (Group A): Best Overall response (BOR)From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to approximately 79 months

Best Overall response (BOR) is defined as the best response per PCWG3-modified RECIST 1.1 as assessed by the Investigator from the start of the treatment until disease progression/recurrence

Phase II (Group A): Duration of response (DOR)From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to approximately 79 months

Duration of response (DOR) defined as time between first documented CR/PR and disease progression per PCWG3-modified RECIST 1.1 as assessed by the Investigator or death due to any cause

Phase II (Group A): Prostate-Specific Antigen 50 (PSA50)From date of randomization till 30 days safety fup, assessed up to approximately 79 months

Prostate-Specific Antigen 50 (PSA50) is defined as a ≥ 50% decrease in PSA levels from baseline at any timepoint, confirmed by a second PSA measurement ≥ 3 weeks without any PSA progression in between

Phase II (Group A): Biochemical Response of <0.1 ng/mLFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

Biochemical Response of \<0.1 ng/mL is defined as PSA level \< 0.1 ng/mL at any timepoint during the trial from randomization

Phase II (Group A): Time to castration-resistant prostate cancer (CRPC)From date of randomization until date of PSA progression, radiological progression by bone lesions, or radiological progression by soft tissue and visceral lesions, whichever comes first, assessed up to approximately 79 months

Time to castration-resistant prostate cancer (CRPC) is defined as the time from randomization to the first occurrence of one of the following events: PSA progression, radiological progression by bone lesions, or radiological progression by soft tissue and visceral lesions

Phase II (Group A): Incidence rate of Adverse Events (AEs) and Serious Adverse Events (SAEs)From date of randomization till 30 days safety fup, assessed up to approximately 79 months

The analysis of adverse events will include categorization by type, frequency, and severity, as graded by the NCI CTCAE version 5.0.

Phase II (Group A): Number of Participants with dose adjustmentsFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

The number of participants with dose adjustments (reductions, interruption, or permanent discontinuation) will be summarized by treatment arm.

Phase II (Group A): Dose IntensityFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

Dose intensity (computed as the ratio of actual cumulative dose received and actual duration of exposure) and the relative dose intensity (computed as the ratio of dose intensity and planned dose intensity) will be summarized by means of descriptive statistics

Phase II (Group A): Duration of exposure to each study drugFrom date of randomization till 30 days safety fup, assessed up to approximately 79 months

Duration of exposure to each study drug will be summarized by means of descriptive statistics

Phase II (Group A): Plasma concentrations of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

In selected number of participants receiving Tulmimetostat and Darolutamide combination therapy in Phase II, or in selected number of participants if only one dose level of Tulmimetostat is evaluated in combination with Darolutamide in Phase II, Tulmimetostat and Darolutamide pharmacokinetic (PK) samples will be obtained and evaluated in all participants at all dose levels by treatment arms

Phase II (Group A): AUC of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

In selected number of participants receiving tulmimetostat and darolutamide combination therapy in Phase II, or in selected number of participants if only one dose level of tulmimetostat is evaluated in combination with darolutamide in Phase II, venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Area under the concentration-time curve from time zero to the time of last quantifiable concentration (AUClast), Area under the concentration-time curve from time zero (pre-dose) extrapolated to infinite time (AUCinf) and Area under the concentration-time curve calculated to the end of a dosing interval (tau) at steady-state (AUCtau) will be listed and summarized using descriptive statistics.

Phase II (Group A): Cmax of Tulmimetostat and DarolutamideCycle 1-2: Day 1 (0 hour, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours and 8 hours). Cycle 1: Day 2 (Tulmimetostat only: 0 hour and 24 hours), Days 8 and 15 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

In selected number of participants receiving tulmimetostat and darolutamide combination therapy in Phase II, or in selected number of participants if only one dose level of tulmimetostat is evaluated in combination with darolutamide in Phase II, venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmax will be listed and summarized using descriptive statistics.

Phase II (Group A): Plasma concentrations of TulmimetostatCycle 1-2: Day 1 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Tulmimetostat pharmacokinetic (PK) samples will be obtained and evaluated in all participants at all dose levels by treatment arms

Phase II (Group A): AUC of TulmimetostatCycle 1-2: Day 1 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Area under the concentration-time curve from time zero to the time of last quantifiable concentration (AUClast), Area under the concentration-time curve from time zero (pre-dose) extrapolated to infinite time (AUCinf) and Area under the concentration-time curve calculated to the end of a dosing interval (tau) at steady-state (AUCtau) will be listed and summarized using descriptive statistics.

Phase II (Group A): Cmax of TulmimetostatCycle 1-2: Day 1 (0 hour and 2 hours). Cycles 3-5: Day 1 (0 hour). 1 cycle = 28 days.

Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmax will be listed and summarized using descriptive statistics.

Phase II (Group A): Time to first symptomatic skeletal event (TTSSE)From randomization until the first occurrence of a new symptomatic bone fracture, spinal cord compression, tumor-related orthopedic surgery, radiation therapy for bone pain, or death, assessed up to 79 months.

Time to first symptomatic skeletal event (TTSSE) is defined as the time from randomization to the first new symptomatic pathological bone fracture, spinal cord compression, tumor-related orthopedic surgical intervention, requirement for radiation therapy to relieve bone pain or death from any cause, whichever occurs first

MedPath

Empowering clinical research with data-driven insights and AI-powered tools.

© 2025 MedPath, Inc. All rights reserved.