An Open-label Dose Escalation and Expansion, Followed by a Phase II Study of Tulmimetostat (DZR123) and JSB462 (Luxdegalutamide) in Patients With Progressive Metastatic Castrate Resistant Prostate Cancer (mCRPC) (TulmiSTAR-01)

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

• Ages 18 years and older
• Men only
• No healthy volunteers
• Adult, Older adult

Trial locations and contacts

35 sites in 14 countries. Contact the study team or a site near you to ask about taking part.

About this study

Official title: TulmiSTAR-01: A Two-part, Phase I Dose Escalation and Expansion Followed by a Randomized, Open-label Multicenter, Phase II Study to Assess the Safety and Efficacy of the Combination of Tulmimetostat (DZR123) and JSB462 (Luxdegalutamide) vs Standard of Care in Patients With Progressive Metastatic Castrate Resistant Prostate Cancer

Conditions

Progressive Metastatic Castrate Resistant Prostate Cancer

Being tested

Tulmimetostat DL1 QD, Tulmimetostat DL2 QD, Tulmimetostat DL3 QD, Tulmimetostat Doses 1 or 2 QD, Tulmimetostat RP2D QD

Keywords

metastatic castrate resistant prostate cancer (mCRPC), tulmimetostat (DZR123), luxdegalutamide (JSB462), Androgen Deprivation Therapy (ADT), Standard of care (SoC), TulmiSTAR-01

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

• Tulmimetostat DL1 QDDrug

  Also called DZR123

  Part 1a (dose escalation):

  Doses of tulmimetostat beyond DL1 once a day (QD) will be opened depending on outcome of Dose Escalation Meetings (DEM(s))

• Tulmimetostat DL2 QDDrug

  Also called DZR123

  Part 1a (dose escalation):

  Doses of tulmimetostat beyond DL1 once a day (QD) will be opened depending on outcome of Dose Escalation Meetings (DEM(s))

• Tulmimetostat DL3 QDDrug

  Also called DZR123

  Part 1a (dose escalation):

  Doses of tulmimetostat beyond DL1 once a day (QD) will be opened depending on outcome of Dose Escalation Meetings (DEM(s))

• Tulmimetostat Doses 1 or 2 QDDrug

  Also called DZR123

  Part 1b (dose expansion and optimization):

  tulmimetostat doses 1 or 2 QD

• Tulmimetostat RP2D QDDrug

  Also called DZR123

  Part 2:

  tulmimetostat Recommended Phase 2 Dose (RP2D) QD

• JSB462 Dose 1 QDDrug

  Also called luxdegalutamide

  JSB462 Dose 1 QD

• JSB462 Dose 2 QDDrug

  Also called luxdegalutamide

  JSB462 Dose 2 QD

• JSB462 QDDrug

  Also called luxdegalutamide

  The dose of JSB462 QD will be determined based on the totality of data from Part 1a

• Standard of Care (SoC)Drug

  Androgen Receptor Pathway Inhibitors (ARPI), chemotherapy or Pluvicto (AAA617) at the discretion of the investigator

What is being measured

The primary outcome is the main question the study is designed to answer.

1. Part 1a: Dose-limiting toxicities (DLTs)

   A dose-limiting toxicity (DLT) is defined as an adverse event or abnormal laboratory value assessed as unrelated to disease, disease progression, inter-current illness/injury, or concomitant medications that occurs within the first 28 days of treatment with tulmimetostat and JSB462 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).

   Measured: Up to 28 days

2. Part 1a and Part 1b: Incidence rate of Adverse Events (AEs) and Serious Adverse Events (SAEs)

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

   Measured: From date of randomization till 30 days safety fup, assessed up to approximately 14 months

3. Part 1a and Part 1b: Number of Participants with dose adjustments

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

   Measured: From date of randomization till 30 days safety fup, assessed up to approximately 14 months

4. Part 1a and Part 1b: Dose Intensity

   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

   Measured: From date of randomization till 30 days safety fup, assessed up to approximately 14 months

5. Part 1a and Part 1b: Duration of exposure to each study drug

   The duration of exposure (in months) to Tulmimetostat and JSB462 (Part 1a and Part 1b) will be summarized by means of descriptive statistics

   Measured: From date of randomization till 30 days safety fup, assessed up to approximately 14 months

6. Part 1b and Part 2: prostate-specific antigen 50 (PSA50) at Month 6

   PSA50 is defined as a PSA reduction of at least 50% from baseline at 6 months confirmed by a second PSA measurement ≥ 3 weeks later.

   Measured: Month 6

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1. First posted3 Oct 2025
2. Study start15 Oct 2025
3. Primary completion9 Nov 2029 (estimated)
4. Study completion1 Dec 2030 (estimated)

Resources

• Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
• Other trials for Progressive Metastatic Castrate Resistant Prostate CancerStudies of the same condition, open and under way.
• More trials run by Novartis PharmaceuticalsThe sponsor's other registered studies.
• What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.