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)
Prostate Cancer
Unknown Primary
18 Years and older, Male and Female
CDZR123A12107 (primary)
NCI-2025-08418
2025-521880-10-00
Summary
This is a two-part, Phase I/II, open-label, global, multicenter study assessing the
safety and efficacy of the combination of tulmimetostat (DZR123) and JSB462
(luxdegalutamide) versus standard of care in participants with progressive metastatic
castrate resistant prostate cancer (mCRPC).
Objectives
The Phase 1 study, comprised of Parts 1a and 1b, aims to assess the safety and
tolerability of the combination of tulmimetostat and JSB462:
1. Part 1a is the parallel dose escalation that aims to determine the recommended
dose(s) of tulmimetostat and JSB462, in combination, for further exploration.
2. Part 1b is the dose expansion/optimization that aims to determine the recommended
dose of the combination for Phase II.
The purpose of the Phase II study (Part 2) is to compare the combination of tulmimetostat
with JSB462 in terms of the biochemical response as assessed by PSA50 compared to the
standard of care (SoC) in adult men with progressive, taxane-naive mCRPC.
Eligibility
- Participant is an adult man = 18 years of age.
- Participant must have histologically and/or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine or small cell features (current or prior biopsy of the prostate and/or metastatic site).
- Participant must have = 1 metastatic lesion that is present on screening/baseline CT, MRI, or bone scan imaging obtained = 28 days prior to start of treatment (Part 1a dose escalation) or randomization (Part 1b dose expansion and Part 2).
- Participant must have progressive mCRPC.
- Participant must have a castrate level of serum/plasma testosterone (< 50 ng/dL or < 1.7 nmol/L).
- Prior ARPI therapy:
- Part 1a and 1b only: must have progressed on at least one prior second generation ARPI (abiraterone, enzalutamide, darolutamide, or apalutamide).
- Part 2 only: must have progressed on one prior second generation ARPI (abiraterone, enzalutamide, darolutamide, or apalutamide).
- Prior chemotherapy:
- Part 1a dose escalation only: may have received = 2 prior lines of chemotherapy in CRPC setting. Note: Prior chemotherapy is permitted in the HSPC setting.
- Part 1b dose expansion/optimization only: may have received up to one prior line of chemotherapy in CRPC setting. Note: Prior chemotherapy is permitted in the HSPC setting.
- Part 2 only: Participants must be taxane-naïve in mCRPC setting; prior chemotherapy permitted in HSPC setting only Key
Treatment Sites in Georgia
**Clinical trials are research studies that involve people. These studies test new ways to prevent, detect, diagnose, or treat diseases. People who take part in cancer clinical trials have an opportunity to contribute to scientists’ knowledge about cancer and to help in the development of improved cancer treatments. They also receive state-of-the-art care from cancer experts...
Click here to learn more about clinical trials.