Recruiting
Phase 1

IDE574, Fulvestrant

Sponsor:

IDEAYA Biosciences

Code:

NCT07540572

Conditions

ER+, HER 2- Breast Cancer

Non-small Cell Lung Cancer (NSCLC)

Castration-resistant Prostate Cancer (CRPC)

Microsatellite Stable (MSS) Colorectal Carcinoma

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

IDE574

Fulvestrant injection

Study Details

Brief summary:

IDE574 is a synthetically manufactured small molecule inhibitor that co-targets the lysine acetyltransferase enzymes KAT6 and KAT7.

The purpose of this study is to evaluate the safety, preliminary efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of IDE574 as monotherapy in participants with locally advanced or metastatic solid tumors and as combination therapy with fulvestrant in participants with advanced or metastatic ER+, HER2- breast cancer.

Conditions

ER+, HER 2- Breast Cancer

Non-small Cell Lung Cancer (NSCLC)

Castration-resistant Prostate Cancer (CRPC)

Microsatellite Stable (MSS) Colorectal Carcinoma

Study ID

NCT07540572

Start date

Mar 17, 2026

Status verified date

May, 2026

Completion date

Jun 30, 2030

Anticipated

Primary completion date

Mar 30, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

Archival Tissue sample for testing

  • Part 1A - Participants with advanced or metastatic ER+, HER2- breast cancer, NSCLC, CRPC, and MSS colorectal adenocarcinoma who have progressed on/after at least one line of standard of care therapy or are intolerant to additional effective therapies.
  • Parts 1B, 2A and 2B: Participants with ER+, HER2- breast cancer who have progressed after at least 1 prior line of treatment with an endocrine therapy and a CDK4/6 inhibitor
  • Female participants with ER+, HER2- breast cancer considered to be of childbearing potential (or have tubal ligations only) must be willing to undergo medically induced menopause (Parts 2A and B only)
  • Female participants of nonchildbearing potential with ER+, HER2- breast cancer must meet at least 1 of the following criteria: Age ≥ 60 years or age <60 years with absence of menstruation for at least 12 months, or had prior removal of both ovaries
  • Have Eastern Cooperative Oncology Group performance status (ECOG PS) of ≤1.
  • Have adequate bone marrow, renal and liver function.
  • Life expectancy of >3 months
  • Able to safely administer and retain orally administered study treatment
  • Able to comply with contraceptive/barrier requirements

Key Exclusion Criteria:

  • Known symptomatic brain metastases or leptomeningeal metastasis
  • Known primary CNS malignancy and any other malignancies within 2 years prior to the first dose with the exception of adequately treated localized tumor.
  • Have impairment of GI function or GI disease that may significantly alter the absorption of IDE574.
  • Have active liver or biliary disease.
  • Have active, uncontrolled bacterial, fungal, or viral infection
  • Have clinically significant cardiac abnormalities and/or blood clotting events within 6 months before the first dose
  • If participants had adverse reactions to previous experimental antitumor treatment that have not recovered to Grade ≤ 1
  • Prior irradiation to >25% of the bone marrow.
  • Known or suspected hypersensitivity to IDE574/excipients or components (Parts 1 \& 2) or fulvestrant/excipients or components (Part 2 only)

Study Design

Enrollment

160 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Monotherapy Dose Escalation (Part 1A)

Participants with the appropriate tumor types will be treated with escalating doses of IDE574

experimental: Monotherapy Dose Expansion (Part 1B)

Participants with ER+ HER2- advanced or metastatic breast cancer will be treated using the chosen monotherapy dose(s) of IDE574

experimental: Combination Dose Escalation (Part 2A) IDE574 + Fulvestrant

Participants with ER+ HER2- advanced or metastatic breast cancer will be treated with escalating doses of IDE574 in combination with fulvestrant

experimental: Combination Dose Expansion (Part 2B)

Participants with ER+ HER2- advanced or metastatic breast cancer will be treated using the chosen combination dose(s) of IDE574 + Fulvestrant

Interventions

IDE574

IDE574

Fulvestrant injection

Fulvestrant Injection

Primary outcome measure

  • Safety and Tolerability of IDE574 in Part 1 A Monotherapy Dose escalation [ Time Frame: 21 days following the first dose of IDE574 ]
  • Safety and Tolerability of IDE574 in Part 1B Monotherapy Dose expansion based on incidence and severity of AEs/SAEs [ Time Frame: Approximately 24 months total study duration ]
  • To evaluate anti-tumor activity of IDE574 of IDE574 in Part 1B Monotherapy Dose expansion based on the ORR per RECIST version 1.1 [ Time Frame: Approximately 24 months total study duration ]
  • To evaluate anti-tumor activity of IDE574 of IDE574 in Part 1B Monotherapy Dose expansion based on DOR per RECIST version 1.1. [ Time Frame: Approximately 24 months total study duration ]
  • Safety and tolerability of IDE574 in combination with Fulvestrant in Part 2A Combination Dose Escalation based on incidence of DLT [ Time Frame: Approximately 24 months total study duration ]
  • Safety and tolerability of IDE574 in combination with Fulvestrant in Part 2B Combination Dose Expansion based on the incidence and severity of AEs/SAEs [ Time Frame: Approximately 24 months total study duration ]
  • Anti-tumor activity of IDE574 in combination with Fulvestrant in Part 2B Combination Dose Expansion based on the ORR per RECIST version 1.1 [ Time Frame: Time Frame: Approximately 24 months total study duration ]
  • Anti-tumor activity of IDE574 in combination with Fulvestrant in Part 2B Combination Dose Expansion based on DOR per RECIST version 1.1. [ Time Frame: Time Frame: Approximately 24 months total study duration ]

Central Contacts and Locations

Central contacts

IDEAYA Clinical Trials

+1-855-433-224IDEAYAClinicalTrials@ideayabio.com

Locations

Florida Clinical Trials Group

Recruiting

Plantation, Florida, United States, 33322

Contacts

Harshad Amin

954-915-9991harshamin@floridactg.com

START Astera, LLC

Recruiting

East Brunswick, New Jersey, United States, 08816

Contacts

Bruno S Fang

732-426-4750info@startresearch.com

START New York Long Island, LLC

Recruiting

Lake Success, New York, United States, 11042

Contacts

Geralinde O'Sullivan Coyne

363-207-5160info@startresearch.com

NEXT Texas LLC - Austin

Recruiting

Austin, Texas, United States, 78758

Contacts

Sheena Sahota

737-610-5200ssahota@nextoncology.com

NEXT Texas LLC - Dallas

Recruiting

Dallas, Texas, United States, 75039

Contacts

Farah Polani

972-893-8800fpolani@nextoncology.com

START Dallas Fort Worth, LLC

Recruiting

Fort Worth, Texas, United States, 76104

Contacts

Henry Xiong

682-350-3010info@startresearch.com

NEXT Texas LLC - Houston

Recruiting

Houston, Texas, United States, 77054

Contacts

Jennifer Segar

832-384-7900jsegar@nextoncology.com

NEXT Texas LLC - San Antonio

Recruiting

San Antonio, Texas, United States, 78229

Contacts

David Sommerhalder

210-580-9500dsommerhalder@nextoncology.com

Start San Antonio, LLC

Recruiting

San Antonio, Texas, United States, 78229

Contacts

Amita Patnaik

2105935250info@startresearch.com

START Mountain Region, LLC

Recruiting

West Valley City, Utah, United States, 84119

Contacts

William B McKean

1 (801) 907-4750info@startresearch.com

NEXT Virginia

Recruiting

Fairfax, Virginia, United States, 22031

Contacts

Mohamad A Salkeni

703-783-4510msalkeni@nextoncology.com

More Information

Sponsor

IDEAYA Biosciences

Last update posted

Jun 16, 2026

Last verified

May, 2026

Keywords

  • ER+, HER 2- Breast Cancer
  • Non-small Cell Lung Cancer (NSCLC)
  • Castration-resistant Prostate Cancer (CRPC)
  • Microsatellite Stable (MSS) Colorectal Carcinoma
  • KAT6A/B
  • KAT7

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by IDEAYA Biosciences on 2026-06-16.