RecruitingInterventionalPhase 1

A Phase 1, First-in-Human Study of MEN2312, a KAT6 Inhibitor, as Monotherapy and in Combination in Participants With Advanced Breast Cancer

NCT ID: NCT06638307Sponsor: Stemline Therapeutics, Inc.Last updated: 2026-06-11

Summary

This is a first-in-human study of MEN2312, a lysine acetyltransferase 6 (KAT6) inhibitor, in adult participants with advanced breast cancer.

Arms & interventions

DrugMEN2312
MEN2312 administered as oral tablets.
DrugElacestrant
Elacestrant administered as oral tablets.

Outcome measures

Primary

Number of Participants Experiencing Dose-limiting Toxicity When Administered MEN2312
Time frame: Baseline through Day 28
Recommended Phase 2 Dose (RP2D) of MEN2312
Time frame: Baseline through Month 6

Secondary

Overall Response Rate (ORR)
Time frame: Baseline through 28 days after the last treatment administration (up to approximately 7 months)
Duration of Response (DOR)
Time frame: Baseline through 28 days after the last treatment administration (up to approximately 7 months)
Clinical Benefit Rate (CBR)
Time frame: Baseline through 28 days after the last treatment administration (up to approximately 7 months)
Progression-free Survival (PFS)
Time frame: Baseline through 28 days after the last treatment administration (up to approximately 7 months)
Overall Survival (OS)
Time frame: Baseline through 3 months after the last treatment administration (up to approximately 9 months)
Time to Response (TTR)
Time frame: Baseline through 28 days after the last treatment administration (up to approximately 7 months)
Area Under the Plasma Concentration-time Curve (AUC) of MEN2312 When Administered as Monotherapy
Time frame: Up to 6 months post dose
AUC of MEN2312 When Administered as Combination Therapy
Time frame: Up to 6 months post dose
Amount of MEN2312 Excreted in Urine When Administered as Monotherapy
Time frame: Up to 2 months post dose
Comparison of Plasma Concentration of MEN2312 Monotherapy With MEN2312 Combination Therapy
Time frame: Up to 6 months post dose

Eligibility criteria

Sex: AllAge: 18 Years and olderHealthy volunteers: No

Key Inclusion Criteria: * Participant has advanced (locoregionally recurrent or metastatic) breast cancer not amenable to curative therapy. * Presence of genetic alterations in PIK3CA/AKT1/PTEN in participants' tumor tissue. * Participant must have received at least 1 prior line of endocrine therapy for advanced/metastatic disease or participant who has radiological evidence of breast cancer recurrence or progression during or within 12 months from the end of adjuvant treatment with endocrine therapy, as these participants are considered as first-line relapsed participants. * Progression on previous cyclin-dependent kinase 4 and 6 inhibitor treatment in combination with fulvestrant or aromatase inhibitor is required. Key Exclusion Criteria: * Active or newly diagnosed central nervous system metastases. * Participants with advanced, symptomatic visceral spread, who are at risk of life-threatening complications in the short term, including massive uncontrolled effusions (peritoneal, pleural, pericardial), pulmonary lymphangitis, or liver involvement \>50%. * Participants with any toxicities related to prior radiation therapy that have not resolved to baseline or to National Cancer Institute Common Terminology Criteria for Adverse Events v5.0 Grade ≤1, except alopecia and peripheral sensory neuropathy (Grade ≤2). Note: Other inclusion/exclusion criteria may apply.

Study locations (35)

Highlands Oncology Group

Springdale, Arkansas, 72703

Recruiting

Joseph Beck, MD · Principal Investigator

City of Hope

Duarte, California, 31010

Recruiting

Hope Rugo · Principal Investigator

UC San Diego Moores Cancer Center

La Jolla, California, 92093-0698

Recruiting

Rebecca Shatsky · Principal Investigator

Stanford Cancer Center

Palo Alto, California, 94304

Recruiting

Jennifer L Caswell-Jin · Principal Investigator

UCSF Helen Diller Family Comprehensive Cancer Center

San Francisco, California, 94158

Recruiting

Amy Chien · Principal Investigator

UCLA Hematology Oncology - Parkside

Santa Monica, California, 90404

Recruiting

Aditya Bardia, MD, MPH · Principal Investigator

Yale Comprehensive Cancer Center

New Haven, Connecticut, 06511

Recruiting

Patricia LoRusso, DO · Principal Investigator

Advent Health Orlando

Altamonte Springs, Florida, 32701

Recruiting

Wassim Mchayleh, MD · Principal Investigator

Sarah Cannon Research Institute at Florida Cancer Specialists

Orlando, Florida, 32827

Recruiting

Cesar Perez Batista, MD · Principal Investigator

Florida Cancer Specialists & Research Institute (FCS) - Sarasota

Sarasota, Florida, 34232

Recruiting

Judy Wang, MD · Principal Investigator

Moffitt Cancer Center

Tampa, Florida, 33612

Recruiting

Hatem Soliman · Principal Investigator

Winship Cancer Institute, Emory University

Atlanta, Georgia, 30322

Recruiting

Manali Bhave · Principal Investigator

University of Illinois Hospital and Health Sciences System (Outpatient Cancer Center)

Chicago, Illinois, 60612

Recruiting

Oana Danciu · Principal Investigator

University of Iowa Health Care

Iowa City, Iowa, 52242

Recruiting

Mark Burkard · Principal Investigator

The University of Kansas Cancer Center

Fairway, Kansas, 66205

Recruiting

Priyanka Sharma · Principal Investigator

Sidney Kimmel Comprehensive Cancer Center

Baltimore, Maryland, 21287

Recruiting

Jessica Tao, MD · Principal Investigator

Massachusetts General Hospital Cancer Center

Boston, Massachusetts, 02114

Recruiting

Seth Wander, MD, PhD · Principal Investigator

Dana-Farber Cancer Institute

Boston, Massachusetts, 02215

Recruiting

Antonio Giordano, MD, PhD · Principal Investigator

START Midwest - Oncology

Grand Rapids, Michigan, 49546

Recruiting

Manish Sharma, MD · Principal Investigator

Mayo Clinic

Rochester, Minnesota, 55905

Recruiting

Karthik Giridhar · Principal Investigator

Astera Cancer Care

East Brunswick, New Jersey, 08816

Recruiting

Siu-Long Yao · Principal Investigator

Perlmutter Cancer Center - Sunset Park

Brooklyn, New York, 11220

Recruiting

Nancy Chan · Principal Investigator

Perlmutter Cancer Center at NYU Langone Hospital - Long Island

Mineola, New York, 11501

Recruiting

Nancy Chan · Principal Investigator

Laura & Isaac Perlmutter Cancer Center at NYU Langone Health

New York, New York, 10016

Recruiting

Nancy Chan · Principal Investigator

Memorial Sloan Kettering Cancer Center

New York, New York, 10065

Recruiting

Sherry Shen · Principal Investigator

Providence Cancer Institute Franz Clinic

Portland, Oregon, 97213

Recruiting

David Page · Principal Investigator

SCRI Oncology Partners Group

Nashville, Tennessee, 37203

Recruiting

Erika P Hamilton, MD · Principal Investigator

University of Texas Southwestern Medical Center

Dallas, Texas, 75390

Recruiting

Heather McArthur · Principal Investigator

The University of Texas M.D. Anderson Cancer Center

Houston, Texas, 77030

Recruiting

Jason Mouabbi, MD · Principal Investigator

START San Antonio, LLC

San Antonio, Texas, 78229

Recruiting

Amita Patnaik, MD · Principal Investigator

University of Texas Health Science Center San Antonio

San Antonio, Texas, 78229

Recruiting

Virginia Kaklamani, MD · Principal Investigator

START Mountain

West Valley City, Utah, 84119

Recruiting

William McKean, MD, PhD · Principal Investigator

NEXT Virginia

Fairfax, Virginia, 22031

Recruiting

Alexander Spira, MD, PhD · Principal Investigator

University of Wisconsin Carbone Cancer Center

Madison, Wisconsin, 53792

Recruiting

Kari Wisinksi · Principal Investigator

Froedtert Hospital & the Medical College of Wisconsin

Milwaukee, Wisconsin, 53226

Recruiting

Lubna Chaudhary · Principal Investigator