Dysautonomia International

A First-in-Human Study of MEN2312 in Adults With Advanced Breast Cancer

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

Participant has advanced (locoregionally recurrent or metastatic) breast cancer not amenable to curative therapy. - Participant must have received at least one 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 or during adjuvant treatment with endocrine therapy, as these participants are considered as first-line relapsed participants. Progression on previous cyclin-dependent kinase 4/6 inhibitor treatment in combination with fulvestrant or aromatase inhibitor is required. No other therapeutic options are considered appropriate by the investigator. - Up to 6 prior lines of systemic therapy (including up to 2 prior lines consisting of chemotherapy, cytotoxic antibody drug conjugate, or a combination of both regimens) are allowed in the advanced/metastatic setting. - Presence of genetic alterations in PIK3CA/AKT1/PTEN in participants' tumor tissue.

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%. Note: Other inclusion/exclusion criteria may apply.

Arm	Description	Assigned Intervention
Experimental MEN2312: Monotherapy	Participants will receive MEN2312.	Drug: MEN2312 MEN2312 administered as oral tablets.
Experimental MEN2312: Combination Therapy (Elacestrant)	Participants will receive MEN2312 in combination with elacestrant.	Drug: MEN2312 MEN2312 administered as oral tablets. Drug: Elacestrant Elacestrant administered as oral tablets. Other names: Orserdu

Highlands Oncology Group
Springdale 4132093, Arkansas 4099753 72703

UC San Diego Moores Cancer Center
La Jolla 5363943, California 5332921 92093-0698

UCSF Helen Diller Family Comprehensive Cancer Center
San Francisco 5391959, California 5332921 94158

UCLA Hematology Oncology - Parkside
Santa Monica 5393212, California 5332921 90404

Yale Comprehensive Cancer Center
New Haven 4839366, Connecticut 4831725 06511

Advent Health Orlando
Altamonte Springs 4145941, Florida 4155751 32701

Sarah Cannon Research Institute at Florida Cancer Specialists
Orlando 4167147, Florida 4155751 32827

Florida Cancer Specialists & Research Institute (FCS) - Sarasota
Sarasota 4172131, Florida 4155751 34232

Sidney Kimmel Comprehensive Cancer Center
Baltimore 4347778, Maryland 4361885 21287

Massachusetts General Hospital Cancer Center
Boston 4930956, Massachusetts 6254926 02114

Dana-Farber Cancer Institute
Boston 4930956, Massachusetts 6254926 02215

START Midwest - Oncology
Grand Rapids 4994358, Michigan 5001836 49546

Mayo Clinic
Rochester 5043473, Minnesota 5037779 55905

Astera Cancer Care
East Brunswick 5097402, New Jersey 5101760 08816

SCRI Oncology Partners Group
Nashville 4644585, Tennessee 4662168 37203

The University of Texas M.D. Anderson Cancer Center
Houston 4699066, Texas 4736286 77030

START San Antonio, LLC
San Antonio 4726206, Texas 4736286 78229

University of Texas Health Science Center San Antonio
San Antonio 4726206, Texas 4736286 78229

START Mountain
West Valley City 5784607, Utah 5549030 84119

NEXT Virginia
Fairfax 4758023, Virginia 6254928 22031

Stemline Trials
1-877-332-7961
clinicaltrials@menarinistemline.com