Study of AC699 in Patients With Estrogen Receptor Positive/Human Epidermal Growth Factor Receptor 2 Negative (ER+/HER2-) Locally Advanced or Metastatic Breast Cancer

NCT ID: NCT05654532

Last Updated: 2025-09-30

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE1

Total Enrollment

100 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-12-29

Study Completion Date

2026-05-31

Brief Summary

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This clinical trial is evaluating a drug called AC699 in participants with estrogen receptor positive/human epidermal growth factor 2 negative (ER+/HER2-) locally advanced or metastatic breast cancer. The main goals of this study are to:

* Identify the recommended dose of AC699 that can be given safely to participants
* Evaluate the safety profile of AC699
* Evaluate the pharmacokinetics of AC699
* Evaluate the effectiveness of AC699

Detailed Description

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This study is a Phase I, first-in-human, open-label dose-escalation study of AC699, an orally bioavailable estrogen receptor degrader, given as a single agent.

Conditions

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Breast Cancer

Study Design

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Allocation Method

NA

Intervention Model

SEQUENTIAL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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AC699 Dose Escalation

Participants will receive an assigned dose of AC699 monotherapy during dose escalation.

One cycle is defined as 28 days.

Group Type EXPERIMENTAL

AC699

Intervention Type DRUG

Participants will receive AC699 orally daily in 28-day cycles.

Interventions

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AC699

Participants will receive AC699 orally daily in 28-day cycles.

Intervention Type DRUG

Eligibility Criteria

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Inclusion Criteria

* Signed written informed consent (ICF)
* Adult male and female participants, at least 18 years-of-age at the time of signature of the ICF
* Female participants must be postmenopausal
* Confirmed diagnosis of advanced, unresectable, and/or metastatic breast cancer following disease progression on standard treatment, or for whom no therapy of proven efficacy exists, or who are not amenable to standard therapies
* Histologically and/or cytologically confirmed diagnosis of estrogen-receptor positive (ER+) human epidermal growth factor 2 negative (HER2-) breast cancer
* Must have received at least 2 prior endocrine or at least 1 prior line of endocrine therapy if combined with CDK4/6 inhibitor
* Prior chemotherapy is not required, but up to 3 prior regimens of cytotoxic chemotherapy will be allowed in the locally advanced/ metastatic setting
* At least 1 measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 (Appendix B) or at least 1 predominantly lytic bone lesion in the absence of measurable disease
* Acceptable organ and hematologic function at baseline
* Life expectancy ≥12 weeks after the start of the treatment

Exclusion Criteria

* Treatment with any of the following:

* Any cytotoxic chemotherapy, investigational agents or other anti-cancer drugs for the treatment of locally advanced or metastatic breast cancer within 14 days prior to the first administration of AC699
* Radiation therapy within 14 days prior to first study drug administration that did not resolve to tolerable toxicity, or prior irradiation to \>25% of bone marrow. Prior palliative radiotherapy to metastatic lesion(s) is permitted, provided it has been completed 7 days prior to study enrollment and no clinically significant toxicities are expected (e.g., mucositis, esophagitis).
* Major surgery within 21 days prior to the first study drug administration (exception: participants may enroll if fully recovered or without intolerable or clinically significant adverse effects but at least 14 days must have elapsed between major surgery and first study drug administration)
* Known symptomatic brain metastases requiring the use of systemic corticosteroids ≥10 mg/day prednisone or equivalents. Asymptomatic and treated, or asymptomatic untreated brain metastases are allowed as long as participants are clinically stable. Stable doses of anticonvulsants are allowed.
* Any condition that impairs a participant's ability to swallow whole pills. Impairment of gastrointestinal function (GI) or GI disease or other condition at baseline that will interfere significantly with the absorption, distribution, or metabolism of AC699.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Accutar Biotechnology Inc

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Site 08

Denver, Colorado, United States

Site Status

Site 07

Orlando, Florida, United States

Site Status

Site 02

Sarasota, Florida, United States

Site Status

Site 06

Rockville, Maryland, United States

Site Status

Site 01

Nashville, Tennessee, United States

Site Status

Site 03

Houston, Texas, United States

Site Status

Site 09

San Antonio, Texas, United States

Site Status

Site 05

Norfolk, Virginia, United States

Site Status

Site 04

Vancouver, Washington, United States

Site Status

Countries

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United States

Other Identifiers

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AC699-001

Identifier Type: -

Identifier Source: org_study_id

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