Investigational Study of Next-Generation Oral Therapy in Solid Tumors Including Breast Cancer
Evaluating a novel approach to selectively target mutant PI3Kα in later-stage cancer
ETX-636 is an investigational oral cancer treatment that uniquely both inhibits and degrades mutant PI3Kα proteins while sparing normal PI3Kα in healthy cells.
About the ETX-636 Study
This Phase 1/2 clinical research study is investigating ETX-636 for the treatment of advanced cancers characterized by PIK3CA mutations, including hormone receptor (HR) positive, HER2 negative/low metastatic breast cancer.
The study is designed to evaluate dose optimization, safety, tolerability, pharmacokinetics, and early clinical activity of ETX-636 in combination with the standard of care selective estrogen receptor degrader (SERD), fulvestrant (FASLODEX™).
Who May Be Eligible?
This study may be an option for people who have:
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- Advanced cancer that has spread or returned
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An advanced recurrent solid tumor with a confirmed PIK3CA mutation
- A type of breast cancer that is HR-positive, HER2-negative/low
- Already received certain standard cancer treatments
- Met additional protocol-defined clinical and laboratory criteria
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This is not a complete list of study requirements. The best way to find out if this study may be a good fit is to speak with a study team member. You can also learn more here: Study Details | NCT06993844 | Phase 1/2 Study of ETX-636 in Participants With Advanced Solid Tumors | ClinicalTrials.gov
What to Expect
1. Pre-Screening
The study team may test for the PI3Kα mutation if the mutation status is not already known.
2. Screening
Before someone can join the study, the study team will review medical history and perform screening tests to help determine if the study may be a good fit
3. Enrollment
If an individual qualifies and chooses to participate, they will be enrolled into the study and assigned to a study treatment group
4. Treatment
Participants will receive ETX-636 alone or in combination with the standard of care selective estrogen receptor degrader (SERD), fulvestrant (FASLODEX™), in patients with advanced HR-positive, HER2-negative/low metastatic breast cancer
Participants will be required to attend regular study visits for imaging, lab work, and safety evaluations
5. Monitoring
The study team will monitor patients throughout the study to assess safety, how the treatment behaves in the body and early signs of clinical activity
Participation is voluntary and all patients will be monitored by experienced clinical teams throughout the study.
Study Details
Study Phase
Phase 1/2 (early-stage clinical research)
Study Arms (treatment groups)
ETX-636 ± current standard of care selective estrogen receptor degrader (SERD), fulvestrant (FASLODEX™), depending on the study group
Objectives
Evaluate safety, tolerability, pharmacokinetics, dose optimization, and early clinical activity to better understand how the treatment works
Duration
Each study part will include a 28-day screening period, followed by a treatment period of up to 6 months or more, with the possibility of additional treatment rounds
Patient Population
Advanced solid tumors with PIK3CA mutations, including HR-positive, HER2-negative/low metastatic or locally advanced and unresectable breast cancer
Locations
Multiple clinical research sites across the United States
Study Site Locations
Study Locations
Newport Beach, California
Hoag Memorial Hospital Presbyterian
Contact: Angela J. Fuller
949-764-4891
aj.fuller@hoag.org
San Francisco, California
UCSF Helen Diller Family Comprehensive Cancer Center
New Haven, Connecticut
Yale University, Yale Cancer Center
Boston, Massachusetts
Beth Israel Deaconess Medical Center
Boston, Massachusetts
Dana-Farber Cancer Institute
Huntersville, North Carolina
Carolina BioOncology Institute
Houston, Texas
The University of Texas MD Anderson Cancer Center
San Antonio, Texas
START San Antonio
Fairfax, Virginia
NEXT Virginia
Seattle, Washington
Fred Hutchinson Cancer Center
Frequently Asked Questions
What is ETX-636?
ETX-636 is an investigational oral therapy being studied in advanced (i.e., Stage 4, recurrent, metastatic) cancers characterized by PIK3CA mutations. PIK3CA is the gene that encodes PI3Kα. ETX-636 both inhibits and degrades mutant PI3Kα proteins while sparing normal PI3Kα in healthy cells, potentially limiting side effects. ETX-636 is not yet approved and is only available in clinical studies.
What is the purpose of this study?
This study is designed to learn about the safety of ETX-636, how it behaves in the body, and the appropriate dose for future studies. Researchers will also look for early signs of how it may impact cancer.
Who can participate in this study?
Adults with advanced solid tumors harboring PIK3CA mutations, including HR-positive, HER2-negative/low metastatic breast cancer, may be eligible. Additional medical criteria will apply.
Is ETX-636 approved?
No. ETX-636 is an investigational therapy and has not been approved for commercial use.
What does “investigational” mean?
An investigational treatment is one that is still being evaluated in clinical research studies and has not yet been approved for general use. Before a study can begin, an ethics committee assesses the study’s purpose, design, and scientific validity to help protect participants’ safety.
Will all study participants receive treatment?
Yes. In one group, advanced tumor patients will receive ETX-636 alone. In other groups, advanced HR-positive/HER2 negative/low metastatic breast cancer patients will be given ETX-636 in combination with the standard of care selective estrogen receptor degrader (SERD), fulvestrant (FASLODEX™), depending on the study group.
What kinds of tests or visits are involved?
Participants will have regular clinic visits, blood tests, imaging scans, and other assessments to monitor their health.
Are there risks associated with participation?
As with any clinical study, there may be risks and potential side effects. The study team will review all known safety information with prospective participants during the informed consent process.
Can participants withdraw from the study?
Yes. Participation is completely voluntary, and patients can leave the study at any time.
Will participants need to travel?
Participants will need to visit a study site for appointments. The study team can provide more details about visit schedules and support.
About Clinical Studies
What is a clinical trial?
A clinical trial, also called a clinical research study, helps researchers learn whether an investigational medication is safe and effective for use in people with a specific medical condition.
Clinical trials follow strict guidelines to help ensure the safety of the participants while researchers learn more about the investigational medication.
What else do potential participants need to know?
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- Each study has specific medical requirements
- A study doctor will review each participant’s health history to confirm eligibility
- Not everyone who applies will qualify