RecruitingPHASE3INTERVENTIONAL

BGB-43395 Plus Letrozole Versus CDK4/6i Plus Letrozole for Patients With Advanced or Metastatic HR+/HER2- Breast Cancer Who Have Not Received Prior Treatment for Advanced or Metastatic Disease

This research study is for people with a specific type of advanced breast cancer called HR+/HER2- breast cancer. This means the cancer is sensitive to hormones but doesn't have too much of a protein called HER2. The study aims to see if a new drug, BGB-43395, when taken with letrozole, works as well as, or better than, current standard treatments. These standard treatments involve another type of drug called a CDK4/6 inhibitor (like abemaciclib, palbociclib, or ribociclib) also taken with letrozole. This study is for people who have not yet received treatment for their advanced or metastatic breast cancer. Researchers want to find out if the new combination is both effective and safe.

At a glance

Status

Recruiting

Phase

PHASE3

Sponsor

BeOne Medicines

Enrolment target

1,056

Start

22 May 2026

Estimated completion

07 Aug 2037

HR+/HER2- Breast Cancer

What is this study about?

This study is investigating a new treatment for advanced breast cancer that is hormone receptor-positive (HR+) and HER2-negative (HER2-). This is a common type of breast cancer where the cancer cells grow in response to hormones, but don't have high levels of the HER2 protein.

The main goal of this study is to compare a new drug called BGB-43395, when given along with an existing drug called letrozole, to the current standard treatments. Standard treatments for this type of cancer often involve a drug that targets CDK4/6 (like abemaciclib, palbociclib, or ribociclib) also given with letrozole. Researchers want to understand if the new combination is a good option for patients who haven't yet received treatment for their advanced breast cancer.

By comparing these treatments, the study aims to see if BGB-43395 plus letrozole is effective at controlling the cancer and if it is well-tolerated, meaning it doesn't cause too many side effects. This kind of research is important because it helps doctors find better ways to treat cancer and improve patients' lives.

Key takeaways

This study is for advanced HR+/HER2- breast cancer that hasn't been treated yet.
It compares a new drug (BGB-43395) with existing standard treatments.
You'll receive either the new drug combination or a standard one, chosen at random.
Participation involves regular check-ups, tests, and monitoring.
The goal is to find better and safer treatments for this type of cancer.

Who may be eligible?

To join this study, you must be at least 18 years old and have been diagnosed with breast cancer that is advanced or has spread (metastatic). Your cancer must also be confirmed as hormone receptor-positive (HR+) and HER2-negative (HER2-). You should be generally well and able to carry out most daily activities without too much difficulty. Also, your body's organs, such as your kidneys and liver, need to be working well.

However, you cannot join the study if you have already received treatment specifically for your advanced or metastatic breast cancer. This study is only for those who are starting their first treatment for advanced disease. You also can't participate if you've previously taken certain specific cancer drugs that target CDK4 or CDK2, or if you have specific brain conditions like active leptomeningeal disease or uncontrolled brain tumours.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you at least 18 years old?
Do you have advanced or metastatic HR+/HER2- breast cancer?
Have you NOT received any prior treatment for your advanced or metastatic breast cancer?
Are you generally well and able to manage most daily activities?
Do you have no specific brain conditions like active meningitis or uncontrolled brain tumours?

Answer every question to see your result.

What does participation involve?

If you choose to take part in this study, you will receive either the new drug combination (BGB-43395 plus letrozole) or one of the standard drug combinations (a CDK4/6 inhibitor plus letrozole). You won't get to choose which one you receive; it will be decided randomly, like flipping a coin. You will have regular appointments for check-ups, blood tests, scans, and to discuss any side effects you might be experiencing. These visits will help the doctors monitor your health and how the treatment is working.

The specific details of how long you'll be on treatment and how often your visits are will be explained fully by the study team. Treatment will continue as long as it is helping you and you are tolerating it well. After you stop treatment, there will be follow-up appointments to monitor your health. The total duration of your involvement could be several months to a few years, depending on how your treatment progresses and the long-term follow-up plan.

Potential risks and benefits

Taking part in a clinical trial offers potential benefits, such as access to a new treatment (BGB-43395) that is not yet widely available, and close monitoring by medical experts. However, there are also potential risks, as new drugs can have side effects that are not yet fully understood. While letrozole and CDK4/6 inhibitors have known side effects, BGB-43395 may have different or additional side effects. It's important to remember that not everyone benefits from treatments in a study, and your cancer might not respond to the study treatment. You will be fully informed of all known risks and benefits before deciding to participate, and you have the right to withdraw from the study at any time, for any reason, without affecting your future medical care.

Locations (108)

Alabama Oncology Princeton
Verified postcode
Birmingham, United States· Recruiting
Alaska Oncology and Hematology, Llc
Verified postcode
Anchorage, United States· Recruiting
Ironwood Cancer and Research Centers Chandler Ii
Verified postcode
Chandler, United States· Recruiting
Genesis Cancer and Blood Institute Hot Springs (Harmony Park)
Verified postcode
Hot Springs, United States· Recruiting
Helios Clinical Research the Oncology Institute Fountain Valley
Verified postcode
Fountain Valley, United States· Recruiting
Ventura County Hematology Oncology Specialists
Verified postcode
Oxnard, United States· Recruiting
Brcr Coral Springs
Verified postcode
Coral Springs, United States· Recruiting
Mid Florida Hematology and Oncology Center
Verified postcode
Orange City, United States· Recruiting
Florida Clinical Trials Group Plantation
Verified postcode
Plantation, United States· Recruiting
Hematology Oncology Associates of the Treasure Coast
Verified postcode
Port Saint Lucie, United States· Recruiting
Florida Clinical Trials Group Tamarac
Verified postcode
Tamarac, United States· Recruiting
Hope and Healing Cancer Services
Verified postcode
Hinsdale, United States· Recruiting

Common questions

What type of breast cancer is this study for?

This study is for advanced or metastatic HR+/HER2- breast cancer. This means your cancer is hormone-sensitive but doesn't have too much of the HER2 protein.

What are the main treatments being tested?

One group will receive BGB-43395 plus letrozole, and the other group will receive a standard CDK4/6 inhibitor (like abemaciclib, palbociclib, or ribociclib) plus letrozole.

Do I get to choose which treatment I receive?

No, the treatment you receive will be chosen randomly, similar to drawing lots, to ensure fairness and good scientific results.

Can I join if I've already had treatment for my advanced breast cancer?

No, this study is specifically for people who have not received any prior treatment for their advanced or metastatic disease.

What is the purpose of this study?

The study aims to find out if the new drug BGB-43395 combined with letrozole is effective and safe compared to current standard treatments for this type of breast cancer.

How to find out more

Study Director

clinicaltrials@beonemed.com 877-828-5568 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.