RecruitingPHASE2INTERVENTIONAL

Genomic and Transcriptomic Predictors of Sequential SG Sensitivity After T-DXd in ER+/HER2-Low Metastatic Breast Cancer

This study is for people with a type of advanced breast cancer (ER+/HER2-low) that has progressed after other treatments, including T-DXd. Doctors want to see how well sacituzumab govitecan (SG) works as a next step. We're also collecting tumour samples to look closely at the genes (genomic) and cell activity (transcriptomic) within them. By doing this after T-DXd treatment but before SG, the researchers hope to find clues about why SG works for some people and not others. This could help doctors choose the best treatments in the future, giving patients more options when standard treatments are no longer effective.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

British Columbia Cancer Agency

Enrolment target

Start

31 Mar 2025

Estimated completion

01 Dec 2028

Breast Cancer

What is this study about?

This study is for individuals in Canada who have advanced (metastatic) breast cancer that is hormone receptor-positive (ER+) and has low levels of HER2 protein (HER2-low). This type of cancer can be challenging to treat, especially when standard therapies, like hormone therapy with CDK4/6 inhibitors and other chemotherapy, have already been tried and the cancer has started to grow again. Importantly, all participants in this study would have already received a specific treatment called trastuzumab deruxtecan (T-DXd).

Doctors are interested in finding out if another treatment called sacituzumab govitecan (SG) can be effective after T-DXd. Both T-DXd and SG are modern cancer treatments known as 'antibody-drug conjugates' (ADCs). They work by delivering powerful chemotherapy directly to cancer cells. Even though they both work in a similar way, the scientific understanding of how effective SG is immediately after T-DXd is still limited. This study aims to gather evidence to help doctors understand if this treatment sequence can be beneficial.

Beyond simply seeing if SG works, a key part of this study involves taking new tumour samples. By analysing the genetic makeup (genomic) and the activity within the tumour cells (transcriptomic) after T-DXd and before SG treatment, researchers hope to uncover specific patterns or 'biomarkers'. These biomarkers could help predict which patients are most likely to respond well to SG. This knowledge is incredibly important because it could lead to more personalised and effective treatment plans for people with advanced breast cancer in the future.

Key takeaways

Tests sacituzumab govitecan (SG) after another drug (T-DXd) for advanced ER+/HER2-low breast cancer.
Aims to find out if SG is effective in this specific situation.
Uses tumour biopsies to find clues in genes about who might respond best.
Could help doctors choose better treatments in the future.
For patients whose cancer has progressed after previous treatments.
Is a Canadian-based study in Vancouver.

Who may be eligible?

This study is looking for certain adults in Canada with advanced breast cancer. You might be able to join if your breast cancer is hormone receptor-positive (ER+) and has low levels of HER2.

To join, you must have already received several treatments for your advanced breast cancer, including a type of hormone therapy with a CDK4/6 inhibitor, and specifically, trastuzumab deruxtecan (T-DXd) as your most recent treatment before joining the study. Your tumour must also be in a place that can be safely biopsied.

There are also general health requirements, like being at least 18 years old, having a good general fitness level (ECOG PS 0-2), and healthy organ function. If you are a woman of childbearing age, you'll need a negative pregnancy test and agree to use contraception during the study and for 12 weeks after your last dose of SG.

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 18 years or older?
Do you have ER+/HER2-low advanced breast cancer?
Have you already had T-DXd treatment as your last therapy?
Can doctors safely take a new tumour sample (biopsy) from you?
Are your general health and organ functions good?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you would receive the study drug, sacituzumab govitecan (SG), through a drip into your vein. This treatment is given on Day 1 and Day 8 of every 21-day cycle. You will continue to receive this treatment for as long as it is helping you and you are not experiencing severe side effects, or until you and your doctor decide to stop.

Before you start treatment, you will undergo a tumour biopsy to collect a fresh sample. Blood samples will also be taken to compare with the tumour biopsy. Throughout the study, you'll have regular hospital visits for blood tests, check-ups with your doctor, and scans (like CT or MRI) to see how the treatment is working. This is a single-centre study in Vancouver, Canada.

Potential risks and benefits

Participating in this study might offer a potential benefit by giving you access to sacituzumab govitecan (SG) after T-DXd, which isn't a standard sequence of treatment and could help control your cancer. However, this treatment can have side effects, as with any cancer medication. Your doctors will carefully monitor you for any issues. You have the right to withdraw from the study at any time, for any reason, without it affecting your future medical care.

Locations (1)

BC Cancer - Vancouver Center
Verified postcode
Vancouver, Canada· Recruiting

Common questions

What is ER+/HER2-low breast cancer?

It's a type of breast cancer where the cells have receptors for hormones (ER+) but only low levels of a protein called HER2 (HER2-low).

What is sacituzumab govitecan (SG)?

It's a targeted cancer drug that delivers chemotherapy directly to cancer cells helping to reduce side effects.

Why do I need a biopsy if I join?

Researchers will study your tumour sample after your previous treatment to find clues (biomarkers) that predict who responds best to the study drug.

Can I join if I haven't had T-DXd treatment?

No, you must have received T-DXd as your most recent treatment before joining this study.

Where is this study taking place?

This study is being conducted at BC Cancer in Vancouver, Canada.

How to find out more

Stephen Chia, MD

schia@bccancer.bc.ca 604-877-6000 Official trial record

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