Study: Trodelvy clinical trial results likely practice-changing for people with metastatic triple-negative breast cancer

Contents

STUDY AT A GLANCE

This study is about:

The ASCENT study, which was done to confirm results of a prior study, IMMU-132. The early-phase IMMU-132 study showed that the drug Trodelvy improved outcomes for patients living with metastatic triple-negative breast cancer.

Trodelvy is a “smart drug”

Smart drugs combine two molecules. Trodelvy is a combination of a chemotherapy drug and an antibody that delivers it specifically to cancer cells. The chemotherapy drug then kills the cancer cells, sparing normal cells.

Why is this study important?

Metastatic triple-negative breast cancer is aggressive. Patients have few options for treatment beyond chemotherapy. On April 22, 2020 the U.S. Food and Drug Administration (FDA) granted accelerated approval of the drug Trodelvy for the treatment of advanced, triple-negative breast cancer based on results of the IMMU-132 study reviewed here. The ASCENT study was conducted to verify results of IMMU-132. It confirmed that Trodelvy benefits patients with triple-negative metastatic breast cancer (TNBC).
 

Why are confirmatory clinical trials important?

Confirming studies are done to show how well a new treatment works after it is shown in early studies to be beneficial for patients. New drugs, such as Trodelvy, that are given accelerated FDA approval are required to be tested in a follow-up, larger clinical trial. This is done to verify that the drug really works when it is tested on many more people in a randomized study. The FDA may remove a drug from the market if a confirmatory study shows that the drug does not benefit patients.

The promising research that resulted in the FDA approval of Trodelvy was first reviewed here.

Study findings:

IMMU-132 study

The early phase (I/II) IMMU-132 study included 108 patients with metastatic TNBC. Of the patients who took Trodelvy:

• 1/3 (33 percent) saw their cancers shrink.
  • More than half (55 percent) had no cancer growth for six months.
  • 17 percent had no cancer growth for a year or longer.

ASCENT study

The phase III ASCENT study was done to measure how well Trodelvy works after it was shown in the IMMU-132 study found that it might benefit patients with triple-negative metastatic breast cancer (TNBC).

Identical to the IMMU-132 study, participants in the ASCENT study were randomized to receive either Trodelvy or their doctor’s choice of chemotherapy.

The ASCENT study included 468 patients with metastatic TNBC. It did not include TNBC patients with brain metastases.

• 235 patients received Trodelvy.
• 233 patients received their doctor’s choice chemotherapy.

On average, patients who took Trodelvy in the ASCENT study:

• had no cancer growth for 4 months longer than those who received chemotherapy (5.6 months compared to 1.7 months).

• lived about 6 months longer than those who received chemotherapy (12 months compared to 6 months).

Side effects

As with most cancer medicines, Trodelvy may cause side effects. The side effects of Trodelvy in the ASCENT study were like the reported side effects from the IMMU-132 study. No new side effects were observed in the ASCENT study. The most common side effects include:

• nausea
• neutropenia (abnormally low levels of white blood cells)
• diarrhea
• fatigue
• anemia
• vomiting
• hair loss
• constipation
• decreased appetite
• rash
• abdominal pain

FDA-required labeling for Trodelvy warns about the possibility of severe neutropenia or diarrhea.

Strengths and limitations:

Results of the ASCENT study confirmed the earlier results of the IMMU-132 study and showed that the smart drug Trodelvy is beneficial for patients living with TNBC metastatic breast cancer.

The preliminary results of the ASCENT study were reported as a late-breaking presentation at the European Society of Medical Oncology (ESMO) Virtual Congress 2020. Full results will be presented at an upcoming medical conference.

Context

The results of the ASCENT study confirmed the results of the early phase IMMU-132 study.  Together and for the first time, these studies showed significant improvement in survival with the smart drug Trodelvy compared to standard treatment in patients with TNBC. These important results will likely change how patients living with metastatic TNBC are treated. 

What does this mean for me?

If you have been diagnosed with locally advanced or metastatic triple-negative breast cancer, you may want to talk to your doctor about Trodelvy.

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Reference

Bardia A, Tolaney SM, et. al. LBA17 - ASCENT: A randomized phase III study of sacituzumab govitecan (SG) vs treatment of physician’s choice (TPC) in patients (pts) with previously treated metastatic triple-negative breast cancer (mTNBC). Annals of Oncology (2020) 31 (suppl_4): S1142-S1215. 10.1016/annonc/annonc325.

Disclosure

FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board before publication to assure scientific integrity.