Please note that this summary only contains information from the full scientific abstract: View ESMO Scientific Abstract

Faulty genes in the tumor tissue of people with advanced breast cancer and an inherited faulty BRCA gene, who were treated with talazoparib

Date of summary: September 2019

Study number: NCT02034916


Study start date: December 2013


Study end date: October 2018


The full title of this abstract is: Next-generation DNA Sequencing (NGS) Results for Tumors From Phase 2 ABRAZO Study of Talazoparib After Platinum or Cytotoxic Non-Platinum Regimens in Patients (pts) With Advanced Breast Cancer (ABC) and Germline BRCA1/2 (gBRCA) Mutations

This study drug is approved to treat the condition under study that is discussed in this summary.


Researchers must look at the results of many types of studies to understand whether a study drug works, how it works, and whether it is safe to prescribe to patients.

This summary reports the results of only one study. The results of this study might be different from the results of other studies that the researchers look at.


More information can be found in the scientific abstract of this study, which you can access here:
View ESMO Scientific Abstract

What did the study look at?

  • Advanced breast cancer is cancer that has spread within or beyond the breast to other parts of the body.
  • Some people with advanced breast cancer have faulty genes within their DNA.
    • DNA is a molecule in a person’s cells that tells the cells how to work. A gene is a section of DNA that can tell the cell how to make a specific molecule, such as a protein.
      • Each gene has a unique name, which can be long. For this reason, genes are commonly known by a set of letters written in italics.
    • Faulty genes can be inherited, such as BRCA1 or BRCA2. Genes can also become faulty when cells grow and divide.
      • Compared with healthy cells, cancer cells grow and divide more quickly and mistakes can happen during this time.
      • Cells normally fix these mistakes using DNA repair mechanisms. If cancer cells cannot repair their DNA, they will die.
  • Talazoparib (TALA for short) is approved to treat people with advanced breast cancer who have a faulty BRCA1 or BRCA2 gene inherited from a parent.
    • TALA stops a type of protein called PARP from repairing damaged DNA in cancer cells.
      • Cells usually have many ways to repair DNA, so TALA will only work in cells that have certain faulty DNA repair mechanisms.
  • The people in this study had advanced breast cancer and had inherited a faulty BRCA1 or BRCA2 gene from a parent. They had previously received chemotherapy treatment for their advanced breast cancer. They all took TALA in this study.
    • The researchers wanted to find out which genes were faulty by testing samples of tumor tissue from these people.
    • The researchers wanted to focus on the types of genes that could be involved in DNA repair.
  • This summary describes which genes were faulty in these people with advanced breast cancer, and how common these faulty genes were.

Who took part in this study?

What were the results of the study?

  • As well as BRCA1 and BRCA2, researchers found other genes that were often faulty, such as TP53 and PIK3CA, in the tumor tissue of people in this study.
  • People with a faulty BRCA1 gene were much more likely to also have a faulty TP53 gene, compared with people who had a faulty BRCA2 gene.
  • The researchers found another 8 genes involved in DNA repair that were faulty in the tumors of a small number of people in this study.

More results from this study can be found here:
View ESMO Scientific Abstract

What was the main conclusion reported by the researchers?

  • The researchers found a number of genes involved in DNA repair that could be faulty in the samples of tumor tissue taken from people with advanced breast cancer.
    • As well as BRCA1 and BRCA2, other genes that were often faulty included TP53 and PIK3CA.
    • The researchers are continuing to look at how these faulty genes might affect the way TALA works in these people.

Who sponsored this study?

Pfizer Inc.
235 East 42nd Street NY, NY 10017
Phone (United States): +1 212-733-2323

Myriad Genetic Laboratories Inc.
320 Wakara Way
Salt Lake City, UT 84108
Phone (United States): +1 800-469-7423 or +1 801-584-3600

Foundation Medicine Inc.
150 Second Street
Cambridge, MA 02141
Phone (United States): +1 888-988-3639

Medivation Inc.
525 Market Street
San Francisco, CA 94105
Phone (United States): +1 415-543-3470

The sponsors would like to thank all of the people who took part in this study.

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