Sea sponge drug could boost advanced breast cancer survival by 5 extra months

Researchers led by Professor Chris Twelves, based at the University of Leeds and Leeds Teaching Hospitals NHS Trust, looked at two major clinical trials of more than 1,800 women with breast cancer that had started to spread to other parts of the body. The phase III trials – the final stage of testing before deciding whether a drug can be prescribed to patients – compared the survival of women treated with eribulin* to those given standard treatment.

The two studies showed an overall improvement in survival of more than two months for women treated with eribulin**. The most significant improvement was seen in women with the advanced triple negative form of breast cancer, where there are limited treatment options; these women's survival improved by nearly five months. There was also a survival boost of more than two months for women with the HER2 negative form of breast cancer***.

Cancer spreading to other organs – called metastasis – is responsible for around 90 per cent of all cancer deaths. And, when patients with breast cancer are diagnosed after the disease has started to spread, 10-year survival is around one in 10, compared to nearly nine in 10 for those diagnosed at the earliest stage.

Study author, Professor Chris Twelves, said: “Our results show a substantial improvement in survival for women with metastatic triple negative breast cancer, and a more modest, but significant, benefit for those with HER2 negative breast cancers.

“Eribulin has previously been offered to women who've already been through several lines of chemotherapy. But the European Union has recently approved eribulin for patients who have received less treatment for their breast cancer, which means we hope to give more patients another treatment option in the not-too-distant future.

“Despite advances in the diagnosis and treatment of women with breast cancer, more than 11,600 women still die from invasive breast cancer each year in the UK. New and better treatments are needed for people fighting the disease.”

Eribulin works by stopping the cancer cells from separating into two new cells. It is a type of drug called a microtubule inhibitor. Eribulin was originally developed from a sea sponge called Halichondria okadai but is now made in the laboratory.

Martin Ledwick, head information nurse at Cancer Research UK, said: “These results are encouraging and may offer valuable extra time to patients whose cancers have stopped responding to conventional treatments and have few options left. Advanced breast cancer can be very difficult to treat so these results take us a small, important step in the right direction.

“Although eribulin isn't a cure, it's an extra treatment option for patients with advanced breast cancer, which can be priceless to them and their families.”

Read the full conference abstract – http://conference.ncri.org.uk/abstracts/2014/abstracts/A036.html

*Eribulin (also called eribulin mesylate or Halaven) is a chemotherapy drug used to treat advanced breast cancer. It is usually given to people who have already had at least two other courses of chemotherapy. Eribulin works by stopping (inhibiting) the cancer cells from separating into two new cells. It is a type of drug called a microtubule inhibitor.

** Overall survival for women treated with eribulin was 15.2 months, compared to 12.8 months for women given standard therapies. Women with HER+ breast cancer saw no statistically significant improvement.

*** HER2 stands for human epidermal growth factor receptor. It is a protein found in small amounts on some normal cells, including breast cells, stomach cells and bladder cells. It is one of the proteins involved in cell growth. Some cancers have cells with large amounts of this protein and they are called HER2 positive. These cancers can be treated with drugs that target the HER2 protein. If a cancer does not have large amounts of the HER2 protein it is called HER2 negative.

Triple negative breast cancers are cancers that don't have receptors for oestrogen, progesterone or Her2. Only around 15 out of every 100 breast cancers (15%) are triple negative.