A trial of doxorubicin, cyclophosphamide and either ixabepilone or paclitaxel as chemotherapy before surgery for early stage breast cancer (CA163100)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 2

This trial was looking at chemotherapy with doxorubicin and cyclophosphamide followed by ixabepilone or paclitaxel before surgery for breast cancer.

Doctors usually treat early stage breast cancer with surgery. Some women have chemotherapy before surgery. This is called neoadjuvant treatment. It can shrink the cancer in the breast and may mean that you can have surgery to remove just the cancer instead of having the whole breast removed (mastectomy).

Two chemotherapy drugs doctors often use are doxorubicin and cyclophosphamide. In this trial, they looked at adding a third drug. This was either paclitaxel or ixabepilone.

Paclitaxel was a drug that doctors could already use to treat breast cancer. Ixabepilone was a new chemotherapy drug. It works in a similar way to paclitaxel and had already been used in clinical trials for more advanced breast cancer.

The aims of this trial were to

See how well ixabepilone worked compared to paclitaxel, following doxorubicin and cyclophosphamide before surgery for early breast cancer
Try and find out if there are genes or proteins that can show which breast cancers are likely to respond better to ixabepilone

Summary of results

The trial showed that ixabepilone and paclitaxel worked about as well as each other.

The trial recruited women in 15 different countries. All the women taking part had doxorubicin and cyclophosphamide for 12 weeks. They were then put into 1 of 2 groups at random.

145 women had ixabepilone every 3 weeks for 12 weeks
144 had paclitaxel once a week for 12 weeks

The trial team looked at the percentage of women who had no sign of cancer in their breast or in the lymph nodes Open a glossary item under their arm after treatment. They found this was very similar in both groups. It was

Just over 24% of the women who had ixabepilone
Just over 25% of the women who had paclitaxel

As the difference is so small, it could have happened by chance so is not statistically significant Open a glossary item .

The side effects were similar in both groups, but more women in the ixabepilone group had a drop in white blood cells that causes an increased risk of infection.

The most common side effect in both groups was numbness and tingling in the hands and feet (peripheral neuropathy).

Women taking part in this trial had a biopsy Open a glossary item before starting treatment. The researchers used the samples to look for proteins that might show which cancers are more likely to respond to ixabepilone. They could see that cancer responded more often in women who had high levels of one particular protein. But this was the same whichever drug they had. So this would not help doctors work out who would benefit from ixabepilone.

The trial team concluded that neither ixabepilone or paclitaxel after doxorubicin and cyclophosphamide caused bad side effects, but there wasn’t much difference in how well the drugs worked.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.