Women with metastatic triple-negative breast cancer respond twice as well to chemotherapy if Cetuximab is added, researchers revealed at the 35th Congress of the European Society for Medical Oncology (ESMO) in Milan, Italy. They said that targeting the epidermal growth factor receptor (EGFR) can double the response rate compared to only cisplatin chemotherapy. Patients with triple negative tumors usually have a poor prognosis because the tumor tends to grow and spread rapidly, and also because they generally do not respond well to several therapies.
The researchers revealed that a Phase II randomized clinical trial involving 173 heavily pre-treated women demonstrated that adding cetuximab, an anti-EGFR antibody to cisplatin chemotherapy not only doubled the response rate, but also doubled the time to progression compared to patients on only cisplatin chemotherapy.
Professor Jose Baselga, who led the study along with investigators from Spain, Belgium, Austria, Portugal, the UK and Israel, said:
We are very excited by these results. Although epidermal growth factor receptor (EGFR) had been considered as a potential target for therapy in breast cancer, this is the first proof that this is the case.
The 173 women, all of whom had metastatic cancer (cancer had spread beyond the breast), were randomly selected to receive either:
- Cetuximab (400 mg/m3 initial dose and then 250 mg/m3 weekly) plus up to six 3-weekly cycles of cisplatin, ..or
- Only cisplatin
The researchers inform that the cetuximab/cisplatin combination group had a response rate of 20%, compared to 10.3% in the other group. The cetuximab/cisplatin combination group also had twice the median length of PFS (progression free survival) compared to the other group - 3.7 compared to 1.5 months.
Prof Baselga said:
These two months are very valuable because they more than double the progression-free survival compared to the cisplatin-alone arm. In this advanced-disease population, this type of improvement is rarely seen and it is highly significant.
Dr Fabrice André from Institut Gustave Roussy in Villejuif, France, commented:
The results of this trial are extremely important and convincing given their magnitude. They need now to be confirmed in the context of a large randomized trial.
In addition to open new avenues in the field of cancer treatment, these results also have implications in the field of cancer biology. They suggest that EGFR could play a role in the progression of triple-negative breast cancer.
Prof Baselga added:
If we work hard at identifying the different subtypes and identify the appropriate targets, we should be able to change the natural history of this disease.
Dr André agreed and said:
The results of this trial and others are showing that new and different treatments may provide benefit in subsets of patients with the disease, suggesting that this form of breast cancer might be further re-segmented according to molecular subtypes.
Cetuximab is marketed under the name Erbitux. It is currently approved for the treatment of metastatic colorectal cancer and head and neck cancer. It is manufactured and distributed in North America by ImClone and Bristol-Myers Squibb, and in the rest of the world distribution is by Merck KGaA.
Written by Christian Nordqvist