2011 SABCS, San Antonio Breast Cancer Symposium, 6-10 December, San Antonio, USA
Results from the GeparQuinto trial
Dr Jens Huober – Kantonsspital St. Gallen, Breast Center, Switzerland
The GeparQuinto trial is a neoadjuvant trial for patients with primary non-metastatic breast cancer. This trial was divided into two main setting: the HER2 negative setting and the HER2 positive setting. The HER2 negative setting was also divided into two parts: patients who have a response to the first four cycles of treatment and patients who do not have a clinical response to treatment. So basically the design was that in the HER2 negative part, and I only focus now on the HER2 negative part because this is the setting I was talking about yesterday, HER2 negative patients were randomised to four cycles of epirubicin/cyclophosphamide plus/minus bevacizumab. Then after four cycles a clinical assessment was done and patients who had a clinical partial or complete remission of the tumour in the breast and in the nodes continued with four cycles of docetaxel plus/minus bevacizumab as it was initially randomly assigned. Patients who did not have a response to the treatment of the four cycles of EC plus/minus bevacizumab were taken off this setting one and were re-randomised to paclitaxel weekly for three months or to paclitaxel weekly in combination with the agent RAD-001.
The primary endpoint of our trial was the histopathological complete remission rate, the PCR rate and what we could see is in those patients not responding to the first four cycles of treatment with chemotherapy plus/minus bevacizumab, that the PCR rate was quite low, it was 4.6% for the whole population of 403 patients treated in this non-responder part of the GeparQuinto trial. What we also could see is that the addition of RAD-001 to paclitaxel did not significantly improve the PCR rate compared to the paclitaxel alone arm. The PCR rate was 3.6% in the paclitaxel RAD-001 arm and it was 5.2% in the paclitaxel alone arm.
The first conclusion is that the trial didn’t meet its endpoint because the aim of the trial was to improve the PCR rate from something like 5% to 12.2%. In this context it was a negative trial. However, we have seen in a session here at the San Antonio meeting that the PCR may not be, in all subgroups of breast cancer, a reliably predictive marker for long-term outcome. So it might be that the PCR rate must not improve but in the long-term we cannot say if the regimen was more beneficial with the combination treatment than the paclitaxel alone. So we have to wait for the disease free survival and the overall survival data which we have in a few years.