A large phase III trial in early-stage HER2-positive breast cancer has shown that adding Herceptin ( Trastuzumab ) to chemotherapy significantly reduces the risk of disease recurrence compared to chemotherapy alone.
This study follows three earlier phase III studies which also confirmed Herceptin's superiority to chemotherapy alone in early-stage breast cancer.
HER2-positive breast cancer is a particularly aggressive form of the disease which affects approximately 2030% of women with breast cancer.
The interim analysis of the BCIRG 006 study showed that Herceptin combined with two chemotherapy regimens significantly reduced the risk of cancer coming back at an early stage for HER2-positive breast cancer patients.
Findings from the three earlier trials showed that Herceptin impressively reduced the risk of cancer recurrence by about half. All in all, data from nearly 12,000 patients analysed now provide consistent evidence of Herceptin's effectiveness as adjuvant treatment for early-stage HER2-positive breast cancer, regardless of when or to which type of chemotherapy regimen it is added.
Enrolment to the BCIRG 006 trial began in March 2001 and approximately 3,200 patients have been enrolled in 43 countries.
The study was a randomised, controlled trial that evaluated the combination of Doxorubicin and Cyclophosphamide ( AC ) followed by Docetaxel, with or without Herceptin, and Carboplatin plus Docetaxel and Herceptin ( TCH ), in women with early-stage HER2-positive breast cancer.
Both lymph node-positive and lymph node-negative patients were eligible for entry into the trial.
The interim analysis met its primary efficacy endpoint by showing statistically significant improvements in disease-free survival for both Herceptin-containing arms.
The reduction in the risk of disease recurrence versus chemotherapy alone was 51% in the arm adding Herceptin to Docetaxel following AC, and 39% in the TCH arm.
The interim analysis compared each of the two Herceptin-containing arms versus chemotherapy alone and did not include a comparison of the two Herceptin-containing regimens.
The BCIRG 006 study has an external Independent Data Monitoring Committee ( IDMC ) that regularly reviews safety data. No safety concerns were raised by the IDMC.
Clinically significant, yet rare, cardiac events were seen in 2.3% of patients who received AC chemotherapy followed by Docetaxel and Herceptin, and in 1.2% of those who received Carboplatin plus Docetaxel and Herceptin, versus 1.2% of those who receive AC chemotherapy followed by Docetaxel alone.
Herceptin is a humanised antibody, designed to target and block the function of HER2, a protein produced by a specific gene with cancer-causing potential.
Herceptin has demonstrated improved survival in the advanced ( metastatic ) setting, where its addition to chemotherapy allows patients to live up to one-third longer than chemotherapy alone.
Herceptin received approval in the European Union in 2000 for use in patients with metastatic breast cancer, whose tumours overexpress the HER2 protein.
In addition to being indicated for use in combination with Docetaxel as a first-line therapy in HER2-positive patients who have not received chemotherapy for their metastatic disease, it is also indicated as a first-line therapy in combination with Paclitaxel where anthracyclines are unsuitable, and as a single agent in third-line therapy.
Source: Roche, 2005