"Taxane Plus Trastuzumab Better for the Heart Than Anthracycline Regimens: Presented at SABCS"
By Charlene Laino
SAN ANTONIO, TX -- December 19, 2006 -- Using a taxane in combination with trastuzumab (Herceptin) results in similar disease-free survival as a regimen containing an anthracycline plus trastuzumab, but with much less cardiac toxicity, a phase 3 study suggests.
Dennis Slamon, MD, PhD, director, clinical and translational research, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California, presented the results during an oral session here on December 14[th at the 29th Annual San Antonio Breast Cancer Symposium (SABCS).
The Breast Cancer International Research Group (BCIRG) 006 study included 3,222 women with early-stage HER2/neu-positive breast cancer, regardless of their axillary lymph node status.
The women were randomized to 1 of 3 arms: group A, the control arm which involved a standard course of 4 cycles of doxorubicin (Adriamycin) and cyclophosphamide followed by 4 cycles of docetaxel (Taxotere); group B received trastuzumab added to the group A regimen; group C received 6 cycles of docetaxel with carboplatin and trastuzumab.
At a median follow-up of 3 years, both experimental regimens were associated with significantly better outcomes compared with group A (standard treatment), Dr. Slamon reported.
Specifically, 7.5% of 1,073 women in group A died, compared with 4.6% of 1,074 women in group B (P = .004 vs control) and 5.2% of 1,075 women in group C (P = .017 vs control). Also, 17.9% patients in group A relapsed, compared with 11.9% in group B (P < .0001 vs control) and 13.2% patients in group C (P = .0003 vs control).
When the 2 experimental arms were compared, however, there was significantly less cardiotoxicity associated with the nonanthracycline regimen. Patients in group B were 5 times more likely to develop congestive heart failure compared with group C (20 vs 4 patients). "And there was a doubling of loss of asymptomatic cardiac function without overt heart failure associated with the anthracycline regimen," with 18% of patients in group B affected versus 8.6% of patients in group C, Dr. Slamon said.
"The benefits of Herceptin are significant," Dr. Slamon said. "But when used with anthracyclines, we may be causing more problems than we are fixing."
"The new results tell us that by using Herceptin with chemotherapy regimens that do not include anthracyclines, we can get just as good results -- without causing potentially fatal heart problems," he said.
Dr. Slamon said he believes the findings are significant enough to change the way clinicians treat women with early-stage breast cancer who carry the HER2/neu gene.
"We should move the anthracyclines out of this setting and reserve it for women with metastatic disease if they have run out of other options. The preferred treatment of choice is Herceptin in combination with a non-anthracycline-containing regimen such as cyclophosphamide and/or docetaxel," he said.
The study was supported by Sanofi Aventis with funding from Genentech.
[Presentation title: BCIRG 006: 2nd Interim Analysis Phase III Randomized Trial Comparing Doxorubicin and Cyclophosphamide Followed by Docetaxel (ACT) With Doxorubicin and Cyclophosphamide Followed by Docetaxel and Trastuzumab (ACTH) With Docetaxel, Carboplatin and Trastuzumab (TCH) in Her2neu Positive Early Breast Cancer Patients. Abstract 52]
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