Lani
12-28-2011, 09:57 PM
therapies
Responses to subsequent anti-HER2 therapy after treatment with trastuzumab-DM1 in women with HER2-positive metastatic breast cancer
E. M. Olson1,
N. U. Lin1,
P. J. DiPiro2,
J. S. Najita3,
I. E. Krop1,
E. P. Winer1 and
H. J. Burstein1,*
+ Author Affiliations
Departments of 1Medical Oncology
2Radiology
3Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
↵*Correspondence to: Dr H. J. Burstein, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Yawkey 12, Boston, MA 02215, USA. Tel: +1-617-632-3000; Fax: +1-617-632-1930; E-mail:hburstein@partners.org
Received February 1, 2011.
Accepted February 8, 2011.
Abstract
Background: Women with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) can respond to multiple lines of anti-HER2 therapy. It is unknown whether these patients will derive further clinical benefit following treatment with trastuzumab-MCC-DM1 (T-DM1).
Patients and methods: We retrospectively identified HER2-positive MBC patients treated with T-DM1 and characterized outcomes during subsequent lines of anti-HER2 therapy. Response was determined by a blinded radiology review. Time-dependent analyses were carried out using Kaplan–Meier estimates.
Results: We identified 23 patients treated with single-agent T-DM1 and report on the 20 patients who discontinued protocol therapy. All patients received trastuzumab-based metastatic therapy before initiation of T-DM1 [median 7 regimens (range 3–14)]. Of these 20 patients, 75% (15 of 20) received further therapy with or without anti-HER2 agents after discontinuing T-DM1. Partial response to either first- or second-subsequent line(s) of therapy was seen in 5 of 15 (33%) treated patients, including 33% (4 of 12) who received a regimen containing trastuzumab and/or lapatinib. Median durations of therapy to first- and second-subsequent regimens after T-DM1 were 5.5 and 6.4 months, respectively.
Conclusions: In heavily pretreated HER2-positive MBC patients, prior exposure to T-DM1 does not exhaust the potential benefit of ongoing anti-HER2 therapy with trastuzumab- and/or lapatinib-based regimens.
Responses to subsequent anti-HER2 therapy after treatment with trastuzumab-DM1 in women with HER2-positive metastatic breast cancer
E. M. Olson1,
N. U. Lin1,
P. J. DiPiro2,
J. S. Najita3,
I. E. Krop1,
E. P. Winer1 and
H. J. Burstein1,*
+ Author Affiliations
Departments of 1Medical Oncology
2Radiology
3Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
↵*Correspondence to: Dr H. J. Burstein, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Yawkey 12, Boston, MA 02215, USA. Tel: +1-617-632-3000; Fax: +1-617-632-1930; E-mail:hburstein@partners.org
Received February 1, 2011.
Accepted February 8, 2011.
Abstract
Background: Women with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) can respond to multiple lines of anti-HER2 therapy. It is unknown whether these patients will derive further clinical benefit following treatment with trastuzumab-MCC-DM1 (T-DM1).
Patients and methods: We retrospectively identified HER2-positive MBC patients treated with T-DM1 and characterized outcomes during subsequent lines of anti-HER2 therapy. Response was determined by a blinded radiology review. Time-dependent analyses were carried out using Kaplan–Meier estimates.
Results: We identified 23 patients treated with single-agent T-DM1 and report on the 20 patients who discontinued protocol therapy. All patients received trastuzumab-based metastatic therapy before initiation of T-DM1 [median 7 regimens (range 3–14)]. Of these 20 patients, 75% (15 of 20) received further therapy with or without anti-HER2 agents after discontinuing T-DM1. Partial response to either first- or second-subsequent line(s) of therapy was seen in 5 of 15 (33%) treated patients, including 33% (4 of 12) who received a regimen containing trastuzumab and/or lapatinib. Median durations of therapy to first- and second-subsequent regimens after T-DM1 were 5.5 and 6.4 months, respectively.
Conclusions: In heavily pretreated HER2-positive MBC patients, prior exposure to T-DM1 does not exhaust the potential benefit of ongoing anti-HER2 therapy with trastuzumab- and/or lapatinib-based regimens.