A Phase II Trial of Lapatinib and Trastuzumab With or Without Endocrine Therapy in Locally Advanced HER2 Overexpressing Breast Cancer Patients
The neoadjuvant setting is especially attractive for studies of predictive biologic
correlates for several reasons including early assessment of response to therapy, access to
the primary tumor, and reduced patient numbers compared to those required in the adjuvant
setting. Response to neoadjuvant therapy is a validated surrogate marker for improved
survival; it may be used to test the overall efficacy of neoadjuvant treatment regimens and
response in the primary tumor mirrors the effect of therapy on micrometastases.
Trastuzumab is an efficacious agent in HER2 overexpressing breast cancers. Our results with
neoadjuvant trastuzumab indicate that its efficacy may be better in patients with
treatment-naïve tumors compared to metastatic disease, with 26% of patients showing a
partial response after only 3 weeks of therapy. No patients progressed during this 3-week
period. We have also conducted a neoadjuvant lapatinib study given as a single agent for 6
weeks. The response rates in this second study have been impressive with greater than 80%
responses in patients with HER2 positive locally advanced breast cancers. It is likely that
the true response rate to HER2 blockade would be higher had therapy been continued for
longer. We therefore hypothesize that lapatinib, a dual tyrosine kinase inhibitor, together
with trastuzumab, will result in tumor regression when given as neoadjuvant therapy in HER2
overexpressing breast cancer. We will compare lapatinib plus trastuzumab for 12 weeks, and
if the tumors express ER, estrogen deprivation will also be administered.
This is a phase II trial. Clinical efficacy will be assessed by bidimensional tumor
measurements of the primary cancer at baseline, and at the end of week 12. Objective tumor
response rate defined as objective bidimensional tumor measurements after neoadjuvant
treatment at 12 weeks will be calculated, and assessed according to standard RECIST
criteria. Pathologic responses will be graded as pathologic complete response if there is no
invasive cancer in the residual breast at the time of surgery. Near pathologic complete
response will also be documented as residual disease of less than 1 cm.
Interventional
Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment
Pathologic Assessment After Study Treatment
Pathologic Assessment After 12 weeks of lapatinib and trastuzumab with or without endocrine therapy. Pathologic complete response: no invasive cancer in the residual breast. Near pathologic complete response: residual disease of less than 1 cm in breast.
12 weeks
No
Mothaffar Rimawi, MD
Principal Investigator
Baylor Breast Center
United States: Food and Drug Administration
H-20464
NCT00548184
September 2008
January 2013
Name | Location |
---|---|
Mayo Clinic Cancer Center | Rochester, Minnesota 55905 |
Vanderbilt-Ingram Cancer Center | Nashville, Tennessee 37232-6838 |
The University of Chicago | Chicago, Illinois 60637 |
UAB Cancer Center | Birmingham, Alabama 35294 |
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Bunting-Blaustein Cancer Research | Baltimore, Maryland 21231-1000 |
Baylor College of Medicine, Lester and Sue Smith Breast Center | Houston, Texas 77030 |