Lapatinib in Metastatic Breast Cancer Resistant to Hormone Therapy
Status:
Terminated
Trial end date:
2011-10-01
Target enrollment:
Participant gender:
Summary
Two thirds or more of breast cancers are dependent on estrogen for growth. We use a number of
estrogen-blocking medicines for treatment of metastatic breast cancer. The treatment response
to these agents is unpredictable, however, and approximately one-third of patients with
metastatic breast cancer with receptors for estrogen or progesterone have no benefit from
hormonal therapy. Nearly all patients with metastatic breast cancer will eventually become
resistant to hormonal therapy despite the fact that the hormone receptors are still present.
Some cells make a different class of growth factor receptor called the Epidermal Growth
Factor Receptor. There is a growing body of experimental evidence showing that breast cancer
cells that make Epidermal Growth Factor Receptors are more resistant to hormonal therapy and
have a poorer prognosis. Several investigators have found that the Epidermal Growth Factor
Receptor can activate the estrogen receptor, even in the presence of estrogen-blocking drugs.
Growth of these cells can be slowed by blockade of both Epidermal Growth Factor Receptor
signaling and estrogen-receptor signaling. Lapatinib is a small molecule which can inhibit
two different forms of the Epidermal Growth Factor Receptor. It has been studied in people
with a number of different cancers, including breast cancer, and a safe dose and its common
side effects have been defined.
Our hypothesis is that the Epidermal Growth Factor Receptor is the dominant receptor pathway
used by breast cancers in our patients with hormone-resistant tumors. Drugs like lapatinib
which block several forms of the Epidermal Growth Factor Receptor would best be able to
reverse resistance to hormonal agents.
Phase:
Phase 2
Details
Lead Sponsor:
Dartmouth-Hitchcock Medical Center Gary Schwartz
Collaborators:
North Shore University Hospital University of Colorado, Denver