(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer
Breast
Breast
This open-label research study is studying (Z)-endoxifen as a possible treatment for
pre-menopausal (still having periods) women with ER+/HER2- breast cancer. (Z)-endoxifen is a
selective estrogen receptor modulator or "SERM." SERMs work to treat cancer by blocking the
body's natural estrogen from binding to cancer cells. This study includes a pharmacokinetic
part (PK, how the drug works in your body) and a treatment part. The primary purpose of the
study is to see how (Z)-endoxifen works on tumor cell growth by monitoring a cancer marker
called Ki-67. Ki-67 will be measured by biopsy of the breast after about 4 weeks of
treatment. If your cancer is responding to treatment based on the Ki-67 results, you may
continue treatment up to 24 weeks or until surgery.
The PK part of the study will be enrolled first, enrolling about 18 study participants who
will all receive oral once daily (Z)-endoxifen treatment. 12 of these participants will be
randomly assigned to treatment with an equal (50/50) chance to be assigned to (Z)-endoxifen
or (Z)-endoxifen + goserelin (a medication given to block the ovaries from making estrogen
and is also called ovarian suppression). This part of the study will help select the dose of
(Z)-endoxifen to use in the treatment part by measuring the levels of (Z)-endoxifen in the
blood stream and determine how long it takes for the body to remove it.
About 160 study participants will be enrolled in the treatment part. The treatment part will
help to determine how oral once daily (Z)-endoxifen, when taken by itself, compares to oral
once daily exemestane (a medication that decreases the amount of estrogen in the body, also
known as an aromatase inhibitor) and monthly injections of goserelin. Exemestane and
goserelin taken together is a standard treatment regimen for premenopausal patients with
ER+/HER2- breast cancer. Study participants are randomly assigned to treatment with an equal
(50/50) chance to be assigned to (Z)-endoxifen or standard treatment.
Study participation is up to 24 weeks of treatment followed by surgery.
pre-menopausal (still having periods) women with ER+/HER2- breast cancer. (Z)-endoxifen is a
selective estrogen receptor modulator or "SERM." SERMs work to treat cancer by blocking the
body's natural estrogen from binding to cancer cells. This study includes a pharmacokinetic
part (PK, how the drug works in your body) and a treatment part. The primary purpose of the
study is to see how (Z)-endoxifen works on tumor cell growth by monitoring a cancer marker
called Ki-67. Ki-67 will be measured by biopsy of the breast after about 4 weeks of
treatment. If your cancer is responding to treatment based on the Ki-67 results, you may
continue treatment up to 24 weeks or until surgery.
The PK part of the study will be enrolled first, enrolling about 18 study participants who
will all receive oral once daily (Z)-endoxifen treatment. 12 of these participants will be
randomly assigned to treatment with an equal (50/50) chance to be assigned to (Z)-endoxifen
or (Z)-endoxifen + goserelin (a medication given to block the ovaries from making estrogen
and is also called ovarian suppression). This part of the study will help select the dose of
(Z)-endoxifen to use in the treatment part by measuring the levels of (Z)-endoxifen in the
blood stream and determine how long it takes for the body to remove it.
About 160 study participants will be enrolled in the treatment part. The treatment part will
help to determine how oral once daily (Z)-endoxifen, when taken by itself, compares to oral
once daily exemestane (a medication that decreases the amount of estrogen in the body, also
known as an aromatase inhibitor) and monthly injections of goserelin. Exemestane and
goserelin taken together is a standard treatment regimen for premenopausal patients with
ER+/HER2- breast cancer. Study participants are randomly assigned to treatment with an equal
(50/50) chance to be assigned to (Z)-endoxifen or standard treatment.
Study participation is up to 24 weeks of treatment followed by surgery.
Breast
II
Abramson, Vandana
NCT05607004
VICCBRE22108
