NCT00097344

The CAT Study: Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer

Phase 3 Study of Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer

• Status: Terminated
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 842 (planned)
• Sponsor: Intarcia Therapeutics · Industry
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to determine whether maximal estrogen suppression achieved via the combination of an experimental drug, atamestane, plus an FDA-approved drug, toremifene (Fareston®), is more effective than another approved drug, letrozole (Femara®), in delaying the growth of breast cancer, and whether the side effects of the combined hormonal therapy are different from the side effects of letrozole.

Detailed description

Aromatase is an enzyme expressed in tissues such as muscle and fat in postmenopausal women. These non-ovarian tissues become the dominant sources of estrogen in postmenopausal women. Breast cancer cells are often very dependent on estrogens to continue to grow. Atamestane blocks the formation of estrogens from androgenic precursors in the body via the aromatase enzyme. Toremifene blocks circulating and intracellular estrogens from stimulating estrogen receptors in breast cancer cells. The goal of therapy with atamestane, an aromatase inhibitor, in combination with the estrogen receptor antagonist, toremifene, is to achieve complete suppression of estrogen stimulation of breast cancer cells. This study is designed to determine whether combined hormonal therapy will lengthen the time to disease progression and the rate of objective response, as compared to single agent therapy with the approved aromatase inhibitor letrozole.

Conditions

• Breast Neoplasms
• Neoplasms, Hormone-Dependent

Interventions

Type	Name	Description
DRUG	Atamestane
DRUG	Toremifene
DRUG	Letrozole
DRUG	Aromatase inhibition
DRUG	Estrogen receptor blocker
PROCEDURE	Hormone therapy
PROCEDURE	Endocrine therapy
PROCEDURE	Antiestrogen therapy

Timeline

• Start date: 2004-12-01
• Completion: 2006-08-01
• First posted: 2004-11-23
• Last updated: 2007-08-23

Locations

104 sites across 5 countries: United States, Bulgaria, Romania, Russia, Ukraine