Neoplasms

All Conditions

Skin and Connective Tissue Diseases

Symptoms and General Pathology

Carcinoma

Breast Neoplasms

Recurrence

Carcinoma, Lobular

Carcinoma, Ductal, Breast

Neoplasms, Hormone-Dependent

Breast Diseases

Skin Diseases

All Drugs and Chemicals

Antineoplastic Agents

Bone Density Conservation Agents

Hormones

Letrozole

Estrogens

Estrogen Receptor Modulators

Aromatase Inhibitors

Toremifene

Atamestane

Estrogen Antagonists

Estrogen Receptor Antagonists

Selective Estrogen Receptor Modulators

Hormone Antagonists

Enzyme Inhibitors

Antineoplastic Agents, Hormonal

Aromatase inhibition

Estrogen receptor blocker

Hormone therapy

Endocrine therapy

Antiestrogen therapy

Edith Perez, MD

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.

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.

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

Intarcia Therapeutics

toremifene

letrozole

Peter Langecker, MD, PhD

Protocol 777-CLP-32 is the treatment and survival continuation protocol of Biomed 777-CLP-29, and will continue to compare combined hormonal therapy using the experimental aromatase inhibitor (AI) atamestane combined with the FDA-approved anti-estrogen toremifene (Fareston®), to the single agent FDA-approved aromatase inhibitor letrozole (Femara®) for the treatment of advanced breast cancer. The purpose of this study is to determine whether maximal estrogen suppression achieved via the combination of atamestane, plus toremifene (Fareston®), is more effective than letrozole (Femara®) in delaying the growth of breast cancer.

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 survival time for subjects with advanced breast cancer.

Treatment and Survival Continuation Study of Atamestane Plus Toremifene vs Letrozole in Advanced Breast Cancer

Open Label Treatment and Survival Continuation Study of Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
The CAT Study: Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer	NCT00097344	Breast Neoplasm... Neoplasms, Horm...	Atamestane Toremifene Letrozole Aromatase inhib... Estrogen recept... Hormone therapy Endocrine thera... Antiestrogen th...	18 Years -	Intarcia Therapeutics
The CAT Study: Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer	NCT00097344	Breast Neoplasm... Neoplasms, Horm...	Atamestane Toremifene Letrozole Aromatase inhib... Estrogen recept... Hormone therapy Endocrine thera... Antiestrogen th...	18 Years -	Intarcia Therapeutics
Treatment and Survival Continuation Study of Atamestane Plus Toremifene vs Letrozole in Advanced Breast Cancer	NCT00267553	Breast Neoplasm... Neoplasms, Horm...	Atamestane toremifene letrozole	18 Years -	Intarcia Therapeutics

Spots Global Cancer Trial Database for complete estrogen blockade