A Phase II Study of CI-1033 in Treating Patients With Metastatic (Stage IV) Breast Cancer

Inclusion Criteria: * Female, at least 18 years of age * Histologically confirmed diagnosis of breast cancer * Metastatic (Stage IV) disease * Progressive or recurrent disease following the most recent therapy * No more than 2 different, prior cytotoxic chemotherapy regimens for metastatic disease * At least one measurable target lesion as defined by Response Evaluation Criteria in Solid Tumors (RECIST) that has not been irradiated * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, determined within 2 weeks prior to randomization * Estimated life expectancy of \> 12 weeks * Capable of giving written informed consent * Capable of swallowing intact CI-1033 capsules * Capable of understanding and adhering to the protocol requirements * No prior exposure to CI-1033 or other agents that target the erbB receptor family (such as Herceptin, Iressa, Tarceva, IMC-C225, and EKB-569) * No known hypersensitivity reaction to tyrosine kinase inhibitors * Adequate liver, renal, or bone marrow function determined within 2 weeks prior to randomization * No cytotoxic chemotherapy within 3 weeks prior to baseline disease assessments (6 weeks for nitrosoureas or mitomycin) * No immunotherapy (including Herceptin) or other biologic therapy within 2 weeks prior to baseline disease assessments * No hormone therapy (including hormone replacement therapy) within 4 weeks prior to baseline disease assessments (6 weeks for megestrol acetate) * Patients must have recovered from the acute effects of any radiation therapy or surgery * No treatment with any other investigational therapy within 4 weeks prior to baseline disease assessments * No history of any cancer other than the present condition (except nonmelanoma skin cancer or carcinoma in situ of the cervix) within the last 5 years * No patients with untreated brain metastases or patients that have not recovered from treatment for brain metastases * No known malabsorption syndrome or other condition that may impair absorption of study medication * No comorbidity or condition which compromises compliance with this protocol as judged by the investigator or that would significantly complicate interpretation of the safety profile of CI-1033 * No patients having reproductive potential who are not using a method of birth control or who are pregnant or breastfeeding or have a positive pregnancy test during baseline Exclusion Criteria: Prior exposure to CI-1033 or other agents that target the erbB receptor family; cytotoxic chemotherapy within 3 weeks prior to baseline disease assessments (6 weeks for nitrosoureas or mitomycin); immunotherapy (including Herceptin) or other biologic therapy within 2 weeks prior to baseline disease assessments; hormone therapy (including hormone replacement therapy) within 4 weeks prior to baseline disease assessments; 6 weeks for megestrol acetate (to exclude the possibility of a hormone-withdrawal response); patients with untreated brain metastases.