A Study to Determine the Antitumor Activity and Evaluate the Safety of MKC-1

Inclusion Criteria:

Histologically or cytologically confirmed advanced or metastatic adenocarcinoma of the breast
18 years or older
Karnofsky performance status greater than or equal to 70%
Radiographic or physical examination evidence of at least one site of unidimensionally-measurable disease, using the Response Evaluation Criteria in Solid Tumors (RECIST) criteria
Must have failed both a taxane and an anthracycline, given sequentially or in combination, either in an adjuvant or metastatic setting
All acute toxicity of any prior chemotherapy, surgery or radiotherapy must have resolved to National Cancer Institute Common Toxicity Criteria (NCI CTC) Grade less than or equal to 1

Lab results, within 10 days of MKC-1 administration:

Hemoglobin less than or equal to 9 g/dL
Absolute neutrophil count greater than or equal to 1.5 x 10^9/L
Platelet count greater than or equal to 75 x 10^9/L
Serum creatinine less than or equal to 1.5 x ULN (upper limit of normal)
AST less than or equal to 2.5 x ULN
Serum albumin greater than or equal to LLN (lower limit of normal)
Total bilirubin less than or equal to ULN
Alkaline phosphatase less than or equal to 2.5 x ULN
Signed informed consent

Exclusion Criteria:

Pre-existing hepatomegaly with disease measures greater than or equal to 2 cm below the costal margin, secondary to malignancy

Administration of cancer specific therapy within the following periods prior to study drug initiation:

chemotherapy less than 3 weeks prior
hormonal therapy less than one week prior
radiation therapy less than 2 weeks prior
Be pregnant or lactating; not employing effective birth control
Known central nervous system (CNS) metastases unless treated, clinically stable and not requiring steroids
Clinical evidence of bowel obstruction, active uncontrolled malabsorption syndromes or a history of total gastrectomy
Administration of any investigational agent (therapeutic or diagnostic) within 4 weeks prior to receipt of study medication
Uncontrolled hypercalcemia (serum calcium-corrected greater than 12 mg/dL)
Serious cardiac condition
Any medical conditions that, in the investigator's opinion would impose excessive risk to the patient
Patients with previous malignancies unless free of recurrence for at least 5 years except basal cell carcinoma of the skin or carcinoma-in-situ of the uterine cervix
Treatment with antiretroviral therapy metabolized through CYP3A4