The purpose of this study is to determine the dose regimen of Ispinesib in combination with carboplatin in patients with solid tumors. Ispinesib is dosed by 1-hour intravenous infusion and carboplatin is dosed by 30 minute intravenous infusion every 3 weeks (on the same day). A patient may continue to receive treatment as long as they are benefiting from the treatment. Blood samples will be taken at specific times to measure the amount of both drugs in your body at specific times after the drug is given. Blood samples will also be taken for lab tests such as complete blood counts and clinical chemistries. Physical exams will be performed before each treatment with Ispinesib. During the treatment phase, the patients will undergo regular assessments for safety and clinical response.

Inclusion criteria:

• Histologically or cytologically confirmed diagnosis of an advanced solid tumor malignancy that is not responsive to standard therapies or for which there is no standard therapy.
• ECOG (Eastern Cooperative Oncology Group) Performance Status of 0-2.

Exclusion criteria:

• Females who are pregnant or nursing.
• Pre-existing hemolytic anemia.
• Pre-existing peripheral neuropathy greater than or equal grade 2. Greater than or equal to 4 prior chemotherapy regimens including neoadjuvant/adjuvant chemotherapy, except breast cancer subjects who may have received more than 4 prior chemotherapy regimens.
• Absolute neutrophil count less than 1,500/mm3.
• Platelets less than 100,000/mm3.
• Hemoglobin less than 9 g/dL.
• Total bilirubin greater than1.5 mg/dL.
• AST/ALT greater than 2.5 X upper limit of normal.
• Creatinine clearance less than or equal to 50 mL/min (calculated by the Cockcroft Gault Formula).
• Known contra-indications to the use of carboplatin, cisplatin, or other platinum-containing compounds.