The primary objective is to assess the efficacy of ZD6474 when given orally to patients with relapsed multiple myeloma. A minimum of 15 and a maximum of 30 evaluable patients will be entered on study

Inclusion Criteria:

• Confirmed diagnosis of multiple myeloma.
• Patients must have a minimum serum M-protein level >=10g/L on serum protein electrophoresis or for patients with light chain only disease, a minimum Bence-Jones protein of 1g/24 hr.
• Patients must have received prior treatment for multiple myeloma: patients may have received 1 or 2 prior regimens of oral alkylating based chemotherapy and must have relapsed following treatment (>= 3 months) OR patients may have relapsed following high dose chemotherapy and SCT as first line treatment provided they have not had any other treatment.
• Lab at inclusion of AGC >= 1.0 x10_9/L and platelets >= 50 x10_9/L Bilirubin, AST and/or ALT <= 1.5 x UNL; creatinine < 2 x UNL, Potassium >= 4.0 mmol/L; calcium and magnesium within normal limits·
• Patients may not have had > 2 prior regimens of chemotherapy and/or prior thalidomide treatment.
• Patients may not have had any non-alkylating based chemotherapy.

Exclusion Criteria:

• Patients with a history of other malignancies, except: adequately treated non-melanoma skin cancer, curatively treated in-situ cancer of the cervix, or other solid tumours curatively treated with no evidence of disease for >= 5 years.
• Pregnant or lactating women. Women of childbearing potential must have a negative pregnancy test within 7 days prior to registration and must be using effective contraception throughout the study.
• Patients who have relapsed during treatment with oral alkylating chemotherapy.
• Patients who have received more than 2 prior regimens of chemotherapy.
• Patients who have received excluded medication or have excluded medical conditions.
• Patients who have received any non-alkylating based chemotherapy regimens as initial therapy, or as therapy for recurrent disease.