Efficacy Study of ZD6474 to Treat Multiple Myeloma Cancer

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.