An Extension Study to Provide Bortezomib to Patients With Relapsed or Refractory Multiple Myeloma Who Previously Participated in a Bortezomib Phase I/II Study and Who May Benefit From Re-Treatment With or Continuation of Bortezomib Therapy

Inclusion Criteria:

* Complete 6 cycles treatment in preceding phase I/II study
* response (CR, PR, MR or NC) was obtained in 6 cycles treatment during the preceding phase I/II study and investigator considers that the patient is expected to have benefit such as antitumor effect, pain relief or improvement of performance state
* Patients who did not have Grade \>=3 non-hematologic toxicity or Grade 4 hematologic toxicity during the preceding phase I/II study or extension treatment of this study
* Investigator considers that the patient is expected to have benefit of this drug such as antitumor effect, pain relief or improvement of performance state.

Exclusion Criteria:

* Patient is known to be HBs antigen positive, HCV antibody positive or HIV antibody positive (check is required for patients who received blood product during phase I/II study)
* Patients who receive G-CSF product or blood transfusion within 7 days before the start of treatment
* Disease progress was observed during the phase I/II or this study when patients receive recommended dose
* Patients who suffer Grade \>=2 peripheral neuropathy or Grade \>=2 neuropathic pain
* Patient has New York Heart Association (NYHA) Class III or IV heart failure, uncontrolled angina, severe uncontrolled ventricular arrhythmias, acute ischemia or active conduction system abnormalities.