At the American Society of Hematology (ASH) meeting this Monday, researchers from Italy reported the positive results of a Phase 2 clinical trial combining Velcade (bortezomib) with thalidomide (Thalomid) and dexamethasone (VTD) for the treatment of newly diagnosed multiple myeloma patients. The drug combination was used as an induction regimen to reduce the tumor in preparation for melphalan-based autologous stem cell transplantation.

Chemotherapy combined with autologous stem cell transplantation – stem cells collected and returned to the same individual - is a typical treatment option in newly diagnosed myeloma patients. Stem cell transplantation replaces the normal stem cells destroyed during the chemotherapy treatment, leading to higher response rates and longer survival. Patients are treated with several cycles of a high-dose induction regimen, followed by treatment with the standard chemotherapy agent melphalan and stem cell transplantation.

The results for the VTD induction regimen were directly compared to the commonly used thalidomide-dexamethasone (TD) combination for newly diagnosed patients. Researchers found that patients treated with three cycles of VTD prior to stem cell transplantation had higher partial rates of response or better than those treated with TD - 92 percent versus 78.5 percent; including a complete response of 21 percent versus 6 percent, a near complete response of 12 percent versus 6 percent, and a very good partial response rate or better of 61 percent versus 30 percent.

Importantly, no patients treated with VTD had disease progression after the induction regimen compared to 4.5 percent of patients treated with TD. Serious adverse effects were similar for the two treatments while VTD treated patients did show a higher frequency of peripheral neuropathy – pain and numbness in hands and feet. However, discontinuation of therapy due to treatment-related adverse side effects was similar for both groups.

After the stem cell transplantation, VTD patients achieved a complete response of 41 percent compared to 20 percent for TD patients, a near complete response of 13 percent versus 9 percent, and a very good partial response or better of 75 percent versus 53 percent.

Patients were also evaluated for a possible second stem cell transplant followed by consolidation therapy with either VTD or TD. Consolidation is used to further reduce the number of cancer cells and achieve even higher response rates. Patients who met the requirements for the second transplant were similar between the VTD and TD treated groups. However, results regarding either the second transplantation or subsequent consolidation therapy have not yet been reported.

An update at the ASH meeting showed that the two-year prolonged progression-free survival for VTD treated patients was 90 percent compared to 80 percent of TD treated patients. The 20-month overall survival rate, however, was 93 percent for both treatment groups.

For more information, see abstract 158 at the ASH meeting website and the associated press release.