According to a recent article published in the Journal of Clinical Oncology, induction therapy with thalidomide and dexamethasone appears effective and better tolerated than standard initial chemotherapy regimens for newly diagnosed multiple myeloma.
- Multiple myeloma is a cancer involving important immune (infection-fighting) cells called plasma cells. Plasma cells aid the body in fighting infection by producing specialized proteins called antibodies that have the ability to target and/or kill foreign cells. In multiple myeloma, cancerous plasma cells produce abnormal and excessive antibodies that do not have the ability to properly fight infection. In addition, the cancerous plasma cells accumulate in the bone marrow, suppressing the normal formation and function of other cells that are necessary for normal production of blood cells and immune functions. The excessive accumulation of cancer cells in the bone marrow ultimately leads to the formation of tumors in the bone and to the breakdown of bone.
One standard treatment approach for multiple myeloma is high-dose therapy followed by an autologous stem cell transplant. High-dose therapy (chemotherapy and/or radiation) kills more cancer cells than moderate doses. However, more healthy cells, including stem cells, are also killed due to the high doses, often causing significant side effects. Stem cells are immature blood cells produced in the bone marrow that mature into red blood cells, which carry oxygen to tissues; white blood cells, which fight infection; and platelets, which aid the blood in clotting. Autologous stem cell transplants involve the collection of patient’s stem cells prior to high-dose treatment and re-infusion following high-dose therapy to restore depleted blood cell levels. However, due to the side effects caused by high-dose therapy, not all patients are eligible to undergo a stem cell transplant, including the elderly or patients with other medical conditions.
Prior to the process of high-dose therapy and an autologous stem cell transplant, patients receive what is called “induction therapy”. Induction therapy typically consists of conventional doses of chemotherapy administered in an attempt to reduce the amount of cancer in a patient’s body prior to high-dose therapy. Patients often have their stem cells collected following induction therapy. Induction therapy may also reduce the amount of cancer cells contaminating the stem cell collection that will be re-infused into the patient and provide optimal chances that high-dose therapy will eliminate most of the remaining cancer cells. However, induction therapy with chemotherapy is often difficult to tolerate and/or kills stem cells in the bone marrow preventing patients from undergoing optimal stem cell collection. A standard induction therapy for multiple myeloma consists of Oncovin® (vincristine), doxorubicin (Adriamycin®) and dexamethasone (VAD).
Thalidomide is a biologic agent that has demonstrated activity in the treatment of multiple myeloma. Furthermore, it is typically well tolerated, does not cause damage to stem cells and is taken orally. Since thalidomide has shown anti-cancer activity in recurrent multiple myeloma, researchers are evaluating its use as induction therapy to provide an effective and easily tolerated regimen. Significant responses have been reported following thalidomide in patients who have relapsed after high-dose chemotherapy with stem cell support. A report in the November issue of the Journal of Clinical Oncology suggested that thalidomide and dexamethasone was an effective regimen for initial treatment of patients with multiple myeloma and allowed adequate collection of stem cells prior to an autologous stem cell transplant in eligible patients.
- Recently, results from a second clinical trial conducted at MD Anderson Cancer Center provide further evidence regarding the effectiveness of induction therapy with thalidomide and dexamethasone for patients with newly diagnosed multiple myeloma. In this study, 28 patients with untreated multiple myeloma were treated with thalidomide alone and 40 with the combination of thalidomide and dexamethasone (steroid). The overall anti-cancer response rate was 36% for those treated with treated with thalidomide alone and 72% for those treated with thalidomide plus dexamethasone. There were no complete anti-cancer responses in the thalidomide alone group, while 16% of patients treated with the combination regimen had a complete response. Following treatment, 21 patients had adequate stem cell collections to undergo an autologous stem cell transplant. The majority of side effects were reported as mild in both treatment regimens.
These researchers concluded that therapy with thalidomide plus dexamethasone appears to be an effective and well tolerated treatment regimen for newly diagnosed multiple myeloma, either as initial therapy or induction therapy prior to an autologous stem cell transplant. The researchers stated that patients not eligible for a stem cell transplant may wish to seek further consolidation therapy following thalidomide and dexamethasone to improve complete anti-cancer responses and possible long-term outcomes. Patients with newly diagnosed multiple myeloma may wish to speak with their physician about the risks and benefits of participation in a clinical trial further evaluating thalidomide and dexamethasone as initial therapy or other promising therapeutic approaches.
- Weber D, Rankin K, Gavino M, et al. Thalidomide alone or with dexamethasone for previously untreated multiple myeloma.
Journal of Clinical Oncology. 2003;21:16-19.
- Rajkumar S, Hayman S, Gertz M, et al. Combination therapy with thalidomide plus dexamethasone for newly diagnosed myeloma.
Journal of Clinical Oncology. 2002;20:4319-4323.