According to an article recently published in the Lancet, the addition of thalidomide to melphalan (Alkeran®) and prednisone appears beneficial in the treatment of elderly patients with multiple myeloma who are not eligible for a stem cell transplant.
Multiple myeloma is a cancer of the blood that affects the plasma cells. Plasma cells are an important part of the immune system; they produce antibodies to help fight infection and disease. Multiple Myeloma is characterized by an excess production of abnormal plasma cells. Symptoms include increased risk of bacterial infections and impaired immune responses.
Myeloma may also damage the kidneys and cause osteoporosis, anemia, and an elevated blood calcium level.
In a stem cell transplant (an important part of myeloma treatment), high doses of therapy are used to kill more cancer cells than conventional doses. However, a large portion of patients with multiple myeloma, such as elderly patients or patients with other existing medical conditions, are not eligible for stem cell transplants, which are often difficult to tolerate.
Those not treated with a stem cell transplant are often treated with the standard regimen known as MP, which consists of the chemotherapy agent melphalan plus the steroid prednisone. In order to improve outcomes for patients treated with MP, researchers continue to evaluate new agents that are easily tolerated in this patient population.
Thalidomide is an agent that has demonstrated anticancer activity in patients with multiple myeloma that has stopped responding to standard therapies. Thalidomide is an immunomodulatory agent that helps the immune system fight cancer. In addition, thalidomide stops or prevents blood vessels from growing and providing cancer cells with nutrients and oxygen for their spread and growth.
Researchers from Italy recently conducted a clinical trial to further evaluate thalidomide in patients with multiple myeloma who were not eligible for a stem cell transplant. This trial included 255 patients aged 60-85 years with newly diagnosed multiple myeloma. All patients were treated with MP; approximately half of the patients also received thalidomide (MPT) until signs of disease progression.
Patients treated with thalidomide had improved outcomes:
- Complete or partial disappearances of detectable cancer occurred in 76% of patients treated with MPT compared with 47.6% for those treated with MP.
- At two years, disease progression or death occurred in 46% of patients treated with MPT, compared with 73% of patients treated with MP.
- At 3 years, survival rates were 80% for patients treated with MPT, compared with 64% for those treated with MP.
- Severe side effects occurred in 48% of patients treated with MPT, compared with 25% of patients treated with MP.
- The occurrence of blood clots was reduced from 20% to 3% with the introduction of enoxaparin (an agent that prevents blood clots) in patients treated with MPT.
The researchers concluded that the addition of thalidomide appears to provide benefit over MP alone in the treatment of elderly patients with multiple myeloma. However, in light of a recent clinical study published in the New England Journal of Medicine reporting that the addition of thalidomide to stem cell transplantation did not improve 5-year survival for patients with newly diagnosed multiple myeloma, the researchers caution that longer follow-up is necessary to truly determine long-term survival benefits of this treatment approach.
Elderly patients with multiple myeloma who are not eligible for a stem cell transplant may wish to speak with their physician regarding their individual risks and benefits of participation in a clinical trial further evaluating thalidomide or other agents in its class.
Reference: Palumbo A, Bringhen S, Caravita T, et al. Oral Melphalan and Prednisone Chemotherapy Plus Thalidomide Comapred with Melphalan and Prednisone Alone in Elderly Patients with Multiple Myeloma: Randomised Controlled Trial. Lancet. 2006; 367: 825-831.