It is recommended that all newly diagnosed multiple myeloma (MM) patients who are possible candidates for blood and marrow transplant receive prompt treatment with dexamethasone (a steroid). The majority of patients will respond to this therapy. The combination of melphalan and prednisone (a less potent steroid) is also effective in myeloma but is not recommended until after patients are assessed for autologous blood and marrow transplant. Melphalan may harm the ability to collect stem cells. With melphalan and prednisone, quality of life is often improved but patients usually survive an average of only 2.5-3 years.
Patients with myeloma may have painful localised collections of cancerous plasma cells within the bone, which may lead to a break or fracture formation. Radiation treatment is often used in patients to provide relief of symptoms or to prevent a fracture from developing. This treatment is often used in combination with other therapies.
Autologous (using patient's own cells) stem cell transplant is becoming increasingly popular in treatment of myeloma and is an option for fit patients. Although autologous BMT is not designed to be a cure in myeloma cases, there is strong evidence to support that it prolongs survival, by an average of one to two years, and greatly improves quality of life. Myeloma has become one of the most common indications for autologous BMT in Vancouver.
Reduced Intensity Conditioning (RIC) Transplant
There is increasing evidence to suggest that myeloma patients with high-risk features at the time of diagnosis do less well with an autologous stem cell transplant.
Recognised high-risk features include some chromosomal abnormalities in the bone marrow and elevation of a serum protein called beta-2 micro globulin. A donor transplantation may be recommended for younger patients if a donor can be identified. This is because the donor's immune system may provide an anti-myeloma effect in its own right. Note that RIC-transplant treatment remains experimental and its benefit in myeloma patients is currently unknown.
Pamidronate is an agent that alters bone metabolism leading to rapid correction of high calcium levels in myeloma patients. There is strong evidence that this treatment reduces the painful bone destruction that is common in myeloma. Some studies have suggested that it may prolong survival. Pamidronate is administered intravenously once monthly and is most frequently used in combination with standard chemotherapy or following bone marrow transplant.
It is currently recommended that all patients with bone disease or aggressive ("Stage III") myeloma receive monthly pamidronate for at least two years with further treatments dependent upon individual assessment of risks and benefits.
This drug was developed over 40 years ago as a sedative but it produced severe malformations in newborns when given to pregnant women. Although the drug was quickly withdrawn from the market, it continued to be used as an experimental agent in patients with leprosy and other disorders of the immune system.
In 1999, a major study was published in the New England Journal of Medicine suggesting that 30% of myeloma patients will respond to thalidomide when all other therapies have failed. Thalidomide has since become available in Canada for use in resistant myeloma. This is done through special permission from the BC Cancer Agency and the Health Protection Branch of Canada.
Thalidomide causes sedation and constipation in every patient and may cause nerve damage in the hands and feet known as peripheral neuropathy. Derivatives of thalidomide are in development that are expected to have similar activity to thalidomide without the prominent side effects.
This drug was developed from thalidomide. It is currently not available in Canada other than in clinical trials. It is expected to be approved for use in relapsed/refractory myeloma by Health Canada by the end of 2008. In combination with dexamethasone, more than 50% of patients respond. Studies have also demonstrated an improvement in survival by several months.
Bortezomib, a "proteasome inhibitor", is a newer therapy which has recently become available for patients with relapsed/refractory myeloma. While it has to be administered intravenously, it appears to be effective in about 30% of myeloma patients whose disease is progressing despite conventional myeloma therapies. Side-effects include possible nerve damage (peripheral neuropathy).