Results from a recent study published in the journal Blood show promising results involving the use of thalidomide derivatives for the treatment of 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. Standard treatment for multiple myeloma is chemotherapy.
Thalidomide is a substance known for its anti-angiogenesis properties. Angiogenesis is the formation of new blood vessels in the body which is a crucial component for the development of cancer. Blood vessels are needed to supply cancer cells with essential nutrients from the blood. Anti-angiogenesis is the inhibition of the formation of new blood vessels. By stopping blood vessels from forming, cancer cells are “starved” of nutrients, ultimately inhibiting cancer development and growth.
Recently, researchers from the Dana-Farber Cancer Institute in Boston evaluated the effects of substances similar in structure to thalidomide, called immunomodulatory drugs (IMiDs), on multiple myeloma cells that stopped responding to standard chemotherapy. In a series of studies, three different IMiDs were combined with multiple myeloma cells in a laboratory setting. All 3 IMiDs produced significant effects in killing myeloma cells and/or inhibiting their replication. The anti-cancer effects asserted by the IMiDs correlated to escalating doses, meaning that greater anti-cancer effects were achieved with higher doses of IMiDs.
These results are important in showing that significant anti-myeloma effects may be achieved by the use of IMiDs, even in myeloma cells that are resistant to standard chemotherapy effects. Additionally, these findings reveal that two mechanisms are used by thalidomide and IMiDS to achieve anti-cancer effects: 1) anti-angiogenesis, and 2) direct activity against cancer cells to induce death or dormancy. Early phase clinical trials are currently underway to determine optimal doses and regimens of IMiDs.
Patients with multiple myeloma may wish to speak with their physicians about the risks and benefits of participating in a clinical trial utilizing IMiDs or other promising new treatment strategies. (Blood, Vol 96, No 9, pp 2943-2950, 2000)