Multiple myeloma is a type of cancer that originates in plasma cells which are located in your bone marrow. Plasma cells produce antibodies that help your immune system function like it should. However, if these cells become cancerous, they can grow out of control and start making an excess of an abnormal antibody instead. This can lead to problems with your bones, kidneys, immune system and red blood cells.
Multiple myeloma is treatable, but there is not a cure at this time. Those diagnosed can generally expect to have periods of remission and relapse. In the past, treatment often consisted of traditional chemotherapy and a stem cell transplant to replace the cancerous bone marrow with healthy bone marrow. This was a long process with many tough side effects. But in recent years, several new treatment options have emerged that appear to be better tolerated, decrease the progression of the disease, and improve overall survival rates.
Immunotherapy and targeted therapy help attack the bone marrow cancer.
Your doctor will likely use a combination of drugs to treat multiple myeloma. This decision will be based on whether you are a candidate for a bone marrow transplant, your previous treatments, your health, and the severity of your disease. While chemotherapy may still be used in some cases, many of the new drugs that have been developed to treat multiple myeloma are forms of immunotherapy and targeted therapy.
Immunotherapy gives the immune system a boost, so it can more successfully destroy the cancer cells. Targeted therapy acts on specific molecules within the cancer cells to stop them from growing or spreading.
These newer drugs fall within a few different categories:
- Immunomodulatory agents: These drugs have significantly helped improve myeloma treatment. They help activate cells within the immune system that attack the cancer. Lenalidomide (Revlimid) is the most commonly used, but pomalidomide (Pomalyst) is newer and more potent. Nerve damage, low blood counts, and blood clots are possible side effects.
- Proteasome inhibitors: This treatment works by making proteins build up within the cancer cells, which slows their growth and leads to their death. Bortexzomib (Velcade) was the first in the class to be used for multiple myeloma and has shown great success when used with an immunomodulatory agent. Carfilzomib (Kyrprolis) and ixazomib (Ninlaro) may be used in subsequent treatments.
- Monoclonal antibodies: Daratumumab (Darzalex) and elotuzumab (Empliciti) are man-made antibodies that attach to proteins on the myeloma cells and help kill them. They are given as an infusion into a vein. These drugs are extremely helpful for patients who do not respond to sufficiently to their early treatments.
- HDAC inhibitors: Panobinostat (Farydak) is given as a capsule. It blocks important enzymes that the cancer cells need to grow.
These drugs are often used with steroids, like Dexamethasone, to enhance their effect and decrease adverse reactions.
New multiple myeloma treatments are right around the corner.
Much of the progress in treating multiple myeloma that has been made in recent years is the result of learning more about the multiple myeloma cells themselves- how they grow and interact with other cells and tissues around them. As researchers continue to delve deeper into this process, more promising treatments are expected to come down the line.
For example, a protein called interleukin-6 (IL-6) is produced by the bone marrow and signals the multiple myeloma cells to grow. Studies are underway to develop treatments that block IL-6, thereby slowing down the cancer growth.
Another exciting clinical trial involves the use of T-cells, a type of white blood cell. Using a process called chimeric antigen receptor (CAR) T-cell therapy, an individual’s T-cells are removed, altered in a lab so they can better target and destroy cancer cells, and then re-injected into the patient’s body. Early results have been very encouraging, with 94% of patients going into cancer remission, but the studies have been small. More research is expected in this area.
A test called gene expression profiling is also being studied in regard to multiple myeloma treatment. A patient’s cancer cells can be studied to determine their unique make-up. This can help predict which treatments might provide the best response, such as whether an immunomodulatory agent or proteasome inhibitor should be prescribed. It can also help identify which patients are at high-risk of relapse. Researchers still need to learn more, but tests like this may eventually become routine.
Response to multiple myeloma treatments will vary from person to person, and sometimes a treatment that worked previously will eventually stop. Yet as new treatments are discovered, the prognosis for multiple myeloma continues to improve. Don’t hesitate to talk to your doctor about what treatment options are available for you.
