Multiple myeloma has long been considered an incurable but manageable cancer.
In recent years, researchers have had some notable successes in developing new treatments. People with multiple myeloma now have options that can reduce symptoms, slow disease progression, provide prolonged remissions, and improve life expectancy and quality.
But there is much more work to be done. While patients with multiple myeloma are living longer than they did two decades ago — in some cases, dramatically longer — the median life expectancy after diagnosis is about five years.
Who Should Be Treated and Who Shouldn’t
With most cancers, the general rule for treatment is “the sooner, the better.” But with multiple myeloma, physicians generally don’t treat early or asymptomatic cancer. This condition is called smoldering multiple myeloma (SMM).
Of people with SMM, about 10 percent per year go on to develop multiple myeloma within five years of diagnosis. Some physicians have historically taken a “wait and watch” approach to symptoms rather than to immediately prescribe medication that can cause side effects.
Clinical trials are underway to see if treatment can improve outcomes for SMM patients at greater risk of progression to “active” myeloma.
Drug Therapies for Treating Multiple Myeloma
Drug therapy is a cornerstone of myeloma treatment.
Physicians generally treat patients with one, two, or three drugs simultaneously. Some patients in intensive programs may be taking as many as six different drugs.
These may be administered orally, by injection, or through a catheter surgically placed in a vein.
Drug therapy has helped some patients achieve long-term remission, and has significantly slowed the progression of the disease in others. A small subset of patients may have such an extended remission that they are considered “functionally” cured.
Key medication strategies include:
Chemotherapy Chemo drugs destroy cancer cells, typically by preventing them from growing and dividing. These medicines include:
- Cyclophosphamide (Cytoxan, Neosar)
- Doxorubicin (Adriamycin, Doxil)
- Melphalan (Alkeran)
- Etoposide (Toposar, VePesid)
- Cisplatin (Platinol)
- Carmustine (BiCNU)
Chemotherapy is often one part of a regimen that includes other categories of drugs.
Targeted Therapy This type of medication homes in on specific genes or proteins in the cancer or in the tissues around it that help malignant cells survive. Targeted drugs block the growth and spread of cancer cells while limiting damage to healthy cells (an issue with chemotherapy drugs).
- Proteasome Inhibitors Drugs such as bortezomib (Velcade), carfilzomib (Kyprolis), and ixazomib (Ninlaro) target specific enzymes in myeloma cells called proteasomes that digest proteins in the cells.
- HDAC Inhibitors The drug panobinostat (Farydak) is an inhibitor of the enzyme histone deacetylase (HDAC). Panobinostat helps uncoil the DNA in myeloma cells and also activates genes that stop or slow cancer-cell growth.
- Monoclonal Antibodies Elotuzumab (Empliciti) and daratumumab (Darzalex) bind to myeloma cells and mobilize the person’s own immune system to attack. These drugs also kill myeloma cells directly.
- Immunomodulating Agents These drugs have been proven to be effective against multiple myeloma by stimulating the immune system. Thalidomide (Thalomid), lenalidomide (Revlimid), and bortezomib are approved to treat newly diagnosed patients. Lenalidomide, pomalidomide (Pomalyst), bortezomib, carfilzomib, panobinostat, ixazomib, elotuzumab, and daratumumab treat recurrent myeloma.
Other Drug Therapies Patients with multiple myeloma are often treated with steroids, such as prednisone or dexamethasone, either alone or in combination therapy. Steroids can both fight inflammation and kill myeloma cells.
Other medication can help prevent the bone damage caused by multiple myeloma from worsening. These drugs include bisphosphonates like pamidronate (Aredia), zoledronic acid (Zometa), and a monoclonal antibody called denosumab (Xgeva).