Multiple myeloma (MM) is a form of blood cancer that begins in bone marrow cells called plasma cells. Abnormal plasma cells begin to grow very quickly, preventing bone marrow from making healthy blood cells.

Abnormal plasma cell growth can lead to anemia (low red blood cell count), infections, bone fractures, and kidney damage. Treatment for multiple myeloma aims to prevent these complications, control symptoms, and prolong life. Treatment often includes various medications and a stem cell transplant. However, it is rarely curable.

An oncologist (a medical doctor who specializes in cancer) can diagnose and create a treatment plan for multiple myeloma. They will use various blood and imaging tests to determine whether you have active myeloma or another condition that can be a precursor to it: monoclonal gammopathy of undetermined significance (MGUS) or smoldering multiple myeloma (SMM). 

If you have MGUS or SMM, your provider will likely suggest watchful waiting rather than active treatment. Multiple myeloma often progresses slowly and may take years to cause symptoms. Therefore, you may not need treatment until your condition progresses to active myeloma (or a different condition).

When you are first diagnosed with active multiple myeloma, your provider will likely start you on a combination drug regimen immediately. This regimen is called induction therapy. It is meant to reduce the number of myeloma cells in your body as much and as quickly as possible.

An induction therapy regimen typically consists of three or four different medications given in several cycles of a few weeks each. For example, you may receive three four-week cycles of a combination of four drugs.

The drugs included in induction therapy can vary depending on several factors, including your specific subtype of myeloma (based on which kind of protein your myeloma cells produce), risk level, and current cancer stage. However, induction therapy typically includes the following types of drugs:

• Immunomodulatory drugs: These drugs work by boosting the immune system to help it fight off the cancer. Examples include Revlimid (lenalidomide) and Pomalyst (pomalidomide).
• Proteasome inhibitors: These drugs block an enzyme that breaks down proteins inside cancer cells. As a result, proteins build up too much in the cancer cells and kill those cells. Examples include Velcade (bortezomib), Ninlaro (ixazomib), or Kyprolis (carfilzomib).
• Corticosteroids: Commonly called steroids, these help prevent inflammation in the body. Decadron (dexamethasone) is one example.

A four-drug regimen may also include an anti-CD38 monoclonal antibody. This drug helps your immune system target certain substances on the surface of myeloma cells. Examples are Darzalex (daratumumab) and Sarclisa (isatuximab).

If you are eligible, you may receive a stem cell transplant after completing induction therapy. Most people receive an autologous stem cell transplant (ASCT). This means that their stem cells are used rather than donor cells. The transplant involves the following steps:

1. Removing your bone marrow stem cells and storing them
2. Giving you high doses of chemotherapy to kill myeloma cells
3. Adding your stem cells back into your bone marrow

Removing your healthy stem cells first protects them from the damaging effects of the chemotherapy. After your stem cells are added back in, they can produce healthy plasma cells.

Recovery generally takes three to six months, and some days will be better than others. You may experience side effects like changes in your taste buds. While stem cell transplants seem to lead to longer progression-free survival rates, they are not proven to prolong overall survival rates.

Eligibility for a Transplant

Not everyone is eligible for a stem cell transplant. Your healthcare team will consider your age, overall health, and personal preferences before approving you for this treatment.

If you are not eligible for a stem cell transplant, you may receive more cycles of induction therapy. Some experts recommend up to eight to 12 cycles in this case. Whether or not you receive a transplant, you will likely move on to maintenance therapy. 

The goal of maintenance drug therapy is to prevent cancer cells from regrowing after induction therapy and/or a stem cell transplant. Maintenance therapy can consist of one or more drugs. These drugs can vary and may include Revlimid, Velcade, and/or Ninlaro.

If your cancer is resistant to treatment (refractory), or if you have a relapse after undergoing the treatments above, your healthcare provider will consider several drug treatment options. 

Your provider will consider your complete health history and symptoms before deciding which medications to prescribe. They may prescribe some of the same medications included in your induction or maintenance phases, such as:

They may prescribe different medications, such as:

• Bispecific antibodies: Like monoclonal antibodies, these are a type of immunotherapy. Examples include Tecvayli (teclistamab), Talvey (talquetamab), and Elrexfio (elranatamab).
• CAR T-cell therapy: These drugs are another type of immunotherapy. They use T cells that have been changed in a lab to target and kill cancer cells. Examples include Abecma (idecabtagene vicleucel) and Carvykti (ciltacabtagene autoleucel). This therapy is usually given in a hospital setting.
• Selective inhibitors of nuclear export (SINE): This newer drug helps prevent myeloma cells from growing. Providers typically prescribe this drug in combination with a steroid. It is meant to treat only people with refractory myeloma. Xpovio (selinexor) is the only drug available.
• Traditional chemotherapy: High-dose chemotherapy helps prepare the body for a stem cell transplant. In lower doses, it also can help treat refractory or relapsed myeloma. Examples include Cytoxan (cyclophosphamide) and VP-16 (etoposide). Combinations of chemotherapy drugs may work best to stop tumor growth. 

Multiple myeloma usually progresses slowly, but not always. Your personal prognosis depends on your age, overall health, and response to treatment. Your subtype of myeloma and current stage, as well as how quickly your cancer is growing, also affect your prognosis.

The relative survival rate of people with multiple myeloma five years after diagnosis is about 61%. There is no cure, but researchers continue to study many new treatments. With advances in treatment, life expectancy is improving over time.

Complications

Possible complications of multiple myeloma that can affect your prognosis include:

• Kidney damage and failure
• Bone fractures
• Hypercalcemia (calcium buildup in the blood)
• Infections
• Anemia (low red blood cell count)

Multiple myeloma treatments can cause a range of side effects and complications. Your healthcare provider will discuss the benefits and risks of each treatment with you before prescribing it. Finding the right treatment may involve some trial and error. 

Side effects of myeloma treatment can include:

• Higher risk of infection
• Higher risk of blood clots
• Digestive symptoms (nausea, vomiting, diarrhea, constipation)
• Mouth sores
• Hair loss
• Achiness
• Extreme fatigue
• Low red blood cell, white blood cell, and platelet count
• Peripheral neuropathy (nerve damage), especially in hands, feet, arms, and legs
• Sleeping challenges

Bispecific antibodies and CAR T-cell therapies may carry unique side effects such as cytokine release syndrome (CRS) and neurotoxicity.

CRS can cause fever and hypotension (low blood pressure). Neurotoxicity can cause neurological symptoms ranging from confusion to seizures. Your healthcare provider will monitor you closely for any side effects.

Supportive Care

Supportive care can help you manage many side effects of treatment. It may include several different methods as needed, including:

• Medications to prevent bone loss and fractures
• Radiation or surgery to remove tumors pressing on your spinal cord or nerves
• Dialysis (filtering blood)) or plasmapheresis (separating plasma from blood) to remove waste products and minimize kidney damage
• Vaccines, antibiotics, or intravenous immunoglobulin (IVIG) to prevent infections 
• Medications or dietary supplements to prevent anemia or blood clots