Multiple myeloma is a cancer that originates in plasma cells, a type of white blood cell found in the bone marrow. These abnormal plasma cells multiply uncontrollably and can crowd out healthy blood cells, leading to various health issues such as bone damage, kidney problems, and anemia. Following initial intensive treatments, which may include chemotherapy or stem cell transplantation, patients often enter a phase called maintenance therapy. This ongoing treatment aims to manage the disease over the long term, helping to suppress any remaining cancer cells and extend periods of disease control.
Purpose of Maintenance Therapy
Maintenance therapy is administered after initial treatment to achieve several important goals in managing multiple myeloma. A primary objective is to prevent or delay disease relapse by keeping lingering cancer cells under control. This strategy aims to prolong remission, the period when disease symptoms lessen or disappear, and contributes to improved overall survival. It also helps maintain the depth of response achieved, potentially preventing disease progression.
Key Medications Used
Several classes of drugs are commonly employed in multiple myeloma maintenance therapy to control the disease. Immunomodulatory drugs (IMiDs), such as lenalidomide (Revlimid), are a frequently used option. Lenalidomide works by modulating the immune system’s activity and directly affecting myeloma cells to cause cell death. It is often taken orally on a cycle, such as three weeks on and one week off.
Proteasome inhibitors, including bortezomib (Velcade) and ixazomib (Ninlaro), represent another class of medications. These drugs inhibit proteasomes, enzyme complexes that break down proteins in cells. This leads to the accumulation of toxic proteins and myeloma cell death. Corticosteroids, such as dexamethasone, are also used, often in combination with other agents, due to their anti-inflammatory and anti-tumor effects.
Managing Side Effects
Patients undergoing maintenance therapy for multiple myeloma may experience side effects, which require careful management. Fatigue is a common complaint. This can be addressed by treating underlying issues like anemia, adjusting diet, and incorporating mild exercise.
Neuropathy is another frequent side effect, particularly with certain proteasome inhibitors. Healthcare providers may adjust drug dosages, change administration schedules, or prescribe medications like gabapentin to help manage nerve pain. Blood count changes, such as low white blood cell counts and low platelet counts, can increase the risk of infection and bleeding. Regular monitoring of blood counts allows for timely interventions, including supportive medications or dose adjustments.
Gastrointestinal issues like diarrhea, constipation, nausea, and reduced appetite may occur. Staying hydrated, making dietary adjustments, and using supportive medications can help alleviate these symptoms. Additionally, skin rashes may develop, which can be managed with appropriate dermatological care.
Duration and Monitoring During Therapy
Maintenance therapy for multiple myeloma is often a long-term commitment, continuing as long as the treatment remains effective and tolerable for the patient. For many, this means continuing therapy indefinitely until disease progression or unacceptable toxicity occurs. Some studies indicate that lenalidomide maintenance can extend remission significantly, from approximately 30 months to 57 months compared to no maintenance treatment.
Regular monitoring is a routine part of maintenance therapy to track disease status and manage any potential side effects. This typically involves periodic blood tests to check for monoclonal protein levels, which indicate disease activity, and to monitor blood counts for any drug-related changes. Imaging studies, such as PET/CT or MRI, may also be used to detect any new bone lesions or other signs of disease progression. Clinical evaluations by the healthcare team are conducted to assess the patient’s overall health, discuss any symptoms, and make necessary adjustments to the treatment plan based on these ongoing assessments.