Most myeloma patients suffer from bone disease, which can cause pain and fractures. Pain caused by bone disease is often treated with localized radiation therapy, and fractures can be stabilized by surgical procedures. However, these therapies only treat symptoms and do not actually slow or prevent further bone disease. Only bisphosphonates (BPs) are commonly used to prevent bone disease associated with myeloma.

BPs are a class of drugs that prevent bone from breaking down. This therapy can decrease bone pain and prevent the development of fractures, but it does not have antitumor effects to cure myeloma.

BP therapy is given by a monthly intravenous dose of either Aredia ^[1] (pamidronate) or Zometa ^[2] (zolendronic acid). Phase 3 trials have shown that Aredia and Zometa are both effective in decreasing complications from bone disease and reducing the need for radiation therapy to relieve pain. Infusion of Aredia takes two hours while Zometa only takes 15 minutes.

The American Society of Clinical Oncology (ASCO) recommends the use of Aredia or Zometa for patients with low bone density, bone destruction, or spinal cord compression. Patients with renal impairment should take Aredia rather than Zometa.

Patients are typically treated with BPs once a month for two years and then discontinued from therapy if they are in remission or a plateau phase. However, the optimal duration and frequency of treatment is not well understood and is currently being studied.

While treatment with BPs slows the progression of bone disease, BPs may also cause adverse side effects. Recent reports ^[3] have linked BP therapy with esophageal cancer and the disease osteonecrosis of the jaw (ONJ). ONJ occurs when there is a loss of blood supply to the jaw, eventually causing jawbone death.

The duration of BP therapy, presence of active myeloma, and previous dental surgery are risk factors for ONJ. Myeloma patients who undergo BP therapy are more likely to develop ONJ than patients who are treated with oral BPs for postmenopausal osteoporosis. Studies also observed that diabetic patients and patients with impaired glucose tolerance are more likely to develop ONJ.

Side effects may appear years after the end of treatment, since BPs can remain in the body for over 10 years.

Myeloma patients should be aware of the advantages and disadvantages of BP therapy. While treatment with BPs slows the progression of bone disease in myeloma patients, BPs may also cause complications.

For more information about myeloma bone disease, see the full article in the American Society of Hematology’s 2008 Education Program Book, Hematology ^[4], and related Beacon articles about the involvement of imaging ^[5] and novel therapies ^[6] for myeloma bone disease.