The majority of multiple myeloma patients suffer from bone disease, and drugs called bisphosphonates are commonly used to help improve bone health in myeloma patients. Dr. David Roodman of the University of Pittsburgh discussed the current use of bisphosphonates in multiple myeloma during an education session on June 7 at the annual American Society of Clinical Oncology (ASCO) meeting.

Treatment of myeloma bone disease is important, since 20 percent of multiple myeloma patients experience a fracture at the time of their myeloma diagnosis, and 60 percent of multiple myeloma patients experience a fracture during their cancer. Additionally, bone disease has a negative impact on the patient’s response to treatment.

“The gold standard [for treatment of myeloma bone disease] is bisphosphonate therapy,” said Dr. Roodman. “Of course the best treatment for myeloma bone disease is treatment of the disease itself.”

Both Aredia (pamidronate) and Zometa (zolendronic acid) decrease the risk of a fracture by an average of almost 50 percent following the first nine months of use. These bisphosphonates also help slow further bone deterioration.

ASCO and Mayo Clinic guidelines currently recommend that myeloma patients with bone disease receive two years of monthly intravenous therapy using Aredia or Zometa. Only patients with active bone disease should continue treatment after two years.

With recent findings, however, physicians are asking whether bisphosphonates should be used longer and in more patients. Besides improving bone health, bisphosphonates may also help fight multiple myeloma.

There was no evidence that bisphosphonates have anti-tumor activity until a presentation on June 6 in which Dr. Gareth Morgan of the Royal Marsden Hospital in London reported on a new study showing that Zometa extends survival in multiple myeloma patients by 5.5 months as compared to Bonefos (clodronate).

According to Dr. Morgan’s study, it appears that bisphosphonates may benefit myeloma patients in terms of survival even if they do not have bone complications. Additional data confirming these findings is expected to be released at the American Society of Hematology meeting in December.

“Bisphosphonates are very effective in treating myeloma bone disease and have really revolutionized the treatment of myeloma bone disease,” said Dr. Roodman.

However, the use of bisphosphonates is not without risk. A patient’s kidneys may be damaged with prolonged use. Bisphosphonates can also cause osteonecrosis of the jaw (ONJ), in which there is a loss of blood supply to the jaw resulting in jawbone death. The complication is more common after long-term use of bisphosphonates, but all three doctors on the educational panel gave anecdotal evidence of seeing fewer and fewer cases of ONJ now that patients are urged to maintain and monitor their dental health.

Dr. Roodman highlighted that a new, experimental drug, denosumab, is looking promising. He also pointed out that Velcade (bortezomib) encourages new bone formation in some patients.

In the question and answer period following the formal presentations, Dr. Todd Zimmerman from the University of Chicago reminded those in attendance that up to 17 percent of newly diagnosed myeloma patients are vitamin D deficient, or have other vitamin D-related issues at diagnosis. He stressed that bisphosphonates are not as effective without enough vitamin D. Therefore, deficiency needs to be corrected.