Multiple Myeloma Clinical Trial Closes Early Due to Significantly Superior Results of Comparative Treatment

Wednesday, April 04, 2007

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ROCHESTER, Minn. — Mayo Clinic Cancer Center announced today that a multiple myeloma clinical trial has shown a significant improvement in survival with lenalidomide plus low-dose dexamethasone therapy compared to lenalidomide plus high-dose dexamethasone.

The study led by the Eastern Cooperative Oncology Group (ECOG) and supported by the National Cancer Institute compared combination treatment of oral medications lenalidomide and either high- or low-dose dexamethasone in 445 patients with newly-diagnosed myeloma. Lenalidomide plus high-dose dexamethasone had a one-year survival rate of 86 percent. The comparative therapy using low-dose dexamethasone showed a significantly higher 96.5 percent overall survival rate at one year, with much less toxicity.

"In my opinion, this is the best one-year survival data that I've seen in a large phase 3 study in myeloma," says Vincent Rajkumar, M.D., Mayo Clinic hematologist and primary investigator of the ECOG study. "This is a major advance in the treatment of this cancer."

All patients on the high-dose dexamethasone arm of the clinical trial will be moved to the low-dose arm. A successor study using lenalidomide plus high-dose dexamethasone was closed early as a result of these findings.

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Questions and Answers:

Who conducted the study?

The study E4A03 was conducted by the Eastern Cooperative Oncology Group (ECOG), a multi-center cancer clinical trials group. Primary investigator for the study is Vincent Rajkumar, M.D., a hematologist at Mayo Clinic Cancer Center.

What was this study looking at?

This study compared the use of two combinations of lenalidomide (trade name Revlimid) and the steroid dexamethasone (high and low doses) for newly-diagnosed myeloma patients.

Currently lenalidomide and high-dose dexamethasone, referred to as Rev/Dex, is used as second-line treatment for myeloma. This same treatment has been used off-label by physicians for their newly-diagnosed patients, with overall response rates and one-year survival rates in the 90 percent range. Their findings from a Phase II clinical trial were published in Blood in July 2006. This alone is quite good, but because of the significant toxicities related to dexamethasone use, Mayo Clinic researchers wanted to find out if using a lower dose would give the same results. This prompted the Eastern Cooperative Oncology Group to open the Phase III trial referenced in the recent news releases.

What are some of most serious toxicities caused by lenalidomide and high-dose dexamethasone combination therapy?

The most serious side effects are blood clots, infections, low blood counts, high blood sugars, and heart problems.

Why was the study closed early?

ECOG conducted the regular annual review of data and found that the preliminary results indicated very successful results for the lenalidomide plus low-dose dexamethasone arm. These results were so significant that a second phase of the trial that used high-dose dexamethasone was immediately suspended and all trial investigators were asked to consider switching to low-dose dexamethasone for all patients receiving the standard treatment.

What were the specific findings of the study?

The results still have to be finalized, but Vincent Rajkumar, M.D., Mayo Clinic hematologist and principal investigator of the study, will be presenting an abstract at the American Society of Clinical Oncology Annual Meeting the first week of June. The preliminary abstract is available online.

What is multiple myeloma?

Multiple myeloma is an incurable plasma cell cancer, for which the cause is unknown. Plasma cells are a type of white blood cells in bone marrow — the soft, blood-producing tissue that fills bones.

Multiple myeloma, also called myeloma, causes abnormal plasma (myeloma cells) to multiply and increase the overall percentage of plasma cells in bone marrow. This can cause bones to erode. Myeloma also interferes with bone marrow function and the immune system, leading to anemia, infection and possibly kidney failure.

The disease is called multiple myeloma because myeloma cells can occur in multiple bone marrow sites in your body and produces multiple bone lesions. The American Cancer Society reports that it will be diagnosed in about 17,000 people this year in the United States.

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