Newswise — CHICAGO — The largest randomized trial involving smoldering multiple myeloma suggests that lenalidomide, a cancer drug, may delay the onset of myeloma symptoms, according to Mayo Clinic researchers. The study was conducted by the Eastern Cooperative Oncology Group and funded by the National Cancer Institute.

The findings, to be presented at the American Society of Clinical Oncology annual meeting in Chicago, are in line with a smaller trial in 2015 by researchers in Spain. "In conjunction with the Spanish data, this trial may support a change in clinical practice," the study says.

"At present, the standard of care for smoldering multiple myeloma is observation without therapy," says S. Vincent Rajkumar, M.D., a Mayo Clinic hematologist and senior author of the trial. "We found that treatment of smoldering myeloma delays progression to symptomatic myeloma and can prevent damage to organs that occurs in multiple myeloma."

The study featured 182 patients, 92 of whom received the drug, which is known by the brand name Revlimid. The 90 other patients did not receive the drug but were observed, as in common practice. Almost half of the patients receiving the drug responded to therapy, while no change was reported among observation patients.

Serious adverse events occurred in 28 percent of patients on lenalidomide, but Dr. Rajkumar says those events were considered manageable.

The results, in combination with the findings in the 2015 Spanish study, support a change in the standard of care for intermediate and high-risk smoldering myeloma patients, says Dr. Rajkumar.

"We show that it is possible to delay progression to multiple myeloma, a serious cancer with significant morbidity, by early therapy administered when the disease is still asymptomatic," he says.

The Spanish study involved two drugs — lenalidomide and dexamethasone, a steroid — and it was not clear whether the beneficial effect was due to the drugs independently or in combination. The present study, which is under review for publication and involved researchers from around the U.S., shows that lenalidomide alone has a similar effect of delaying disease progression. Sagar Lonial, M.D., of Emory University's Winship Cancer Institute, is the study's lead author.

The 55th annual American Society of Clinical Oncology annual meeting, which runs May 31–June 4, is the largest meeting of international oncology clinicians, allied staff and researchers.

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Meeting Link: American Society of Clinical Oncology Annual Meeting