People with high-risk, smoldering multiple myeloma who are treated with Revlimid (lenalidomide) and dexamethasone (Decadron) take longer to progress to full-blown multiple myeloma than their counterparts, according to interim results of an ongoing Phase 3 study. Researchers presented the findings at the American Society of Hematology’s (ASH) 51st Annual Meeting.

“For the first time, we are seeing a study which is addressing the question of the early treatment of patients with smoldering myeloma,” said Dr. Brian Durie, a physician with the Cedars-Sinai Medical Center in Los Angeles and a founder of the International Myeloma Foundation, in an IMF webcast.

People with smoldering multiple myeloma have elevated blood protein and plasma cell levels, but don’t have any symptoms, such as bone pain or kidney failure. For them, the standard advice so far has been to “go home and keep in touch”—doctors check on their smoldering myeloma patients frequently, but don’t treat them until they have multiple myeloma.

The rationale is that unnecessary early treatment puts patients through chemotherapy’s grueling side effects without providing any proven benefits, and many people with smoldering myeloma never get multiple myeloma. Half of the people who have smoldering myeloma progress to cancer within the first five years, with the risk dropping to three percent per year for the next five years, then one percent per year onwards, according to a study published in The New England Journal of Medicine in 2007.

However, doctors have long suspected that certain people with smoldering myeloma are at higher risk of developing multiple myeloma and may benefit from early treatment. Researchers have found some risk factors, published in the journal Blood in 2007 and 2008 and in The New England Journal of Medicine.

It is “very likely” that in the future, studies will show that people with high-risk smoldering multiple myeloma should be treated, wrote Dr. S. Vincent Rajkumar, multiple myeloma physician and professor of medicine at the Mayo Clinic, in an e-mail to the Myeloma Beacon.

In the interim findings that were presented at the ASH meeting, scientists from cancer centers in Spain and Portugal looked at 40 smoldering myeloma patients at high risk for progressing to multiple myeloma. Some patients were not treated, while others were treated with Revlimid and dexamethasone for nine months, then with Revlimid until they developed multiple myeloma. The ASH abstract did not specify exactly how many of the 40 study participants were assigned to the treated and untreated groups.

When researchers followed up on the study participants sometime between 12 and 20 months later, none of the people treated with Revlimid and dexamethasone had developed multiple myeloma. Eight of the untreated participants developed multiple myeloma, including six people who experienced bone lesions from the cancer.

“The early results are really quite remarkable,” said Dr. Durie.

The Revlimid and dexamethasone treatment led to some side effects. Seven people developed anemia, weakness, diarrhea, or blood clots deep in the body. Five had serious side effects, including gastrointestinal bleeding, delirium, glaucoma, and infections, and two of these participants needed to drop out of the study. Two other study participants opted out.

These findings are interim results of the overall clinical trial researchers are currently conducting. They are still examining 40 additional patients and eventually plan to enroll and study 120 people overall, to determine if Revlimid and dexamethasone therapy is a viable preemptive treatment for people with high-risk smoldering myeloma. Patients may volunteer for the study at one of the participating hospitals in Spain. Please see Clinical Trial NCT00480363 for more information.

For more information on the results presented at ASH, please see abstract 614 on the ASH meeting Web site.