Triple-Combo Treatment of Smoldering Multiple Myeloma May Stall Disease Progression

Early treatment with a combination of anti-cancer drugs in patients with smoldering myeloma, who are at high risk of developing multiple myeloma, may avoid disease progression to its full-blown state, according to the interim results of a Phase 2 clinical trial.

The data was presented recently by researchers from the Dana-Farber Cancer Institute at this year’s 58th annual meeting of the American Society of Hematology in San Diego, Calif.

Patients are considered to have smoldering multiple myeloma if they have pathological signs of the disease or evidence of cancer in their bone marrow. Although the disease is asymptomatic, these patients have a 50% chance of developing the full, symptomatic form of multiple myeloma within two years.

Researchers have been trying to find a way to prevent this early myeloma stage from progressing, and a number of clinical trials are underway to investigate whether early intervention in patients with the smoldering disease can suppress disease progression and safely keep myeloma at bay.

The current Phase 2 trial (NCT02279394) is a single-arm, non-randomized, open-label study, designed to assess the efficacy of the immunotherapy drug Empliciti (elotuzumab) in combination with Revlimid (lenalidomide) and dexamethasone in preventing patients with high risk smoldering multiple myeloma from progressing.

The study’s primary goal was the proportion of patients who had not progressed two years following treatment, and secondary endpoints included response rate, time to progression, overall survival, and safety of the combination therapy.

Data referred to 47 of the 50 patients included in the study so far, of which 23 have completed nine treatment cycles.

The triple-drug therapy lead to an overall response rate of 82.6% (of the 23 patients who completed the treatment), including 34.8% complete and very good partial responses. The triple-drug therapy also was well-tolerated by the patients, and researchers reported little occurrence of adverse side effects (grades 3 and 4).

“Many of these patients are in remission at a median follow-up time of seven months,” Irene Ghobrial, MD, the first author of the study, said in a press release. “Some patients have been followed for 23 months, and we haven’t seen progression to symptomatic disease in any patient,” she said.

The researchers say these results surpass those seen in a previous trial, in which patients with smoldering myeloma were treated with Revlimid and dexamethasone alone, suggesting that the addition of the immunostimulatory antibody, Empliciti, to the therapy might be beneficial to patients. Nonetheless, they believe that a randomized Phase 3 trial is required before this early intervention becomes standard of care for smoldering multiple myeloma patients.