Long-term results of response to therapy, time to progression, and survival with lenalidomide plus dexamethasone in newly diagnosed myeloma.

OBJECTIVE

To determine the long-term effects of a combined regimen of lenalidomide and dexamethasone (Rev-Dex) on time to progression, progression-free survival, and overall survival (OS) in patients with multiple myeloma.

PATIENTS AND METHODS

From March 2004 through October 2004, 34 patients were registered for the study. They were treated with 25 mg/d of lenalidomide on days 1 through 21 of a 28-day cycle and 40 mg/d of dexamethasone on days 1 through 4, 9 through 12, and 17 through 20 of each cycle. After 4 cycles of therapy, patients were allowed to discontinue treatment to pursue autologous stem cell transplant (SCT). Treatment beyond 4 cycles was permitted at the physician s discretion.

RESULTS

Thirteen patients proceeded to SCT after initial therapy and were censored at that time point for purposes of calculation of response. Thirty-one patients achieved an objective response, defined as a partial response or better (91%; 95% confidence interval, 79%-98%), with a complete response plus very good partial response rate of 56%. The complete response plus very good partial response among the 21 patients who received Rev-Dex without SCT was 67%. The 2-year progression-free survival rates for patients proceeding to SCT and patients remaining on Rev-Dex were 83% and 59%, respectively; the OS rates were 92% and 90% at 2 years and 92% and 85% at 3 years, respectively. The 3-year OS rate for the whole cohort was 88%.

CONCLUSION

The Rev-Dex regimen is highly active in the treatment of newly diagnosed multiple myeloma. Responses are durable with a low progression rate at 2 years. Randomized trials that incorporate quality-of-life measures are needed to determine if this and other combination regimens are better used early in therapy or should be reserved for later interventions.