Phase III trial of lenalidomide plus high-dose dexamethasone versus lenalidomide plus low-dose dexamethasone in newly diagnosed multiple myeloma (E4A03): A trial coordinated by the Eastern Cooperative Oncology Group

LBA8025 Background: We compared lenalidomide plus high (standard) dose Dex (R+HighD) versus lenalidomide plus low dose Dex (R+LowD) in newly diagnosed MM. Methods: Pts with untreated, symptomatic MM were eligible. Pts in both arms received lenalidomide 25 mg/day PO days 1–21 every 28 days. In addition, pts in the R+HighD arm received Dex 40 mg days 1–4, 9–12, and 17–20 PO every 28 days; pts in the R+LowD arm received Dex 40 mg days 1, 8, 15, and 22 PO every 28 days. The primary null hypothesis was that response rates at 4 months on the 2 arms are equivalent. Planned sample size was 196 eligible pts per arm with one-sided 0.10 Type I and 0.05 Type II error rate. Pre-planned interim analysis is performed by an independent DMC when full information is available on 25%, 50% and 75% of accrual. All analysis were intent to treat. Results: 445 pts (median age, 65 yrs) were accrued; 223 randomized to R+HighD, 222 to R+LowD. Arms were well balanced for age, gender, stage, bone lesions, hemoglobin, beta-2 microglobulin, performance status, bone marrow plasma cells, and M protein levels at baseline. Major grade 3 or higher toxicities included thromboembolism (22.1% with R+HighD vs 6.1% in R+LowD), infection/pneumonia (15.7% vs 7.5%) and hyperglycemia (9.7% vs 6.6%). Grade 3 or higher non-hematologic toxicities occurred in 65.9% (R+HighD) versus 54.9% (R+LowD) respectively; corresponding grade 4 or higher rates were 20.3% vs 13.1% respectively. Overall survival (OS) at first interim analysis was significantly superior with R+LowD, P<0.001; one year survival 96.5% (R+LowD) versus 86% (Rev+HighD). OS differences in favor of R+LowD were seen in pts <65 (P=0.015; one year rate 98% vs 90%) and pts 65 and older (P=0.004; one year rate 95% vs 83%), respectively. DMC recommended release of survival results, and recommended switching all pts to R+LowD. DMC also recommended closure of an expansion phase trial of R+HighD investigating optimal thromboprophylaxis. Conclusions: Lenalidomide plus low-dose dexamethasone is associated with superior OS compared to lenalidomide plus high-dose dexamethasone. This study has major implications for future use of high-dose dexamethasone in the treatment of MM. No significant financial relationships to disclose.