Continuous Treatment with Lenalidomide and Low-dose Dexamethasone in Transplant-ineligible Patients with Newly Diagnosed Multiple Myeloma in Asia: Subanalysis of the FIRST Trial

The phase 3 FIRST (Frontline Investigation of REVLIMID + Dexamethasone Versus Standard Thalidomide) trial demonstrated that lenalidomide plus low-dose dexamethasone (Rd) until disease progression (Rd continuous) is an effective treatment option for transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM). Given genetic differences between Asian and Western populations, this subanalysis of the FIRST trial examined the safety and efficacy of Rd (given continuously or for 18 cycles [Rd18]) and MPT (melphalan, prednisone, thalidomide) in 114 Asian patients from Mainland China, South Korea and Taiwan. Efficacy and safety with Rd continuous in Asian patients were consistent with those in the overall study population. The overall response rates were 77·8% for Rd continuous, 57·5% for MPT and 65·8% for Rd18. The risk of progression or death was reduced by 39% with Rd continuous versus MPT and by 35% with Rd continuous versus Rd18. Rd continuous improved the 3-year survival rate compared with MPT (70·2% vs. 56·4%) and Rd18 (58·1%). Common grade 3/4 adverse events in the Rd continuous and MPT arms were neutropenia (25·0% vs. 43·6%), infection (19·4% vs. 28·2%) and anaemia (19·4% vs. 15·4%), respectively. Thromboembolic event rates were low, and no second primary malignancies were observed. Rd continuous is safe and effective in transplant-ineligible Asian patients with NDMM.