Tran-Der Tan1#, Ying-Chung Hong2#, Sin-Syue Li3,4, Jui-Ting Yu5, Yung-Chuan Sung6,7, Po-Nan Wang8*, Chieh-Lin Jerry Teng9,10,11

Hematology and Medical Oncology, Koo Foundation Sun Yat‐Sen Cancer Center, Taipei, Taiwan, 2Division of Hematology and Oncology, Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 3Division of Hematology and Oncology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan, 4College of Medicine, National Cheng Kung University, Tainan, Taiwan, 5Division of Hematology/Medical Oncology, Department of Medicine, Tungs’ Taichung MetroHarbor Hospital, Taichung, Taiwan, 6Division of Hematology/Oncology, Department of Medicine, Cathay General Hospital, Taipei, Taiwan, 7School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan, 8Division of Hematology‐Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan, 9Division of Hematology/Medical Oncology, Department of Medicine, Taichung Veterans General Hospital, Taichung, Taiwan, 10Department of Life Science, Tunghai University, Taichung City, Taiwan, 11School of Medicine, Chung Shan Medical University, Taichung City, Taiwan

Abstract

Lenalidomide with dexamethasone (Len/Dex) is considered to be an effective and well-tolerated regimen to treat multiple myeloma (MM) patients relapsing after bortezomib induction therapy. With the increase in novel agents targeting refractory and relapsed MM, the identification of clinical or laboratory variables that can predict the appropriate candidates of Len/Dex is essential. To address this question, we prospectively assessed 38 adult MM patients who received bortezomib-based induction therapy and were administered Len/Dex for their first relapse. These 38 patients were stratified into the symptomatic relapse group (n = 10) and biological relapse group (n = 28) according to the disease status when Len/Dex was initiated. The overall response rate in the symptomatic group and biological relapse group was 70.0% (7/10) and 60.7% (17/28), respectively (P = 0.964). These two groups harbored a comparable median Len/Dex treatment duration (139 vs. 225 days; P = 0.876) and progression-free survival 2 (PFS2) (501 vs. 1289 days; P = 0.410). Multivariate analyses failed to show that treating biological relapse (hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 0.43–3.88; P = 0.648), PFS with bortezomib-based induction therapies ≥18 months (HR: 1.79; 95% CI: 0.64–5.01; P = 0.266), autologous hematopoietic stem cell transplantation (HR: 2.18; 95% CI: 0.56–8.55; P = 0.262), and high-risk cytogenetics (HR: 0.85; 95% CI: 0.18–3.93; P = 0.835) were attributed to depth of Len/Dex treatment. In conclusion, whether MM patients treated by Len/Dex for biological relapse would have a better outcome than those prescribed for symptomatic relapse remains inconclusive. Treating significant biological relapse and symptomatic relapse remains the current consensus.