PS1384 TREATMENT CHOICES AND OUTCOMES FOR PATIENTS WITH MULTIPLE MYELOMA AFTER RELAPSE ON LENALIDOMIDE MAINTENANCE THERAPY: RESULTS FROM THE CONNECT ® MM REGISTRY

Please indicate where the abstract has been published before: Jagannath S, et al. Treatment Choices and Outcomes for Patients with Multiple Myeloma after Relapse on Lenalidomide Maintenance Therapy: Results from the Connect ® MM Registry. Blood. 2018;132(suppl 1). Abstract 3232. Background: Treatment for relapsed multiple myeloma (MM) has evolved with the availability of many novel agents; outcomes in patients with newly diagnosed MM have improved with IMiD agents (lenalidomide [R] or pomalidomide) and proteasome inhibitor (PI) use. Regardless of transplant, many patients receive R maintenance therapy. However, there is a lack of data about the nature of relapse and treatment choices for patients progressing on R maintenance therapy. The Connect MM Registry is a US, multicenter, prospective observational cohort study designed to examine diagnostic and treatment patterns, clinical outcomes and quality of life in mostly community‐based (84% of sites) patients with MM. Aims: To describe nature of relapse, second‐line (2L) treatment choice, and outcomes in patients progressing on R maintenance therapy using Connect MM Registry data. Methods: Adult patients ≤ 60 d from MM diagnosis were enrolled from 250 sites, (N = 3011), treated at physicians’ discretion, and followed up for treatment and outcomes until death, early discontinuation or study end. Transplant‐eligible and ‐ineligible patients who relapsed during R maintenance therapy (≤ 15 mg; assessed by treating physician), were analyzed for baseline (BL) characteristics, nature of relapse, and 2L treatment. Patients with symptoms at time of relapse (symptomatic) were defined by the presence of ≥ 1 CRAB (hyperCalcemia, Renal failure, Anemia, and Bone disease) criterion ± 60 d from progressive disease (PD); nonsymptomatic relapse was the absence of CRAB criteria at PD. Primary endpoint was progression‐free survival (PFS) and secondary endpoints were overall survival (OS) and safety (serious adverse events; SAEs); all from start of 2L. Logistic regression analyses on all BL factors and factors before start of 2L treatment were performed to identify covariates differentiating comparator groups. Survival outcomes were analyzed using a Cox regression after adjusting for covariates. Results: Data cutoff: 1/15/18. Of 2939 treated patients, 1109 entered 2L, 234 having received R maintenance therapy in 1L. Of those patients, 52% (n = 122) and 48% (n = 112) experienced symptomatic and nonsymptomatic relapse, respectively. Median duration of prior maintenance therapy (369 d [IQR: 565] vs 488 d [IQR: 585]) and time from first progression to start of 2L treatment (0.3 vs 0.3 mo) did not differ notably between nature of relapse groups. A PFS benefit was seen for patients receiving triplet+ (≥ 3 agents; n = 112) vs doublet‐ (≤ 2 agents; n = 122) regimens (15.0 vs 9.0 mo; HR: 0.68) from start of 2L. PFS and OS were better for patients receiving regimens containing IMiD agent + PI vs PI (without IMiD agents) in 2L (PFS: HR, 0.67; Figure ; OS: 44.3 vs 25.8 mo; HR, 0.53). SAEs rates were similar among treatment groups: 43%, 35%, and 33% with IMiD agent + PI (n = 61), IMiD agent (without PI; n = 57), and PI (n = 102), respectively. Summary/Conclusion: This is the first description of relapse patterns, 2L treatment choice and survival outcomes after PD on R maintenance therapy in community‐based patients. Similar numbers of patients had symptomatic or nonsymptomatic relapse. After PD on R maintenance, ∼50% of patients switched to PI, 25% received IMiD agent + PI, and 25% recieved IMiD agent. Our data show PFS benefit for triplet+ over doublet‐ treatment in 2L. Patients in the IMiD agent + PI group gained PFS and OS benefits over patients in the PI group. Characterization of patients in the IMiD agent group are ongoing. These data may be used to better inform treatment choices after relapse on R maintenance therapy.