Grieb, Brett

Abstract Background The survival of patients with multiple myeloma (MM) has improved significantly over the past two decades with the introduction of novel treatment agents. However, MM is still largely considered an incurable malignancy with a relapsing-remitting course. A follow-up of at least 10 years from active disease is required to determine whether a plateau in progression-free survival has been attained. Prior literature has used 10 years as a cutoff for "long-term survivorship". In this study, we have assessed the biological disease characteristics and outcomes of long-term survivors with MM (≥10 years from active disease). Methods All patients with active MM evaluated at the Mayo Clinic, Rochester between January 1, 1999 and July 1, 2008 were included in the study after approval of the Institutional Review Board. Patients with smoldering multiple myeloma were excluded. The overall survival (OS) was calculated from the time of symptomatic disease requiring treatment. Patients were then divided into two cohorts: (1) long-term survivors, which included patients who had an overall survival of at least 10 years; and (2) short-term survivors, which included patients who had an overall survival of less than 5 years from the diagnosis of active MM. The baseline characteristics between these two groups were compared using Wilcoxon, chi-square, and Fisher's exact test as applicable. All time-to-event analyses were performed using the Kaplan-Meier method and the survival curves were compared using Log-Rank test. Results During the time frame of the study, 2,125 patients were identified who fulfilled the diagnostic criteria for active MM. The median follow-up for the entire cohort was 12.6 years (95% CI: 12.5-13.4).The median OS for the entire cohort was 4.4 years (95% CI: 4.2-4.7 years). Three-hundred and ninety nine (18.7%) patients survived at least 10 years whereas 872 patients (41%) survived less than 5 years from the date of initial diagnosis. The median OS was 14.1 years for the long-term survivors (95% CI: 13.9-14.6 years) and 2.1 years for the short-term survivors (95% CI: 1.8-2.2 years). The clinical features at diagnosis comparing long-term survivors and short-term survivors are shown in Table 1. Among long-term survivors (n=399), based on the available data regarding remission and ongoing treatment status, 331 patients were categorized into 6 cohorts (Table 2). The MM specific survival data of these 6 cohorts is depicted in Table 2.Figure 1 shows survival outcomes from the 10-year landmark. Of the 6 cohorts, 38 patients in Cohort 1 and 19 patients in Cohort 2 (total 57; 17% of long term survivors, ~3% of the entire cohort ) have been off therapy for at least 5 years and remain in remission, representing a distinct group of patients with 100% 15-year survival. Conclusion In our large database with prolonged follow-up, long-term survivors appear to have distinct baseline characteristics, but also constitute a heterogenous group of patients with disparate outcomes. A small subset (17% of long-term survivors) was identified that may represent patients closest to being considered as 'operationally cured'. Disclosures Lacy: Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Teva: Consultancy; spectrum: Consultancy, Honoraria; Medscape: Consultancy; Physicians Education Resource: Consultancy; Amgen: Consultancy; Apellis: Consultancy; Alnylam: Honoraria; Abbvie: Consultancy; janssen: Consultancy; celgene: Consultancy; Prothena: Honoraria; annexon: Consultancy; Ionis: Honoraria; Research to Practice: Consultancy. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding.

Background:Previous literature has established “long‐term survivors” as patients who survive greater than 10 years from diagnosis of active multiple myeloma (MM). With the rapid discovery and evolving use of novel therapeutic agents, a greater proportion of patients are reaching this milestone. Although these patients share in their extended survival, they also constitute a heterogeneous group in terms of treatments and outcomes.Aims:The aim of this study is to examine a large cohort of long‐term survivors with protracted follow‐up as an attempt to identify a subset of patients within ten‐year survivors who have longstanding disease remission, and examine the predictors of their especially exceptional prognosis.Methods:All patients with active MM evaluated at Mayo Clinic, Rochester between January 1, 1999 and July 1, 2008 were included in the study. Patients with MGUS, smoldering MM, and solitary plasmacytoma were excluded. The overall survival (OS) was calculated from time of symptomatic disease requiring treatment. Patients with greater than 10 year survival from diagnosis were then divided into three cohorts based upon treatment and remission status: Cohort 1 included patients off therapy ≥ 5 years and in sustained remission, Cohort 2 included patients on maintenance therapy ≥ 5 years and in sustained remission, and Cohort 3 included patients who had relapsed within the past 5 years. Differences between the groups were compared using Wilcoxon, Chi‐square, and Fisher's exact test as applicable. “Early” stem cell transplant was defined as patients who received a stem cell transplant within one year of diagnosis.Results:During the time frame of the study, 2,125 patients were identified who fulfilled the diagnostic criteria for active MM. Three‐hundred ninety nine (19%) had survived at least 10 years from diagnosis. Among these patients, based on the available data regarding remission and ongoing treatment status, 332 patients were categorized into three cohorts, seen in Table 1. Sixty patients (18% of long‐term survivors) comprised Cohort 1, 48 patients (14% of long‐term survivors) comprised Cohort 2, and 224 patients (68% of long‐term survivors) comprised Cohort 3. Sex difference was statistically significant between the groups, with more females constituting Cohorts 1 and 2 (p = 0.03). Within Cohort 1, 77% of patients underwent an autologous stem cell transplant (ASCT). The median progression free survival following ASCT in this cohort was not reached (95% CI 15–NR, p < 0.001). In addition, patients in Cohort 1 and Cohort 2 were more likely to undergo an early ASCT as compared to patients in Cohort 3 (p = 0.002). There were no significant differences in high or intermediate risk FISH/cytogenetics at diagnosis, ISS at diagnosis, or induction therapies used at diagnosis among the three groups.Summary/Conclusion:Our study identified a small subset (3% of all patients diagnosed with active MM) of long‐term survivors who are off of therapy and remain in sustained longstanding remission. Female sex, progression free survival following ASCT, and receiving an early ASCT were factors that portended a positive prognosis amongst long term survivors.image