Background:Venetoclax is a B cell lymphoma 2 (BCL‐2) inhibitor that has shown activity as a single agent and in combination with other therapies in patients with multiple myeloma, particularly those harboring t(11;14) associated with high BCL‐2 expression. Although early clinical trial data is encouraging (monotherapy response rate of 21% and 40% amongst t(11;14) and a response rate of 97% when used in combination with bortezomib and dexamethasone), data on outcomes in patients treated outside of clinical trial setting are sparse.Aims:We aimed to identify the efficacy of venetoclax in patients with multiple myeloma treated outside clinical trial.Methods:We conducted a retrospective review of all patients with multiple myeloma treated with venetoclax between December 2016 and February of 2019 at the Mayo Clinic outside of a clinical trial setting.Results:A total of 29 patients that were treated with venetoclax for relapsed or refractory multiple myeloma were identified. Characteristics of the cohort are reported in Table 1. Two thirds of the cohort had t(11;14) detected on cytogenetic studies and 48% (n = 14) had presence of high risk abnormalities. Median number of prior therapies was 6 (range 1–15) and 21% (n = 6) of patients had received ≥10 prior lines of therapy. Eighty three percent (n = 24) of patients had received prior autologous transplant and 76% (n = 22) were penta refractory or exposed. Median time from diagnosis of myeloma to initiation of venetoclax therapy was 5.3 years (range 0.8–23.6 years).Venetoclax used as monotherapy or a doublet in combination with dexamethasone in 59% (n = 17) of patients and a triplet or quadruplet in 41% (n = 12) given at 800 mg (55%) or 400 mg (35%) daily. Triplet and quadruplet regimens combined venetoclax with a variety of proteasome inhibitors or daratumumab. One patient had a quadruplet of venetoclax, carfilzomib, pomalidomide and dexamethasone. 93% (n = 27) patients were refractory to at least on proteasome inhibitor and immunomodulatory drug. Dose titration and escalation was used in 31% (n = 9) of patients. None of the patients experienced tumor lysis syndrome. At last follow‐up 55% (n = 16) of patients remain on venetoclax therapy. Overall response rate in the 24 patients evaluable for response was 46% (21% CR, 8% VGPR, 17% PR). Patients with t(11;14) had a numerically higher response rate than those without (50% vs 33%, p = 0.64). Patients with high risk cytogenetic abnormalities were less likely to respond (ORR 69% for standard risk vs 18% for high risk, p = 0.019). Median time to response was 2.6 months (range 1.1–6.9 months). Median duration of response was 5.2 months (range 2.2–12.9 months). After a median follow‐up time of 7.2 months for the cohort, the median PFS and OS are 5.8 and 14.6 months, respectively, Figure 1A/B. High risk cytogenetic abnormalities were associated with a shorter PFS (median PFS 3 months vs 14 months for standard risk, p = 0.002). The outcomes with venetoclax monotherapy and combination therapies are reported separately in the Table.Summary/Conclusion:Venetoclax is an effective oral agent in relapsed and/or refractory myeloma and can produce deep and durable responses in heavily pretreated patients. Further studies are needed to elucidate its role earlier in the disease and its effectiveness in combination with other anti‐myeloma therapies.image
PS1397 OUTCOMES OF LONG‐TERM SURVIVORS WITH ACTIVE MULTIPLE MYELOMA
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