Citations

8000 Background: The diagnostic criteria for MM were revised in 2014, recategorizing ultra-high risk (i.e., 80% at two years) as active myeloma requiring therapy. The removal of patients at the highest risk of progression from the smoldering group requires reassessment of current risk stratification models. Methods: We designed a multicenter, retrospective study of SMM patients to develop a risk stratification model. Patients diagnosed with SMM on/after January 1, 2004 were included if they had no disease progression within 6 months, had baseline data from diagnosis (+/- 3 months), had a follow up of ≥1 year, and did not participate in a therapeutic trial of SMM. Various clinical and laboratory factors were explored to identify factors that predicted progression at 2 years. Univariate Cox regressions were run for each factor. For factors with p-values ≤ 0.25, optimal cut points were identified using Youden’s index. Binary factors were used in stepwise regression to fit multivariable Cox model and significant risk factors were determined (F-test). Results: Overall, 2004 patients were included (ages 26-93, 51% female). Factors independently associated with progression (optimal cutoffs) included: Serum M protein (2 g/dL), involved to uninvolved serum-free light chain ratio (20), and marrow plasma cell % (20%). Patients were stratified using the risk factors: Low- (0 factors), Intermediate- (1), and High-Risk (≥2). Previously used high risk markers such as Bence Jones proteinuria (≥500 mg/24 hours) and severe immunoparesis (50% decrease in uninvolved immunoglobulin levels) were both significant in univariate analysis, but were eliminated on step wise selection. Compared to the low risk group, intermediate- and high-risk groups had significantly higher rate of progression (Table). Within the high-risk group, having all 3 risk factors (n=61) versus 2 did not add to the model, with insufficient separation between 2 and 3 factors. Conclusions: We have developed a risk stratification model for SMM that incorporates revised cutoffs for previously used parameters (20/2/20) that can be universally applied. Additonal analysis are being conducted to develop models that utilize common cytogenetic abnormalities, as well as those without FLC given lack of availability of all tests across the world. [Table: see text]

7559 Background: Waldenström macroglobulinemia (WM) is a rare indolent lymphoma commonly treated with rituximab (R)-based therapy. The use of rituximab maintenance (mR) in WM is controversial. We present a case-control study of patients (pts) with WM treated with mR. Methods: Pts evaluated at Mayo Clinic, Rochester with active WM that received mR between 1/2000 & 6/2018 were included. Cases comprised pts who received mR following R-based induction as primary therapy. Cases were matched based on the time of diagnosis in 1:2 ratio with a control group treated with R-based primary induction therapy without mR. Time to event analyses were performed from initiation of R-based induction. Results: Of 776 pts with active WM, 42 (5%) cases received mR and 84 pts were selected as controls. The median follow-up and the proportion of high risk pts were comparable between the two cohorts (Table). Pts in the mR cohort show a trend toward longer time to next therapy (TTNT) and a significantly longer overall survival (OS) compared to the control group (Table). The R-based induction therapies were comparable in the two cohorts (p = 0.6). Median duration of mR was 1.9 yrs (95% CI 1.6-2) and mR was used most frequently every (q) 2 (range 1-6) months. Of the 42 mR pts, 25 (60%) received an R-based combination for induction and 17 (40%) received R monotherapy as induction. Five (12%) pts discontinued mR due to toxicity, infections were reported in 13 pts (31%) during mR therapy and 3 pts (7%) received IVIg infusions for recurrent infections. Conclusions: R-based induction followed by mR demonstrates a longer OS in WM compared to R-treated control population not receiving mR, albeit at a high rate of infections. Despite limitations of a retrospective study, with a heterogeneously treated cohort, these data add to the body of literature supporting Rituximab maintenance. Results from an ongoing randomized controlled trial are awaited. [Table: see text]

7509 Background: Waldenstrom macroglobulinemia (WM) is a rare lymphoma for which scant comparative data exist to guide frontline therapy. Herein, we compare 3 commonly used regimens in WM: R-Benda, DRC, and BDR in frontline setting. Methods: Patients (Pts) with active WM seen at Mayo Clinic between 2000 & 2018 who received R-Benda, DRC or BDR as primary therapy were included in this retrospective study. Response rates were assessed by Consensus Criteria. All time to event analyses were performed from the frontline therapy, using Kaplan-Meier method. Results: The study included 172 pts with active WM (R-Benda, n=67, DRC, n=75, BDR, n=30).The median follow-up for the entire cohort was 3.7 years (y) (95% CI 3.7-3.0). Baseline characteristics, including IPSS, and time to frontline therapy from WM diagnosis were similar across the 3 cohorts. Clinically relevant endpoints are shown in the Table. Hematologic and non-hematologic toxicities were similar across the 3 groups. Grade 3 neuropathy requiring treatment discontinuation was encountered in 13% pts treated with BDR. 56 pts received subsequent salvage therapy [(10% in R-Benda arm, 44% in DRC arm, & 53% in BDR arm]; 29% pts in the R-Benda arm and 30% pts in DRC arm received a PI-based regimen while 69% pts in the BDR arm received alkylator-rituximab based therapy. Conclusions: Outcomes (MRR, TTNT and EFS) with frontline R-Benda are superior in comparison to frontline DRC or BDR in patients with WM. Clinically relevant endpoints are not significantly different with DRC vs. BDR. The toxicity profile across the 3 groups was comparable. [Table: see text]

8606 Background: The rapidity of response to initial therapy in multiple myeloma (MM) depends on a variety of factors. There is limited data on its implications on long term outcomes in patients (pts) with newly diagnosed MM. Methods: We retrospectively examined the outcomes in a cohort of 454 pts with newly diagnosed MM between Jan 2000- Dec 2011 undergoing induction therapy. Results: The median age at diagnosis was 66 yrs (29-92). Pts had measurable serum M-spike (>= 1 g/dL), dFLC (>=10 mg/dl) or 24 hour urinary M protein excretion (UrM; >=200 mg) in 70, 63 and 39% respectively. We first examined the relationship between the response to first cycle of therapy and overall survival (OS). We divided pts into quartiles based on their % reduction in the serum M spike, dFLC or UrM. The median OS (Table) was poorest for pts with the least reduction of serum M protein (P<0.001) and of dFLC. The cutoffs for Q1 was 25, 40and 40% decrease for serum M spike, dFLC and 24 hr UrM respectively. Among various baseline characteristics only higher age was predictive of a poor (Q1) response. Given the trend toward worse OS among the Q 4 group (maximum decrease in serum M spike), we examined the relationship to cytogenetic risk. Among 232 pts with FISH data available, proportion of pts with high-risk disease was 27, 12, 22 and 31% respectively in quartiles 1 - 4). In a multivariate analysis, quartile 1 and 4 of serum M-protein response and the high-risk FISH were independent risk factors associated inferior OS. Conclusions: Both shallow and very deep response to therapy in cycle 1 is a strong indicator of eventual disease outcome and should be considered as marker of high-risk disease, likely through different mechanisms. For the shallow responders, prospective trials should assess if a change in therapeutic management will alter the outcome of these pts. The rapid deep responders also appear represent a different high-risk biology, emphasizing the fact that pts with high-risk disease often have excellent initial responses, but poor long term outcomes. [Table: see text]

8600 Background: The combination of bortezomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide and etoposide (VDTPACE) was developed as an intense regimen for disease control prior to tandem transplantation for multiple myeloma (MM) in total therapy protocols. The regimen is very effective in this setting, and since has also been used in the relapsed setting. We examined the outcomes of a set of patients undergoing VDTPACE therapy for relapsed MM at our institution. Methods: We identified 71 patients who received VDTPACE for relapsed MM, at Mayo Clinic from 7/2006 to 7/2012. Plasma cell leukemia was excluded. All data was extracted from clinical records. Results: The median age of patients was 59 years (range, 39-80); 48 (67.6%) were male. The median time from diagnosis to initiation of VDTPACE was 38.2 months (range, 2-125). The median number of cycles given was 1 (range, 1-9). The overall response rate after one cycle was 57.1% (14.3% VGPR, 22.2% PR and 20.6% MR) in the 63 patients in whom the response was evaluable. The median overall survival (OS) post-VDTPACE was 8.2 months (95% CI, 5.7-10.9). Eighteen (25.4%) patients went on to autologous stem cell transplantation (SCT), and 7 (9.9%) received matched allogeneic SCT following VDTPACE, and the median OS post-VDTPACE was significantly longer for these groups compared to those who were not transplanted (15.3 and 20.5 months, respectively vs 5 months, p-value <0.001). Thirty eight of 66 (57.6%) patients were rehospitalized after initial admission for infusion therapy for a median duration of 6 days (range, 1-26). The median platelet and red cell transfusions were 4 (range, 0-21) and 5 (range, 0-22) units, respectively. Renal toxicity was seen in 13/62 (21%) patients and 27/65 (41.5%) patients developed neutropenic fever. The median duration to absolute neutrophil and platelet count recovery was 18 (range 12-42) and 27 (range, 12-42) days, respectively. Three (4.2%) patients died within 30 days and 11 (15.5%) within 8 weeks of initiating VDTPACE. Conclusions: VDTPACE is an effective therapy in relapsed MM but is associated with significant morbidity and short-term mortality. It appears to be more effective when followed by an autologous or allogeneic SCT.

8592 Background: Accrual to NCI clinical trials(CT)is often slower than planned at times mandating premature closure resulting in loss of valuable resources and delay of scientific progress. Methods: The NCI-MYSC AWG identified 10 potential BtA. SWOG, ECOG and Alliance investigators were queried and agreed that these barriers impede accrual (results stratified for academic and community sites). The MYSC AWG developed in collaboration with NCI and FDA strategies to overcome these barriers. Results: Strategies listed for the 3 most often cited BtA: 1. Reimbursement for CT related expenses:increase awareness of improved reimbursement for phase II CT; tailor reimbursement according to CT complexity; request funds from industry and other sources ( http://biqsfp.cancer.gov ) for qualifying ancillary CT components. 2. Spectrum of available treatment options influences CT participation: educate patients and providers about the significance of a new CT using social media, presentations at national meetings and by adding educational material to CT protocol; encourage opinion leaders and advocacy groups not to promote a new therapy as “standard” in the absence of phase III data. 3. Requirement of CT specific therapy at NCI designated sites only: “MYSC AWG Drug Administration Table” describes NCI/FDA approved rules for CT specific drug administration; CT protocol will outline which standard treatment components of a CT can be administered at any site as long as protocol specific guidelines are followed and conduct is supervised by enrolling investigator. Examples of additional strategies to overcome identified BtA: determine feasibility, indication and insurance coverage of CT specific tests during protocol development; discourage narrow eligibility criteria; avoid competing CT; allow up to 1 cycle of commercially available therapy prior to enrollment; CIRB support for phase II CT. Conclusions: The MYSC Accrual Working Group developed in collaboration with NCI and FDA strategies to overcome barriers to myeloma clinical trial accrual. These strategies may be applicable to NCI-sponsored clinical trials evaluating interventions in other diseases.

8541 Background: Achievement of a complete response (CR) to treatment is an important predictor of outcome for patients (pts) with myeloma (MM). The goal of the current study was to assess whether the treatment that resulted in CR has any impact on the outcomes. Methods: We identified 462 pts with MM, who fulfilled the IMWG criteria for CR, seen at Mayo Clinic between 1991 and 2011. The treatment was classified into groups by the regimen that led to CR (Table), and also based on whether an autologous stem cell transplant (ASCT) was part of the regimen. The remaining 21 pts had a variety of regimens and are not included in the Table. Results: The median age at diagnosis was 58.5 yrs (27.1–82.3 yrs) with 56% males. The overall survival (OS) from diagnosis for the entire cohort was 10.7 yrs (95% CI; 9.3, NR). The median interval from diagnosis to the recorded CR was 10.3 mos (range 1- 170), with 272 (58.4%) and 385 (82.7%) obtaining a CR in <12 mos and <24 months from diagnosis. We first compared the outcomes based on whether ASCT was part of the regimen; 328 had an ASCT while 117 pts received only chemotherapy. Median time to progression (TTP) following a CR was 5.1 yrs for the ASCT group compared with 5.5 yrs for the rest (P=0.3). Median OS from CR was 9.1 yrs for the ASCT group and 7.5 yrs for the rest (P=0.5) and OS from diagnosis was 10.1 yrs for the ASCT group and 12.6 for the rest (P=0.5). Examining the outcomes based on the regimen utilized showed that the TTP and OS from CR as well as OS from diagnosis were similar for all the groups (Table). Among pts who had a CR within a year of diagnosis, there were no differences in terms of the TTP or OS from the onset of CR or from diagnosis between the ASCT vs. chemotherapy groups or between the different regimens (P=NS for all comparisons). Conclusions: The current study highlights an important message regarding CR in MM. The results suggest that the prognostic value of CR is independent of the nature of therapy, and likely reflects the contribution of disease biology to obtaining a CR. [Table: see text]

8517 Background: An increased risk of SPM in MM pts treated with len has been reported. We performed an IPD metanalysis to estimate the incidence of SPM according to len exposure. Methods: Randomized studies of MM, from PubMed and ASCO/IMW/ASH (after 2000), that met the following criteria, were included: randomization to treatment with len (len-trials); randomization to treatment including new drug but not len (no-len-trials); available SPM data. Primary aim was to estimate cumulative incidence of SPMs by len exposure, corrected for death (competing event). Results: Data from 6,383 pts (3,218 from 8 len-trials, 3,165 from 10 no-len-trials) were analyzed. Median age was 69 years. During follow-up (median=30 mos) 420 (6.6%) SPMs were reported: 188 (2.9%) hematologic and 232 (3.6%) solid cancers. Solid tumors occurred with similar incidence in all groups. Incidence of hematologic SPM was significantly higher in patients receiving len (3.2 vs 1.1, p=0.04), but risk is limited to patients treated with melphalan+len (4.1, 95%CI: 2.4-5.8) with no excess in other combinations (len without melphalan: 1.2, 0.0-2.6; melphalan without len: 1.1, 0.0-2.7) (p=0.003). The cumulative incidence of death for any cause was much higher than the risk of SPM. Conclusions: The risk of hematologic SPMs was higher in pts receiving melphalan+len. The benefit/risk profile of len treatment remains positive. Cumulative incidence (%) of SPMs and death (95%CI). [Table: see text]

8516 Background: There is consensus that light chain amyloidosis (AL) patients with CRAB criteria (abnormal calcium or renal function, anemia or lytic bone lesions) also have multiple myeloma (MM). These patients are typically excluded from AL trials; however, AL patients with >= 10% bone marrow plasma cells (BMPC) in the absence of CRAB are included in trials along with AL with < 10% BMPC. We postulated that the currently used dichotomy may be incorrect and examined the spectrum of AL with and without MM. Methods: We identified 1,272 patients with AL seen within 90 days of diagnosis, between January 1, 2000, and December 31, 2010. We defined the population of patients with coexisting MM based on the existence of CRAB (AL-CRAB-MM). Patients without CRAB were divided into two groups, AL-only (<10% BMPC) and AL-PC-MM (>=10% BMPC). Results: Among the 1,272 patients, 117 (9%) had AL-CRAB-MM, 476 (37%) had AL-PC-MM, and 679 (53%) had AL only. Their respective median overall survivals (OS) were 16.2, 15.8, and 28.4 months (p<0.0001). Autologous stem cell transplant (ASCT) was performed in 203 (30%), 138 (29%) and 23 (20%) patients respectively. Since the outcomes of AL-CRAB-MM and AL-PC-MM were similar, they were pooled for univariate and multivariate analyses. On multivariate analysis, AL-CRAB-MM and AL-PC-MM retained negative prognostic value independent of age, cardiac stage, prior autologous stem cell transplant (ASCT), beta 2 microglobulin, and dFLC. We next considered whether patients received ASCT as part of their treatment. For those patients who never received ASCT, the 5-year OS were 19%, 14%, and 31%, p<0.001, for AL-CRAB-MM, AL-PC-MM, and AL only respectively. In contrast, for those patients who received ASCT, the respective 5-year OS were 46%, 56%, and 73%, p<0.001. Conclusions: AL patients with >=10% BMPCs have a poor prognosis similar to patients with AL-CRAB-MM and should therefore be considered as AL with MM.