Citations

e19503 Background: The risk of venous thromboembolic events (VTE) despite mandatory thromboprophylaxis (TPx) in patients with multiple myeloma (MM) receiving contemporary lenalidomide (Len)-based regimens is not well-defined. Methods: Medline, Embase, and CENTRAL databases were queried to identify phase 1-3 clinical trials of Len-based regimens with mandatory TPx published until April 2018. Random effects meta-analysis was performed using CMAv3 software to obtain crude, and per 100 patient-cycle incidence rate (IR). Prespecified subgroup analyses were performed to obtain IR for VTE by (1) line of treatment (newly diagnosed [ND], relapsed/refractory [RR] and maintenance [Mx] phase) and (2) different Len-based regimens. Results: We screened 1069 citations and analyzed data from 43 trials with 8696 patients, including 17 in ND, 23 in RR and 3 in Mx phase. 12 out of 43 were Phase 3 randomized controlled trials. The overall incidence of VTE in 8696 patients was 4.6% (95% CI, 3.7-5.8%), with 1.0 event (95% CI, 0.7-1.4%) per 100 patient cycles. In patients with NDMM (n = 3295), 193 (5.9%) experienced VTE with a pooled IR of 0.9 (95% CI, 0.3-2.3) per 100 patient-cycle. Among RRMM patients (n = 3981), 251 (6.3%) experienced VTE with a pooled IR of 1.0 (95% CI, 0.4-2.3) per 100 patient-cycle. The incidence of VTE was highest with the following triplet regimens: Rd + Proteasome inhibitor (PIs) and Rd + Anthracycline (Ac) [+/- Vincristine], with the latter having a high risk of VTE regardless of the treatment phase (table). With Len Mx (n = 1420), 38 (2.7%) patients had VTE, with a pooled IR of 0.2 (95% CI, 0-2.1) per 100 patient-cycle. Conclusions: Patients with MM undergoing treatment with Len-based regimens remain at risk of VTE despite current TPx strategies. The estimates of VTE IR provided by this analysis can guide clinicians in assessing treatment-related risk of VTE in this setting. [Table: see text]

8049 Background: Monoclonal gammopathy of undetermined significance (MGUS) is rare in young patients (pts; age <40 years at diagnosis), with a prevalence of < 0.3%, representing approximately 2% of all patients with MGUS. We hypothesized that MGUS detected in pts <40 years of age may be associated with a higher risk of progression. Methods: We identified 249 pts with MGUS <40 yrs old, evaluated at Mayo Clinic, Rochester from 1997 to 2016. The endpoint was time to progression assessed by Kaplan-Meier method. Results: 119 were male, 130 were female. Most (n= 179, 72%) were diagnosed between the ages of 30-39. The type of MGUS was IgG 69%, IgA 10%, IgM 15%, and other 5%. 135 pts (54%) had concurrent immune-related conditions, including autoimmune, inflammatory, and infectious disorders at the time of diagnosis of MGUS. Pts without immune-related conditions tend to have higher M protein compared to pts with immune-related conditions (mean, 0.36 gm/dl VS 0.20 gm/dl, p =0.057). During follow up, the M protein resolved in 36 patients. The M protein was more likely to resolve in pts with immune-related conditions compared with pts without immune-related conditions (RR 1.91, 95% CI 1.02-3.59). Progression was seen in 16 pts: 9 smoldering multiple myeloma (SMM), 4 multiple myeloma (MM), 1 macroglobulinemia, 2 non-Hodgkin’s lymphoma. The rate of progression to SMM, MM, or related disorder at 5 and 10 years was 6.0% and 13.8%, respectively. The size of M protein was a significant risk factor for progression (HR 4.23, 95% CI 2.17-7.91) The risk of progression at 5 and 10 years for pts with immune-related conditions concurrently present when MGUS was first diagnosed was 1.5% and 10.1% respectively; corresponding rate in pts without immune-related conditions at the time of diagnosis was higher at 12.3% and 18.9%, respectively (p =0.016), (HR 2.36, 95% CI 0.85-6.52). Similar results were seen when patients in whom the M protein resolved were excluded. Conclusions: Young patients with MGUS may have a higher risk of progression, 1.4% per year; approximately 50% are diagnosed in the setting of immune-related disorders. When occurring in the setting of immune related disorders, the M protein is smaller, more likely to resolve, and may have a lower risk of progression than in pts in whom MGUS is detected without concurrent immune-related disorder.

8039 Background: Treatment of MM has evolved significantly over the past decade, with increasing use of multi-drug combinations for initial therapy. In addition, supportive care approaches have also improved. We examined how these improvements have translated to survival outcomes in patients with newly diagnosed MM. Methods: Patients (n=3449) with a diagnosis of MM made between 2004 and 2017 and seen at Mayo Clinic within six months of the diagnosis, were included in this analysis. Patients were divided into three groups based on the year of diagnosis; group 1- 2004-07 (n=831), group 2-2008-12 (n=1161), and group 3-2013-17 (n=1457). Survival of the groups were estimated using Kaplan-Meier method, and compared using log rank test. Results: The median age was 64 years (22 to 96); 60% were male and 40% were female. 14% were >75 years, 33% were aged 65-75 and 53% were <65 years. The median overall survival for the whole cohort was 5.7 years (95%CI; 5.4, 6.3). The median OS for the groups 1, 2 and 3 were 3.9, 6.3 and NR, respectively; p<0.001. The 4-year survival estimates were 50%, 62%, and 75%, respectively. We then explored the improvements in patient subgroups. While all patients experienced improvements in OS over time, improvement in group 3 was most prominent for those >75 years. In patients <65 years, the 4-yr OS for groups 1, 2 and 3 were 57, 71, and 79% respectively. In patients 65-75 years of age, the 4-yr OS for groups 1, 2 and 3 were 48, 60, and 75% respectively. In patients >75 years, the 4-yr OS for groups 1, 2 and 3 were 24, 35, and 56% respectively. While patients with high-risk disease did not see as much benefit in the earlier period, substantial progress was seen in the last group. The 3-yr OS for patients with high-risk cytogenetics were 52, 55, and 73% for groups 1, 2 and 3 compared to 67, 75, and 85% for standard-risk cytogenetics respectively. 2067 patients were staged according to the International Staging System and the median OS for stages 1, 2 and 3 were 6.5, 4.6 and 2.4 in group 1; 9.2, 6.6 and 3.5 in group 2 and NR for any of the stages in group 3. Conclusions: The results confirm continued improvement in survival of newly diagnosed multiple myeloma patients, including elderly and high-risk MM.

8034 Background: Minimal residual disease (MRD) assessment in multiple myeloma (MM) has improved our ability to assess disease activity, resulting in more advanced prognostication. While MRD assessment remains confined to the bone marrow (BM) plasma cell population, serum studies including immunofixation (IFE) are required to complete response evaluation. The significance of those who are MRDneg yet have detectable monoclonal protein through IFE remains unclear. Methods: We retrospectively studied 256 MM patients who had MRD assessment via the Euroflow multiparametric flow cytometry on the BM with concomitant serum IFE testing. Patients who were MRDneg were included in the study. Outcomes included probability of disease progression (PD) at 1 year. The Cox-proportional hazards model was used to compare probability of PD among different groups. Time to progression (TTP) was calculated as the difference from date of MFC analysis to PD in months. Results: Among the entire cohort, 178 (70%) patients were MRDneg and median follow-up from MRD assessment was 6.3 months. Among these patients, 74 (42%) had a positive IFE at the time of MRD analysis. Within the MRDneg/IFEpos group, 31 (42%) patients remained IFEpos after a median follow up of 5.5 mo from initial MRD/IFE testing while 34 patients eventually became IFEneg after a median of 2.8 mo with no subsequent IFE available in 9 patients. The 1 year probability of PD in the MRDneg/IFEneg group was 20% compared to 41% in the MRDneg/IFEpos group (P < 0.01, Wilcoxon test). When comparing subsequent IFE status in those who were MRDneg/IFEpos, those who remained IFEpos had a trend towards shorter TTP compared to patients who later became IFEneg. Conclusions: Persistent monoclonal protein in the face of MRD negativity predicts for a shorter TTP. This likely reflects persistent disease that was not sampled on the BM aspirate in many of these patients compared to those who eventually become IFEneg with a trend towards longer TTP owing to the prolonged half-life and therefore clearance of M protein. This supports the current strategy of assessing for MRD at the time of suspected complete response to reduce the chance of positive MRD tests and thus avoidance of multiple BM exams.

8031 Background: Our prior studies identified the prognostic significance of ≥400 cPCs/150,000 analyzed events quantified by MFC in NDMM. We evaluated if a similar quantification of cPCs using MFC can add prognostic value to the current R-ISS classification of NDMM pts. Methods: We evaluated all NDMM pts seen at the Mayo Clinic, Rochester from 2009-2017 who had their peripheral blood samples evaluated by 6-color MFC prior to therapy. The cPCs detected were reported as the number of clonal events/150,000 collected total events. Survival analysis was performed by the Kaplan-Meier method and differences assessed using the log rank test. Results: This cohort consisted of 566 consecutive pts with NDMM with a median age of 66 years (27-95). The distribution of the R-ISS classification of this cohort is as follows: Stage 1- 128 (23%) pts, Stage 2- 369 (65%) pts and Stage 3- 69 (12%) pts. The median number of cPCs was 59 (0-46,412) / 150,000 events. The median time-to-next-treatment (TTNT) and overall survival (OS) for pts with ≥400 cPCs (n = 140, 25%) was 19 months and 46 months compared with 34 months and 77 months for those with < 400 cPCs respectively (n = 426, 75%) (p < 0.001 for both). The median TTNT and OS for pts based on their R-ISS classification as well as with and without the presence of ≥400 cPCs by MFC was as follows in the following Table. Conclusions: Quantifying ≥400 cPCs/150,000 analyzed events by MFC can potentially upstage the R-ISS classification of a subset of NDMM pts with stage I and II disease and identify those pts with a worse than expected survival outcome.[Table: see text]

8020 Background: BCMA (B-cell maturation antigen) is a TNF receptor family member found on normal and malignant B-cells, including multiple myeloma (MM). It plays a role in proliferation and antiapoptotic pathways. Levels of serum (s)BMCA are elevated in patients (pts) with plasma cell disorders (PCD) and increase with each stage of disease: healthy donor< MGUS<SMM< active untreated MM. The purpose of this study was to test whether sBCMA levels predict progression of MGUS or SMM to MM. Methods: There were 3 cohorts in this retrospective study: MGUS progressing to MM (n=42); MGUS not progressing to MM (n=49); SMM progressing to MM (n=32). sBCMA levels were measured using an ELISA-based assay with a polyclonal anti-BCMA antibody from R&D Systems (Minneapolis, MN). The Kruskal-Wallis analysis was used to assess differences. The relationships between sBCMA and both time to progression and overall survival were also assessed using Cox proportional hazard models. Results: The highest values of sBCMA were seen among pts with more advanced PCD (Table). The lowest baseline levels were seen in pts with MGUS who did not progress; the change of sBCMA over time was lowest in the MGUS non-progressors. ROC analysis identified a cutoff of 74.4 ng/mL to be predictive of progression at 5 years. This cut-point was associated with a risk ratio of progression of 5.8 (95%CI 3.2, 11.3) for all comers, a risk ratio of death for all comers of 2.5 (95%CI 1.5, 4.2), and a risk ratio of death for MGUS pts of 3.3 (95%CI 1.9, 5.7). Conclusions: Serum BCMA levels were predictive of diagnosis, progression and death among pts with MGUS or SMM. Limitations of the current study are that only a minority of pts had baseline bone marrow exams or serum FLCs to place sBCMA risk in the context of other previously described risk factors. Serum FLC is now being determined on all patients. [Table: see text]

8019 Background: POEMS syndrome is a rare paraneoplastic syndrome caused by an underlying plasma cell disorder. Most of the information regarding treatment has been gleaned from retrospective data. The combination of a proteasome inhibitor, an IMiD and corticosteroid is known to be highly effective among patients with myeloma. Methods: We designed a pilot using a 28-day oral regimen of ixazomib (4 mg days 1, 8, 15), lenalidomide (25 mg days 1-21), and dexamethasone (20 mg days 1, 8, 15, 22). Aspirin and acyclovir were used for prophylaxis. Eligibility included a diagnosis of POEMS syndrome, a plasma VEGF > 200 pg/ml, a PS < 3. There were two groups [gp] (intended enrollment 15 per gp): Gp A, 13 cycles for patients (pts) who had relapsed or refractory disease; Gp B, 3 cycles for pts destined for high-dose chemotherapy with stem cell transplant. Primary endpoint was VEGF complete response (CR = normalization) after 3 cycles. Secondary endpoints included safety, hematologic response, and overall survival at 3 and 12 months. Other domains including PET response, clinical responses including neurologic response were also studied. To date, 13 pts enrolled since 10/31/2016—4 to Gp A and 9 to Gp B. 11 pts were analyzed (2 dropped out before receiving any therapy). Data were frozen as of 1/21/2019. Results: Median age was 55; 73% were male. So far, overall 64% met primary endpoint of VEGF CR (Table). The median follow-up of survivors is 12.4 mo (6, 24). 1 pt came off study for non-responsive disease and died thereafter. 38% of patients had grade 3+hematologic AE; 72% had grade 3-4 non-hematologic AE. These included: rash, respiratory infection and hypotension in 2 each; atrial fibrillation, diarrhea, edema, dyspnea, and thromboembolism in 1 each. 4 pts had non-objective worsening of their neuropathy. Conclusions: These preliminary results suggest that Ixa-Len-Dex is an effective and tolerable regimen for patients with POEMS syndrome. Clinical trial information: NCT02921893. [Table: see text]

8015 Background: Multiple myeloma (MM) is a heterogeneous disease with varying survival outcomes depending on the presence of certain genetic abnormalities. Common abnormalities include trisomies, translocations involving chromosome 14, and amplifications or deletions of chromosomes 1, 13, and 17. t(11;14), occurring in approx. 15% of patients (pts) with MM, is considered a standard risk abnormality, but recent data suggest that the prognosis may be inferior to what had been expected. This is of particular relevance as new therapeutic options such as the BCL-2 inhibitor venetoclax has been shown to be effective in t(11;14) pts. Methods: This was a multicenter study designed and conducted by the IMWG, to identify the outcomes of pts with t(11;14) using a retrospective cohort of pts. Pts with MM diagnosed between 2005 and 2015 with t(11;14) identified on FISH performed within six months (mos) of diagnosis, and with treatment details available and if alive, a minimum of 12 mos of follow up, were enrolled. Results: The current analysis includes 848 pts with a median age of 64.4 years; 60.0% are male. The median follow-up from diagnosis for the entire cohort was 45.7 mos; 84.7% of the pts were alive at the last follow up. ISS stage distribution included: Stage 1 (35.3%), Stage II (38.9%) and stage III (25.8%). The distribution of FISH abnormalities included: del 13q (14.5%), 1q amp (12.1%), del 17p or monosomy 17 (6.1%). Pts received initial therapy with different regimens: IMiD-24.3%, PI-41.0%, both-20.8% and 13.8% had no novel agent. The drug classes by line of therapy are shown in table. An early stem cell transplant (SCT) was used in 40.8% of pts. The median time to next treatment (TTNT) after initial treatment was 15.0 (95% CI: 12.2 to 17.7) mos. The median overall survival from diagnosis for the entire cohort was 82.5 (95% CI: 73.5 to 95.8) mos. Conclusions: This is the first study to examine the outcomes of a large group of myeloma pts with t(11;14) abnormality. Pts receiving a combination if a PI and an IMiD appear to have the best survival outcomes and thse receiving an early SCT appear to have excellent survival with median OS approaching 10 years. Additional pts are being accrued to this study and additional analysis examining the variables affecting response duration and survival will be presented. [Table: see text]

8004 Background: The primary objective of this phase 3 trial was to demonstrate progression free survival (PFS) improvement of isatuximab (Isa), a novel anti-CD38 monoclonal antibody, combined with pomalidomide (P)/dexamethasone (d) versus (vs) Pd. Methods: Patients (pts) with RRMM who received ≥2 prior lines, including lenalidomide (len) and a proteasome inhibitor (PI), refractory to last therapy were enrolled. IsaPd arm received Isa 10 mg/kg IV weekly for first 4 weeks (wks), then every 2 wks. Both arms received approved schedules of pom and dex (4mg PO days 1-21; 40mg [20mg if >75 yrs] PO or IV weekly) every 28 days until progression or unacceptable toxicity. Results: 307 pts (154 IsaPd, 153 Pd) were randomized and analyzed (ITT). Patient characteristics were well balanced across arms. Median age: 67 (36-86) yrs; median prior lines of therapy: 3 (2-11); estimated GFR: <60ml/min in 33.9% pts; 92.5% refractory to len, 75.9% to PI; and 19.5% pts had high-risk cytogenetics. At median follow-up of 11.6 months (mos), median PFS was 11.5 mos IsaPd vs 6.5 mos Pd; HR 0.596 (95% CI 0.44-0.81), P=0.001. PFS benefit was consistent across all major subgroups. ORR (≥PR) was 60.4% IsaPd vs 35.3% Pd, P<0.0001. VGPR rate or better was 31.8% IsaPd vs 8.5% Pd, and MRD negativity (NGS, 10-5) was seen in 5.2% IsaPd pts vs 0% Pd. At analysis date, overall survival (OS) was immature (99 events) but a trend to OS improvement in IsaPd (vs Pd) was observed (HR 0.687; 95% CI 0.461-1.023). Median treatment duration was 41 wks IsaPd vs 24 wks Pd; median Isa infusion (inf.) duration was 3.3h at 1st inf. and 2.8h at subsequent inf. Grade ≥3 AEs were observed in 86.8% IsaPd vs 70.5% Pd; 7.2% IsaPd and 12.8% Pd pts discontinued due to AEs; 7.9% IsaPd and 9.4% Pd pts died due to AEs. Inf. reactions were reported in 38.2% (2.6% grade 3-4) IsaPd. Grade ≥3 infections were seen in 42.8% IsaPd and 30.2% Pd, grade ≥3 neutropenia in 84.9% (febrile 11.8%) IsaPd and 70.1% (febrile 2.0%) Pd. Conclusions: IsaPd significantly improved PFS and ORR vs Pd, with a manageable safety profile. IsaPd is an important new treatment option for the management of RRMM. Clinical trial information: NCT02990338.

8001 Background: Smoldering multiple myeloma (SMM) is a precursor to myeloma, wherein current standard of care is observation (obs). Data from a randomized Spanish trial (Mateos et al, NEJM 2015) suggest that lenalidomide(len)/dexamethasone improves time to developing myeloma (TTP) and overall survival (OS) for patients (pts) with high risk (HR) SMM over obs. However, pts were not screened with advanced imaging techniques, used a HR definition that is not routinely available, and combination therapy limited the ability to isolate the effect of len, and thus has not become standard of care. Methods: E3A06 is a randomized phase III intergroup trial, testing the effect of single agent len compared with obs for pts with intermediate or high risk SMM. In an initial phase II run in all pts received len to demonstrate safety. Eligibility required ≥10% PCs and abnormal serum FLC ratio (<0.26 or >1.65). The primary endpoint was progression PFS was estimated by the Kaplan-Meier method and compared using the one-sided stratified log-rank test. Results: PII enrolled 44 pts and PIII randomized 182 pts to either len (n=90) or obs (n=92) [stratified on time since SMM diagnosis ≤1y vs >1y]. Baseline characteristics were similar between the arms. 80% (PII) and 51% (PIII) are off len, primarily due to adverse events (AE) or pt withdrawal. Among the len treated pts, G3/4 non-hematologic AE occurred in 28% of PIII pts with fatigue being most common (n=5). G4 hematologic AE rate was 5.7%, primarily neutropenia (n=4). 3-year cumulative incidence of invasive SPMs was 5.2% (len) and 3.5% (obs). Overall response rate was 47.7% for the phase II study, and in phase III, 48.9% for the len arm, and 0% for the obs arm. Median follow up was 71 months (PII), and 28 months (PIII). 3-year PFS was 87% for the PII cohort. One, 2 and 3-year PFS was 98%, 93%, and 91% for len, and 89%, 76%, and 66% for the obs arm (HR 0.28, p=0.0005) favoring the len arm. No difference in QOL score was noted between arms. Conclusions: Overall, this trial represents the largest randomized trial in SMM to date. In conjunction with the Spanish data, this trial may support a change in clinical practice. Clinical trial information: NCT01169337. [Table: see text]