Citations

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.

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]

8583 Background: Poor prognosis and therapy exhaustion have been associated with reduced QOL in RRMM. In MM-003, a randomized, multicenter, open-label phase 3 trial, POM + LoDEX (n = 302) significantly improved progression-free and overall survival vs. high-dose dexamethasone (HiDEX; n = 153) in pts who failed lenalidomide (LEN) and bortezomib (BORT) and progressed on their last therapy. This analysis evaluated QOL changes in these pts. Methods: To assess pt-reported outcomes, cross-sectional and longitudinal analyses were performed. Minimal important differences for 5 clinically relevant EORTC QLQ-C30 domains (Global Health Status, Physical Functioning, Fatigue, Emotional Functioning, and Pain) were calculated as meaningful change thresholds (1 standard error of measurement) from baseline through cycle (C) 5. Time to QOL worsening was compared between arms using the Kaplan-Meier method. Results: Favorable trends were observed for POM + LoDEX vs. HiDEX in each of the 5 relevant domains. The cross-sectional analysis indicated statistically or marginally significant (P < .10) differences favoring POM + LoDEX in Global Health Status (C2, 4), Physical Function (C2, 3, 4), Emotional Function (C2, 3, 4), and Fatigue (C2) scores. Longitudinal comparisons between arms confirmed the significance of score changes for Global Health Status (C2; P = .01), Physical Functioning (C3 and 4; P = .018 and .028, respectively), Emotional Functioning (C3; P = .018), and Fatigue (C5; P = .008) for POM + LoDEX vs. HiDEX. HiDEX pts exhibited clinically meaningful worsening in Global Health Status and Physical Functioning scores vs. POM + LoDEX by C2 (P = .04) and C3 (P = .02), respectively. POM + LoDEX extended median time to meaningful worsening vs. HiDEX for Global Health Status (114 vs. 85 days, P = .05), Physical Functioning (174 vs. 106 days; P = .09), Fatigue (113 vs. 60 days; P = .02), Emotional Functioning (190 vs. 124 days; P = .04), and Pain (147 vs. 113 days; P = .2). Conclusions: In heavily pretreated pts who failed LEN and BORT, POM + LoDEX resulted in better clinical outcomes as well as improvement in clinically relevant QOL measurements over the course of treatment. Clinical trial information: NCT01311687.

8528 Background: RRMM patients (pts) who fail lenalidomide (LEN) and bortezomib (BORT) have poor prognosis. High-risk cytogenetics predict shorter survival. POM + LoDEX has demonstrated efficacy in pts with prior LEN and BORT and high-risk cytogenetics. MM-003 is an open-label, multicenter, phase III trial comparing POM + LoDEX vs. HiDEX in RRMM pts who failed LEN and BORT treatment (Tx) and have progressed on their last therapy. Methods: Pts must have been refractory to the last prior Tx (progressive disease [PD] during or within 60 days) and failed LEN and BORT after ≥ 2 consecutive cycles of each (alone or in combination). Randomization was 2:1 to POM 4 mg D1–21 + DEX 40 mg (20 mg for pts aged > 75 y) weekly; or DEX 40 mg (20 mg for pts aged > 75 y) D1–4, 9–12, and 17–20 (28-day cycles). Tx continued until PD or unacceptable adverse events (AEs). The primary endpoint was progression-free survival (PFS). Secondary endpoints included OS and AEs. This analysis examined pts meeting modified high-risk cytogenetic criteria—del(17p13) and/or t(4p16/14q32). Results: 302 pts received POM + LoDEX, and 153 pts received HiDEX. 225 and 107 pts, respectively, were evaluable for cytogenetics. Baseline characteristics were similar. Median PFS and OS were significantly longer with POM + LoDEX vs. HiDEX, regardless of cytogenetic risk (Table). The most common grade 3/4 AEs were neutropenia, anemia, and infection (Table). Discontinuation due to AE was low: 4% vs. 6% (high risk) and 10% vs. 4% (standard risk). Conclusions: Median PFS and OS were significantly longer with POM + LoDEX vs. HiDEX in pts with cytogenetically-defined high-risk disease, consistent with results from the intent-to-treat population. Tolerability was acceptable. POM + LoDEX should be considered a new Tx option in pts failing LEN and BORT. Clinical trial information: NCT01311687. [Table: see text]

8527 Background: Pts who have exhausted lenalidomide (LEN) and bortezomib (BORT) treatment (Tx) have a poor prognosis. A significant proportion of pts have RI with increasing incidence during disease course. POM + LoDEX has demonstrated efficacy in pts with prior LEN and BORT, including those with RI. MM-003 is an open-label, multicenter, phase 3 trial comparing POM + LoDEX vs HiDEX in RRMM pts who failed LEN and BORT and progressed on their last Tx. Methods: Pts must have failed LEN and BORT after ≥ 2 consecutive cycles of each (alone or in combination) and must have been refractory to last prior Tx (progressive disease [PD] during Tx or within 60 days). Pts with creatinine clearance (CrCl) < 45 mL/min were excluded. Randomization was 2:1 to POM 4 mg D1–21 + DEX 40 mg (20 mg for pts aged > 75 y) qw; or DEX 40 mg (20 mg for pts aged > 75 y) D1–4, 9–12, and 17–20 (28-D cycles). Tx continued until PD or unacceptable adverse event (AE). The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and AEs. This analysis examined pts with or without moderate RI (CrCl < 60 vs ≥ 60mL/min). Results: 302 pts received POM + LoDEX; 153 pts received HiDEX, 31% and 39% had moderate RI, respectively. Pts with moderate RI were more likely to be older (64% vs 36% aged > 65 y) vs no RI. Median follow-up was 4 mo. Median PFS and OS were significantly longer with POM + LoDEX vs HiDEX regardless of RI (Table). Similar AE rates for POM + LoDEX as well as HiDEX Tx were seen in pts with and without moderate RI (Table). Discontinuation due to AE was 5% vs 7% (no moderate RI) and 11% vs 5% (moderate RI). Conclusions: POM + LoDEX significantly extended PFS and OS vs HiDEX in pts with or without moderate RI. Tolerability of POM + LoDEX was acceptable across subgroups, with few discontinuations due to AE. Clinical trial information: NCT01311687. [Table: see text]

8510 Background: RRMM patients (pts) who have exhausted treatment (Tx) with bortezomib (BORT) and lenalidomide (LEN) or thalidomide have a poor prognosis with short overall survival (OS). HiDEX is a well-established standard Tx in RRMM. POM has demonstrated clinical efficacy in pts refractory to LEN and BORT. MM-003 compared POM + LoDEX vs. HiDEX in RRMM pts who failed LEN and BORT and who progressed on their last Tx. Methods: Pts must have been refractory to last prior Tx (progressive disease [PD] during Tx or within 60 days) and failed LEN and BORT after ≥ 2 consecutive cycles of each (alone or in combination). Pts were randomized 2:1 to receive 28-day cycles of POM 4 mg D1–21 + DEX 40 mg (20 mg for pts aged > 75 y) weekly or DEX 40 mg (20 mg for pts aged > 75 y) D1–4, 9–12, and 17–20. Tx continued until PD or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included OS, overall response rate (ORR; ≥ partial response), and safety. Analyses were based on intent to treat. Results: 455 pts were randomized to POM + LoDEX (n = 302) or HiDEX (n = 153). The median number of prior Tx was 5 (range 1-17). 72% were refractory to LEN and BORT. Median follow-up was 4 months. POM + LoDEX significantly extended median PFS (3.6 vs. 1.8 months, HR = 0.45, P < .001) and OS (not reached vs. 7.8 months, HR = 0.53, P < .001) vs. HiDEX. The OS benefit was observed despite 29% of HiDEX pts receiving POM after PD. The trial met the primary endpoint of PFS, crossed the upper boundary for OS superiority, and the Data Monitoring Committee recommended crossover from HiDEX to POM ± DEX. With updated data, the ORR was 21% for POM + LoDEX vs. 3% for HiDEX (P < .001) and 24% vs 3% for pts randomized ≥ 6 months post-enrollment (P < .001). The most frequent grade 3/4 adverse events (AEs) for POM + LoDEX vs. HiDEX were neutropenia (42% vs. 15%), anemia (27% vs. 29%), and infection (24% vs. 23%). Discontinuation due to AEs was infrequent (7% vs. 6%). Updated data will be presented. Conclusions: POM + LoDEX significantly extended PFS and OS vs. HiDEX in pts who failed LEN and BORT. POM + LoDEX should become a standard of care in RRMM pts who have exhausted Tx with LEN and BORT. Clinical trial information: NCT01311687.

5020 Background: V+C was well tolerated in a phase I trial and responses and prolonged disease stabilization were observed in BRCA + patients (pts).To assess the relative contribution of the PARP inhibitor to the efficacy observed for the combination, we conducted a randomized multicenter trial comparing the response rate (RR) of V and C to the RR of C alone in patients with deleterious BRCA mutations and recurrent ovarian, or primary peritoneal, fallopian tube or high-grade serous ovarian cancer. Methods: Pts were ≥ 18 yrs, KPS ≥ 70%, had adequate organ function, prior therapy with PARP inhibitors was allowed.Both drugs were administered orally qd; C 50 mg, V 60 mg; 21 day cycles. Pts were randomized to receive either C alone or V+C. At disease progression, pts on C alone were allowed to cross over to the combination. Radiologic imaging was performed at baseline and q 3 cycles for assessment of response. Dose reduction of V was allowed to 40 mg for gr 3 non-hematologic or gr 4 hematologic toxicities. The study design had an 88% power to detect the difference between a 15% RR for C alone versus 35% for V+C, early closure if fewer responses were observed on the combination arm in the first 65 pts enrolled (half of the total projected accrual). Results: Total of 74 pts were enrolled (36 pts C, 38 pts V+C), median age 58 (37-79 yrs), # of prior therapies: median 4 (1-9), 2 pts had prior PARP therapy. Treatment was well tolerated, Gr ≥ 2 toxicities per arm for initial regimen (# of pts): C alone: lymphopenia (2), mucositis (1); V+C: lymphopenia (4), anemia (2), leucopenia (2), neutropenia (2). Of the 74 pts evaluable for response at the interim analysis, 3 PRs observed in 36 pts on V+C and 5 PRs of 38 pts on C alone arm; thus accrual was stopped. PAR levels assessed by validated ELISA were inhibited (>80%) in PBMCs in 9/10 pts 4 hours post V, no inhibition with C alone. Conclusions: Addition of V, a PARP inhibitor, to C did not improve RR versus C alone. Exomic sequencing, gene expression studies, and Fanconi Anemia triple stain immunofluorescence (FATSI) assay for FancD2 nuclear foci formation using archival tissue are ongoing.

8095 Background: Multiple myeloma (MM) remains incurable and invariably relapses after initial therapy. There is no uniform approach to management of relapsed MM and is dictated by type of initial therapy and the response seen, and availability of new drugs. The outcomes associated with current approaches have not been systematically examined. Methods: We enrolled 383 patients (pts) with myeloma who had a documented relapse between Jan 2007 and June 2010, including 220 from Europe, 106 from Asia, and 31 from South America and 26 from North America. Time Zero (T0) was defined as date of treatment after first relapse. Results: Across the study, 61% were male and 49% were over 65 years at T0. ISS stage distribution at diagnosis included 26, 40 and 33% of patients in stages 1, 2 and 3, respectively. Among regimens used at first relapse; bortezomib (Btz) containing regimens were most common (54%), followed by lenalidomide (Len, 25%) and cyclophosphamide (21%). The overall response rate (>=PR) to first therapy after relapse was 58% including 14% with a CR. There was a progressive decrease in the response rates with successive regimen; 45%, 30% and 15% for regimens 2, 3 and 4 respectively. Len use was considerably lower in the Asian cohort, while Btz use was comparable across the regions. The median PFS from T0 was 13 mos and OS was 35 mos, for the entire cohort. The PFS to first salvage regimen was similar across the regions, while OS was shorter for the Asian and South American cohorts. In a univariate analysis, ISS stage 3, presence of cytogenetic abnormalities, history of plasma cell leukemia or extramedullary disease (EMD), bone marrow PC% > 33% and presence of renal insufficiency were all associated with a shorter PFS as well as shorter OS (P<=0.01). In a multivariate model, ISS stage 3 and presence of EMD were most associated with short OS. Conclusions: Median PFS for current second line regimens, typically containing Btz or Len appear to be 1 yr with an OS from first relapse of about 3 yrs. The OS from first relapse is nearly double that seen in a cohort of patients in first relapse prior to introduction of new drugs. Clear-cut regional differences can be seen in terms of patterns of drug use and likely reflect drug availability and healthcare costs.

AbstractPrevious transcriptome‐wide association studies (TWAS) have identified breast cancer risk genes by integrating data from expression quantitative loci and genome‐wide association studies (GWAS), but analyses of breast cancer subtype‐specific associations have been limited. In this study, we conducted a TWAS using gene expression data from GTEx and summary statistics from the hitherto largest GWAS meta‐analysis conducted for breast cancer overall, and by estrogen receptor subtypes (ER+ and ER−). We further compared associations with ER+ and ER− subtypes, using a case‐only TWAS approach. We also conducted multigene conditional analyses in regions with multiple TWAS associations. Two genes, STXBP4 and HIST2H2BA, were specifically associated with ER+ but not with ER– breast cancer. We further identified 30 TWAS‐significant genes associated with overall breast cancer risk, including four that were not identified in previous studies. Conditional analyses identified single independent breast‐cancer gene in three of six regions harboring multiple TWAS‐significant genes. Our study provides new information on breast cancer genetics and biology, particularly about genomic differences between ER+ and ER− breast cancer.

Abstract Background The purpose of this study was to estimate precise age-specific tubo-ovarian carcinoma (TOC) and breast cancer (BC) risks for carriers of pathogenic variants in RAD51C and RAD51D. Methods We analyzed data from 6178 families, 125 with pathogenic variants in RAD51C, and 6690 families, 60 with pathogenic variants in RAD51D. TOC and BC relative and cumulative risks were estimated using complex segregation analysis to model the cancer inheritance patterns in families while adjusting for the mode of ascertainment of each family. All statistical tests were two-sided. Results Pathogenic variants in both RAD51C and RAD51D were associated with TOC (RAD51C: relative risk [RR] = 7.55, 95% confidence interval [CI] = 5.60 to 10.19; P = 5 × 10-40; RAD51D: RR = 7.60, 95% CI = 5.61 to 10.30; P = 5 × 10-39) and BC (RAD51C: RR = 1.99, 95% CI = 1.39 to 2.85; P = 1.55 × 10-4; RAD51D: RR = 1.83, 95% CI = 1.24 to 2.72; P = .002). For both RAD51C and RAD51D, there was a suggestion that the TOC relative risks increased with age until around age 60 years and decreased thereafter. The estimated cumulative risks of developing TOC to age 80 years were 11% (95% CI = 6% to 21%) for RAD51C and 13% (95% CI = 7% to 23%) for RAD51D pathogenic variant carriers. The estimated cumulative risks of developing BC to 80 years were 21% (95% CI = 15% to 29%) for RAD51C and 20% (95% CI = 14% to 28%) for RAD51D pathogenic variant carriers. Both TOC and BC risks for RAD51C and RAD51D pathogenic variant carriers varied by cancer family history and could be as high as 32–36% for TOC, for carriers with two first-degree relatives diagnosed with TOC, or 44–46% for BC, for carriers with two first-degree relatives diagnosed with BC. Conclusions These estimates will facilitate the genetic counseling of RAD51C and RAD51D pathogenic variant carriers and justify the incorporation of RAD51C and RAD51D into cancer risk prediction models.