Dimopoulos, Meletios Α.

Abstract Introduction: Selinexor is a novel, oral Selective Inhibitor of Nuclear Export (SINE) compound that blocks exportin 1 (XPO1). Selinexor treatment results in nuclear accumulation and activation of tumor suppressor proteins, inhibition of NF-kB, and translational suppression of several oncoprotein mRNAs (e.g., c-myc, cyclin D).Multiple myeloma (MM) remains incurable, and most patients (pts) eventually progress through standard drug classes of proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), anti-CD38 mAbs and others. The increased use of combinations in MM treatment, (PIs/IMiDs/mAbs), has led to a growing number of pts with penta-refractory MM (pts that have been treated with bortezomib (bort), carfilzomib (carfil), lenalidomide (len), pomalidomide (pom) and daratumumab (dara)). Active novel therapies with different mechanisms of actions are needed to address this unmet medical need. Part 1 of STORM enrolled pts with both quad- (bort, carfil, len, pom, treated MM) or penta-refractory MM and demonstrated an overall response rate (ORR) of 21% (Vogl et al, JCO 2018). Based on these findings, the Pivotal Part 2 of STORM was initiated, enrolling an additional cohort of 122 patients with penta-refractory MM. Methods: Pts with penta-refractory MM were treated with 80 mg selinexor plus 20 mg dexamethasone (Sd) twice weekly. Pts must have received an alkylator, bort, carfil, len, pom and dara, and had MM refractory to ≥1 PI, ≥1 IMiD, dara, a glucocorticoid, and their last therapy. Pts must have a total ANC ≥1000 mm3,platelets ≥50k/mm3 (or ≥75k if marrow plasma cells <50%), and creatinine clearance ≥20 mL/min. The primary endpoint was ORR. Secondary endpoints: duration of response (DOR), clinical benefit rate (CBR), progression free survival (PFS), and overall survival (OS). Efficacy was assessed by an Independent Review Committee (IRC) based on IMWG criteria. OS was also compared to a cohort of pts with PI, IMiD, dara refractory MM from the Flatiron Health Analytic Database (FHAD), (ref: ASH 2018 abs ID: 116493),who met all the inclusion criteria for STORM. Results: As of 1-Jun-2018, 122 pts (71 M/ 51 F) were enrolled in 38 sites (US and EU). Pt characteristics were [medians (range)]: age 65 yrs (40-85); 7 (3 - 18) prior treatment regimens, 6.6 yrs (<1 - 23.4) from initial MM diagnosis.65 pts (53%) had high risk cytogenetics, 86 pts (70%) had prior dara in combination, 102 pts (84%) had prior stem cell transplantation, 2 pts had prior CAR-T therapy. All pts enrolled with progressive disease (PD), 72% of pts had increases (3% - 792%) in MM markers from screening to C1D1 (median 11 days). Frequently reported Sd treatment related adverse events (AEs) included (all grades, grades 3/4): thrombocytopenia (67%, 53%), nausea (67%, 10%), fatigue (68%, 21%), anorexia (50%, 2%), anemia (46%, 28%), and weight loss (46%, 0%). Eight pts remain on study and 114 pts discontinued treatment (most commonly for PD). There were 4 deaths on treatment: sepsis, respiratory failure, pulmonary embolism, and an unrelated, unspecified cardiac event. IRC determined ORR (≥PR) was 26.2%, with 6.5% ≥ very good partial response, including 2 stringent complete responses (sCRs; MRD negative at 1:10-6 and at 1:10-4sensitivity). Both pts who relapsed after CAR-T achieved PRs. The CBR (≥minimal response, [MR]) was 39.3%, and 79% of pts achieved ≥stable disease (SD). Responses typically occurred within the first month. Medians: DOR 4.4 months (mo) (range <1 - 10 mo), PFS 3.7 mo, and OS 8.0 mo. Pts with ≥MR had significantly longer OS than pts with PD/NE (median not reached vs 1.9 mo, p=<0.0001). Compared to the FHAD cohort, STORM cohort had longer OS (Figure 1, HR 0.41, p=0.0001). Conclusions: Results of the pivotal STORM Part 2 in penta (PI, IMiD, dara)-refractory MM demonstrated that oral selinexor plus low-dose dexamethasone (Sd) was highly active with an ORR of 26.2%. Importantly, responses were rapid and deep with 2 patients achieving sCRs (both MRD negative) in these heavily pre-treated penta-refractory MM pts (median 7 prior regimens, 53% high risk). AEs are a function of dose/schedule/disease severity and can be managed with dose modifications and supportive care. No major organ toxicity was observed and AEs were typically transient and reversible. Sd is an all-oral, first in class mechanism with novel MOA and represents a potential therapeutic option to the growing number of pts with penta-refractory MM who have exhausted approved therapies. Disclosures Chari: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnology: Membership on an entity's Board of Directors or advisory committees; The Binding Site: Consultancy; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Array Biopharma: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Consultancy. Vogl:Karyopharm Therapeutics: Consultancy. Dimopoulos:Takeda: Honoraria; Bristol-Myers Squibb: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Celgene: Honoraria. Nooka:GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Adaptive technologies: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Spectrum Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Moreau:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cole:University of Michigan: Employment; Cancer Support Community myeloma advisory board: Membership on an entity's Board of Directors or advisory committees. Dingli:Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Vij:Jazz Pharmaceuticals: Honoraria; Karyopharm: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Takeda: Honoraria, Research Funding; Bristol Myer Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Raab:BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Weisel:Amgen, BMS, Celgene, Janssen, and Takeda: Honoraria; Amgen, Celgene, Janssen, and Sanofi: Research Funding; Amgen, BMS, Celgene, Janssen, Juno, Sanofi, and Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees. Delforge:Celgene and Janssen: Research Funding; Amgen, Celgene, Janssen and Takeda: Consultancy. Stewart:Amgen Inc., BMS, Celgene, Takeda, Roche, Seattle Genetics, Janssen, Ono: Consultancy; Amgen Inc., Celgene, Roche, Seattle Genetics: Research Funding. Mohty:Amgen: Consultancy, Honoraria; Molmed: Consultancy; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Servier: Consultancy; Jazz Pharmaceuticals: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; MaaT Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria; Takeda: Honoraria, Speakers Bureau; Bristol Myers: Consultancy, Research Funding. Sylvain:Gilead: Other: scientific advisor board. Costa:Celgene: Honoraria, Research Funding; Abbvie: Research Funding; Karyopharm: Research Funding; Janssen: Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria; BMS: Research Funding. Shah:Karyopharm Therapeutics: Employment. Picklesimer:Karyopharm Therapeutics: Employment. Saint-Martin:Karyopharm Therapeutics: Employment. Li:Karyopharm Therapeutics: Employment. Kauffman:Karyopharm Therapeutics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Shacham:Karyopharm Therapeutics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene: 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; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Jagannath:Celgene: Consultancy; Bristol-Myers Squibb: Consultancy; Multiple Myeloma Research Foundation: Speakers Bureau; Medicom: Speakers Bureau; Novartis: Consultancy; Merck: Consultancy.

Abstract Introduction Maintenance therapy has been extensively explored as a strategy for prolonging the duration of disease control and potentially survival following ASCT. To date, only lenalidomide has been approved for this indication. However, lenalidomide maintenance is associated with the development of second primary malignancies and tolerability issues. PIs are a backbone of MM treatment, and bortezomib-based maintenance has shown promising activity post-ASCT, yet the benefit of PI-based maintenance has not been demonstrated in a phase 3 trial vs placebo. Moreover, the feasibility of bortezomib maintenance in routine clinical practice is limited due to tolerability and the need for regular parenteral administration. There is a need for an oral PI maintenance therapy that can be administered for a prolonged period, improve depth of response without cumulative or late-onset toxicity, and improve convenience for patients. Methods The phase 3, double-blind, placebo-controlled, multicenter TOURMALINE-MM3 study (NCT02181413) compared weekly ixazomib vs placebo maintenance in NDMM patients who had at least a partial response (≥PR) to induction therapy with a PI and/or immunomodulatory drug (IMiD) followed by single ASCT. Patients were randomized (3:2) to receive ixazomib or matched placebo on days 1, 8, and 15 of 28-day cycles for up to 2 years or until progressive disease (PD) or unacceptable toxicity. Randomization was stratified by induction regimen (PI without IMiD vs IMiD without PI vs PI+IMiD), pre-induction ISS stage (I vs II or III), and post-ASCT response (complete response [CR] or very good partial response [VGPR] vs PR). Patients were ineligible if they had received post-ASCT consolidation or tandem ASCT. The ixazomib dose was 3.0 mg during cycles 1-4, increasing to 4 mg from cycle 5 if tolerated during cycles 1-4. The primary endpoint was PFS per independent review committee (IRC), who were blinded to treatment assignment. The key secondary endpoint was OS. Here, we report data from the final analysis for PFS (data cut-off: April 16, 2018). Results 656 patients were randomized (395 ixazomib; 261 placebo). Patient demographics were balanced between groups; overall median age was 57 years (range, 24-73), 37% vs 63% had ISS I vs II or III, 59%/11%/30% had received PI without IMiD / IMiD without PI / PI+IMiD induction therapy, 34%/45%/21% had achieved CR / VGPR / PR following induction/ASCT, and 18% had high-risk cytogenetics [del(17p), t(4;14), or t(14;16)]. After a median follow-up of 31 months with 54% of PFS events, there was a 28% reduction in the risk of progression/death, corresponding to a 39% improvement in PFS with ixazomib vs placebo (median 26.5 vs 21.3 months; hazard ratio [HR] 0.72; 95% CI: 0.582, 0.890; p=0.002; Figure). In a landmark analysis from ASCT, PFS was 30.7 vs 24.9 months (HR 0.684; 95% CI: 0.551, 0.848; p<0.001). Median PFS2 and OS have not yet been reached in either arm. Ixazomib maintenance led to higher rates of deepened response compared with placebo (relative risk 1.41; 95% CI: 1.10, 1.80; p=0.004). Conversion from documented MRD positivity at study entry to MRD negativity occurred at a higher rate with ixazomib compared with placebo (12% vs 7%). PFS benefit was seen broadly across subgroups, including ISS III (HR 0.661), PI-exposed (HR 0.750), PI-naïve (HR 0.497), and patients with high-risk cytogenetics (HR 0.625). Discontinuation due to AEs was low (7% ixazomib vs 5% placebo). With ixazomib vs placebo, 42% vs 26% of patients had grade ≥3 AEs; 27% vs 20% had serious AEs; and 1 patient vs 0 died on treatment. Common grade ≥3 AEs were infections (15% vs 8%) including pneumonia (6% vs 4%), gastrointestinal disorders (6% vs 1%), neutropenia (5% vs 3%), and thrombocytopenia (5% vs <1%). Peripheral neuropathy rates were 19% vs 15% (<1% vs 0 grade 3). Rate of second primary malignancies was 3% in both arms. Global Quality of Life scores (EORTC QLQ-C30) on ixazomib were similar to placebo. Conclusions This study demonstrated a 28% reduction in the risk of progression/death, corresponding to a 39% improvement in PFS with ixazomib maintenance, with deepening of responses and increased conversions to MRD negativity over control, as well as a favorable safety profile, including an absence of risk of second primary malignancies and low rates of peripheral neuropathy, supporting ixazomib as a valuable option for maintenance therapy in responding patients post-ASCT. Figure. Figure. Disclosures Dimopoulos: Janssen: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria. Gay:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Takeda Celgene, Amgen, BMS, and Roche: Other: Advisor; Janssen, Amgen, Takeda, Celgene, BMS: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Schjesvold:Oncopeptides: Consultancy; Abbvie: Honoraria; Novartis: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Adaptive: Consultancy; Bayer: Consultancy; Bristol Myers Squibb: Consultancy; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Beksac:Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Deva: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hajek:Amgen: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Novartis: Research Funding. Weisel:Amgen, BMS, Celgene, Janssen, and Takeda: Honoraria; Amgen, BMS, Celgene, Janssen, Juno, Sanofi, and Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen, Celgene, Janssen, and Sanofi: Research Funding. Goldschmidt:Novartis: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Adaptive Biotechnology: Consultancy; Sanofi: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Chugai: Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; ArtTempi: Honoraria; Mundipharma: Research Funding. Maisnar:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria. Moreau:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Chng:Merck: Research Funding; Takeda: Consultancy, Honoraria, Other: Travel, accommodation, expenses; Amgen: Consultancy, Honoraria, Other: Travel, accommodation, expenses; Aslan: Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Celgene: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding. Kaiser:Janssen: Consultancy, Honoraria; Takeda: Consultancy, Other: Travel Support; Bristol-Myers Squibb: Consultancy, Other: Travel support; Chugai: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Zweegman:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corp.: 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, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Mateos:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Spencer:Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen-Cilag: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; BMS: Research Funding; Takeda: Honoraria, Research Funding, Speakers Bureau; STA: Honoraria. Iida:Janssen: Consultancy, Honoraria, Research Funding; Kyowa-Hakko Kirin: Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Astellas: Research Funding; Chugai: Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Ono: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Toyama Chemical: Research Funding; MSD: Research Funding; Gilead: Research Funding; Teijin Pharma: Research Funding; Sanofi: Consultancy. Morgan:Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria. Teng:Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Suryanarayan:Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Skacel:Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment; Department of Hematology, Charles University General Hospital, Prague, Czech Republic: Other: Affiliation. Dash:Takeda Pharmaceuticals International Co.: Employment. Labotka:Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment.

Abstract Introduction: The phase 3 A.R.R.O.W. study (NCT02412878) has shown a favorable benefit-risk profile of once-weekly carfilzomib (K) at 70 mg/m2 over twice-weekly K at 27mg/m2 plus dexamethasone (d) for the treatment of patients (pts) with relapsed and refractory multiple myeloma (RRMM) (Moreau. Lancet Oncol. 2018;19:953-964). Once-weekly significantly improved progression-free survival (PFS) compared with twice-weekly (median 11.2 vs 7.6 months [mos]; hazard ratio [HR]: 0.69; 95% confidence interval [CI]: 0.54, 0.88; P=0.0014). Herein, we present a subgroup analysis of once-weekly vs twice-weekly Kd by previous therapy in pts with RRMM. Methods: 478 pts with RRMM, previously treated with 2 or 3 prior therapies including a proteasome inhibitor and an immunomodulatory agent were randomized 1:1 to receive either once-weekly (n=240) or twice-weekly (n=238) Kd. The once-weekly group received K (30-min intravenous infusion [IV]) on days (D) 1, 8, and 15 of all cycles (20 mg/m2 on D1 [cycle 1]; 70 mg/m2 thereafter). The twice-weekly group received K (10-min IV) on D1, 2, 8, 9, 15 and 16 (20 mg/m2 on D1 and 2 during cycle 1 and 27 mg/m2 thereafter). All pts received d at 40 mg/m2 on D1, 8, 15 (all cycles), and 22 (cycle 1-9 only). Treatment was given in 28-day cycles until disease progression or unacceptably toxicity. The primary endpoint was progression-free survival (PFS). The study secondary endpoints were overall response rate (ORR), survival, safety, and pharmacokinetics. Results: Baseline characteristics were generally balanced. PFS, ORR, and safety outcomes by prior lines of therapy are shown in the Table; PFS curves by prior lines are shown in the Figure. With a median follow-up time of 12.6 mos in the once-weekly group and 12.0 mos in the twice-week group, PFS for pts with 2 prior lines (N=241) was 12.1 mos vs 7.6 mos (HR: 0.61; 95% CI: 0.43, 0.86). Median PFS for pts with 3 prior lines (N=237) was 8.9 mos for once-weekly vs 7.9 mos for twice-weekly (HR: 0.82; 95% CI: 0.59, 1.15). ORRs for once- vs twice-weekly were 62.9% vs 40.8% (OR: 2.46; 95% CI: 1.47, 4.14) in pts with 2 prior lines and 62.9% vs 40.7% (OR: 2.47; 95% CI: 1.46, 4.17) in pts with 3 prior lines. In the 2 prior lines group, 9.5% vs 3.2% of pts had a complete response or better with once- vs twice-weekly Kd respectively. Complete responses or better in pts with 3 prior lines were obtained in 4.8% of pts receiving once-weekly and no pts with twice-weekly Kd. In A.R.R.O.W., 401 (83.9%) pts had prior lenalidomide (LEN) exposure. Median PFS for once- vs twice-weekly was 11.1 mos vs 7.4 mos (HR: 0.72; 95% CI: 0.56, 0.94) for LEN exposed pts and NE (not estimable) vs 9.4 mos (HR: 0.63; 95% CI: 0.33, 1.21) for pts without prior LEN exposure. ORRs for once- vs twice-weekly were 62.3% vs 39.2% (OR: 2.57; 95% CI: 1.72, 3.84) in pts with prior LEN exposure, and 66.7% vs 47.7% (OR: 2.19; 95% CI: (0.86, 5.58) in pts without prior LEN exposure. Grade ≥3 treatment-emergent adverse events (AEs) occurred in 59.1% vs 65.0% (once- vs twice-weekly) of pts with 2 prior lines of therapy, and 75.6% vs 58.0% (once- vs. twice-weekly) of pts with 3 prior lines of therapy. The incidence of Grade ≥3 AEs of interest by prior lines can be found in the Table. Grade ≥3 AEs occurred in 69.3% vs 60.2% (once- vs twice-weekly) of pts with prior LEN, and 57.6% vs 68.2% (once- vs. twice-weekly) of pts without prior LEN. Conclusions: Once-weekly Kd resulted in a favorable benefit-risk profile regardless of the number of prior lines. Although the median PFS was prolonged in both groups, pts with 2 prior lines achieved a greater benefit, underlining the need for using once-weekly Kd early to optimize outcomes for pts with RRMM. Safety profiles were consistent with previous findings and reports. Importantly, low incidences of heart failure were reported across all subgroups and no additional toxicities were found. As described for other K-based regimens, efficacy of K can be further enhanced by being used in earlier lines of therapy for pts with RRMM. This subgroup analysis further confirmed the positive results from A.R.R.O.W. of using once-weekly Kd at 70 mg/m2 regardless of prior therapies and should be considered an additional option to treat pts with RRMM. Disclosures Moreau: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:Amgen Inc., Celgene, Roche, Seattle Genetics: Research Funding; Amgen Inc., BMS, Celgene, Takeda, Roche, Seattle Genetics, Janssen, Ono: Consultancy. Lazzaro:Celgene: Consultancy, Research Funding; Amgen: Research Funding. Dimopoulos:Janssen: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Takeda: Honoraria; Bristol-Myers Squibb: Honoraria. Cavo:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ailawadhi:Amgen: Consultancy; Pharmacyclics: Research Funding; Takeda: Consultancy; Janssen: Consultancy; Celgene: Consultancy. Iskander:Amgen: Employment, Equity Ownership. Huang:Amgen: Employment, Equity Ownership. Zahlten-Kumeli:Amgen: Employment, Equity Ownership. Mateos:GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract Background Melphalan, prednisone and thalidomide (MPT) is a standard therapy for NDMM recognized worldwide based on a statistically significant advantage in overall survival (OS) and progression-free survival (PFS) vs. MP (Facon Lancet 2007; Fayers Blood 2011; NCCN 2013). The combination of lenalidomide and low-dose dexamethasone (Rd) increased OS with fewer adverse events (AEs) than treatment with lenalidomide and high-dose dexamethasone in NDMM pts (ECOG E4A03) (Rajkumar Lancet Oncol 2010). The FIRST trial is a multicenter, open-label, phase III trial comparing the efficacy and safety of Rd versus MPT in transplant-ineligible NDMM pts. Methods NDMM pts either ≥ 65 years of age, or not candidates for SCT were randomized to one of three arms: Rd in 28-day cycles until disease progression (Arm A), Rd in 28-day cycles for 72 weeks (18 cycles, Arm B), or MPT in 42-day cycles for 72 weeks (12 cycles, Arm C). Assessments by International Myeloma Working Group criteria were done after each cycle. Pts with renal impairment were enrolled; however, pts on dialysis were excluded. Starting doses of lenalidomide and dexamethasone were adjusted based on renal function and age, respectively. Melphalan starting dose was adjusted based on age, absolute neutrophil count, platelet count, and renal function; and thalidomide was adjusted for age. Dose adjustments were permitted for AEs. All pts were required to receive anti-thrombotic prophylaxis. Stratification factors included age, International Stage System, and country. The primary endpoint was a comparison of PFS in Arm A vs. Arm C. Secondary endpoints included OS, overall response rate (ORR), time to response, duration of response (DOR), safety, and quality of life (QOL). A preplanned additional analysis included time from randomization to second progression event or death (PFS2). The final preplanned analysis of independently adjudicated progressive disease (PD) events in Arm A vs. Arm C conducted after 960 events of death or PD, and an interim of OS in 64% of survival events (574/896 events) are presented in this abstract. Comparisons of PFS and all secondary endpoints, including OS for all three arms, will be presented at the meeting. Results A total of 1,623 pts were randomized 1:1:1 in three arms. As of today, 121 pts continue to receive lenalidomide on study (Arm A). The median age was 73 (40.0–92.0) years; 35% pts were aged ≥ 75 years; and 41% of pts had ISS stage 3 disease. After a median follow-up of 37 months, the trial met its primary endpoint (PFS), demonstrating a 28% reduction in risk of progression or death (HR=0.72; p= 0.00006). The preplanned interim analysis of OS demonstrated a 22% reduction in risk of death in favor of Arm A vs. Arm C (HR=0.78, p=0.01685); however, the pre-specified boundary (p<0.0096) was not crossed. All other secondary endpoints consistently showed improvement in favor of Arm A vs. Arm C; ORR (PR or better) 75% vs. 62% (p < 0.00001), DOR (HR=0.63; p<0.00001), and PFS2 (HR=0.78, p=0.0051). Relevant Grade 3/4 adverse events in Arm A vs. Arm C were neutropenia (28% vs. 45%), thrombocytopenia (8% vs. 11%), febrile neutropenia (1% vs. 3%), infection (29% vs. 17%), neuropathy (5% vs. 15%), and deep-vein thrombosis (5% vs. 3%). The incidence of secondary primary malignancies (SPM) was evaluated. Hematologic malignancies were 0.4% in Arm A vs. 2.2% in Arm C; the overall incidence of solid tumors was identical (2.8%). Conclusion Continuous treatment with the all oral doublet Rd significantly improved the primary endpoint of PFS compared with the standard triplet, MPT. All secondary endpoints support the clinical benefit of continuous Rd treatment. The safety profile of Rd was manageable, with reduced hematologic SPM compared to MPT. Disclosures: Facon: Celgene: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Off Label Use: Lenalidomide as treatment for NDMM. Dimopoulos:Celgene, Orthobiotech: Honoraria. Dispenzieri:Celgene, Millenium, Jansenn, Pfizer: Research Funding. Catalano:Celgene, Roche: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Hulin:Janssen: Honoraria; Celgene: Honoraria. Cavo:Celgene, Janssen, Millennium, Onyx, Brystol Myers Squibb: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees. Pinto:Mundipharma: Consultancy, Honoraria; Roche: Honoraria; Celgene: Consultancy, Honoraria. Weisel:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Ludwig:Celgene: Honoraria, Research Funding, Speakers Bureau. Bahlis:Celgene: Consultancy, Honoraria. Delforge:Celgene: Honoraria. Chen:Celgene: Consultancy, Research Funding; Lundbeck: Consultancy; Johnson & Johnson: Consultancy, Research Funding; Roche: Honoraria; GlaxoSmithKline: Research Funding. Oriol:Celgen: Consultancy. White:Celgene: Honoraria, Research Funding. Binder:Celgene: Research Funding. Anderson:Acetylon, OncoPep: Equity Ownership; Celgene, Onyx, Sanofi Aventis, Gileod: Consultancy. Moreau:Celgene Corporation: Honoraria, Speakers Bureau. Attal:Janssen: Lectures, Lectures Other, Membership on an entity’s Board of Directors or advisory committees; Celgene Corporation: Lectures Other, Membership on an entity’s Board of Directors or advisory committees. Knight:Celgene: Employment, Equity Ownership. Chen:Celgene: Employment. Van Oostendorp:Celgene: Employment. Jacques:Celgene: Employment. Ervin-Haynes:Celgene: Employment, Patents & Royalties. Benboubker:Celgene: Consultancy.

Abstract Introduction: Multiple myeloma (MM) accounts for about 20% of deaths from hematological cancers and remains incurable despite conventional and high-dose chemotherapy. Two phase III trials in patients with relapsed or refractory MM (MM-009 and MM-010) showed that lenalidomide combined with dexamethasone resulted in significantly improved response rates and significantly prolonged median time to progression (TTP) and overall survival (OS) compared with dexamethasone alone. This current sub-analysis of lenalidomide plus dexamethasone therapy assessed whether there was a survival benefit in maintaining patients on therapy after achieving their best response and what the impact of early discontinuation on TTP and OS was. Methods: Of the 353 patients from MM-009 and MM-010 treated with lenalidomide plus dexamethasone, 32 did not respond. Of the remaining 321 responding patients, 214 had a partial response (PR) or better and 107 patients had stable disease (SD). In this post-hoc sub-analysis, we first assessed the outcome of continuing treatment for ≤10 months vs. >10 months in all 321 patients who achieved SD or better, after they achieved their best response. In this landmark analysis, OS was measured from the time of achieving best response to death from any cause or to last contact. In a second analysis, we assessed the impact of early discontinuation due to adverse events or withdrawn consent on OS and TTP in all patients who achieved SD or better. Therefore, we excluded patients who discontinued treatment due to disease progression, death, or lack of efficacy. Patients who achieved SD or better and who continued on therapy were compared with those who discontinued. OS and TTP were assessed from time of randomization. Results: In the landmark analysis, of the 321 responding patients (≥PR, n=214; SD, n=107), 223 patients received treatment for ≤10 months after achieving their best response and 98 patients for >10 months after achieving their best response. Patients who continued therapy for >10 months after achieving their first best response had significantly longer OS vs. those who received therapy for ≤10 months (not reached vs. 23.4 months; p<0.0001). At 24 months after achieving their best response, significantly more patients were alive if they continued therapy >10 months vs. ≤10 months (93.8% vs. 48.4%, p<0.0001). In the second analysis, in order to evaluate the impact of discontinuation in patients achieving SD or better, we excluded 134 patients due to disease progression, death, or lack of efficacy. Of the remaining 187 responding patients, 72 discontinued treatment for AE (n=42) or withdrew consent (n=30), while the remaining 115 patients continued treatment. Median OS and TTP were significantly longer for patients who continued vs. those who discontinued treatment (median OS: not reached vs. 29.5 months, p<0.0001; median TTP: not reached vs. 13.6 months, p<0.0001). Conclusions: In patients achieving SD or better, prolonged duration of treatment was associated with significantly longer OS and TTP. In contrast, early discontinuation of treatment led to reduced OS and TTP. Therefore, efforts should be made to manage adverse events while maintaining patients on therapy. Furthermore, maintaining treatment with lenalidomide and dexamethasone after achieving the optimal response ensures a significant improvement in OS for patients with relapsed or refractory MM.

Abstract Introduction Few treatments options are available for patients (pts) with relapsed/refractory multiple myeloma (RRMM) who have previously been treated with lenalidomide (LEN) and bortezomib (BORT), and their prognosis is poor. Pomalidomide (POM) is a distinct IMiD® immunomodulatory agent with a mechanism of action consisting of direct anti-myeloma, stromal-support inhibitory, and immunomodulatory effects. In randomized phase 2 and 3 trials (MM-002 and MM-003), POM plus low-dose dexamethasone (POM+LoDEX) demonstrated marked efficacy in RRMM pts who had received multiple prior therapies, including LEN and BORT. This side-by-side analysis presents the most recent survival and safety data from these trials. Methods The MM-002 and MM-003 trials enrolled pts with ≥ 2 prior therapies, including LEN and BORT. In MM-002, pts received POM (4 mg/day on days 1–21 of each 28-day cycle) alone or in combination with LoDEX (40 mg/week). In MM-003, pts were randomized 2:1 to receive POM+LoDEX or high-dose DEX alone (HiDEX) (40 mg/days 1–4, 9–12, 17–20 in a 28-day cycle); HiDEX was chosen as the comparator to isolate the effects of POM, as at the time of trial design it was the standard salvage therapy for heavily pretreated pts. Thromboprophylaxis was required for all pts treated with POM and pts at high risk of developing venous thromboembolism. Data cutoff was February 1, 2013 for MM-002 and March 1, 2013 for MM-003. The primary endpoint in both trials was progression-free survival (PFS). Secondary endpoints included overall survival (OS), response rates, duration of response, and safety. Results In each study, pts had received a median of 5 prior therapies (range 1-17), and all pts had received prior LEN and BORT. In MM-002, 113 pts were treated with POM+LoDEX and 108 were treated with POM alone (60% of POM alone pts subsequently received DEX). A total of 79% of pts were LEN refractory; 62% were refractory to both LEN and BORT; and 35% had received LEN as their last prior therapy. With a median follow-up of 14.2 months (mos), median PFS was 4.2 mos, OS was 16.5 mos, and overall response rate (ORR, defined as at least a partial response) was 33% with POM+LoDEX (Table 1). In MM-003, 302 pts were treated with POM+LoDEX and 153 pts were treated with HiDEX (50% of HiDEX pts subsequently received POM). A total of 94% of pts were LEN refractory; 74% were both LEN and BORT refractory; and 29% had received LEN as their last prior therapy. Survival outcomes were similar in MM-003; with a median follow-up of 10 mos, median PFS was 4.0 mos, OS was 12.7 mos, and ORR was 31% with POM+LoDEX. In both trials, LEN as last prior therapy did not impact response, PFS, or OS vs the overall population. Commonly observed adverse events (AEs) are presented in Table 2 for pts treated with POM+LoDEX. Grade 3 and 4 neutropenia was 28% and 13% in MM-002, and 26% and 22% in MM-003 for the POM+LoDEX arms, respectively. AEs were generally manageable for POM+LoDEX in MM-002 and MM-003 with dose interruptions (67% for both) and reductions (29% and 26%, respectively), and standard supportive care, including growth factor support (46% and 43%), red blood cell transfusions (45% and 49%), platelet transfusions (14% and 20%), and anti-infective agents (89% in both trials). Rates of POM discontinuation due to treatment-related AEs were low (2–4% with POM+LoDEX). In MM-002 and MM-003, 49% and 51% of pts in the POM+LoDEX arms experienced neutropenia of any grade. With appropriate AE management, 9% and 23% had dose interruptions, 4% and 8% had dose reductions, and 1 pt in both MM-002 and MM-003 discontinued due to neutropenia. Febrile neutropenia developed in 3% and 10% of pts; 1% and 4% had dose interruptions, 0% and 2% had dose reductions, and no pts discontinued due to febrile neutropenia in the MM-002 and MM-003 studies, respectively. The majority of infections occurred in the absence of neutropenia of any grade (54% in MM-002 and 66% in MM-003). The rate of POM discontinuation due to infection was low (1% in MM-002 and 2% in MM-003). Conclusion In both the MM-002 and MM-003 trials, POM+LoDEX consistently extended PFS in advanced RRMM pts. PFS, OS, and ORR were not negatively impacted in patients who were refractory to LEN or BORT, even as last prior therapy. Both trials demonstrated that with dose modifications and supportive care POM was well tolerated, leading to few discontinuations. POM+LoDEX should be considered a standard of care for pts with advanced RRMM who have exhausted LEN and BORT. Disclosures: Siegel: Celgene Corporation: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Onyx: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Millennium: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Richardson:Millennium: Membership on an entity’s Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity’s Board of Directors or advisory committees; Celgene Corporation: Membership on an entity’s Board of Directors or advisory committees. Dimopoulos:Celgene Corporation: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Chen:Celgene Corporation: Consultancy, Honoraria, Research Funding. Song:Celgene Corporation: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau. Vij:Onyx: Consultancy, Research Funding; Millenium: Speakers Bureau; Celgene Corporation: Consultancy, Research Funding, Speakers Bureau. Bahlis:Celgene Corporation: Consultancy, Honoraria, Research Funding. Baz:Millenium: Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding; Celgene Corporation: Research Funding. Hofmeister:Celgene Corporation: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Weisel:Celgene Corporation: Consultancy, Honoraria, Research Funding. Jagannath:Millennium: Honoraria; Celgene Corporation: Honoraria. Lonial:Millennium: Consultancy; Novartis: Consultancy; Bristol Myers Squibb: Consultancy; Sanofi: Consultancy; Onyx: Consultancy; Celgene Corporation: Consultancy. Delforge:Celgene Corporation: Honoraria. Talpaz:Ariad, Sanofi, Novartis: Membership on an entity’s Board of Directors or advisory committees; Ariad, Novartis, BMS, Pfizer: Speakers Bureau; Ariad, BMS, Sanofi, INCYTE: Research Funding. Moreau:Celgene Corporation: Honoraria, Speakers Bureau. San Miguel:Jansen, Celgene Corporation, Onyx, Novartis, Millenium: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees. Karlin:Janssen: Honoraria; Celgene Corporation: Consultancy, Expert board committee Other, Honoraria. Goldschmidt:Celgene Corporation, Janssen, Novartis: Consultancy, Honoraria, Research Funding. Oriol:Celgene Corporation: Consultancy. Alegre:Janssen: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Cavo:Millennium: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Onyx: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Celgene Corporation: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees. Martinez-Lopez:Celgene Corporation: Honoraria, Research Funding. Lacy:Celgene Corporation: Research Funding. Chen:Celgene Corporation: Employment, Equity Ownership. Casey:Celgene Corporation: Employment, Equity Ownership. Sternas:Celgene Corporation: Employment, Equity Ownership. Zaki:Celgene Corporation: Employment, Equity Ownership. Jacques:Celgene Corporation: Employment, Equity Ownership. Anderson:Onyx: Consultancy, Equity Ownership; Gilead: Consultancy, Equity Ownership; sanofi aventis: Consultancy, Equity Ownership; Oncopep: Consultancy, Equity Ownership; Acetylon: Consultancy, Equity Ownership; Celgene Corporation: Consultancy, Equity Ownership.

Abstract Abstract 806FN2 POEMS syndrome is defined by the presence of peripheral neuropathy (P), monoclonal plasma cell disorder (M), organomegaly (O), endocrinopathy (E) and skin changes (S). The majority of patients have sclerotic bone lesions, although the underlying mechanisms are still unclear. Increased circulating vascular endothelial growth factor (VEGF) is another feature of the disease. However, there is almost no information on the role of other angiogenic molecules in POEMS biology. The aim of the study was to evaluate bone metabolism and angiogenic cytokines in POEMS and compare the results with multiple myeloma (MM) and osteosclerotic patients of other etiology. We retrospectively studied 61 POEMS patients (40M/21F, median age 52 years) who were diagnosed between 1996 and 2010 and were treated and followed in Mayo Clinic Rochester (MN, USA), Hôpital Saint-Louis, Paris (France) and in Alexandra Hospital, Athens (Greece). We evaluated the following indices of bone remodeling and angiogenesis in all patients at diagnosis and in 22 of them one month after front-line treatment: i) osteoclast regulators [sRANKL and osteoprotegerin (OPG)]; ii) osteoblast inhibitor dickkopf-1 (Dkk-1); iii) bone resorption marker CTX; iv) bone formation markers [bone-specific alkaline phosphatase (bALP) and osteocalcin]; and v) angiogenic cytokines [VEGF, angiogenin (ang), angiopoietin (angp)-1 and -2]. These molecules were also measured in 60 newly diagnosed, untreated MM patients (34M/26F, median age: 54 years) and 44 healthy controls. Bone markers were also evaluated in 24 patients with HbS/beta-thalassemia (10M/14F, median age: 43 years) who presented with osteosclerosis, defined as osteosclerotic bone lesions in plain radiography and high T-score of lumbar spine DXA (median: +3.6, range: +2 to +7.9). All POEMS patients presented with P and M, while 90% had E, 83% had S, 61% had O and 32% had papilloedema. One or more documented sclerotic bone lesions in plain X-rays were observed in 78% of patients (diffuse lesions in 44%), while 43% of patients had also an osteolytic component. Seven patients had Castleman disease. At diagnosis, compared to controls, POEMS patients had increased levels of bALP (mean ± SD: 48.3 ± 22.9 IU/L vs. 21.6 ± 8.2 IU/L; p<0.001), CTX (0.97 ± 0.94 ng/ml vs. 0.33 ± 0.24 ng/ml; p<0.001), Dkk-1 (p<0.001), sRANKL (p<0.001) and sRANKL/OPG ratio (p<0.001). Patients with diffuse osteosclerosis had increased levels of Dkk-1 compared to others (p = 0.05), suggesting a balance effect to increased formation activity. Patients with POEMS had increased levels of bALP and decreased levels of CTX compared to MM patients (p<0.001 and p = 0.03, respectively), while they had increased levels of CTX and sRANKL/OPG ratio compared to HbS/beta-thal patients (p = 0.001 for both comparisons). There were no other differences regarding bone markers among studied groups. Regarding angiogenic cytokines, at diagnosis, POEMS patients had elevated VEGF (1232 ± 565 pg/ml vs. 195 ± 211 pg/ml; p<0.001), ang (266 ± 82 ng/ml vs. 190 ± 45; p<0.001) and angp-2 (3.5 ± 2.2 ng/ml vs. 1.2 ± 0.6 ng/ml; p<0.001) and decreased angp-1 (p =0.05) and angp-1/angp-2 ratio (reflects increased angiogenic capacity; 9.1 ± 8.8 vs. 44.8 ± 76.1; p<0.001) compared to normal controls. We found no strong correlations between the levels of VEGF, ang and angps. When compared to MM patients, POEMS patients had increased circulating VEGF (p = 0.001) without any difference regarding the other angiogenic cytokines. Response to therapy was accompanied by a dramatic reduction of VEGF only (551 ± 541 pg/ml compared to baseline 1800 ± 1510 pg/ml; p = 0.003). Receiver-operating characteristic (ROC) curve analysis showed that high levels of angiopoietin-2 (≥ 2.3 ng/ml) and high bALP (≥ 38 IU/l) each have a 95% specificity for patients with POEMS syndrome. These results suggest that patients with POEMS syndrome have high bone turnover with increased bone formation as compared to healthy subjects, to MM patients, who have reduced bone formation, and to osteosclerotic HbS/beta-thal patients, who have diminished bone resorption. Importantly, our analysis supports the use of angp-2, bALP along with VEGF as minor criteria for the diagnosis of POEMS. Successful treatment reduced VEGF, which seems to be a suitable marker for the follow-up of POEMS patients. Furthermore the imbalance of angp-1/angp-2 pathway may indicate possible targets for the development of novel agents against POEMS. Disclosures: No relevant conflicts of interest to declare.

Abstract POEMS syndrome is defined by the presence of peripheral neuropathy (P), monoclonal plasma cell disorder (M), organomegaly (O), endocrinopathy (E), and skin changes (S). Virtually all patients will have sclerotic bone lesions, although the mechanisms of their development have not been clarified to-date. Increased plasma level of VEGF is another characteristic of the disease. However, there is very little information for the role of other angiogenic molecules in POEMS pathogenesis. The aim of this study was to evaluate bone metabolism and angiogenic cytokines in POEMS and compare the results with multiple myeloma (MM) and osteosclerotic patients of other etiology. Seven patients with POEMS at diagnosis (6M/1F; median age: 49 years) were evaluated. A series of bone remodeling indices were measured: i) bone resorption markers [C- and N- telopeptide of type-I collagen (CTX and NTX), TRACP-5b], ii) bone formation markers [bone-alkaline phosphatase, osteocalcin (OC), and C-terminal propeptide of type-I collagen (CICP)], and iii) osteoclast regulators [soluble RANKL, osteoprotegerin (OPG), MIP-1α, and TNF-α]. Furthermore, the following angiogenic cytokines were measured in the plasma of POEMS patients: VEGF, VEGF-A, angiogenin, angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and bFGF. All above molecules were also measured in 25 newly diagnosed, untreated MM patients (14M/11F, median age: 64 years) and 20 healthy controls. Bone markers were also evaluated in 24 patients with HbS/beta-thalassemia (10M/14F, median age: 43 years) who presented with osteosclerosis, i.e. osteosclerotic bone lesions in plain radiography and a median T-score of lumbar spine Bone Mineral Density of +3.6 (range: +2 to +7.9). All POEMS patients had P, O, E, S, edema and thombocytosis; 6 had E and 2 Castleman’s disease. Six patients had sclerotic bone lesions, while 4 had also a lytic component in their bone lesions. POEMS patients had increased levels of sRANKL (p=0.003), OPG (p=0.008), TNF-α (p=0.001), NTX (p<0.001), CTX (p=0.001) and CICP (p=0.001) compared with controls. Interestingly, NTX levels were even higher in POEMS than in MM patients (p<0.01). NTX and CTX were elevated in POEMS compared with osteosclerotic HbS/β-thal patients (p<0.01), who had reduced bone resorption compared with controls. POEMS patients had increased levels of OC and CICP compared with MM (p=0.02 and p=0.003, respectively), and increased levels of OC compared with osteosclerotic HbS/β-thal patients (p<0.01). In terms of angiogenic cytokines, POEMS patients had increased levels of all studied cytokines compared with controls (p<0.01). All POEMS patients had at least 1.8-fold higher value of VEGF-A (the major angiogenic component of VEGF) compared with the higher value observed in controls. Furthermore, VEGF (p=0.03), VEGF-A (p<0.001), angiogenin (p<0.001), and bFGF (p=0.01) were higher in POEMS than in MM. The ratio of Ang-1/Ang-2 was very low in POEMS compared with both controls and MM. These results suggest that POEMS patients have increased bone turnover in contrast to MM patients who have reduced bone formation and osteosclerotic HbS/β-thal patients who have diminished bone resorption. Furthermore the imbalance of Ang-1/Ang-2 pathway and the increased levels of angiogenic cytokines, even compared with MM, may indicate possible targets for the development of novel agents against POEMS.

Abstract Background: The use of low-dose dexamethasone (Dex) in combination with lenalidomide (Len), an immunomodulatory compound, improves overall survival (OS) compared with high-dose Dex plus Len in patients (pts) with newly diagnosed multiple myeloma (MM) (Rajkumar et al. 2007). Two phase III randomised trials of pts with relapsed/refractory MM showed that Len/Dex had significantly better overall response (OR), complete response (CR), OS and time to progression (TTP) than Dex alone. Dex dose reductions were permitted in relation to severity of adverse events (AEs). We investigated the effect of Dex dose reductions on efficacy and tolerability of Len/Dex in relapsed/refractory MM. Methods: Data were pooled from the MM-009/010 studies for pts treated in the Len/Dex group who had an unchanged Len dose (n=233). Pts were treated with Len (25mg/day on day 1–21 of each 28-day cycle) and Dex 40mg on day 1–4, 9–12, and 17–20 (for the first four cycles). After four cycles, Dex 40mg/day was administered only on day 1–4. Dex dose reductions were: 40mg day 1–4 every 2 weeks (level -1), 40mg day 1–4 every 4 weeks (level -2), and 20mg day 1–4 every 4 weeks (level -3). Response to therapy, TTP, OS, and progression-free survival (PFS), as well as AEs were assessed. Response rate and TTP were based on data obtained before unblinding (June/August 2005 [MM-009/010]. Results: Of 233 pts in this post-hoc analysis, 177 pts were treated with Dex 40 mg/day throughout the study and 46 received Dex dose reductions. Forty-one pts received a dose reduction due to AEs. Baseline characteristics were balanced between treatment groups. Pts who received Dex dose reductions had a significantly higher OR rate, including a higher CR, compared with those who received standard Dex dose (Table). Pts in the Dex reductions group had significantly longer median TTP, median OS, and median PFS, compared with those who received Dex at the assigned dose. At the end of the study, rates of serious AEs, grade 3–4 AEs, treatment-related AEs and withdrawals because of AEs were comparable between pts who received Dex dose reductions and those who received an unchanged Dex dose. Although most Dex dose reductions were made for an AE, by reducing the dose pts were able to maintain a similar safety profile to those who did not require dose reductions. Grade 3–4 haematological AEs in pts who received Dex dose reductions and those who did not were neutropenia (23.7% and 32.6%, respectively), thrombocytopenia (8.5% and 6.8%, respectively) and anaemia (6.8% and 6.2%, respectively). No febrile neutropenia was reported in these pts. Conclusion: Dex dose reductions improved the efficacy of Len/Dex without affecting tolerability in pts with relapsed/refractory MM. Len/Dex Dex unchanged (n=177) Dex reduced (n=46) P *Most conservative median estimate obtained assuming all censored patients die right right after the censor date Response, % OR 50.8 69.6 <0.05 CR 13.0 23.9 <0.01 nCR 19.8 37.0 <0.01 PR 18.1 8.7 <0.01 Median TTP, weeks* >24.1 >59.9 0.002 Median OS, weeks* >109.7 >121.9 0.19 Median PFS, weeks* >24.1 >59.9 0.001

Abstract Introduction: Cytogenetic abnormalities in patients (pts) with multiple myeloma (MM) are of prognostic importance and can be associated with poor outcomes (Bergsagel, Blood, 2011). The FIRST trial is a pivotal phase 3 study with the largest data set in transplant-ineligible pts with newly diagnosed MM (NDMM). This subanalysis evaluates the impact of cytogenetics on outcomes in transplant-ineligible pts with NDMM continuously treated with lenalidomide plus low-dose dexamethasone until disease progression (Rd continuous). Methods: Transplant-ineligible pts with NDMM were randomized to 1 of 3 treatment arms: Rd continuous, Rd18 (Rd for 18 cycles [72 weeks]), or melphalan-prednisone-thalidomide (MPT; for 12 cycles [72 weeks]). Cytogenetics were assessed using fluorescence in situ hybridization. Pts were categorized into cytogenetic risk groups according to International Myeloma Working Group criteria. High-risk cytogenetics included del(17p), t(4;14), and t(14;16); all other pts were categorized as non-high risk. The primary endpoint was progression-free survival (PFS; primary comparators were Rd continuous vs MPT), and key secondary endpoints were overall survival (OS), overall response rate (ORR), and safety. Results: A total of 762 of 1623 pts from the intent-to-treat population had validated cytogenetic profiles, with 142 pts in the high-risk group and 620 pts in the non-high-risk group. Baseline characteristics were well balanced across cytogenetic risk groups (Table 1). The median follow-up for OS was 40.2 months for the 762 pts in this analysis (data cutoff, March 03, 2014). In the non-high-risk group, median duration of treatment was 19.4 months with Rd continuous and 16.6 months with both Rd18 and MPT. In the high-risk group, median duration of treatment was 10.0 months with Rd continuous, 8.2 months with Rd18, and 12.0 months with MPT. Rd continuous treatment resulted in a 24% reduced risk of death or progression compared with MPT and an even greater 32% reduced risk in pts without high-risk cytogenetics (Table 2). In non-high-risk pts, median PFS was 31.1 months with Rd continuous compared with 21.2 and 24.9 months with Rd18 and MPT, respectively (Figure). However, in high-risk pts, the observed numerical median PFS favoring Rd18 is mainly due to small pt numbers influenced by long runners (n = 5), and the greatly overlapping 95% CIs from all 3 arms show the difference is likely to be minimal. Rd continuous treatment resulted in a 28% reduced risk of death vs MPT overall and a 34% reduced risk in pts without high-risk cytogenetics. OS was similar across treatment arms for high-risk pts. ORRs in all cytogenetic risk groups favored Rd continuous vs MPT. In pts with high-risk cytogenetics, higher-quality responses were also observed with Rd continuous vs MPT treatment. Similar results were seen with Rd continuous compared with Rd18, although OS and ORR benefits overall and in pts without high-risk cytogenetics were not as pronounced. In all 3 treatment arms, adverse events were consistent across cytogenetic risk groups. Conclusions: Rd continuous treatment resulted in PFS and OS benefits vs MPT in pts with validated cytogenetic profiles. This was largely due to PFS and OS improvements in pts without high-risk cytogenetics. In the high-risk group, the longest PFS was observed with Rd18 treatment and OS was similar across treatment arms. Despite being on the continuous vs fixed duration treatment arm, high-risk pts on Rd continuous received a shorter duration of treatment than those on MPT, which may explain why PFS favored MPT vs Rd continuous. Higher response rates were observed with Rd continuous vs MPT, regardless of cytogenetic risk, and greater quality responses were observed in pts with high-risk cytogenetics. The safety profile of Rd continuous was manageable and consistent between cytogenetic risk groups. Results support Rd continuous as a standard treatment option for pts with NDMM who are ineligible for transplant, especially those without high-risk cytogenetics. Additional PFS and OS benefits may be achieved in pts with high-risk cytogenetics when Rd continuous is used as a backbone for combination therapy with a novel agent. Promising activity in pts with high-risk cytogenetic abnormalities has been demonstrated using this approach (Lonial et al, N Engl J Med, 2015; Stewart et al, N Engl J Med, 2015). Disclosures Hulin: Celgene Corporation: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Bristol Myers Squibb: Honoraria. Dimopoulos:Celgene: Honoraria; Onyx: Honoraria; Novartis: Honoraria; Janssen-Cilag: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Genesis: Honoraria. Reece:Lundbeck: Honoraria; Amgen: Honoraria; Merck: Research Funding; Bristol-Myers Squibb: Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Onyx: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Millennium Takeda: Research Funding; Otsuka: Research Funding. Catalano:Roche: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Celgene Corporation: Consultancy, Honoraria. Pinto:Takeda: Honoraria, Research Funding; Celgene Corporation: Honoraria; Spectrum: Honoraria. Ludwig:Takeda: Research Funding; Celgene Corporation: Honoraria, Speakers Bureau; Onyx: Honoraria, Speakers Bureau; Bristol Myers Squibb: Honoraria, Speakers Bureau; Janssen Cilag: Honoraria, Speakers Bureau. Bahlis:Celgene Corporation: Honoraria, Research Funding. Cavo:Janssen-Cilag, Celgene, Amgen, BMS: Honoraria. Moreau:Takeda: Other: Adboard; Janssen: Other: Adboard; Novartis: Other: Adboard; Amgen: Other: Adboard; Celgene: Honoraria, Other: Adboard. Qiu:Johnson & Johnson: Speakers Bureau; Celgene Corporation: Speakers Bureau; Roche: Speakers Bureau. Schots:Celgene Corporation: Research Funding. Marek:Celgene Corporation: Employment, Equity Ownership. Chen:Celgene Corporation: Employment, Equity Ownership. Yiu:Celgene Corporation: Employment, Equity Ownership. Ervin-Haynes:Celgene Corporation: Employment. Facon:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Pierre Fabre: Membership on an entity's Board of Directors or advisory committees.