Hajek, Roman

Abstract Recent therapeutic advances, including bispecific antibodies (bsAbs), have improved outcomes for patients with relapsed/refractory multiple myeloma (RRMM). However, early mortality (EM) remains a significant challenge, even in the era of novel immunotherapies. We conducted a multicenter, retrospective analysis of real-world patients with RRMM treated with commercial bsAbs to evaluate the incidence and causes of EM. Between May 2022 and June 2025, a total of 441 patients were treated across 7 countries. EM, defined as death within 12 months of therapy initiation, occurred in 148 patients (34%), with a median time from bsAb initiation to death of 2.87 months (interquartile range, 1.38-6.85). The leading cause of EM was progressive disease (72%), followed by infection (13%); regardless of the cause of death, 82% had active disease at the time of death. Our findings highlight that despite encouraging efficacy, EM remains high among real-world bsAb recipients, emphasizing the need for improved disease control strategies and supportive care interventions.

Background Emerging evidence has demonstrated rare subacute to late neurological toxicities (NTs) after BCMA CAR T-cell therapy (CAR-T) in multiple myeloma (MM). These adverse events can be categorized as: 1) Parkinsonism (PD), 2) cranial nerve (CN) palsies, and 3) peripheral neuropathies/Guillan Barré syndrome (GBS). These toxicities can cause significant morbidity, but given their relative rarity in clinical trials, there is limited data regarding evaluation and treatment. To our knowledge, this is the largest and only global registry of delayed NTs after BCMA CAR-T. Methods We retrospectively established a registry of NTs via the Immune Therapy Working Committee of the International Myeloma Working Group (IMWG). We gathered data pertaining to demographics, MM characteristics, MM response, NT signs/symptoms, diagnostic workup, and treatment. Result A total of 52 patients with delayed neurotoxicity were included from 14 institutions and 6 countries; 92% received ciltacel, 4% idecel, and 4% investigational CAR-T. Median age at CAR-T infusion was 65 years; 69% were male and 88% were Caucasian. Median bone marrow plasma cell (PC) burden was 15% prior to CAR-T (range 0-95%). Patients received a median of 4 prior lines of therapy (LOT), with 67% progressing on last LOT. Seventeen percent had pre-existing neurological diagnoses (including stroke, epilepsy, migraines). We identified sixteen cases of PD (94% with movement disorder, 69% with cognitive impairment, 75% with personality changes), occurring at a median of 26 days (range: 15-87) after CAR-T. Ninety four percent had CRS (grade (G)1 50%, G2 38%, G3 6%, G4 0%), while 19% had ICANS (G1 13%, G2 6%, G3-G4 0%). Median peak absolute lymphocyte count (ALC) was 9.5 x 109/L, peak C-reactive protein (CRP) 60.9 mg/L, and peak ferritin 1893.5 ug/L within the first 30 days. Concurrently, 3 upper respiratory infections (URIs) and 2 low-level HHV7 in the cerebrospinal fluid (CSF) were detected. A median of 73% of T-cells in the CSF were CAR-T, based on a flow cytometry assay. Ten patients received steroids (median 19 days after symptoms, 70% partial response, 20% no response, 10% unknown), 2 received intrathecal (IT) methotrexate-based therapy (median 32 days after symptoms, 1 with no response, 1 unknown), 5 received intravenous (IV) cyclophosphamide (median 31 days after symptoms, 40% full response, 20% partial response, 40% no response), 4 received high-dose IVIG ≥1g/kg for one or more dose (50% partial response, 50% no response), and 6 received dopamine agonists. There were 37 CN palsies (76% CN7, 15% CN6, 7% CN5, 2% CN3), occurring at a median of 37.5 days (range: 7-482) after CAR-T. Eighty one percent had CRS (G1 68%, G2 14%, G3-G4 0%); 11% had G1 ICANS (G2-G4 0%). Median peak ALC was 4.1 x 109/L, CRP 25.4 mg/L, and ferritin 543 ug/L within the first 30 days. We identified 2 concurrent URIs, 4 CMV viremia (50% with viral load >1500 IU/mL), 1 HHV6 viremia, and 1 HSV in the CSF. Thirty-two (86%) received steroids for a median duration of 12 days, 50% with full response, 3% with no response, and 47% with partial response (of which 43% had later full recovery without further intervention). One received IT methotrexate and another received IV cyclophosphamide without response. Thirteen (41%) received IVIG, of which 38% was high-dose IVIG. Four patients with CN palsies developed peripheral neuropathy/GBS. Eight patients (15%) in this cohort were not heavily pre-treated (≤1 prior LOT); 7 developed CN palsies (6 after ciltacel, 1 after investigational CAR-T) and 1 PD (after idecel). These patients had median <5% PC; none had extramedullary disease. Median ALC was 4.14 x 109/L, CRP 33 mg/L, and ferritin 448.5 ug/L within the first 30 days. Conclusions Delayed NT requires prompt recognition, evaluation for alternative causes, and treatment. In our cohort, the majority of patients were male and Caucasian, suggesting that sex and race may impact the likelihood of developing NT. Individuals with PDs had greater inflammatory response (CRS, ALC, CRP, ferritin) compared to those with CN palsies. CN palsies responded to steroids and/or IVIG, whereas PD had at best partial response to steroids, prompting additional therapy. These toxicities notably did occur in less heavily pre-treated patients, perhaps driven by immune fitness and greater circulating T-cells rather than MM burden. At the time of the annual meeting, data will be updated with additional NTs from less heavily pre-treated patients.

Background Panobinostat (Pano), a pan-histone deacetylase inhibitor, is approved for the treatment of relapsed or relapsed/refractory multiple myeloma (RRMM) in combination with bortezomib and dexamethasone (FVd) in patients who have received ≥2 prior lines of therapy, including bortezomib and an immunomodulatory agent (IMiD). The pivotal phase 3 PANORAMA 1 trial, which used intravenous (i.v.) bortezomib, demonstrated significant progression-free survival benefit with FVd compared with placebo-Vd; however, adverse events (AEs) were also more frequent (San-Miguel J. et al., Lancet Oncol. 2014). The randomized phase 2 PANORAMA 3 study was conducted to optimize FVd by comparing three regimens with varying dose and schedule of Pano and by incorporating subcutaneous (s.c.) bortezomib. Methods PANORAMA 3 (NCT02654990) was a randomized, open-label, international, multicenter phase 2 study conducted in compliance with the Declaration of Helsinki. Eligible patients were ≥18 years old with 1‒4 prior lines of therapy, including an IMiD. Patients refractory to bortezomib were excluded. Patients were randomized 1:1:1 to Pano 20 mg three times weekly (TIW; the currently approved dosing regimen; Days 1, 3, 5, 8, 10, 12), Pano 20 mg twice weekly (BIW; Days 1, 4, 8, 11), or Pano 10 mg TIW (Days 1, 3, 5, 8, 10, 12), all administered in 21-day cycles. Randomization was stratified by number of prior treatment lines (1 vs 2 vs 3 or 4) and by age at screening (≤75 vs >75 years). For Cycles 1-4, all patients ≤75 years old received s.c. bortezomib 1.3 mg/m2 BIW (Days 1, 4, 8, 11) and oral dexamethasone 20 mg (Days 1, 2, 4, 5, 8, 9, 11, 12). Patients aged ≤75 years from Cycle 5 onwards, and patients >75 years for all cycles, received bortezomib 1.3 mg/m2 weekly (Days 1 and 8) and dexamethasone 20 mg on Days 1, 2, 8, and 9. Patients were treated until progressive disease or death, or until discontinuation due to toxicity or withdrawal of consent. The primary endpoint was overall response rate (ORR; IMWG 2011 criteria) after up to 8 treatment cycles by Independent Review Committee assessment. Secondary endpoints included best response, time to response (TTR), duration of response (DOR) and safety. Results In total, 248 patients were randomized (Pano: 20 mg TIW, N=82; 20 mg BIW, N=83; 10 mg TIW, N=83) and 241 patients received treatment (Pano: 20 mg TIW, N=79; 20 mg BIW, N=82; 10 mg TIW, N=80). Mean (SD) age was 65 (9) years; 55% of patients were male. Overall, patients had a median (range) time since diagnosis of 49 months (7‒242) and a median (range) of 2 (1-4) prior lines of therapy; 17% and 2% of patients were refractory to lenalidomide and pomalidomide, respectively. In total, 68% of patients had relapsed and 32% had relapsed/refractory disease. High-risk molecular findings were present in 15% of patients, with either del(17p) or t (4;14) at screening by fluorescence in situ hybridization. For the Pano 20 mg TIW, 20 mg BIW, and 10 mg TIW arms, respectively, median (range) number of treatment cycles completed was 9 (1; 50), 8 (1; 40) and 7 (1; 39); ORR (95% CI) after up to 8 treatment cycles was 62% (51; 73), 65% (54; 75), and 51% (39; 62); median TTR was 1, 2, and 3 months, with a median (95% CI) DOR of 22 (14, not estimable), 12 (9, 21), and 11 (6, 14.5) months. Best responses are presented in Table 1. In the Pano 20 mg TIW, 20 mg BIW, and 10 mg TIW arms, respectively, treatment-related AEs Grade ≥3 were reported in 78%, 72%, and 54% of patients; serious AEs were reported in 54%, 48%, and 44% of patients; and discontinuations due to AEs occurred in 29.5%, 28%, and 15% of patients, respectively. Most common treatment-emergent AEs (≥20% patients) are presented in Table 2. Grade ≥3 diarrhea occurred in 11.5%, 10%, and 5% of patients, respectively. There were 14 (6%) on-treatment deaths during the study (20 mg TIW, n=5; 20 mg BIW, n=3; 10 mg TIW, n=6), with none causally related to therapy and with 12 of 14 directly attributable to progressive disease. Conclusion In patients with RRMM, the 20 mg TIW and 20 mg BIW dosing regimens provided favorable outcomes, with most durable and deepest responses observed in the 20 mg TIW arm. The rate of AEs, including diarrhea, with Pano 20 mg TIW was lower than those observed with the same dosing regimen in PANORAMA 1, suggesting s.c. administration of bortezomib improves tolerability compared with i.v. administration. Moreover, all three regimens of FVd proved generally manageable; Pano 20 mg TIW had greatest efficacy, while 10mg TIW proved best tolerated. Disclosures Schjesvold: Celgene, Amgen, Janssen, Oncopeptides: Research Funding; Amgen, Celgene, Janssen, MSD, Novartis, Oncopeptides, Sanofi, Takeda: Consultancy; Amgen, Celgene, Janssen, MSD, Novartis, Oncopeptides, Sanofi, SkyliteDX, Takeda: Honoraria. Dimopoulos:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees. Lech-Marańda:Roche, Amgen, Gilead: Speakers Bureau; Roche, Novartis, Takeda, Janssen-Cilag, Amgen, Gilead, AbbVie, Sanofi: Consultancy. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Hajek:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Honoraria; PharmaMar: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Oncopeptides: Consultancy. Wróbel:Roche: Honoraria, Research Funding; Takeda, Celgene, Janssen, Amgen, AbbVie, Teva, Sandoz: Consultancy, Honoraria. Sureda Balari:Takeda: Consultancy, Honoraria, Speakers Bureau; Merck Sharpe and Dohme: Consultancy, Honoraria, Speakers Bureau; Sanofi: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Gilead/Kite: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Incyte: Consultancy; Celgene: Consultancy, Honoraria; BMS: Speakers Bureau; Roche: Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria. Beksac:Janssen&janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Deva: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Goncalves:Janssen, Takeda, Amgen, Bayer, Novartis, Merck, Bayer, Celgene, GSK, BMS: Research Funding; Janssen: Consultancy, Speakers Bureau. Bladé Creixenti:Celgene: Honoraria; Amgen: Honoraria; Oncopeptides: Honoraria; Takeda: Honoraria; Janssen: Honoraria. Chari:Bristol Myers Squibb: Consultancy; Pharmacyclics: Research Funding; Novartis: Honoraria; Oncopeptides: Consultancy; Takeda: Consultancy, Research Funding; Antengene: Consultancy; Sanofi Genzyme: Consultancy; Seattle Genetics: Consultancy, Research Funding; Secura Bio: Consultancy; Adaptive Biotechnology: Honoraria; Array BioPharma: Honoraria; Karyopharm: Consultancy; Glaxo Smith Kline: Consultancy; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; The Binding Site: Honoraria. Lonial:JUNO Therapeutics: Consultancy; Merck: Consultancy, Honoraria, Other: Personal fees; Abbvie: Consultancy; GSK: Consultancy, Honoraria, Other: Personal fees; BMS: Consultancy, Honoraria, Other: Personal fees, Research Funding; Janssen: Consultancy, Honoraria, Other: Personal fees, Research Funding; Novartis: Consultancy, Honoraria, Other: Personal fees; Takeda: Consultancy, Other: Personal fees, Research Funding; Amgen: Consultancy, Honoraria, Other: Personal fees; Onyx: Honoraria; Genentech: Consultancy; Karyopharm: Consultancy; Sanofi: Consultancy; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Honoraria. Spencer:Haemalogix: Consultancy, Honoraria, Other: Grant/Research Support; Secura Bio: Consultancy, Honoraria; Pharmamar: Other; Abbvie: Consultancy, Honoraria, Other: Grant/Research Support; Janssen: Consultancy, Honoraria, Other: Grant/Research Support, Speakers Bureau; Roche: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; TheraMyc: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Grant/Research Support; BMS: Honoraria, Other: Grant/Research Support, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria; Servier: Consultancy, Other: Grant/Research Support; Takeda: Honoraria, Other, Speakers Bureau; Antegene: Consultancy, Honoraria. Maison-Blanche:Chiesi Pharmaceutical, Sanofi, Novartis: Honoraria. Moreau:Novartis: Honoraria; Sanofi: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding. San-Miguel:Amgen, BMS, Celgene, Janssen, MSD, Novartis, Takeda, Sanofi, Roche, Abbvie, GlaxoSmithKline and Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees.

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 Background: Patients (Pts) with multiple myeloma (MM) who relapse within 12 months of autologous stem cell transplantation (SCT) have a poor prognosis. As reported by Mahmood et al. (ASCO 2007), of 432 pts who received SCT at the Mayo Clinic between 1994–2005, those with early relapse within 12 months (94/432– 22%) showed poorer median overall survival. Kaplan-Meier estimates of 12-month survival from the date of first relapse were 37% for pts relapsing within 12 months after SCT as compared to 85% for those relapsing after 12 months. In that study, pts had received regimens other than B. In a recent report of a large, phase III study (DOXIL-MMY3001), the combination of PLD+B improved time to progression (TTP) as compared to B alone (Orlowski et al. JCO 2007). The present analysis examined the 12-month post-randomization survival of patients who had early (<12 months) vs. late (≥12 months) relapse following SCT, as well as the effect of PLD+B vs. B alone in pts who had relapsed early. Methods: This was a retrospective analysis of 646 pts who received intravenous B, 1.3 mg/m2 on days 1,4,8 and 11 of every 21-day cycle ± PLD, 30 mg/m2 on day 4. Results: 359 pts had previously received transplant, 114 (32%) of whom relapsed within 12 months from SCT. The median age, gender distribution, time from diagnosis trial enrollment, measures of disease burden (M-Protein levels and B2M) and renal function were comparable between the early and late relapse groups. There was no difference in overall response rates [complete + partial response (CR+PR)] or very good PR (VGPR) rates between the two groups, or between treatment arms within each group. There was no significant difference in TTP between early vs. late relapse groups (HR=0.94). 12-month survival from randomization was significantly lower in the early relapse group as compared to late relapse (83% vs. 92% respectively, p=0.009). However, within the early relapse group 12-months post-randomization survival rate was significantly superior following treatment with PLD+B as compared to B alone [52/56 patients (93%) vs. 43/58 patients (74%) respectively, p=0.01]. Correspondingly, TTP was better in this group with PLD+B vs. B alone (276 days vs. 205 days respectively, p=0.13). Overall, the toxicity profiles of the combination and B alone were comparable regardless of early or late relapse following SCT. Conclusions: The present analysis of the MMY3001 study corroborates the prior Mayo observation of lower survival in MM pts relapsing within 12 months of SCT. Importantly, it demonstrates that PLD+B may provide a therapeutic advantage for high-risk MM pts with early relapse following SCT.

Abstract Introduction: Single-agent carfilzomib has shown encouraging activity in patients with relapsed and refractory multiple myeloma who harbor high-risk cytogenetic abnormalities (Jakubowiak et al, Leukemia 2013;27:2351-56). The phase 3 study ASPIRE (NCT01080391; N=792 patients) demonstrated that progression-free survival (PFS) was significantly improved with carfilzomib, lenalidomide, and dexamethasone (KRd), compared with lenalidomide and dexamethasone (Rd) in patients with relapsed multiple myeloma (RMM) (Stewart et al, N Engl J Med 2015;372:142-52). We present a pre-planned subgroup analysis of the efficacy and safety of KRd vs Rd in the ASPIRE study according to baseline cytogenetic risk status. Methods: Adults with RMM (1-3 prior lines of therapy) were eligible. Patients were randomized (1:1) to KRd or Rd. Treatment was administered in 28-day cycles. Patients in the KRd arm received carfilzomib as a 10-minute intravenous infusion on days 1, 2, 8, 9, 15, and 16 (starting dose, 20 mg/m2 on days 1 and 2 of cycle 1; target dose, 27 mg/m2 thereafter) during cycles 1-12; carfilzomib was omitted on days 8 and 9 during cycles 13-18 and was discontinued after 18 cycles. All patients received lenalidomide 25 mg on days 1-21 and dexamethasone 40 mg on days 1, 8, 15, and 22. The primary end point was PFS. Secondary end points included overall survival, overall response rate (ORR), duration of response (DOR), health-related quality of life, and safety. Cytogenetic risk status was assessed using fluorescence in situ hybridization. The high-risk group consisted of patients with the genetic subtype t(4;14) or t(14;16) or with deletion 17p in ≥60% of plasma cells, according to central review of bone marrow samples obtained at study entry. The standard-risk group consisted of all other patients with known baseline cytogenetics. The cutoff value of 60% for the proportion of plasma cells with deletion 17p was used on the basis of recommendations from the International Myeloma Workshop Consensus Panel 2 (Munshi et al. Blood 2011;117:4696-700). Results: A total of 792 patients were randomized to KRd (n=396) or Rd (n=396). In patients with known baseline cytogenetics, baseline cytogenetic risk status was similar between the treatment arms (high-risk: KRd, 24.6%; Rd, 23.4%; standard-risk: KRd, 75.4%; Rd, 76.6%). Efficacy outcomes by cytogenetic risk status are presented in the Table. Median PFS in the high-risk group (n=100) was 23.1 months (95% confidence interval [CI]: 12.5-24.2) for KRd vs 13.9 months (95% CI: 9.5-16.7) for Rd (hazard ratio [HR]: 0.639; 95% CI: 0.369-1.106). Median PFS in the standard-risk group (n=317) was 29.6 months (95% CI: 24.1-not estimable) for KRd vs 19.5 months (95% CI: 14.8-26.0) for Rd (HR: 0.657; 95% CI: 0.480-0.901). ORRs were 79.2% (KRd) vs 59.6% (Rd) in the high-risk group, and 91.2% (KRd) vs 73.5% (Rd) in the standard-risk group. In the high-risk group, 29.2% (KRd) and 5.8% (Rd) of patients achieved a complete response (CR) or better, including 16.7% (KRd) and 3.8% (Rd) with a stringent complete response (sCR). In the standard-risk group, 38.1% (KRd) and 6.5% (Rd) of patients achieved ≥CR, including 15.0% (KRd) and 3.5% (Rd) with an sCR. Median DOR in the high-risk group was 22.2 months for KRd vs 14.9 months for Rd. Median DOR in the standard-risk group was 30.4 months for KRd vs 20.4 months for Rd. The rate of grade ≥3 adverse events was 89.1% (KRd) vs 78.4% (Rd) in the high-risk group, and 85.6% (KRd) vs 84.5% (Rd) in the standard-risk group. Rates of grade ≥3 adverse events of interest (dyspnea, hypertension, acute renal failure, cardiac failure, ischemic heart disease, and peripheral neuropathy) by cytogenetic risk status are presented in the Table. Conclusion: In patients with high-risk cytogenetics, treatment with KRd resulted in a median PFS of nearly 2 years, which was a 9-month improvement relative to that in patients treated with Rd. Treatment with KRd also led to a 10-month improvement in median PFS vs Rd in patients with standard-risk cytogenetics; similar reductions in the risk of progression or death with Kd vs Vd were observed in both cytogenetics risk groups. Treatment with KRd also led to higher response rates, greater response depth, and a longer DOR compared with Rd in patients with high- or standard-risk cytogenetics. KRd had a favorable benefit-risk profile in patients with RMM, irrespective of baseline cytogenetic risk status, and improved outcomes in patients with high-risk disease. Disclosures Fonseca: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Applied Biosciences: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Onyx/Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Binding Site: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Siegel:Celgene Corporation: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Merck: Speakers Bureau. Dimopoulos:Celgene: Honoraria; Onyx: Honoraria; Genesis: Honoraria; Janssen-Cilag: Honoraria; Novartis: Honoraria; Janssen: Honoraria; Amgen: Honoraria. Spicka:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Masszi:Novartis: Consultancy; Janssen-Cilag: Consultancy; BMS: Consultancy; Takeda: Consultancy. Hájek:Janssen-Cilag: Honoraria; Celgene, Merck Sharp & Dohme: Consultancy, Honoraria. Rosiñol:Celgene: Honoraria; Janssen: Honoraria. Mateos:Janssen-Cilag: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Takeda: Consultancy; Onyx: Consultancy. Wang:Celgene: Research Funding. Niesvizky:Celgene: Consultancy, Speakers Bureau. Oriol:Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Jakubowiak:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SkylineDx: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi-Aventis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: institutional funding for support of clinical trial conduct, Speakers Bureau; Onyx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi-Aventis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SkylineDx: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Palumbo:Celgene, Millennium Pharmaceuticals, Amgen, Bristol-Myers Squibb, Genmab, Janssen-Cilag, Onyx Pharmaceuticals: Consultancy, Honoraria; Novartis, Sanofi Aventis: Honoraria. Bensinger:Onyx: Research Funding, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Acetylon: Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Research Funding. Kukreti:Lundbeck: Honoraria; Ortho: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Tonda:Onyx: Employment. Obreja:Amgen Inc: Employment. Moreau:Bristol-Myers Squibb: 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; Millennium: 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; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract Purpose: Deep vein thrombosis (DVT) is increasingly recognized as a major complication of thalidomide (T; Thal) and lenalidomide (R; Rev) based therapy for multiple myeloma. Estimated incidence varies widely in the literature. There is no consensus on specific risk factors, indications for thromboprophylaxis or the agent of choice for DVT prophylaxis. The purpose of this study was to develop a consensus among members of the IMWG. Patients and Methods: A survey was electronically mailed to 67 IMWG members on July 21, 2006 and consisted of 24 multiple-choice questions. Results: Twenty-three IMWG members (34%) sent in their responses by the cut-off date. All (100%) felt that DVT was an important question, but most (95%) did not avoid Thal/Rev based therapy because of the DVT risk. Overall results are summarized in the Table below. A majority of physicians felt that concomitant therapy with high dose dexamethasone (90% of physicians), alkylators (55%), doxorubicin/liposomal doxorubicin (90%), and erythropoietin (75%) increase the risk of DVT associated with Thal or Rev based therapy. Aspirin (81 mg or 325 mg per day) was the preferred choice of prophylaxis when necessary. However, 65% of respondents preferred warfarin to a therapeutic INR or LMW heparin if either doxorubicin or liposomal doxorubicin was added to the regimens. Most (95–100%) felt that DVT prophylaxis was not indicated for: VAD, MP, bortezomib +/− dexamethasone regimens. Seventy-five percent felt it to be safe to resume therapy with Thal/Rev after therapeutic anticoagulation. Most (95%) believed randomized trials were needed. Conclusion: DVT is recognized as a major clinical problem associated with Thal/Rev containing regimens. Most respondents felt that the DVT risk did not warrant any prophylaxis when either Thal or Rev were used as single agents. Aspirin was the preferred form of DVT prophylaxis for most Thal/Rev containing regimens, except when doxorubicin/liposomal doxorubicin or melphalan were added. Additional responses will be analyzed both electronically and by conference call prior to the meeting. Therapy Estimated incidence of DVT (% respondents) Choice of thromboprophylaxis (% respondents) Single agent thal <5% (61%) None (65%) Single agent Rev <5% (80%) None (65%) Thal-Dex 10–20% (52%) Aspirin (60%) Rev-Dex 10–20% (48%) Aspirin (60%) MPT 10–20% (65%) Aspirin (40%) R-MP 5–10% (57%) Aspirin (70%)

Abstract Background: Lenalidomide with dexamethasone (Rd) is a standard of care used for pts with relapsed multiple myeloma (RMM). The randomized, open-label, multicenter, phase 3 study ASPIRE (NCT01080391) is comparing carfilzomib, lenalidomide, and dexamethasone (KRd) to Rd in pts with RMM. The primary end point is progression-free survival (PFS; assessed by an independent review committee). Secondary end points include overall survival (OS), overall response rate (ORR), duration of response (DOR), health-related quality of life (EORTC QLQ-C30 Global Health Status/QoL), and safety. Methods: Adults with RMM who received 1–3 prior regimens were eligible. Pts were randomized (1:1) to receive KRd or Rd and were stratified by β2-microglobulin levels (<2.5 vs ≥2.5 mg/L), prior bortezomib (no vs yes), and prior R (no vs yes). All pts received lenalidomide (25 mg) on days 1–21 and dexamethasone (40 mg) on days 1, 8, 15, and 22 of a 28-day cycle. In addition, KRd pts received K as a 10-min infusion on days 1, 2, 8, 9, 15, and 16 during cycles 1–12 (20 mg/m2 [days 1 and 2 of cycle 1]; 27 mg/m2 thereafter); K was omitted on days 8 and 9 during cycles 13–18 and was not administered beyond 18 cycles. Cycles were repeated until disease progression, unacceptable toxicity, or withdrawal of consent. The study had 90% power to detect a 25% reduction in risk for PFS events for KRd vs Rd (hazard ratio [HR]=0.75) at a 1-sided significance level of 0.025. A stratified log-rank test was used for the PFS comparison. Results: Data are presented for KRd followed by Rd throughout the abstract. Between July 2010 and March 2012, 792 pts from 20 countries were randomized. Baseline characteristics were balanced between the 2 groups. Median age was 64.0 years (range: 31.0‒91.0). Pts received a median of 2 prior regimens in each group. In both the KRd and Rd groups, 66% of pts received prior bortezomib; 20% of pts in each arm received prior R. Median treatment exposure was 22 cycles (KRd) and 14 cycles (Rd). At the time of the prespecified interim analysis, the study met the primary end point for PFS (HR=0.69; 95% confidence interval [CI]: 0.57–0.83; P<.0001), with a longer duration of median PFS in the KRd group (26.3 months [mo]; 95% CI: 23.3–30.5) compared with the Rd group (17.6 mo; 95% CI: 15.0–20.6). Median OS was not reached in either group; however, there was a trend toward longer OS with KRd compared with Rd (HR=0.79; 95% CI: 0.63–0.99; P=.018), which did not meet the prespecified statistical boundary at the interim analysis of survival (P=.005). The Kaplan-Meier OS event-free rates at 24 mo were 73.3% (95% CI: 68.6‒77.5) and 65.0% (95% CI: 59.9‒69.5). The ORR was 87.4% (95% CI: 83.7–90.5) with KRd and 66.9% (95% CI: 62.0–71.5) with Rd. Median DOR was 28.6 mo (95% CI: 24.9–31.3) and 21.2 mo (95% CI: 16.7–25.8). In the KRd and Rd groups, 31.8% vs 9.4% achieved a stringent complete response (sCR) or complete response (CR) (sCR: 14.1% vs 4.3%; CR: 17.7% vs 5.1%), and 70.4% and 40.7% achieved ≥very good partial response. KRd consistently improved Global Health Status/QoL compared with Rd over 18 cycles of treatment (P=.0001). Treatment discontinuation due to an adverse event (AE) occurred in 15.2% (KRd) and 17.4% (Rd) of pts. In each group, 7.7% and 8.5% of pts died while still on study treatment or within 30 days of receiving the last dose of study treatment. The most common hematologic treatment-emergent AEs (TEAEs) (≥grade 3) included neutropenia (29.6% vs 26.5%), anemia (17.9% vs 17.2%), and thrombocytopenia (16.6% vs 12.3%). The most common nonhematologic TEAEs (all grade) included diarrhea (42.3% vs 33.7%), fatigue (32.9% vs 30.6%), and cough (28.8% vs 17.2%). The most common nonhematologic TEAEs (≥grade 3) included pneumonia (12.5% vs 10.5%), hypokalemia (9.4% vs 4.9%), and hypophosphatemia (8.4% vs 4.6%). Other TEAEs of interest (grouped terms; all grade) included dyspnea (22.4% vs 18.0%), hypertension (preferred term; all grade: 14.3% vs 6.9%; grade 3: 4.3% vs 1.8%), acute renal failure (8.4% vs 7.2%), cardiac failure (6.4% vs 4.1%), and ischemic heart disease (5.9% vs 4.6%). Rates of peripheral neuropathy (PN) (grouped terms; all grade) were 17.1% and 17.0%; ≥grade 3 PN was infrequent (2.6% and 3.1%). Conclusion: The addition of carfilzomib to lenalidomide and dexamethasone in pts with RMM resulted in a statistically significant and clinically meaningful improvement in PFS. KRd had an acceptable safety and tolerability profile and represents a potential new standard of care. Disclosures Stewart: Novartis: Consultancy; Array BioPharma: Consultancy; BMS: Consultancy; Millenium: Research Funding; Celgene: Consultancy. Off Label Use: Carfilzomib is approved in the United States for the treatment of patients with multiple myeloma who have received at least two prior therapies including bortezomib and an immunomodulatory agent and have demonstrated disease progression on or within 60 days of completion of the last therapy. ASPIRE is a randomized, multi-center, phase 3 study investigating the use of carfilzomib in combination with lenalidomide and dexamethasone for the treatment of patients with relapsed multiple myeloma who have received 1–3 prior regimens.. Dimopoulos:Celgene: Consultancy, Honoraria; Onyx: Consultancy, Honoraria. Masszi:Janssen Cilag: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Spicka:Janssen-Cilag: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Oriol:Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau. Hájek: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; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees. Rosiñol:Celgene: Honoraria; Janssen: Honoraria. Siegel:Onyx: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Millennium: Honoraria, Speakers Bureau. Niesvizky:Onyx Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau; Millennium: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Jakubowiak:Onyx Pharmaceticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. San Miguel:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; MSD: Membership on an entity's Board of Directors or advisory committees; Millinnium: Membership on an entity's Board of Directors or advisory committees. Ludwig:Celgene: Research Funding, Speakers Bureau; Takeda Celgene: Research Funding, Speakers Bureau; Bristol-Myers: Research Funding, Speakers Bureau. Zojwalla:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Tonda:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Xing:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Moreau:Novartis: 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; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees. Palumbo:Onyx Pharmaceuticals: Consultancy, Honoraria; Millennium Pharmaceuticals: Consultancy, Honoraria; Janseen-Cilag: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Genmab A/S: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen, Inc,: Consultancy, Honoraria; Array BioPharma: Honoraria.

Abstract Introduction: IgM-secreting myeloma is rare, encompassing about 1% of all the myeloma cases. Given its rarity, the characteristics and survival of these patients have not been extensively studied. Therefore, we carried out a multicenter retrospective study in patients with IgM myeloma. Methods: The study protocol was reviewed and approved by the Institutional Review Board of each participating institution. Clinical data were gathered and included age, sex, hemoglobin, calcium, LDH, estimated glomerular filtration rate (GFR), presence of lytic bone lesions, International Staging System score, cytogenetic abnormalities, final outcome and overall survival (OS) time. OS was defined as the time in months from diagnosis to last follow-up or death. The Chi-square and the rank-sum tests were used to compare categorical and continuous variables, respectively. The Kaplan-Meier method was used to estimate OS and the log-rank waas used to compare groups. The Cox proportional-hazard regression method was used to fit univariate and multivariate survival models, reported as hazard ratio (HR) with 95% confidence intervals (CI). All reported p-values are two-sided, and were considered significant if less than 0.05. Results: A total of 159 patients with IgM myeloma from 20 centers from Europe, USA and Latin America were included in this analysis. Patients were diagnosed between 1996 and 2015. The median age at diagnosis was 65 years (range 37-86 years) with a male predominance (68%). The median serum IgM level was 2510 mg/dl (range 27-12,100 mg/dl) with 25% of patients having a serum IgM within normal limits but an IgM monoclonal spike detectable in serum electrophoresis. Hemoglobin levels <10 g/dl were seen in 49 patients (32%), serum calcium was elevated in 24 (16%), estimated GFR of 60 ml/min or less in 56 (37%), lytic lesions were detected in 86 (58%), and serum LDH was elevated in 28 (24%). ISS scores of 1, 2 and 3 were seen in 53 (36%), 63 (43%) and 31 (21%) of patients, respectively. Although immunohistochemistry and/or flow cytometry data were limited, CD20 expression was seen in 15/26 (58%) and cyclin D1 in 10/15 (67%) patients. The most common cytogenetic abnormalities were t(11;14) in 26/67 (39%), del13q in 25/76 (33%) and del17p in 6/76 (8%) patients. 149 patients (94%) received at least one line of systemic therapy for myeloma of which 13 (9%) received rituximab as part of initial therapy. After a median follow-up of 47 months, 74 patients (47%) have died. The median OS was 62 months (95% CI 51-79 months). Cause of death was known in 38 patients, and the most common was myeloma progression (74%). IN the univariate analysis, prognostic factors associated with a worse OS were age (HR 1.03, 95% CI 1.01-1.06; p=0.01) and ISS score (ISS 2: HR 1.43, 95% CI 0.83-2.48; p=0.2, and ISS 3: HR 3.03, 95% CI 1.54-5.98; p=0.001, using ISS 1 as reference group), while male sex was associated with a better OS (HR 0.56, 95% CI 0.34-0.90; p=0.02). Hemoglobin, calcium, estimated GFR and lytic lesions were not associated with OS. In the multivariate analysis, male sex was associated with a better OS (HR 0.57, 95% CI 0.35-0.95; p=0.03) and ISS with worse OS (ISS 2: HR 1.57, 95% CI 0.89-2.74; p=0.12, and ISS 3: HR 2.76, 95% CI 1.38-5.55; p=0.004, using ISS 1 as reference group). Conclusion: Patients with IgM myeloma apparently present with similar clinical characteristics as patients with non-IgM myeloma. Pathologically, CD20 and cyclin D1 expression is common. The most common cytogenetic abnormalities identified were t(11;14) and del13q. Survival does not appear shorter than non-IgM myeloma patients, and the ISS appears to have similar prognostic value. Disclosures Castillo: Millennium: Research Funding; Janssen: Honoraria; Otsuka: Consultancy; Biogen: Consultancy; Abbvie: Research Funding; Pharmacyclics: Honoraria. Ghobrial:Celgene: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria; Takeda: Honoraria; Noxxon: Honoraria; Amgen: Honoraria. Hájek:Celgene: Consultancy, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; BMS: Honoraria; Takeda: Consultancy. Hungria:International Myeloma Foundation Latin America: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Amgen: Consultancy; Roche: Consultancy; Bristol: Consultancy; Janssen: Consultancy, Speakers Bureau. Niesvizky:Celgene: Consultancy, Research Funding, Speakers Bureau; Takeda: Consultancy, Research Funding, Speakers Bureau; Onyx: Consultancy, Research Funding, Speakers Bureau. Reagan:Alexion: Honoraria; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees. Spicka:Janssen Cilag: Consultancy, Honoraria, 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, Research Funding; Amgen: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Honoraria. Gertz:Celgene: Honoraria; Med Learning Group: Honoraria, Speakers Bureau; Research to Practice: Honoraria, Speakers Bureau; Alnylam Pharmaceuticals: Research Funding; Novartis: Research Funding; Prothena Therapeutics: Research Funding; Ionis: Research Funding; NCI Frederick: Honoraria; Sandoz Inc: Honoraria; GSK: Honoraria; Annexon Biosciences: Research Funding.