Citations

Abstract Background: Isatuximab (ISA) is an anti-CD38 monoclonal antibody with multiple modes of action for killing tumor cells through immune cell engagement and direct tumor targeting. In preclinical studies, pomalidomide (Pom) enhanced both the direct and indirect anti-tumor activity of ISA to a greater degree than lenalidomide (Len) (Jiang et al. Leukemia 2016). Here, we report the preliminary results of an ongoing Phase Ib dose-escalation study of ISA plus Pom and dexamethasone (Dex) in patients with relapsed and refractory multiple myeloma (RRMM) (NCT02283775). Methods: Patients with RRMM (≥2 prior MM therapies, including Len and a proteasome inhibitor) with adequate bone marrow reserve/organ function were sequentially enrolled to receive ISA 5, 10 or 20 mg/kg (weekly × 4 doses, then every 2 weeks until disease progression or intolerable toxicity) in combination with Pom 4 mg (days 1-21) and Dex 40 mg (days 1, 8, 15, and 22; 20 mg if ≥75 years old), in 28-day cycles. Pom or Dex dose reductions were permitted after Cycle 1, or during Cycle 1 in response to dose-limiting toxicities (DLTs). The primary objective was to determine the maximum tolerated dose (MTD) or recommended dose, based on the occurrence of treatment-related DLTs. Secondary objectives included evaluation of efficacy (by objective response assessment according to IMWG criteria), safety, and pharmacokinetics (PK). Results: At data cut-off (May 11, 2016), 14 patients had been treated in the first 2 dose-escalation cohorts: 8 patients at 5 mg/kg and 6 patients at 10 mg/kg. Overall, median age was 65.5 (range, 42-77) years and median time from diagnosis was 4.25 (1.0-12.5) years. Half of the patients (7/14) had received at least 5 prior regimens (median 4.5 [2-11]; prior carfilzomib in 50% of patients). Ten patients (71%) had received at least one prior stem cell transplant. Median duration of dosing was 21.2 (4-42) and 8.1 (4-12) weeks in the 5 mg/kg and 10 mg/kg cohorts, respectively, with the latter cohort also having the shortest follow-up. Three patients discontinued treatment, all in the 5 mg/kg cohort: 2 due to confirmed disease progression (discontinuation after 2 and 4 treatment cycles, respectively) and 1 due to patient withdrawal (discontinuation in Cycle 1 and patient not evaluable for response). There were no discontinuations due to treatment-emergent adverse events (TEAEs) in either cohort. Two DLTs were reported: one in the 5 mg/kg cohort (prolonged grade [Gr] 4 neutropenia), and the other in the 10 mg/kg cohort (Gr 4 neutropenic infection); both DLTs resolved with Pom dose delay/reduction. MTD has not yet been reached; the 20 mg/kg dose level is under enrollment. Overall, Gr 3/4 TEAEs were reported in 10 (71%) patients; serious TEAEs in 6 (43%) patients. The most frequent TEAEs were fatigue (64%), upper respiratory tract infection, tremor, dyspnea, and cough (29% each). The most common Gr 3/4 hematologic abnormality (laboratory assessment) was neutropenia (Gr 1, 0%; Gr 2, 7%; Gr 3, 43%; Gr 4, 43%). Gr 3/4 thrombocytopenia was reported in 4 (29%) patients (Gr 3, n=2; Gr 4, n=2). Infusion-associated reactions (IARs) occurred in 8 (57%) patients, with all cases Gr 1/2 in severity. IARs occurred during the first infusion in most patients; 3/14 (21%) patients experienced IARs at a subsequent infusion, of whom only one had IARs after Cycle 1. Of the patients evaluable for confirmed response, 8/13 (62%) achieved at least partial response (PR), and 10/13 (77%) at least minimal response (MR). At 5 mg/kg, 1 patient achieved complete response (CR), 2 very good partial response (VGPR) and 2 PR. At 10 mg/kg, 2 patients achieved VGPR, 1 PR, and 2 MR. Of the eight patients who achieved at least PR, all continued to respond without confirmed disease progression at data cut-off. The PK parameters of ISA were not affected by co-administration with Pom/Dex. Conclusions: These preliminary data suggest that the combination of ISA and Pom/Dex is generally well tolerated and clinically active in patients with heavily pre-treated RRMM. Enrollment continues and longer term follow-up from this study, including data from the 20 mg/kg cohort, will be presented. A Phase III trial to evaluate ISA plus Pom/Dex is planned. Disclosures Richardson: Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mikhael:Sanofi: Research Funding; Celgene: Research Funding; Abbvie: Research Funding; Onyx: Research Funding. Usmani:Pharmacyclics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Skyline: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Britsol-Myers Squibb: Consultancy, Research Funding; BioPharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Array: Research Funding; Novartis: Speakers Bureau. Raje:Amgen: 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; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: 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; AstraZeneca: Research Funding; Eli Lilly: Research Funding. Bensinger:Takeda: Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; Acetylon: Research Funding; Bayer: Research Funding. Campana:Sanofi: Employment. Gao:Sanofi: Employment. Dubin:Sanofi Oncology: Employment. Wack:Sanofi: Employment. Anderson:Gilead: Membership on an entity's Board of Directors or advisory committees; Oncoprep: Equity Ownership; Oncoprep: Equity Ownership; Millennuim: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Acetylon: Equity Ownership; Acetylon: Equity Ownership; Millennuim: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees.

Abstract It is well-recognized that Helicobacter pylori infection causes gastrointestinal blood loss and iron deficiency. H. pylori gastritis has also been implicated in iron deficiency refractory to oral iron replacement therapy. Although H. pylori infection is common in multiple populations, less is known about the extent to which H. pylori contributes to iron deficiency in different racial/ethnic groups. To address this question, we tested the serum collected from men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study to identify those with iron deficiency (defined as serum ferritin ≤ 12 mg/L [cases]) and iron-replete controls (serum ferritin > 100 mg/L in men, serum ferritin > 50 mg/L in women). All samples were tested for H. pylori IgG antibodies and for antibodies to CagA (cytotoxin-associated gene-bearing strain). We tested 571 cases and 1142 controls. Participants were considered to have evidence of H. pylori infection if they had positive results for both antibodies or for either antibody alone. Participants who did not have a result for either test were excluded. We examined the association between the presence of H. pylori in cases and controls among Caucasians, Asian/Pacific Islanders, African Americans, and Hispanics. Among Caucasians, evidence of H. pylori infection was comparable in cases and controls; 170 of 735 controls (23.1%) and 97 of 363 cases (26.7%), respectively, were positive. Similar results were found in African Americans (56.3% of 144 controls; 55.8% of 77 cases) and Hispanics (66.7% of 159 controls; 59.5% of 79 cases). However, in Asian/Pacific Islanders, the prevalence of H. pylori was higher among cases (62.8% of 51) than controls (44.1% of 102), p=0.029 by the likelihood ratio Chi-Square test. The relative risk (RR) of iron deficiency among those with H. pylori-positivity was significantly greater than in those without (RR, 1.66; 95% CI [1.04, 2.66]). A comparison of subgroups by positivity for IgG or CagA showed that the relative risk of iron deficiency was increased among those with IgG positivity, with or without Cag A positivity (RR, 1.80 and 1.90, respectively), but not among those with CagA positivity alone (RR, 1.00). H. pylori infection is a frequent contributor to iron deficiency but is also common in the general population. Our results indicate that among HEIRS Study Asian/Pacific Islander participants, H. pylori infection is more prevalent in cases with iron deficiency than in controls. In contrast, there was no difference in the prevalence of H. pylori infection between cases and controls among Caucasians, African Americans, and Hispanics. These results have implications for the investigation of iron deficiency in Asians and Pacific Islanders. Disclosures No relevant conflicts of interest to declare.

Abstract Interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) mediate growth of MM cells via activation of the mitogen-activated protein kinase (MAPK), JAK2/STAT3, and phosphatidylinositol 3′-kinase/Akt kinase (PI3-K/Akt) signaling cascades. We have previously demonstrated the in vitro and in vivo activity of Revlimid™ (CC-5013), an immunomodulatory analog (IMiD) of thalidomide, in MM. In the present study, we have examined the anti-MM activity of rapamycin, a specific mTOR inhibitor, combined with Revlimid™. This combination was highly synergistic at 0.1nmol/L of rapamycin with 0.1mmol/L of Revlimid™, and remained synergistic at higher concentrations. Based on the Chou-Talalay method, combination indices of < 1 were noted for all dose ranges of Revlimid™ and rapamycin, suggesting strong synergism. Importantly, this combination was able to overcome drug resistance when tested against MM cell lines resistant to conventional (doxorubicin, melphalan, dexamethasone) chemotherapy. Moreover, the combination, but not rapamycin alone, was able to overcome the growth advantage conferred on MM cells by IL-6, IGF-1, or adherence to bone marrow stromal cells (BMSCs). Cytotoxicity triggered by a combination of rapamycin with Revlimid™ resulted in apoptosis of MM cells. Furthermore, differential signaling cascades, including the MAPK and PI3-K/Akt pathways, were targeted by these drugs individually and in combination, suggesting the molecular mechanism by which they interfere with MM growth and survival. These studies therefore provide the framework for the clinical evaluation of targeted agents like mTOR inhibitors combined with immunomodulatory agents like Revlimid™ to improve patient outcome in MM.

Abstract Background: BT062 (Biotest AG Dreieich, Germany) is an antibody-drug conjugate (ADC), comprising the anti-CD138 chimerized MAb (nBT062) and the maytansinoid DM4 as a cytotoxic agent. It is designed to bind to CD138 on cancer cells, and then release DM4 after internalization to cause cell death. CD138 (Syndecan-1) is highly overexpressed on various solid tumors and in hematological malignancies, and represents one of the most specific target antigens for identification of multiple myeloma (MM) cells. BT062 was investigated as a single agent and found to have an acceptable tolerability profile and evidence of activity in patients with heavily pretreated relapsed and/or refractory MM (1). Preclinical studies showed enhanced anti-MM activity when BT062 was combined with lenalidomide and dexamethasone (Len/Dex). Based on these data, a Phase I/IIa study in MM was initiated to evaluate the safety and efficacy of BT062 in combination with Len/Dex. Objectives: To determine the dose-limiting toxicities (DLTs), the maximum tolerated dose (MTD), the recommended phase II dose (RPTD), pharmacokinetics (PK), and anti-MM activity of increasing doses of BT062 (days 1, 8, and 15, every 4 weeks) used in combination with Len (25 mg, daily on days 1-21) and low dose Dex (40 mg on days 1, 8, 15, and 22) in patients with relapsed and/or refractory MM. Methods: This is a prospective, open label, multicenter Phase I/IIa study. The Phase I part includes dose escalation, and the Phase IIa the expansion of the RPTD cohort. Patients aged ≥18 years with relapsed and/or refractory MM who have failed at least one prior therapy were eligible to participate. Prior treatment with Len and/or Dex was allowed. Patients with clinical response (or no evidence of progressive disease) and without unacceptable toxicities were eligible for additional treatment cycles. Patients were enrolled in cohorts of at least 3 at each dose level; DLT in the first cycle triggered cohort expansion. Toxicities were assessed by CTCAE v4 and clinical response was assessed according to International Myeloma Working Group criteria. Results: The maximum administered dose (MAD) was 120 mg/m². Two of six patients treated at this dose had a DLT: mucosal inflammation (CTC grade 3) and anemia (CTC grade 3). The MTD was defined as 100 mg/m² and selected as RPTD. Additional patients are being treated at this RPTD to further evaluate safety and efficacy. Enrollment into the study is ongoing. As of July 2014, a total of 45 patients had received BT062 at dose levels of 80 mg/m² (N=3), 100 mg/m² (N=36) or 120 mg/m² (N=6). Fifteen patients discontinued study treatment: 5 for disease progression, 7 for adverse events, 1 died (not treatment related) and 2 for withdrawal of consent. The other 30 patients remain on treatment. The median treatment duration was 123 days (range 1–597). The median number of prior therapies was 3 (range 1–11). 68% of patients had prior exposure to both Len and bortezomib, 73% of patients had prior Len exposure, and 30% were Len-refractory. According to preliminary data from this ongoing study, about 89% of reported Adverse Events (AEs) were CTC grade 1 or 2. The most common reported AEs were diarrhea, fatigue, nausea, and hypokalemia. Amongst the 36 patients across all dose levels currently evaluable for efficacy, the overall response rate (ORR) is 78%; including 1 stringent complete response, 2 complete responses, 10 very good partial responses, and 15 partial responses. Two patients achieved a minor response and 6 patients disease stabilization, resulting in a clinical benefit in 100% of the evaluable patients. The ORR was 83% among the 30 evaluable patients receiving the RPTD. Interestingly, the ORR was 70% among the 23 patients with prior exposure to Len and bortezomib, and among 10 patients refractory to prior treatment with Len. Conclusion: Preliminary data from this ongoing study indicate that BT062 is well tolerated in combination with Len/Dex at dose levels that induce responses in patients with relapsed and/or refractory multiple myeloma, including patients with prior exposure to both Len and bortezomib and patients refractory to prior treatment with Len. Updated results on safety and efficacy will be presented. References Heffner et al, BT062, an Antibody-Drug Conjugate Directed Against CD138, Given Weekly for 3 Weeks in Each 4 Week Cycle: Safety and Further Evidence of Clinical Activity. Blood. 2012; 120: Abstract 4042. Disclosures Kelly: Celgene: Speakers Bureau. Heffner:Amgen: Honoraria, Research Funding; Biotest: Research Funding; Dana Farber CI: Research Funding; Genentech: Research Funding; Gilead: Research Funding; Idera: Research Funding; Janssen: Research Funding; Pfizer: Research Funding; Pharmacyclics: Honoraria, Research Funding; Onyx: Research Funding; Spectrum: Research Funding; Talon Therapeutics: Research Funding. Somlo:Millennium: 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; Celgene: Membership on an entity's Board of Directors or advisory committees. Siegel:Celgene: Honoraria, Speakers Bureau; Onyx: Honoraria, Speakers Bureau; Millennium: Honoraria, Speakers Bureau. Munshi:Celgene: Consultancy; Onyx: Consultancy; Janssen: Consultancy; Sanofi-Aventis: Consultancy; Ocopep: Consultancy, Equity Ownership, Patents & Royalties. Jagannath:Celgene: Consultancy; Millennium: Consultancy; Sanofi: Consultancy. Lonial:Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Ailawadhi:Millennium: Consultancy, Honoraria. Barmaki-Rad:Biotest AG: Employment. Chavan:Biotest Pharmaceuticals: Employment. Patel:Biotest Pharmaceuticals: Employment. Wartenberg-Demand:Biotest AG: Employment. Haeder:Biotest AG: Employment. Anderson:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi Aventis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncopep: Equity Ownership; Acetylon: Equity Ownership.

Abstract Background: Large deletions involving the beta globin complex are relatively rare. They can be categorized generally into five groups by deletion size and/or location: 1) beta zero thalassemia (BZT); 2) delta beta thalassemia (DBT); 3) hereditary persistence of fetal hemoglobin (HPFH); 4) gamma delta beta thalassemia (GDBT); and 5) epsilon gamma delta beta thalassemia (EGDBT). These deletions are not well understood but often have significant clinical impact, either when present alone or in combination with other hemoglobin mutations. In this study, we analyze phenotypic and molecular data on a large number of cases with deletions in the beta globin gene complex to better classify these five groups of deletions as they occur in isolation. Methods: A query of the routine clinical testing patient files from the Mayo Clinic Metabolic Hematology and Molecular Genetics Laboratories from 2010 to 2015 identified 179 patients with a deletion confirmed by a Multiplex Ligation-dependent Probe Amplification (MLPA) assay. Twenty-four probes sets were placed from the 5' locus control region (LCR) to the 3' hypersensitivity region, spanning the beta globin gene complex. Using a Luminex LX200 flow cytometer, a gene dosage ratio was calculated for each probe set using the median fluorescent intensity value collected. The size and location of the deletion and patient phenotype were compared. Results: Of the 179 total cases, the following large deletions were identified: beta gene (HBB) (n = 47), delta (HBD) through HBB (n = 105), A-gamma (HBG2) through HBB (n = 20), and locus control region (LCR) through HBB (n = 7). One case had a deletion involving the LCR epsilon with the rest of the complex left intact. A subset (n = 60) of cases had compound hemoglobin mutations that altered the phenotype. The BZT cases had relatively high Hb A2 levels and variable Hb F levels consistent with promotor region loss. The main differences between DBT and HPFH included Hb F and Hb A2 levels. GDBT cases presented with median Hb F levels higher than that observed in DBTs, normal Hb A2, and microcytic anemia. EGDBT cases had variable features according to age of the patient and Hb F level; severe microcytic anemia was observed in neonates, milder microcytic anemia in young children, and microcytosis without anemia in an adult case. The phenotypic features of 119 patients with isolated large deletions are compiled in table 1. Conclusion: In general, all five categories of large deletions in an isolated heterozygous state can present with microcytic anemia and are typically benign with the exception of transient severe microcytic anemia in neonatal EGDBT cases. Although phenotypes associated with large deletions involving the beta globin gene complex are frequently distinctive, significant phenotypic overlap can be seen in a subset of cases. These cases require molecular analysis due to their clinical importance when in combination with another beta globin gene complex mutation for an adequate diagnosis and treatment approach. Table 1. Deletion type Age n HbF (%) HbA2 (%) Hb (g/dL) MCV (fL) RBC (10^12/L) RDW (%) MCH (pg/cell) BZT 20 6.3 (0.6-94.4) 6.8 (3.4-11.6) 11.1 (8.3-14.5) 65.4 (60.8-77.2) 5.4 (4.2-6.2) 19.2 (16.6-21.2) 20.9 (18.3-25.7) DBT 56 10.6 (2.7-22.4) 2.7 (2.5-3.1) 11.7 (8.6-14.4) 68.9 (61.3-83.5) 5.3 (4.1-7.3) 21.4 (18.2-26.8) 21.6 (19.9-39.2) HPFH 23 25.9 (17.6-39.7) 2.0 (1.5-2.4) 11.6 (8.1-16.7) 78.4 (60.2-101.9) 4.4 (3.0-6.3) 17.5 (14.1-22.3) 25.4 (17.6-29.7) GDBT 14 13.3 (8.2-19.0) 2.6 (1.8-2.7) 11.0 (8.6-14.1) 72.5 (57.9-82.1) 5.1 (3.5-6.2) 20.6 (17.4-23.5) 22 (17.9-25.1) EGDBT* 28 Y 1 0.3 3 13.3 59.4 6.9 15.4 19.2 1-4 Y 3 0.9 (0-1.6) 3.2 (2.9-3.5) 9.5 (8.8-13.3) 57.8 (57.6-59.4) 5.2 (4.9-6.9) 16.6 (15.4-17.4) 18.5 (18.1-19.2) <6 month 2 21.4 (14.8-27.9) 2.6 (2.2-2.9) 6.3 (6.0-6.6) 61.3 (59.9-62.6) 3.4 (3.3-3.3) 21.5 (21.2-21.7) 18.4 (18.1-18.7) medians, (min, max); *stratified by age Disclosures No relevant conflicts of interest to declare.

Abstract HCT entails substantial TRM justifying continued efforts to better risk stratify patients. Single institutional studies have suggested several clinically available biomarkers of CRP, ferritin and albumin influence TRM if not overall survival (OS). We sought to confirm the independent prognostic value of these biomarkers in a large multi-institutional cohort. The study population consisted of 784 adults with AML in remission (80%) or MDS (20%) undergoing unrelated donor HCT between 2008 and 2010 and available cryopreserved samples through the Center for International Blood and Marrow Transplant Research (CIBMTR) repository. CRP and ferritin were centrally quantified by ELISA from cryopreserved plasma whereas albumin levels obtained from center reported data. Correlation studies for biomarkers required log transformation of CRP and ferritin to produce a normal distribution. Multivariate models were fitted separately for each biomarker applying protocol specified thresholds generated from the literature of CRP > 10 mg/L, ferritin > 2500 ng/mL, albumin < 3.5 g/dL on TRM. Further analysis explored optimal cutpoints for this cohort for all significant clinical variables for TRM. HCT characteristics included a median age of 50 (range 18-78) years, HCT-CI (co-morbidity index) 3 or more in 35%, single allele/antigen mismatch (7/8) in 23%, PB as stem cell source in 83%, and myeloablative conditioning in 72%. Biomarker data were available in 783, 781 and 695 cases for CRP, ferritin and albumin respectively. The median values and ranges for each biomarker were as follows: 5.0 mg/L (0.3 - 316) for CRP, 1148 ng/mL (51 – 14,298) for ferritin and 3.6 g/dL (0.6-5.3) for albumin. Log transformed CRP and ferritin showed a modest correlation (r=0.35, P<0.001), and log CRP was marginally associated with albumin (r=-0.12, P=0.002). HCT-CI had no correlation to CRP and albumin. Higher ferritin was associated with HCT-CI (P=0.014) and disease (P<.001). In the entire population, TRM and overall survival (OS) at 2 years were 23% and 54%, respectively. The table shows the independent association of each biomarker with TRM and OS. Ferritin had no association with these outcomes but only 12% had levels above 2500 by ELISA. The optimal cutpoints for TRM were defined as follows: CRP > 3.67 (HR=1.75, P=0.001); albumin < 3.4 (HR 1.70, P <0.001); and ferritin as a continuous variable (HR 1.30, P = 0.008). A risk score was created modeling optimal biomarker thresholds to predict TRM based on the following formula: risk score = 0.44633*I(CRP>3.67)+0.18330*ln(Ferritin)+0.44730*I(albumin<3.4), where “I” is an indicator function and represent 1 or 0 depending on the presence of the abnormal biomarker level in parenthesis. The risk score included adjustment for HCT-CI. The biomarkers did not influence the incidence of relapse or graft-versus-host disease with any of these models. Elevated CRP and ferritin and decreased albumin prior to HCT were associated with impaired transplant survival, primarily through higher TRM. Integration of a biomarker panel in clinical practice once validated can enhance risk-stratification, improve adjustment for comparative studies and point towards the design of biomarker driven trials. Abstract 422. Table: Multivariate analysis of TRM and OS for biomarkers, and biomarker panel risk score* Abnormal, N (%) Transplant related mortality Overall Survival Biomarker HR 95% CI P HR 95% CI P Protocol defined CRP >10 mg/L 184 (24) 1.52 1.11 – 2.07 0.008 1.22 0.98 – 1.53 0.072 Ferritin >2500 ng/mL 93 (12) 1.26 0.84 – 1.88 0.27 1.15 0.86 – 1.54 0.35 Albumin < 3.5 g/dL 290 (42) 1.48 1.10 – 2.0 0.010 1.39 1.13 – 1.72 0.002 Optimal threshold, combined model ** CRP >3.67 mg/L 497 (64) 1.56 1.11 – 2.19 0.010 1.24 1.00 – 1.55 0.054 Log(Ferritin), linear n/a 1.20 0.99 – 1.46 0.07 1.20 1.04 – 1.38 0.010 <3.4 g/dL 203 (29.5) 1.58 1.16 – 2.15 0.004 1.37 1.10 – 1.72 0.005 Biomarker Score ** N Low (<1.5) 200 1.0 - - 1.0 Intermediate (1.5-2.0) 331 1.66 1.10-2.49 0.015 1.38 1.06-1.80 0.017 High (>2.0) 159 2.72 1.77-4.19 <0.001 2.01 1.51-2.70 <0.001 * biomarkers adjusted for significant covariates of BMI, disease, mismatch, and CMV serostatus and stratified on conditioning regimen ** combined model includes all biomarkers and HCT-CI Disclosures No relevant conflicts of interest to declare.

Abstract Multiple myeloma (MM) is 2-3 times more common among African-Americans compared to non-Hispanic whites. The 2-3-fold increased risk among family members of cases suggests a genetic contribution to risk. Genome-wide association studies (GWAS) in populations of European ancestry have identified seven novel risk loci at 2p23.3 (rs6746082), 3q26.2 (rs10936599), 3p22.1 (rs1052501), 6p21.32 (rs2285803), 7p15.3 (rs4487645), 17p11.2 (rs4273077) and 22q13.1 (rs877529) (Broderick, et al. Nat Genet, 2011, Chubb, et al. Nat Genet, 2013), three of which were replicated in another European series (Martino et al., Br J Haematol, 2012). Here we examined the index signals and conducted fine-mapping for each locus in a case-control study of 1,049 multiple myeloma cases and 7,084 controls of African ancestry to identify better markers of risk and novel independent loci in seven previously reported regions in this high risk population. Incident cases were recruited from 10 clinical centers and SEER cancer registries from 2011 to 2013 and genotyped using the Illumina HumanCore GWAS array. Control data were obtained from previous genome-wide studies of breast and prostate cancer, genotyped using the Illumina 1M-Duo in 4425 male controls from the African Ancestry Prostate Cancer Consortium (consisting of 14 independent studies) and 2632 female controls from a breast cancer GWAS of African-American women (consisting of 9 independent studies). Imputation to 1000 Genomes (March 2012 release) was conducted for regions around six of the previously identified single nucleotide polymorphisms [SNPs] (the HLA region harboring rs2285803 is still being imputed, results will be presented). A case-control analysis of SNPs/indels >1% frequency within 250 kb of each index variant was conducted using unconditional multivariable logistic regression adjusting for age, sex and five leading principal components. Region-specific alpha levels were determined through permutation tests. The minimum alpha level across the six regions was α=0.002. All previously reported risk variants were common in African-Americans (minor allele frequency [MAF] >0.05). For five of the six SNPs, we had ≥94% power to detect the same effect observed in non-Hispanic whites, and 64% power for the less common variant rs10936599 (MAF=0.07). We observed directionally consistent effects (odds ratio [OR]>1) for the six risk variants tested, with three replicating at p≤0.05 (7p15.3, p=1.4x10-7; 17p11.2, p=0.05; 22q13.1, p=0.02). For three of the six regions, we observed better markers of risk in African-Americans that were correlated with the index SNP in Europeans (7p15.3, rs56333627, p=1.5x10-5, r2=0.89; 17p11.2, rs34562254, p=2.9x10-3, r2=0.90; 22q13.1, rs2092410, p=1.1x10-4 r2=.71). The missense variant identified in the 17p11.2 region (rs34562254, Pro251Leu) is located in TNFRSF13B, which encodes the protein TACI, a B cell surface receptor which plays a role in B cell maturation, apoptosis and antibody production by inducing activation of transcription factors including NFAT and NFκβ. In addition, there is evidence suggesting that TACI is involved in MM pathogenesis. Our results demonstrate that many of the risk loci for MM found in European ancestry populations are also risk loci in men and women of African ancestry and that by fine-mapping, we are able to identify variants that better capture risk in populations of African ancestry. Disclosures Terebelo: Celgene Corp: Membership on an entity's Board of Directors or advisory committees. Lonial:Millennium: The Takeda Oncology Company: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding.

Abstract Background: The control of hemoglobin F (Hb F) expression has proven an elusive puzzle with several postulated but not mutually exclusive hypotheses. A silencing mechanism hypothesis, which predicts the existence of a regulatory element that suppresses HbF expression, has been supported by recent investigations into a 3.5 kb region upstream from the delta globin gene (HBD). To test this hypothesis, we have investigated our historical case files in a tertiary care high-throughput clinical laboratory and compared the patient phenotype (Hgb, MCV, MCH, RDW, Hb F %, and flow cytometry Hb F distribution) with the status of this 3.5 kb region. Methods: A query of clinical testing patient files from Mayo Clinic Metabolic Hematology Laboratory yielded 179 patients confirmed by Multiplex Ligation-dependent Probe Amplification (MLPA) to contain large deletions located within the epsilon through beta globin genes. Of these, 27 unrelated patients with breakpoints between the pseudobeta (HBBP1) and HBD genes were identified. Four additional MLPA probe pairs were placed in this region and the patient phenotypes were compared. Results: The interior two (of the four added) probes between HBBP1 and HBD stratified all 27 cases. The other two (flanking) probes were never discriminatory, thus refining the area of interest to 2.4 kb. Sixteen cases showed breakpoints within hg19 g.5260154-5259135 (5' region) and eleven cases showed breakpoints within hg19 g.5259136-5257692 (3' region) upstream of HBD. Patients who displayed a phenotype of HPFH (n = 9) contained breakpoints in the 5' region whereas those with a delta beta thalassemia (DBT) phenotype (n = 11) were associated with breakpoints in the 3' region. A subset (n = 7) with breakpoints in the 5' region had indefinite phenotypic features, but of these, all but one showed homocellular Hb F distribution. Conclusion: Our molecular and phenotypic correlation of 27 patients with large deletional breakpoints between HBBP1 and HBD supports the hypothesis of a silencing element located upstream of HBD and further narrows the area that segregates many HPFH and DBT patient phenotypes from 3.5 kb to 2.4 kb. Several potential silencing effectors with binding sites in this region include HDAC1, GATA1 and H3K27me3; interestingly, the BCL11A binding site may be outside of the regulatory area. Table 1. Phenotypic data of patients with deletions between HBBP1 and HBD. Case Age/Sex Hb F Hb A2 Hb X Hgb RBC MCV MCH MCHC RDW Hb F Flow (Y) (%) (%) (%) (g/dL) ( 10^12/L) (fL) (pg/cell) (hg/cell) (%) 3' Region 1 47 M 25.5 2.1 16.7 6.3 81.4 26.7 32.8 15.7 H 2 5 M 28.3 2.4 12.5 4.9 74.6 25.4 34 15.9 H 3 24 F 30.3 1.7 11.6 4.23 92.7 27.4 29.6 15.2 H 4 9 F 36.3 2.2 S = 62 13.1 5.2 69.9 NA NA 14.8 5 24 F 37.3 2.1 C = 61 12.9 5.1 72.9 25.5 35 14.3 6 3 M 39.7 2.1 12.4 4.4 88.7 28.1 31.7 16.3 7 27 F 40.2 3.4 S = 56 12.2 4.4 79.7 27.8 34.9 15 8 16 M 43.7 2.2 S = 54 15.9 6.8 71.5 23.5 32.9 14.1 9 7m M 100.0* 0.0 12.8 4.8 76 26.5 34.9 16.8 3' Region 10 28 F 20.9 2 10.11 4.4 70.9 22.7 32.1 19 H 11 64 M 21.4 2.3 10.51 4.1 81.1 25.8 31.8 18.1 12 2.5 M 24 2.1 10.21 5.3 59.4 19.3 32.5 20.9 H 13 58 F 24 2.1 9.51 4.4 72.2 21.5 29.8 17.7 H 14 14 F 25.4 1.5 10.81 4.9 69.4 22 31.8 17.6 H 15 52 F 26.9 1.8 8.42 3.6 72 23.5 32.7 19.4 T 16 34 M 38.7 1.7 S = 60 11.4 4.7 71.6 NA NA 21.6 5' Region 17 24 F 2.7 2.9 12.3 6.1 62.2 20 32.2 18.2 18 32 F 6.1 2.7 10.2 5.1 61.3 19.9 32.5 19.3 19 27 F 7.2 2.9 11 5.1 72.9 21.7 29.8 19.9 20 29 F 7.8 2.7 10.2 4.7 72.2 21.7 30 20.5 21 15 M 7.8 2.5 12.7 6.2 64.7 20.4 31.5 21.2 22 42 M 7.8 3.1 10.6 4.9 75.1 21.5 28.6 23.7 23 60 M 10.1 2.5 11 4.5 74.8 24.7 33 23.4 24 41 M 10.7 2.8 8.6 4.1 73.3 21.2 29 26.8 25 30 F 11.5 2.7 12.1 5.5 67.4 21.9 32.5 21.8 26 25 F 13.2 2.8 12.1 5.3 68.4 22.8 33.3 21.6 27 3 F 18.3 2.6 11.9 5.79 63.6 20.6 32.3 22.7 T Normal values <1 2-3.3 0 H = homocellular; T= heterocellular; I = indeterminate; *homozygous deletion -- = no deletion; + = deletion present (all alpha deletions were single -3.7 kb 'rightward' deletions) 1 = Suspected Fe deficiency; 2 = recent transfusion Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 2095 Celiac disease (CD) is an increasingly recognized disorder in Caucasian populations of European origin. Little is known about its prevalence in non-Caucasians. While CD is thought to be a cause of iron deficiency anemia, the extent to which CD contributes to iron deficiency in Caucasians and especially non-Caucasians is unknown. Iron deficiency is one of the most common nutritional deficiencies in both the developed world and in developing countries. Thus, it is important to know the prevalence of CD in different populations and in iron-deficient and iron-replete persons. To answer these questions, we tested serum collected from Caucasian and non-Caucasian men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. In the HEIRS Study, 101,168 participants were screened with serum biochemical tests of iron status, which not only detected participants with iron overload but also identified a unique multiethnic population of participants with iron deficiency. We hypothesized that CD is more common in those with iron deficiency than in iron-replete individuals. We also examined the difference in frequency of CD between Caucasians and non-Caucasians with iron deficiency. Cases with iron deficiency (defined as serum ferritin ≤ 12 μg/L [cases]) and iron-replete controls (serum ferritin > 100 μg/L in men, serum ferritin > 50 μg/L in women) were further evaluated by using a sequential serological testing scheme whereby all samples were tested with an ELISA for human recombinant tissue transglutaminase IgA antibodies, and positive values were confirmed by endomysial antibodies. Those positive for both tests were considered double positives and were presumed to have untreated CD. Those positive for tissue transglutaminase IgA antibodies but not for endomysial antibodies were termed single positives and were considered indeterminate and excluded from analysis. We further hypothesized that low serum ferritin and an appropriate human leukocyte antigen (HLA) variant, may be predictive of CD. We used SNP-based analysis to determine HLA genotype and DQ8, DQ2.2 or DQ4, and DQ2.5 risk variants. Fisher's exact test was used to examine the association between iron−deficient case and control status and the presence of celiac disease. Log-binomial regression was applied to estimate the odds of celiac disease in iron-deficient cases relative to that of controls. A total of 1713 subjects were tested for tissue transglutaminase IgA antibodies. Participants included 1100 Caucasians, 221 African Americans, 153 Asians, and 239 Hispanics. Fourteen of 571 iron-deficient cases were positive for the double serology compared to just one of 1142 controls. All of the seropositive tests were seen in Caucasians and none in the non-Caucasians. Excluding data from participants with indeterminate serological screen results (6 Caucasians, 4 non-Caucasians), we found that CD occurred in 14 of 567 cases (2.5%) and in only 1 of 1136 (0.1%) controls (Fisher's exact test, p=1.92 10−6). CD was more common in Caucasian cases (14 of 363, 4%) than in non-Caucasian cases (0 of 204, p=0.003). Only one Caucasian control and none of the non-Caucasian controls had CD. The odds of CD in individuals with iron deficiency was 28 (3.7, 212.8) times that in controls. Thirteen of 14 iron-deficient cases with CD carried the DQ2.5 variant of the HLA genotype. Presence of DQ2.5 was highly significantly associated with celiac disease status in iron-deficient cases compared to controls (Fisher's exact test, p = 7.183 × 10−8). The results indicate that CD is a small but significant contributor to iron deficiency in Caucasians. CD is very rare in other races, even among individuals with features frequently seen in CD, such as iron deficiency. CD is also rare in Caucasians who are iron replete. CD testing should be considered for adult Caucasian males or post-menopausal females having iron deficiency without evidence of other etiologies such as gastrointestinal blood loss. Patients identified with CD may benefit from appropriate treatment. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 750 Background: DKK1 is a negative regulator of the Wnt signaling pathway in bone that is overexpressed in a subset of newly-diagnosed MM patients with osteolytic lesions as well as in refractory and relapsed patients. Expression also correlates with the number of osteolytic lesions in untreated MM patients. BHQ880 is a novel anti-DKK1 human monoclonal antibody. Alleviation of DKK1 inhibition by BHQ880 results in activation of the Wnt signaling pathway, leading to increased bone mass mediated via upregulation of osteoblasts in mice and monkeys. In murine models of MM bone disease; this anabolic activity of BHQ880 increased trabecular and cortical bone density. Lytic bone disease in MM is caused by osteoclast activation and osteoblast inhibition. Current approved therapies for the treatment of MM bone disease are focused on osteoclast inhibition (e.g., bisphosphonates) and BHQ880 therapy may be able to reverse the effects of DKK1-induced osteoblast inhibition. Therefore, dual therapy with zoledronic acid to decrease bone resorption and BHQ880 to increase new bone formation may provide an effective treatment strategy for MM bone disease. Methods: In the phase I portion of this phase I/II study, patients with relapsed or refractory MM with prior skeletal-related event (SRE) were treated with BHQ880 as an IV infusion Q28 days. Patients also received Zol (4 mg) and approved MM Tx (bortezomib not allowed). Bone markers and total DKK1 levels along with bone mineral density are being measured. Full PK profiles were collected during the first and second cycle, after which predose (trough) samples were collected to assess accumulation. Results: Ten pts (6:M, 4:F), median age: 66.5 yrs (range 41- 70), performance status-0(5 pts), 1(4 pts), 2 (1 pts) have been enrolled in the following dose levels (mg/kg) 3 (2 pts), 10 (starting dose level -4 pts), 20 (4 pts) and have been on treatment for 1 day to 5 28-day cycles. No BHQ880-related AE's have been observed to date. Bone mineral density (BMD) data from the first two patients treated at 10 mg show the following: a.) Pt 1 (hip +5.8%, spine N/A due to surgery, wrist -1.8%); b.) Pt 2 (hip -0.2%, spine +6.1%, wrist not done). The biomarker data from these patients show: a.) Pt 1 shows a maximal +98% change over baseline in PINP at day 15 post-treatment, while osteocalcin (OC) changes +17% at day 15, reaching a +56% change over baseline at cycle 4 day 1; uNTx/Cr changes – 43 % at cycle 2 day 15. b) Partial data from Pt 2 suggests a -44 % change in PINP and –73 % change in OC and a +73% change in uNTx/Cr. Baseline total DKK1 levels on 3 patients ranged from 8.8 to 21.5 ng/mL. Preliminary PK analysis is available in 1 out of 3 patients treated at 10mg/kg. The Cmax achieved after the first infusion was 165 ug/mL and 201 ug/mL after the second infusion. Calculated t1/2 was 188 hours after the first infusion and 254 hours after the second infusion. Regarding overall exposure, AUC0-672 hours after first infusion was 36081 hr*ng/mL and 48533 hr*ng/mL after the second infusion. Conclusion: BHQ880 given IV Q28 days appears to be well tolerated in combination with Zol and chosen MM Tx. Once safety of 40 mg/kg BHQ880 or the MTD dose has been determined, pts will be enrolled in the phase II portion to assess activity on a SRE endpoint. Updated safety, efficacy, bone density and biomarker data will be presented on all patients at the upcoming ASH meeting. Disclosures: Padmanabhan: Genentech: Consultancy, Honoraria; GSK: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Off Label Use: BHQ880, a novel osteoblast activating, anti-DKK1 antibody. Dzik-Jurasz:Novartis: Employment, Equity Ownership. Gangolli:Novartis: Employment, Equity Ownership. Ettenberg:Novartis: Employment, Equity Ownership. Miner:Novartis: Employment, Equity Ownership. Bilic:Novartis: Employment, Equity Ownership. Whyte:Novartis: Employment, Equity Ownership. Mehdi:Novartis: Employment, Equity Ownership. Chiang:Novartis: Employment, Equity Ownership. Rae:Novartis: Employment, Equity Ownership. Shah:Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Millenium: Research Funding, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Elan: Consultancy. Giles:Novartis: Consultancy, Research Funding; BMS: Research Funding; Merck: Research Funding; Clavis: Research Funding. Stewart:Novartis: Consultancy; Amgen: Consultancy; Millenium: Consultancy, Research Funding; Proteolix: Consultancy; Celgene: Honoraria.