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Introduction: The phase 2/3 PROTECT VIII main study demonstrated efficacy and safety of BAY 94–9027 (damoctocog alfa pegol; Jivi®), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to extend its half-life. Aim: To report the final efficacy and safety data for BAY 94–9027 from the PROTECT VIII extension. Methods: Previously treated males aged 12–65 years with severe haemophilia A (FVIII

Introduction BAY 94‐9027 (damoctocog alfa pegol; an extended half‐life PEGylated recombinant factor VIII [FVIII]) demonstrated efficacy and safety in previously treated paediatric patients (PTPs) aged

The beta-lactam antibiotic amoxicillin and the beta-lactamase inhibitor clavulanic acid in combination with amoxicillin are known to cause both immediate- and nonimmediate-type hypersensitivity.To characterize a large cohort of patients with a history of amoxicillin or amoxicillin-clavulanic acid hypersensitivity.A retrospective analysis was conducted of the demographics, presentation, investigation, and management of 331 patients presenting to 1 allergy center with a history of hypersensitivity to amoxicillin or amoxicillin-clavulanic acid.Hypersensitivity was confirmed in 37 of 221 patients (17%) who took amoxicillin and 47 of 110 patients (43%) who took amoxicillin-clavulanic acid as the index drug. In immediate hypersensitivity, skin test results confirmed the diagnosis in 66 of 139 patients (47%). Penicillin cross-reactivity was observed in 16 of 36 patients (44%). Of the 16 patients who were cross-reactive, 13 (81%) reacted to amoxicillin-clavulanic acid as the index drug. All patients who had negative skin test results (73/139) underwent drug provocation. The negative predictive value of skin tests was 89%. In nonimmediate hypersensitivity, delayed intradermal tests confirmed diagnosis in 12 of 170 patients (7%). Of the 12 patients whose skin test results were positive, 8 (67%) presented with drug reaction with eosinophilia and systemic symptoms. All patients with a negative skin test result (158/170) underwent drug provocation. The negative predictive value of skin tests was 95%. Penicillin cross-reactivity was observed in 3 of 12 patients (25%). Ten patients were diagnosed with hypersensitivity to clavulanic acid.The negative predictive value of skin tests in both immediate and nonimmediate hypersensitivity reactions is excellent and excludes severe allergy. Nonimmediate hypersensitivity is rare. Confirmed hypersensitivity is more likely if amoxicillin-clavulanic acid is the index drug. Cross-reactivity was more common in patients presenting with immediate hypersensitivity, typically involving benzylpenicillin. A minority of patients were allergic to clavulanic acid.

Introduction The newly diagnosed pancreatic ductal adenocarcinoma (PDAC) population has a high unmet need for effective treatments, with median survival of < 1 year. The phase 3 APACT (Adjuvant Pancreatic Adenocarcinoma Clinical Trial) evaluated the use of adjuvant nab-paclitaxel plus gemcitabine vs. gemcitabine in 866 patients with surgically resected PDAC. We explored the tumor microenvironment (TME) of >500 baseline resected APACT tumors to identify TME features that are associated with adverse outcomes. Methods Biopsy analyses included RNA-seq, DNA-seq, and multiplexed immunohistochemistry (mIHC). We quantified, for 533 patient biopsies, via mIHC the spatial arrangement of 7 immune cell types and 2 checkpoint markers relative to tumor and nontumor regions, and pairwise colocalization relative to each other. We identified combinations of biomarkers that correlate significantly with molecular signatures, predefined patient subsets, and overall survival (OS). Hazard ratios (HR) and p-values were computed via a Cox proportional hazards regression model which included resection and lymph node status as covariates. Significantly differentially-expressed transcripts were associated with biomarkers derived from the mIHC via unpaired t-test. Results Higher densities of CD8+ T cells within tumor regions correlated with longer OS (hazard ratio HR=0.76; p=0.03), and higher overall densities of CD163+ macrophages correlated with shorter OS (HR=1.44; p=0.006). We furthermore identified a patient subset (n=72) with a combination of higher CD8+ T cell and lower CD163+ macrophage densities that had a strikingly significant decreased HR of 0.46 (p=0.009). Moreover, patients with a high degree of spatial colocalization between CD8+ T cells and dual-positive CMAF+CD163+ M2-like macrophages observed a significant increased HR of 1.51 (p=0.0006), a biomarker only surpassed by nodal status in significance of correlation with OS (HR=1.9; p=0.00015). While this cellular colocalization was computed to be independent of cell densities, we found that the association of this colocalized pair of cell types with shorter OS was most significant for patients with lower overall CD8+ T cell densities (HR=1.84; p=0.0004). We further identified differentially regulated transcripts associated with this interaction and found specific putative ligand-receptor pairs that were also associated with lower OS. Conclusion A combination of greater infiltration of CD8+ cytotoxic T cells and lower infiltration of macrophages is associated with longer OS in the APACT trial. Moreover, the spatial colocalization between CD8+ T cells and CMAF+ M2 macrophages is associated with shorter OS. These findings were observed across both treatment arms of the study. Future investigation of this apparent interaction, and associated differentially expressed transcripts, may inform management of patients with pancreatic adenocarcinoma and increase effectiveness of PDAC therapies. Citation Format: David J. Reiss, Andrew Browne, Brian Fox, Alexander V. Ratushnyy, Maria Wang, Andrew V. Biankin, Thomas Lila. Spatial arrangements of immune cells of the pancreatic ductal adenocarcinoma tumor microenvironment correlated with outcomes in the phase 3 APACT trial [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C085.

LEOPARD was a single arm, phase II study of lenalidomide (LEN) and alternate day prednisolone maintenance in patients with newly diagnosed multiple myeloma (MM) following autologous stem cell transplantation (ASCT). Sixty patients were enrolled. Estimated median potential follow-up was 44 m, median PFS was 38.3 m, median OS was not reached (landmark 36 m OS: 71.4%). Correlative immunohistochemistry performed on pre-ASCT trephines demonstrated high MM tumor cereblon (total/cytoplasmic) was associated with superior OS (p = .045, p = .031, respectively), whereas high c-Myc was associated with inferior PFS (p = .04). Patients with high cereblon (total/nuclear) were more likely to improve depth of response, whereas patients with high c-Myc were less likely, suggesting alternative/more effective post-ASCT strategies for patients with high c-Myc need identification. Peripheral blood immune profiling (mass cytometry) informed a more sustained response to LEN maintenance, demonstrating enrichment of activated/cytotoxic NK cells and cytotoxic T cells in patients with durable responses, contrasting with enrichment of B-regs in early relapsers.

We present a new human-human dialogue dataset - PhotoChat, the first dataset that casts light on the photo sharing behavior in online messaging. PhotoChat contains 12k dialogues, each of which is paired with a user photo that is shared during the conversation. Based on this dataset, we propose two tasks to facilitate research on image-text modeling: a photo-sharing intent prediction task that predicts whether one intends to share a photo in the next conversation turn, and a photo retrieval task that retrieves the most relevant photo according to the dialogue context. In addition, for both tasks, we provide baseline models using the state-of-the-art models and report their benchmark performances. The best image retrieval model achieves 10.4% recall@1 (out of 1000 candidates) and the best photo intent prediction model achieves 58.1% F1 score, indicating that the dataset presents interesting yet challenging real-world problems. We are releasing PhotoChat to facilitate future research work among the community.

In preclinical studies, oral azacitidine (CC-486), a hypomethylating agent, has been shown to have a direct anti-MM effect and in vitro anti-MM synergism when combined with lenalidomide (LEN). We present a phase 1b, single center, 3 × 3 dose escalation study with planned expansion at maximum tolerated dose (MTD), which assessed the safety and efficacy of combining CC-486 with LEN (25 mg d1-21/28) and dexamethasone (DEX) (40 mg weekly) in patients with relapsed/refractory MM who had previously failed LEN. Twenty-four patients were enrolled. The MTD of CC-486 was 150 mg d1-21; recommended expansion dose was 100 mg d1-21. Adverse events were predictable and manageable. ORR was 37.5%; clinical benefit rate was 50%. Median OS was 10.3 m; median PFS was 2.6 m. Correlative proteomics demonstrated that higher MM tumor cell cereblon expression (pretreatment, C1D5) was associated with superior PFS/OS. CC-486, LEN and DEX produced meaningful clinical responses in heavily treated LEN refractory MM patients. Proteomics may have utility in predicting clinical outcomes.

OBJECTIVES: This report aims to characterize the kinetics of serum albumin in critically ill patients with coronavirus disease 2019 compared with critically ill patients with sepsis-induced acute respiratory distress syndrome. DESIGN: Retrospective analysis. SETTING: We analyzed two critically ill cohorts, one with coronavirus disease 2019 and another with sepsis-induced acute respiratory distress syndrome, treated in the New York Presbyterian Hospital-Weill Cornell Medical Center. PATIENTS: Adult patients in the coronavirus disease 2019 cohort, diagnosed through reverse transcriptase-polymerase chain reaction assays performed on nasopharyngeal swabs, were admitted from March 3, 2020, to July 10, 2020. Adult patients in the sepsis-induced acute respiratory distress syndrome cohort, defined by Sepsis III criteria receipt of invasive mechanical ventilation and a Pao(2)/Fio(2) ratio less than 300 were admitted from December 12, 2006, to February 26, 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We evaluated serial serum albumin levels within 30 days after ICU admission in each cohort. We then examined the albumin progression trajectories, aligned at ICU admission time to test the relationship at a similar point in disease progression, in survivors and nonsurvivors. Albumin trajectory in all critically ill coronavirus disease 2019 patients show two distinct phases: phase I (deterioration) showing rapid albumin loss and phase II (recovery) showing albumin stabilization or improvement. Meanwhile, albumin recovery predicted clinical improvement in critical coronavirus disease 2019. In addition, we found a deterioration and recovery trends in survivors in the sepsis-induced acute respiratory distress syndrome cohort but did not find such two-phase trend in nonsurvivors. CONCLUSIONS: The changes in albumin associated with coronavirus disease 2019 associated respiratory failure are transient compared with sepsis-associated acute respiratory distress syndrome and highlight the potential for recovery following a protracted course of severe coronavirus disease 2019.

Relapsed/refractory multiple myeloma patients treated with pomalidomide and dexamethasone have an overall response rate (ORR) of ∼30% and median progression-free survival (PFS) of 4-5 months. Previous studies explored addition of weekly cyclophosphamide, but we hypothesized that daily dosing allows for better synergy. We report the open-label, single-center phase II study of pomalidomide, daily cyclophosphamide and weekly dexamethasone (PCD). Thirty-three patients were evaluable for efficacy and underwent 28-day cycles of pomalidomide (4 mg/day, D1-21), cyclophosphamide (50 mg b.i.d., D1-21) and weekly dexamethasone. All were lenalidomide-refractory and 55% were refractory to lenalidomide and proteasome inhibitor. ORR was 73%; median PFS and overall survival were 13.3 months and 57.2 months respectively. Grade 3/4 toxicities were primarily hematologic but manageable with dose reductions. Early disease progression correlated with MYC expression and flow cytometry demonstrates an activated microenvironment post-PCD. Addition of metronomic cyclophosphamide to pomalidomide and dexamethasone is a cost-effective, oral regimen with encouraging PFS.

Targeted protein degradation via small-molecule modulation of cereblon offers vast potential for the development of new therapeutics. Cereblon-binding therapeutics carry the safety risks of thalidomide, which caused an epidemic of severe birth defects characterized by forelimb shortening or phocomelia. Here we show that thalidomide is not teratogenic in transgenic mice expressing human cereblon, indicating that binding to cereblon is not sufficient to cause birth defects. Instead, we identify SALL4 as a thalidomide-dependent cereblon neosubstrate. Human mutations in SALL4 cause Duane-radial ray, IVIC, and acro-renal-ocular syndromes with overlapping clinical presentations to thalidomide embryopathy, including phocomelia. SALL4 is degraded in rabbits but not in resistant organisms such as mice because of SALL4 sequence variations. This work expands the scope of cereblon neosubstrate activity within the formerly 'undruggable' C2H2 zinc finger family and offers a path toward safer therapeutics through an improved understanding of the molecular basis of thalidomide-induced teratogenicity.

Introduction BAY 94-9027 (damoctocog alfa pegol) is an extended-half-life PEGylated recombinant factor VIII approved for use in patients with hemophilia A aged ≥12 years (USPI; https://www.fda.gov/). Due to age-related pharmacokinetic and other differences to adult patients, there is a need to assess FVIII replacement products in pediatric populations (Shah et al, Haemophilia 2018, 24(5):733-40). In the PROTECT VIII Kids main study (NCT01775618), BAY 94-9027 was efficacious for the prevention and treatment of bleeds in previously treated patients (PTPs) aged Methods In PROTECT VIII Kids, male PTPs aged Results Of the 73 PTPs enrolled in the main or expansion study, 59 continued in the extension phase (n=32 aged Median annualized bleeding rate (ABR) for total bleeds was 1.54 for all patients aged During the extension, 4 patients (6.8%) experienced study-drug-related adverse events (AEs): 1 patient ( Conclusion In both younger and older pediatric patients with severe hemophilia A, long-term treatment (median 5.8 years) with BAY 94-9027 prophylaxis was efficacious and well-tolerated. Financial support: Study funded by Bayer. Disclosures Ahuja: Genentech: Consultancy; Sanofi-Genzyme: Consultancy; XaTec Inc.: Consultancy; Sanofi-Genzyme: Honoraria; Genentech: Honoraria; XaTec Inc.: Research Funding; XaTec Inc.: Divested equity in a private or publicly-traded company in the past 24 months. Fischer:Bayer, Baxter/Shire, SOBI/Biogen, CSL Behring, Octapharma, Pfizer, NovoNordisk: Research Funding; Bayer, Biogen, Pfizer, Baxter/Shire, and Novo Nordisk: Research Funding; Bayer, Baxter, Biogen, CSL Behring, Freeline, Novo Nordisk, Pfizer, Roche, and Sobi: Consultancy. Biss:Bayer, Boehringer Ingelheim: Honoraria. Maas Enriquez:Bayer: Current Employment. Mancuso:Bayer, CSL Behring, Novo Nordisk, Roche, Sobi, Octapharma, Kedrion, Pfizer, Shire/Takeda, Biomarin, Grifols: Speakers Bureau; Bayer, CSL Behring, Novo Nordisk, Roche, Sobi, Octapharma, Kedrion, Shire/Takeda, Biomarin, Grifols, Catalyst: Honoraria; Bayer, CSL Behring, Novo Nordisk, Roche, Sobi, Octapharma, Kedrion, Pfizer, Shire/Takeda, PedNet Foundation: Consultancy. Wang:Bayer: Current Employment. Kenet:Bayer, Pfizer, Takeda, BioMarin, Novo Nordisk: Speakers Bureau; PI Healthcare, CSL Behring: Honoraria; Bayer, Pfizer, Roche, Alnylam (Sanofi), Shire: Research Funding; Bayer, Pfizer, BioMarin, Takeda, Roche, Novo Nordisk, Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: BAY 94-9027 (damoctocog alfa pegol), current indication for patients with hemophilia A aged >12 years. We report efficacy and safety data in patients aged

Doctors play an important role in a multidisciplinary team, however therapeutic relationships are not limited to between a doctor and a patient. In Community Mental Health Teams, patients are allocated a care coordinator - usually a community psychiatric nurse or a social worker - and they usually become the healthcare provider the patient is most regularly in contact with. Similarly, a practice nurse in General Practice may be the healthcare professional a patient is most familiar with. In these instances, the patient-provider relationship may be stronger than the doctor-patient relationship. Non-doctor and patient relationships play an increasingly important role in improving the patient experience and contributing to information gathering, shared-decision making, and establishment and adherence to treatment plans. Care coordinators may be in a more superior position than doctors to accurately recognise the ongoing and changing needs of a person with mental illness. Patients value continuity of care, compassion, and mutual trust and respect: these qualities can potentially all be provided by any trained healthcare professional. In this paper, we will review the literature on the emerging role of the care coordinator and other healthcare professionals in the management of chronic mental illness in the community.

With the explosion of immuno-oncology and the approval of many immune checkpoint therapies by regulatory agencies in the last few years, understanding the tumor microenvironment (TME) in the context of patients' immune status has become essential. Among available immune profiling techniques, multiplex immunofluorescence (mIF) assays offer the unique advantage of preserving the architectural features of the tumor and revealing the spatial relationships between tumor cells and immune cells. A number of mIF and image analysis assays have been described for solid tumors but most are not sufficiently suitable in lymphoma, where the lack of clear tumor-stromal boundaries and high tumor density present significant challenges. Here we describe the development and optimization of a reliable workflow using Akoya Opal staining kits to label and analyze 6 markers per slide in diffuse large B-cell lymphoma (DLBCL) tissue sections. Five panels totaling 30 markers were developed to characterize infiltrating immune cells and relevant check-point proteins such as PD1, PD-L1, ICOS, SIRP-alpha and Lag3 on 70 DLBCL sections. Multiplexed sections were scanned using an Akoya multispectral scanner. An image analysis workflow using InForm and Matlab was developed to overcome challenges inherent to the DLBCL environment. Using the assays and workflows detailed here, we were able to quantify cell densities of subsets of infiltrating immune cells and observe their spatial patterns within the tumors. We highlight heterogeneous distribution of cytotoxic T cells across tumors with similar T cell density to underscores the importance of considering spatial context when studying the effects of immunological therapies in DLBCL.

Treatment options for relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) are limited, with no standard of care; prognosis is poor, with 4- to 6-month median survival. Avadomide (CC-122) is a cereblon-modulating agent with immunomodulatory and direct antitumor activities. This phase 1 dose-expansion study assessed safety and clinical activity of avadomide monotherapy in patients with de novo R/R DLBCL and transformed lymphoma. Additionally, a novel gene expression classifier, which identifies tumors with a high immune cell infiltration, was shown to enrich for response to avadomide in R/R DLBCL. Ninety-seven patients with R/R DLBCL, including 12 patients with transformed lymphoma, received 3 to 5 mg avadomide administered on continuous or intermittent schedules until unacceptable toxicity, disease progression, or withdrawal. Eighty-two patients (85%) experienced ≥1 grade 3/4 treatment-emergent adverse events (AEs), most commonly neutropenia (51%), infections (24%), anemia (12%), and febrile neutropenia (10%). Discontinuations because of AEs occurred in 10% of patients. Introduction of an intermittent 5/7-day schedule improved tolerability and reduced frequency and severity of neutropenia, febrile neutropenia, and infections. Among 84 patients with de novo R/R DLBCL, overall response rate (ORR) was 29%, including 11% complete response (CR). Responses were cell-of-origin independent. Classifier-positive DLBCL patients (de novo) had an ORR of 44%, median progression-free survival (mPFS) of 6 months, and 16% CR vs an ORR of 19%, mPFS of 1.5 months, and 5% CR in classifier-negative patients (P = .0096). Avadomide is being evaluated in combination with other antilymphoma agents. This trial was registered at www.clinicaltrials.gov as #NCT01421524.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, commonly described by cell-of-origin (COO) molecular subtypes. We sought to identify novel patient subgroups through an unsupervised analysis of a large public dataset of gene expression profiles from newly diagnosed de novo DLBCL patients, yielding 2 biologically distinct subgroups characterized by differences in the tumor microenvironment. Pathway analysis and immune deconvolution algorithms identified higher B-cell content and a strong proliferative signal in subgroup A and enriched T-cell, macrophage, and immune/inflammatory signals in subgroup B, reflecting similar biology to published DLBCL stratification research. A gene expression classifier, featuring 26 gene expression scores, was derived from the public dataset to discriminate subgroup A (classifier-negative, immune-low) and subgroup B (classifier-positive, immune-high) patients. Subsequent application to an independent series of diagnostic biopsies replicated the subgroups, with immune cell composition confirmed via immunohistochemistry. Avadomide, a CRL4(CRBN) E3 ubiquitin ligase modulator, demonstrated clinical activity in relapsed/refractory DLBCL patients, independent of COO subtypes. Given the immunomodulatory activity of avadomide and the need for a patient-selection strategy, we applied the gene expression classifier to pretreatment biopsies from relapsed/refractory DLBCL patients receiving avadomide (NCT01421524). Classifier-positive patients exhibited an enrichment in response rate and progression-free survival of 44% and 6.2 months vs 19% and 1.6 months for classifier-negative patients (hazard ratio, 0.49; 95% confidence interval, 0.280-0.86; P = .0096). The classifier was not prognostic for rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone or salvage immunochemotherapy. The classifier described here discriminates DLBCL tumors based on tumor and nontumor composition and has potential utility to enrich for clinical response to immunomodulatory agents, including avadomide.

Introduction BAY 94-9027 is an extended-half-life, site-specifically PEGylated, B-domain-deleted recombinant factor VIII (FVIII). The PROTECT VIII main study demonstrated efficacy of bleed control using extended-interval prophylaxis with BAY 94-9027 for 36 weeks. Aim To report long-term efficacy and safety of prophylaxis with BAY 94-9027 in a descriptive analysis of the ongoing PROTECT VIII extension with a total treatment time of up to >5 years. Methods Previously treated males aged 12-65 years with severe haemophilia A who completed the PROTECT VIII main study were eligible for the open-label extension. Patients received on-demand treatment or prophylaxis (30-40 IU/kg twice weekly, 45-60 IU/kg every 5 days, or 60 IU/kg every 7 days) and could switch regimens as needed. Results Patients (N = 121; on demand, n = 14; prophylaxis, n = 107) accumulated a median (range) of 3.9 years (297-1965 days) and 223 (23-563) total exposure days by 31 January 2018. During the extension, median (quartile [Q]1; Q3) annualized bleeding rates (ABRs) for total bleeds were 1.6 (0.3; 4.6) for patients receiving prophylaxis and 34.1 (20.3; 36.6) for patients receiving on-demand treatment. ABRs for twice-weekly (n = 23), every-5-days (n = 33), every-7-days (n = 23) and variable frequency (n = 28) treatments were 1.7, 1.2, 0.7 and 3.1, respectively. Of prophylaxis patients, 20.6% were bleed-free throughout the extension (median time, 3.2 years), and 44.5% were bleed-free during the last 6 months. No patients developed FVIII inhibitors. Conclusions BAY 94-9027 prophylaxis was efficacious and well tolerated with dosing intervals up to every 7 days for a median (range) of 3.9 years (0.8-5.4 years).

Supplemental Digital Content is available in the text., Clinical interest in the measurement of Cereblon (CRBN), the primary target of the IMiDs immunomodulatory drugs lenalidomide and pomalidomide, has been fueled by its essential requirement for antitumor or immunomodulatory activity of both drugs in multiple myeloma (MM). However, limited analyses of clinical samples for CRBN gene expression or protein levels have utilized unvalidated reagents and assays, raising uncertainty about the interpretation of these results. We previously described a highly specific rabbit monoclonal antibody CRBN65 against 65-76 AA of human Cereblon. Here we describe a validated dual color bright-field Cereblon/CD138 immunohistochemical (IHC) assay utilizing CRBN65 and a commercial mouse monoclonal CD138 antibody. Sensitivity and specificity of the assay was determined and assay precision was shown for both cytoplasmic and nuclear Cereblon in MM bone marrow samples with coefficient of variation values of 5% and 2%, respectively. The dual IHC assay was effective for detecting a continuous range of Cereblon levels in 22 MM patient bone marrow core biopsies and aspirate clots, as shown by average cytoplasmic H-scores ranging from 63 to 267 and nuclear H-scores ranging from 17 to 250. Interpathologist comparison of MM sample H-scores by 3 pathologists demonstrated good concordance (R2=0.73). This dual assay demonstrated superior Cereblon IHC measurement in MM samples compared with the single IHC assay using a published commercial rabbit polyclonal Cereblon antibody and could be used to explore the potential utility of Cereblon as a biomarker in the clinic.

8531 Background: CC-92480 is a novel cereblon (CRBN) E3 ligase modulator (CELMoD) agent under investigation in a first-in-human phase 1 study (NCT03374085) in RRMM patients (pts). In preclinical studies, CC-92480 demonstrated efficient and sustained degradation of Ikaros/Aiolos leading to broad antiproliferative effects and induction of apoptosis in MM cell lines, and enhanced immune stimulatory effects. Methods: Eligible RRMM pts received escalating doses of CC-92480 + dexamethasone. Several dosing schedules were evaluated in parallel; more continuous with 4-day or 7-day breaks and intensive with longer breaks in a 28-day cycle. Peripheral blood and bone marrow aspirates (BMA) were taken before and during treatment at multiple time points. Levels of Ikaros/Aiolos in T cells, and effects on immunomodulation were assessed by flow cytometry. Weekly levels of free light chain (sFLC) and B-cell maturation antigen (sBCMA) were determined in serum during the first 2 cycles of treatment. BMA clots were analyzed by immunohistochemistry for CRBN, Ikaros, Aiolos, ZFP91, c-Myc, and IRF-4. Results: The rate and depth of Ikaros/Aiolos degradation in T cells increased with dose and reached maximal at ≥0.6 mg QD with sustained degradation over 24 hrs. Substrate recovery occurred during drug holidays with faster recovery at lower doses, and reached full recovery with ≥7-day break for all dose levels tested. B cells decreased with increasing dose, and T-cell proliferation was demonstrated at all doses/schedules. Substrate degradation was also evident in bone marrow plasma cells including in the setting of low CRBN levels. In these heavily pretreated, including triple-class-refractory, RRMM pts, CC-92480 dosing periods led to rapid and sustained decreases in sFLC and sBCMA. This was dose and schedule dependent and correlated with plasma exposure; the longer breaks in the intensive schedules led to rapid rebound of these markers, while the more continuous schedules maintained the depth of suppression. Conclusions: PD responses correlated with dose and schedule. PD samplings at multiple time points during treatment allowed dynamic changes and kinetics of each biomarker in all schedules to be followed and to inform next steps. Ikaros/Aiolos degradation and recovery, coupled with changes in sFLC and sBCMA, guided the adjustment of the dosing schedule during dose escalation in order to optimize efficacy and tolerability. The study is ongoing and selection of the recommended phase 2 dose is pending.

Introduction: It is strikingly difficult to develop successful treatments for PDAC; even with curative resection, most patients die from early occult metastases. Prior studies identified the presence of tumor-infiltrating lymphocytes (TILs) in primary PDAC tumors as having prognostic significance in the PDAC adjuvant setting, sharpening the questions of what fraction of patients have immune-infiltrated tumors and what therapeutic strategies should be pursued in these patients vs. the non-infiltrated group. The phase 3 APACT trial evaluated the use of adjuvant nab-paclitaxel plus gemcitabine vs. gemcitabine in 866 patients with PDAC who had undergone primary tumor resection, with the primary endpoint of disease-free survival evaluated by independent review. We extended studies of the tumor microenvironment of PDAC to a large set of resected APACT primary tumors in an effort to further refine features of tumor or immune infiltrate that influence disease progression and to determine if chemotherapy regimen–specific predictive signatures are identifiable. Tissue analyses for a large subset of APACT samples included RNA-seq, DNA-seq, multiplexed immunohistochemistry (IHC), and proteomics. Methods: We imaged and quantified markers for tumor cells, 7 different immune cells, and 2 immune checkpoint markers using bright-field chromogenic multiplexed IHC from pretreatment samples for more than 500 APACT primary tumor samples. We computationally defined the tumor, tumor margin, and distal stromal (> 150 μm from tumor boundary) regions, and quantified densities and distributions of immune cells in these regions. As part of an initial analysis of more than 400 samples, we applied both unsupervised clustering and supervised classification to these IHC measurements to identify patient subgroups with similar spatial arrangements of immune cells relative to tumor regions. Results: The preliminary analysis of normalized cell densities across all 3 tissue regions revealed 3 patient subgroups: one in which immune cells are mixed within the tumor regions; a second where immune cells approach the tumor boundary but are depleted within the tumor; and a third in which immune cells are depleted in both tumor and its margin, remaining at high densities only in the distal stromal regions. Within these latter subgroups, CD20+, CD4+, and CD8+ cells were more prevalently depleted from tumor and/or margin, whereas CD163+ and CD163+CMAF+ cells showed less of this arrangement. Nearly 85% of patients fell in the second or third patient group. Conclusions: We are pursuing analyses of these data in conjunction with upcoming molecular and genetic profiling data to further elucidate the association of the immune cell populations and these subgroups with clinical outcomes. These data will provide an unprecedented opportunity for exploratory analysis and discovery of immune, molecular, and genetic biomarkers for PDAC patient stratification. Citation Format: David J. Reiss, Thomas Lila, Suzana Couto, Sitharthan Kamalakaran, Yan Ren, Doug Bowman, Amber Ortiz, Maria Wang, Clifton Drew, Kao-Tai Tsai, Mathieu Marella, Brian Fox, Garth McGrath, Matthew Trotter, Fadi Towfic, Ian Cushman, Alexander Ratushny, Brian Lu, Daniel Pierce, Jim Cassidy. Spatial organization of pancreatic ductal adenocarcinoma (PDAC)–associated immune cells from the Adjuvant Pancreatic Adenocarcinoma Clinical Trial (APACT) study [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A43.

Multiple myeloma (MM) patients who become refractory to anti-MM drugs have a very poor prognosis. Therefore, it is important to gain insight into the mechanisms of resistance to these drugs. Immunomodulatory drugs (IMiDs) have immune-stimulatory and anti-angiogenic properties as well as direct anti

Lenalidomide is an immunomodulatory agent that has demonstrated clinical benefit for patients with relapsed or refractory mantle cell lymphoma (MCL); however, despite this observed clinical activity, the mechanism of action (MOA) of lenalidomide has not been characterized in this setting. We investigated the MOA of lenalidomide in clinical samples from patients enrolled in the CC-5013-MCL-002 trial (NCT00875667) comparing single-agent lenalidomide versus investigator's choice single-agent therapy and validated our findings in pre-clinical models of MCL. Our results revealed a significant increase in natural killer (NK) cells relative to total lymphocytes in lenalidomide responders compared to non-responders that was associated with a trend towards prolonged progression-free survival and overall survival. Clinical response to lenalidomide was independent of baseline tumour microenvironment expression of its molecular target, cereblon, as well as genetic mutations reported to impact clinical response to the Bruton tyrosine kinase inhibitor ibrutinib. Preclinical experiments revealed lenalidomide enhanced NK cell-mediated cytotoxicity against MCL cells via increased lytic immunological synapse formation and secretion of granzyme B. In contrast, lenalidomide exhibited minimal direct cytotoxic effects against MCL cells. Taken together, these data provide the first insight into the clinical activity of lenalidomide against MCL, revealing a predominately immune-mediated MOA.

The Cul4-Rbx1-DDB1-Cereblon E3 ubiquitin ligase complex is the target of thalidomide, lenalidomide and pomalidomide, therapeutically important drugs for multiple myeloma and other B-cell malignancies. These drugs directly bind Cereblon (CRBN) and promote the recruitment of substrates Ikaros (IKZF1) and Aiolos (IKZF3) to the E3 complex, thus leading to substrate ubiquitination and degradation. Here we present the crystal structure of human CRBN bound to DDB1 and the drug lenalidomide. A hydrophobic pocket in the thalidomide-binding domain (TBD) of CRBN accommodates the glutarimide moiety of lenalidomide, whereas the isoindolinone ring is exposed to solvent. We also solved the structures of the mouse TBD in the apo state and with thalidomide or pomalidomide. Site-directed mutagenesis in lentiviral-expression myeloma models showed that key drug-binding residues are critical for antiproliferative effects.

Venous thromboembolism (VTE) (deep vein thrombosis [DVT] and pulmonary embolism [(PE]) represents a substantial economic burden to the healthcare system. Using data from the randomized EINSTEIN DVT and PE trials, this North American sub-group analysis investigated the potential of rivaroxaban to reduce the length of initial hospitalization in patients with acute symptomatic DVT or PE.A post-hoc analysis of hospitalization and length-of-stay (LOS) data was conducted in the North American sub-set of patients from the randomized, open-label EINSTEIN trial program. Patients received either rivaroxaban (15 mg twice daily for 3 weeks followed by 20 mg once daily; n = 405) or dose-adjusted subcutaneous enoxaparin overlapping with (guideline-recommended 'bridging' therapy) and followed by a vitamin K antagonist (VKA) (international normalized ratio = 2.0-3.0; n = 401). The open-label study design allowed for the comparison of LOS between treatment arms under conditions reflecting normal clinical practice. LOS was evaluated using investigator records of dates of admission and discharge. Analyses were carried out in the intention-to-treat population using parametric tests. Costs were applied to the LOS based on weighted mean cost per day for DVT and PE diagnoses obtained from the Healthcare Cost and Utilization Project dataset.Of 382 patients hospitalized, 321 (84%), had acute symptomatic PE; few DVT patients required hospitalization. Similar rates of VTE patients were hospitalized in the rivaroxaban and enoxaparin/VKA treatment groups, 189/405 (47%) and 193/401 (48%), respectively. In hospitalized VTE patients, rivaroxaban treatment produced a 1.6-day mean reduction in LOS (median = 1 day) compared with enoxaparin/VKA (mean = 4.5 vs 6.1; median = 3 vs 4), translating to total costs that were $3419 lower in rivaroxaban-treated patients.In hospitalized North American patients with VTE, treatment with rivaroxaban produced a statistically significant reduction in LOS. When treating DVT and PE patients, clinicians should consider newer anti-coagulants with less complex treatment regimens.

The phase III EINSTEIN DVT and EINSTEIN PE trials demonstrated the potential of oral rivaroxaban for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). The length of initial hospitalization in patients presenting with either symptomatic DVT or PE was assessed using hospitalization records from these trials.Analyses were carried out in the intention-to-treat population, using non-parametric and parametric statistical methods.Overall, 52% (1781/3434) of EINSTEIN DVT patients and 90% (4328/4821) of EINSTEIN PE patients were admitted to hospital. The proportion of hospitalized patients with a length of stay of five or fewer days receiving rivaroxaban was 54% compared with 31% for enoxaparin/vitamin K antagonist (VKA) in patients with DVT. For patients with PE, the corresponding values were 45% and 33%. Stays of 6-10 days were observed in 29% of rivaroxaban-treated patients compared with 45% of enoxaparin/VKA-treated patients for DVT. For patients with PE, these values were 39% and 46% in the rivaroxaban and enoxaparin/VKA groups, respectively. Overall, length of stay was significantly shorter in the rivaroxaban group, compared with the enoxaparin/VKA group across all analyses performed (p 0.0001). Across regions, the observed admission rates and length of stay duration varied greatly: Asia had the longest overall hospitalization rates, whereas the lowest rates were reported in North America, Australia and New Zealand. Nevertheless, a consistent trend was observed: length of hospital stay in patients with DVT or PE receiving rivaroxaban was shorter than, or at least similar to, patients receiving enoxaparin/VKA.A single-drug regimen with rivaroxaban may reduce the burden on healthcare systems and patients, and provides effective and well tolerated treatment. The studies shared an open-label design that allowed comparison of initial hospitalization, but limitations include the well monitored clinical trial setting in which decisions on admission and discharge could vary from real-world management.

Introduction Response to treatment in patients with multiple myeloma (MM) is variable. With increasing possibilities of treatment regimens, predictive factors for response are important. Immune modulating agents (IMiDs) require Cereblon (CRBN) for activity. Therefore, the aim of this study was to identify the genes involved in the CRBN pathway which predict the response to therapy with IMiDs. Methods Paraffin embedded bone marrow (BM) biopsies were used from newly diagnosed patients included in HOVON-87/NMSG-18 trial obtained at inclusion. In this trial, elderly patients with MM were randomized between treatment with Melphalan-Prednisone (MP)-Thalidomide (MPT) followed by thalidomide maintenance versus MP-Lenalidomide (MPR) followed by lenalidomide maintenance (Zweegman et al. Blood 2016;127:1109-1116). BM biopsies were stained with a fully automated dual color, bright-field immunohistochemical assay for CRBN, its neosubstrates Ikaros and Aiolos and the downstream targets IRF4 and c-MYC. CD138 was used to identify MM plasma cells in the BM samples. For CRBN, both nuclear and cytoplasmic staining was evaluated. The distribution and intensity of the immunostaining was assessed using the H-score. The H-scores were calculated using the following formula: [1 × (% cells 1+) + 2 × (% cells 2+) + 3 × (% cells 3+)] and range from 0-300 (0-600 for combined cytoplasmic-nuclear CRBN H-score). For the Cox regression analysis H-scores were corrected by dividing these by a factor 100: hazard rates were considered per 100 points increase of the H-score. Protein levels of the CRBN pathway were compared between patients with complete response (CR) or very good partial response (VGPR) vs partial response (PR) and no change/progressive disease (NC/PD). High-risk cytogenetic aberrations (FISH) were defined as having deletion of 17p, and/or translocation t(4;14) and/or t(14;16). Statistical analysis was done using univariate and multivariate Cox regression analysis for progression free survival (PFS) and overall survival (OS), and the Mann-Whitney test for comparing response groups. Kaplan-Meier survival curves were generated to illustrate survival. Results BM samples obtained at diagnosis from 149 patients were evaluated. Seventy-one patients were treated in the thalidomide arm vs 78 patients in the lenalidomide arm. Median age was 73 years [range 60-90]. Revised ISS stages I/II/III were 12%/80%/8% respectively. At the time of analysis, median follow up of the 45 patients still alive was 83 months [range 23 - 114 months]. Best response on protocol treatment was sCR/CR in 22%, VGPR in 30%, PR in 36% and NC/PD in 12%. Protein expression across the response groups showed higher nuclear CRBN in patients who responded better (sCR/CR/VGPR; median H-score: 178 (49-273)) compared to patients with a worse response (PR/NC/PD; median H-score: 157 (67-251)), albeit not statistically significant (Mann-Whitney p-value=0.06). Higher H-score of nuclear staining of CRBN was associated with a longer PFS and OS, with a hazard ratio (HR) of 0.52 for PFS (95% confidence interval (CI)=0.37-0.86, p In a multivariate analysis (which included study arm (MPT vs MPR), nuclear CRBN, high-risk cytogenetic aberrations and R-ISS), nuclear CRBN remained independently associated with OS as well as R-ISS and study arm. For PFS, only nuclear CRBN remained statistically significant after backward selection. Despite treatment arm being a statistically significant term in the multivariate Cox model for OS, no relation was found for treatment arm and nuclear CRBN, in terms of OS. Conclusions In this study we demonstrate that higher expression of nuclear CRBN in myeloma cells in BM of patients with MM was associated with a superior PFS and OS. Disclosures Couto: Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Ren:Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Thakurta:Celgene: Employment, Equity Ownership. Zweegman:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: 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. Broyl:Celgene, amgen, Janssen,Takeda: Honoraria. Sonneveld:Amgen: Honoraria, Research Funding; BMS: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; SkylineDx: Research Funding.

Background: Diffuse large B-cell lymphoma (DLBCL) is a genetically heterogeneous disease of malignant B cells most often classified by tumor gene expression and/or mutations. DLBCL is also characterized by a tumor microenvironmental influence that has not been well described. Immuno-oncology-targeting agents such as immune checkpoint inhibitors have limited clinical activity in DLBCL, highlighting the need for a better understanding of the DLBCL tumor microenvironment for rational drug development, combinations, and disease stratification. Here, we systematically characterize the immune composition of more than 100 DLBCL tumors using 2 imaging technologies and provide insight into the complexity of DLBCL disease biology. Methods: A total of 110 cases of newly diagnosed DLBCL were analyzed by multiplex immunohistochemistry (IHC; n=70) and multiplexed ion beam imaging (MIBI) (n=40), each with 10 common markers (CD20, CD3, CD8, Foxp3, CD56, CD163, CD11c, CD56, PD-1, PD-L1) and a few platform-specific markers. Both IHC and MIBI images were digitalized to generate marker-positive cell counts (including single, double, or triple positivity), cell density (cell count/mm2), and population fraction (% of total nucleated cells). Marker density was analyzed for the major components of tumor-infiltrating cell types and correlation between any pair of markers. In addition, RNAseq data and fluorescence in situ hybridization (FISH) data on MYC, BCL-2, and BCL-6 translocation were generated. Results: In the IHC cohort, T cells (CD3+), dendritic cells (DCs; by CD11c+), and macrophages (CD163+)were the major immune components, with median population fractions of 22%, 16%, and 2.7%, respectively. Natural killer cells (CD56+CD20−) were a minor component at a median of 0.1%. A significant negative correlation was observed between tumor cells (CD20+) and CD4+ (Spearman ρ = −0.47; P = 1.3 × 10−04), and CD8+ T cells (Spearman ρ = −0.42; P = 1.4 × 10−03) cells, and an unexpectedly negative correlation between DCs (CD11c+) and macrophages (CD163+, r = −0.63; P = 9.8 × 10−06) was found. Similar to follicular lymphoma, 2 PD-1+ T-cell populations were identified: PD-1bright and PD-1dim. The PD-1bright cells co-stained with CXCR5, indicating T follicular helper cells (Tfh). The PD-1dim were expressed on exhausted effector cells that co-stained with Tim3 or Lag3. The median population fraction of Tim3+ or Lag3+ among T cells was 25%, whereas that of PD-1dim among T cells was 0.2%, indicating that PD-1 was not a useful marker for exhausted T cells. PD-L1 was predominantly found on DCs and macrophages, and the median population fraction of PD-L1+ among tumor cells was only 6.2%. By unsupervised hierarchical clustering on marker density, 3 major immune-infiltration patterns (P1, P2, and P3) were identified. The first 2 segments (P1 and P2) were 20% and 25% of the total cases, respectively. Both were characterized by high T-cell, macrophage, and DC infiltration. P1 was enriched for PD-1+ T cells, whereas P2 was void of any PD-1+ cells. The third segment (P3) that comprised 55% of the cases was predominantly tumor cells with low T-cell, macrophage, and DC infiltration. PD-L1+ cells were primarily found in segments P1 and P2 but rare in segment P3. Additional analysis on the associations between the 3 immune-infiltration patterns and prognostic DLBCL molecular features such as cell-of-origin, double-hit gene signature, and double-hit FISH will also be presented. Conclusions: These data show the complexity of DLBCL disease biology and show classification of DLBCL at the immune-infiltration level as 3 distinct patterns. The overall low expression of PD-1+ T cells and the restricted pattern of PD-L1+ tumor cells provide a possible explanation for the lack of clinical activity of PD-1/PD-L1 blockade in DLBCL. We also observed other exhausted T cells expressing Lag3 and Tim3, suggesting alternative therapeutic opportunities in stratified populations. These data also highlight the opportunity to develop rational immuno-oncology-targeted agents based on the immune infiltration pattern of DLBCL and selection of patients who may respond more favorably to particular agents. Disclosures Huang: Celgene Corporation: Employment, Equity Ownership. Nakayama:Celgene Corporation: Employment, Equity Ownership. Stokes:Celgene Corporation: Employment, Equity Ownership. Towfic:Celgene Corporation: Employment, Equity Ownership. Lee:Celgene Corporation: Employment, Equity Ownership. Ren:Celgene Corporation: Employment, Equity Ownership. Marella:Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Hagner:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Couto:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Newhall:Celgene Corporation: Employment, Equity Ownership. Gandhi:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties.

Introduction: Despite advances in treatment strategy, multiple myeloma (MM) remains a challenging, incurable disease as patients (pts) often relapse. Here we describe preclinical data of a novel cereblon (CRBN) E3 ligase modulatory compound (CELMoD), iberdomide (IBER; CC-220), as well as clinical and translational data from a current phase 1/2 clinical trial (NCT02773030). These data support a differentiated profile for IBER from immunomodulatory agents (IMiD agents), and development of IBER as a foundation of combination therapy for the treatment of relapsed/refractory MM (RRMM). Methods: Preclinical analyses were performed on pomalidomide (POM)-sensitive and acquired-resistant MM cell lines and peripheral blood mononuclear cells from healthy volunteers. Eligible pts enrolled on the clinical trial had RRMM and had received ≥ 2 prior regimens, containing at least an IMiD agent and proteasome inhibitor (PI), and had experienced disease progression within 60 days of last MM therapy. Escalating doses of IBER were given on Days 1-21, in combination with dexamethasone (DEX; 40 mg; 20 mg in pts aged > 75 years) on Days 1, 8, 15, and 22, of each 28-day cycle. Immunohistochemistry (IHC) data on CRBN, Ikaros, Aiolos, and ZFP91 expression was obtained from pt bone marrow specimens at screening and at Cycle 2, Day 15. Immune profiling was evaluated by flow cytometry of peripheral blood at Cycle 1, Day 1 and Cycle 2, Day 15. Primary objectives were to evaluate maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), safety, and preliminary efficacy. Results: Preclinically, IBER exhibited potent tumoricidal anti-MM and immunostimulatory activity. IBER was more potent than lenalidomide (LEN) or POM in overcoming the immunosuppressive activity of bortezomib (BORT), inducing a more than twofold increase in T cell proliferation in the presence of BORT. IBER also enhanced the antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity of daratumumab (DARA), leading to deeper responses than combinations with LEN or POM. Further differentiating from both LEN and POM, IBER showed activity alone and in combination with BORT or DARA in POM-resistant MM cell lines. As of June 28, 2019, 69 pts with RRMM had received IBER + DEX. Median age was 65 years (range 33-80), and median number of prior regimens was 5 (range 2-12). Prior therapies included autologous stem cell transplantation (80%), LEN (100%), POM (70%), PIs (100%), DARA (71%) and anti-BCMA (6%), including CAR T cells. Clinical activity was observed across all dose levels with an overall response rate (ORR) of 29%, clinical benefit rate of 45%, and disease control rate of 80%. ORR was 30%, 28% and 29% in IMiD agent-refractory, DARA-refractory and Quad-class (IMiD agents/PIs/steroids/CD-38 antibodies)-refractory pts, respectively. IBER + DEX showed a favorable safety profile, with grade 3-4 neutropenia, infections, and thrombocytopenia, occurring in 29%, 25%, and 12% of pts, respectively. To date, IBER doses range from 0.3 to 1.3 mg and the MTD/RP2D has not yet been reached. Pharmacodynamic immunophenotyping changes were dose-dependent. Treatment with IBER (at doses > 0.75mg) + DEX doubled the percentage of proliferating T cells and NK cells (P < 0.001 for each) and increased activated and effector memory CD8+ and CD4+ T cells by > 50% (P < 0.01 for each subset). Pharmacodynamic changes in pt bone marrow by quantitative IHC scoring showed significant degradation of substrates (Ikaros, P = 0.006; Aiolos, P < 0.001; ZFP91, P < 0.001) and downregulation of c-myc (P = 0.027), including in pts refractory to POM and with low CRBN expression. Conclusions: IBER + DEX has shown notable clinical activity and favorable tolerability in heavily pretreated pts with RRMM, including pts refractory to prior IMiD therapy. Preclinical and translational data suggest a differentiated profile of IBER from IMiD agents in regard to activity in POM-resistant models, potency in combination with BORT and DARA, and by inducing changes in CD4+ T cells that were not observed in pts treated with POM from prior studies. Taken together, these data support a differentiated profile for IBER from IMiD agents, and the clinical development of IBER as a foundation of combination therapy for the treatment of RRMM. This study is ongoing, and includes cohorts evaluating the combinations of IBER + DEX with DARA, BORT, and carfilzomib. Updated results will be presented at the meeting. Disclosures Lonial: Karyopharm: Consultancy; GSK: Consultancy; Takeda: Consultancy, Research Funding; Celgene Corporation: Consultancy, Research Funding; Amgen: Consultancy; Genentech: Consultancy; Janssen: Consultancy, Research Funding; BMS: Consultancy. Amatangelo:Celgene Corporation: Employment, Equity Ownership. Popat:Celgene Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria; Takeda: Honoraria, Other: travel, accommodations, expenses; Janssen: Honoraria, Other: travel support to meetings. Minnema:Gilead: Honoraria; Celgene Corporation: Honoraria, Research Funding; Amgen: Honoraria; Servier: Honoraria; Jansen Cilag: Honoraria. Zonder:Alnylam: Consultancy, 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, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Intellia: Consultancy, Membership on an entity's Board of Directors or advisory committees; Caelum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Larsen:Janssen Oncology: 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. Oriol Rocafiguera:Celgene Corporation: Consultancy, Speakers Bureau; Janssen: Consultancy; Amgen: Consultancy, Speakers Bureau. Rodriguez Otero:Celgene Corporation: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria; Takeda: Consultancy; BMS: Honoraria; Kite Pharma: Consultancy. Badros:Celgene Corporation: Consultancy; Amgen: Consultancy. Siegel:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Jagannath:Bristol-Myers Squibb: Consultancy; Janssen Pharmaceuticals: Consultancy; Karyopharm Therapeutics: Consultancy; AbbVie: Consultancy; Merck & Co.: Consultancy; Celgene Corporation: Consultancy. Bringhen:Bristol-Myers Squibb: Honoraria; Celgene Corporation: 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; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy. Gironella:Amgen: Honoraria; Janssen: Honoraria; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kaiser:Takeda, Janssen, Celgene, Amgen: Honoraria, Other: Travel Expenses; Abbvie, Celgene, Takeda, Janssen, Amgen, Abbvie, Karyopharm: Consultancy; Celgene, Janssen: Research Funding. Cook:Janssen, Takeda, Sanofi, Karyopharm, Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen, Bristol-Myers Squib, GlycoMimetics, Seattle Genetics, Sanofi: Honoraria; Celgene, Janssen-Cilag, Takeda: Honoraria, Research Funding. Gamberi:Janssen: 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; Amgen: Honoraria; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Sonneveld:SkylineDx: Research Funding; Takeda: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Honoraria; Amgen: Honoraria, Research Funding. Nguyen:Celgene Corporation: Employment, Equity Ownership. Chen:Celgene Corporation: Employment, Equity Ownership. Homan:Celgene Corporation: Employment. Bjorklund:Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Pierceall:Celgene Corporation: Employment, Equity Ownership. Bensmaine:Celgene Corporation: Employment, Equity Ownership. Thakurta:Celgene: Employment, Equity Ownership. Peluso:Celgene Corporation: Employment. Van De Donk:Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: 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, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AMGEN: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees.

Background Treatment of relapsed/refractory multiple myeloma (RRMM) remains challenging as durable remissions are achieved in patient sub-groups only. Identifying patients that are likely to benefit prior to or early after starting relapse treatments remains an unmet need. MUKseven is a trial specifically designed to investigate and validate biomarkers for treatment optimization in a 'real-world' RRMM population. Design In the randomized multi-center phase 2 MUKseven trial, RRMM patients (≥2 prior lines of therapy, exposed to proteasome inhibitor and lenalidomide) were randomized 1:1 to cyclophosphamide (500 mg po d1, 8, 15), pomalidomide (4 mg days 1-21) and dexamethasone (40 mg; if ≥75 years 20 mg; d1, 8, 15, 21) (CPomD) or PomD and treated until progression. All patients were asked to undergo bone marrow (BM) and peripheral blood (PB) bio-sampling at baseline, cycle 1 day 14 (C1D14, on-treatment) and relapse. For biomarker discovery and validation, IGH translocations were profiled by qRT-PCR, copy number aberrations by digital MLPA (probemix D006; MRC Holland), GEP by U133plus2.0 array (Affymetrix), PD protein markers by IHC and PB T-cell subsets by flow cytometry for all patients with sufficient material. Primary endpoint was PFS, secondary endpoints included response, OS, safety/toxicity and biomarker validation. Original planned sample size was 250 patients but due to a change in UK standard of care during recruitment with pomalidomide becoming available, a decision was made to stop recruitment early. Results In total, 102 RRMM patients were randomized 1:1 between March 2016 and February 2018. Trial entry criteria were designed to include a real-world RRMM population, permitting transfusions and growth factor support. Median age at randomization was 69 years (range 42-88), 28% of patients had received ≥5 prior lines of therapy (median: 3). Median follow-up for this analysis was 13.4 months (95% CI: 12.0-17.5). 16 patients remained on trial at time of analysis (median number of cycles: 19.5; range 8-28). More patients achieved ≥PR with CPomD compared to PomD: 70.6% (95% CI: 56.2-82.5%) vs. 47.1% (CI: 32.9-61.5%) (P=0.006). Median PFS was 6.9 months (CI: 5.7-10.4) for CPomD vs. 4.6 months (CI: 3.5-7.4) for PomD, which was not significantly different as per pre-defined criteria. Follow-up for OS is ongoing and will be presented at the conference. High-risk genetic aberrations were found at following frequencies: t(4;14): 6%, t(14;16)/t(14;20): 2%, gain(1q): 45%, del(17p): 13%. Non-high risk lesions were present as follows: t(11;14): 22%, hyperdiploidy: 44%. Complete information on all high-risk genetic markers was available for 71/102 patients, of whom 12.7% had double-hit high-risk (≥2 adverse lesions), 46.5% single-hit high-risk (1 adverse lesion) and 40.8% no risk markers, as per our recent meta-analysis in NDMM (Shah V, et al., Leukemia 2018). Median PFS was significantly shorter for double-hit: 3.4 months (CI: 1.0-4.9) vs. single-hit: 5.8 months (CI: 3.7-9.0) or no hit: 14.1 months (CI: 6.9-17.3) (P=0.005) (Figure 1A). GEP was available for 48 patients and the EMC92 high-risk signature, present in 19% of tumors, was associated with significantly shorter PFS: 3.4 months (CI: 2.0-5.7) vs. 7.4 (CI: 3.9-15.1) for EMC92 standard risk (P=0.037). Pharmacodynamic (PD) profiling of cereblon and CRL4CRBN ubiquitination targets (including Aiolos, ZFP91) in BM clots collected at baseline and C1D14 is currently ongoing. Preliminary results for the first 10 patients demonstrate differential change of nuclear Aiolos (Figure 1C), with a major decrease in Aiolos H-scores in 7/10 patients from baseline to C1D14 and reconstitution at relapse. T-cell PB sub-sets were profiled at baseline and C1D14 by flow cytometry. Specific sub-sets increased with therapy from baseline to C1D14, e.g. activated (HLA-DR+) CD4+ T-cells, as reported at last ASH. CD4+ T-cell % at baseline was associated with shorter PFS in these analyses in a multi-variable Cox regression model (P=0.005). PD and T-cell biomarker results will be updated and integrated with molecular tumor characteristics and outcome. Discussion Our results demonstrate that molecular markers validated for NDMM predict treatment outcomes in RRMM, opening the potential for stratified delivery of novel treatment approaches for patients with a particularly high unmet need. Additional immunologic and PD biomarkers are currently being explored. Disclosures Croft: Celgene: Other: Travel expenses. Hall:Celgene, Amgen, Janssen, Karyopharm: Other: Research funding to Institution. Walker:Janssen, Celgene: Other: Research funding to Institution. Pawlyn:Amgen, Janssen, Celgene, Takeda: Other: Travel expenses; Amgen, Celgene, Janssen, Oncopeptides: Honoraria; Amgen, Celgene, Takeda: Consultancy. Flanagan:Amgen, Celgene, Janssen, Karyopharm: Other: Research funding to Institution. Garg:Janssen, Takeda, Novartis: Other: Travel expenses; Novartis, Janssen: Research Funding; Janssen: Honoraria. Couto:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Wang:Celgene Corporation: Employment, Equity Ownership. Boyd:Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Pierceall:Celgene: Employment. Thakurta:Celgene: Employment, Equity Ownership. Cook:Celgene, Janssen-Cilag, Takeda: Honoraria, Research Funding; Janssen, Takeda, Sanofi, Karyopharm, Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen, Bristol-Myers Squib, GlycoMimetics, Seattle Genetics, Sanofi: Honoraria. Brown:Amgen, Celgene, Janssen, Karyopharm: Other: Research funding to Institution. Kaiser:Takeda, Janssen, Celgene, Amgen: Honoraria, Other: Travel Expenses; Celgene, Janssen: Research Funding; Abbvie, Celgene, Takeda, Janssen, Amgen, Abbvie, Karyopharm: Consultancy.

Cereblon, a member of the cullin 4 ring ligase complex (CRL4), is the molecular target of the immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide and is required for the antiproliferative activity of these agents in multiple myeloma (MM) and immunomodulatory activity in T cells. Cereblon's central role as a target of lenalidomide and pomalidomide suggests potential utility as a predictive biomarker of response or resistance to IMiD therapy. Our studies characterized a cereblon monoclonal antibody CRBN65, with high sensitivity and specificity in Western analysis and immunohistochemistry that is superior to commercially available antibodies. We identified multiple cereblon splice variants in both MM cell lines and primary cells, highlighting challenges with conventional gene expression assays given this gene complexity. Using CRBN65 antibody and TaqMan quantitative reverse transcription polymerase chain reaction assays, we showed lack of correlation between cereblon protein and mRNA levels. Furthermore, lack of correlation between cereblon expression in MM cell lines and sensitivity to lenalidomide was shown. In cell lines made resistant to lenalidomide and pomalidomide, cereblon protein is greatly reduced. These studies show limitations to the current approaches of cereblon measurement that rely on commercial reagents and assays. Standardized reagents and validated assays are needed to accurately assess the role of cereblon as a predictive biomarker.

Abstract 3287 Background: Durable responses with lenalidomide monotherapy have been reported in patients with non-Hodgkin lymphoma. In relapsed/refractory diffuse large B-cell lymphoma (DLBCL), higher responses were observed in the activated B-cell-like (ABC) subtype than in the germinal centre B-cell (GCB)-like subtype (Czuczman, et al. British Journal of Haematology, 2011, 154, 477–481). Herein, the molecular mechanisms involved in the differential efficacy of lenalidomide in DLBCL subtypes were investigated. Methods: A panel of DLBCL cell lines, with 5 of ABC-subtype and 11 of non-ABC subtype, was collected and cell of origin subtype was confirmed based on literature, molecular and genetic analysis. The direct antiproliferative effect of lenalidomide on DLBCL cells was assessed using the 3H-thymidine incorporation assay and apoptosis analysis. The molecular mechanisms involved in the antiproliferative efficacy of lenalidomide in DLBCL subtypes were investigated by western blot, immunohistochemistry (IHC) and qRT-PCR analysis of key signaling events during B-cell receptor (BCR)-dependent NF-κB activation. The critical roles of interferon regulatory factor 4 (IRF4), and cereblon (CRBN) in lenalidomide efficacy were established by knock-in or knock-down of these proteins in sensitive ABC cells. Finally, a mouse xenograft model was used to confirm the antitumor effect of lenalidomide and the relevance of the molecular mechanism involved. Results: Using DLBCL cell lines, lenalidomide treatment was found to preferentially suppress proliferation of ABC-DLBCL cells in vitro at a concentration range of 0.01–100 μM (the median plasma concentration at Cmax for patients receiving 25 mg lenalidomide is 2.2 μM) and delay tumor growth in a human tumor xenograft model of OCI-Ly10 cells (lenalidomide 3–30 mg/kg, p.o. qdX28), with minimal effect on non-ABC-DLBCL cells. This tumoricidal effect of lenalidomide was associated with downregulation of IRF4, a survival factor in ABC-DLBCL cells. Treatment with lenalidomide for 1–3 days, similar to the inhibitors of PKCb and MALT1 (LY-333,531 and z-VRPR-fmk, respectively), was found to significantly (p Furthermore, knockdown of CRBN in OCI-Ly10 (p Conclusions: These data may provide a mechanism for the preferential efficacy of lenalidomide in ABC-DLBCL observed in clinical studies. These findings suggest that lenalidomide has direct antitumor activity against DLBCL cells, preferentially ABC-DLBCL cells, by blocking IRF4 expression and the BCR-NF-κB signaling pathway in a cereblon-dependent manner (also see Figure below). Disclosures: Zhang: Celgene Corp: Employment, Equity Ownership. Kosek:Celgene Corp: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Heise:Celgene Corporation: Employment, Equity Ownership. Schafer:Celgene: Employment, Equity Ownership. Chopra:Celgene Corporation: Employment, Equity Ownership.

This paper discusses a method for the direct patterning of Au electrodes at nanoscale resolution using dip-pen nanolithography, with proof-of-concept demonstrated by creating single-walled carbon nanotube devices. This technique enables insight into three key concepts at the nanoscale: using dip-pen nanolithography as an alternative to electron-beam lithography for writing contacts to carbon nanotubes, understanding the integrity of contacts and devices patterned with this technique, and on a more fundamental level, providing a facile method to compare and understand electrical and Raman spectroscopy data from the same isolated carbon nanotube. Electrical contacts to individual and small bundle single-walled carbon nanotubes were masked by an alkylthiol that was deposited via dip-pen nanolithography on a thin film of Au evaporated onto spin-cast, nonpercolating, and highly isolated single-walled carbon nanotubes. A wet Au etching step was used to form the individual devices. The electrical characteristics for three different single-walled carbon nanotube devices are reported: semimetallic, semiconducting, and metallic. Raman analysis on representative devices corroborates the results from AFM imaging and electrical testing. This work demonstrates a technique for making electrical contact to nanostructures of interest and provides a platform for directly corroborating electrical and optical measurements. The merits of using dip-pen nanolithography include flexible device configuration (such as varying the channel length and the number, size, and orientation of contacts), targeted patterning of individual devices with imaging and writing conducted in the same instrument under ambient conditions, and negligible damage to single-walled carbon nanotubes during the fabrication process.