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Only a subset of cancer patients responds to checkpoint blockade inhibition in the clinic. Strategies to overcome resistance are promising areas of investigation. Targeting glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) has shown efficacy in preclinical models, but GITR engagement is ineffective in controlling advanced, poorly immunogenic tumors, such as B16 melanoma, and has not yielded benefit in clinical trials. The alkylating agent cyclophosphamide (CTX) depletes regulatory T cells (Tregs), expands tumor-specific effector T cells (Teffs) via homeostatic proliferation, and induces immunogenic cell death. GITR agonism has an inhibitory effect on Tregs and activates Teffs. We therefore hypothesized that CTX and GITR agonism would promote effective antitumor immunity. Here we show that the combination of CTX and GITR agonism controlled tumor growth in clinically relevant mouse models. Mechanistically, we show that the combination therapy caused tumor cell death, clonal expansion of highly active CD8+ T cells, and depletion of Tregs by activation-induced cell death. Control of tumor growth was associated with the presence of an expanded population of highly activated, tumor-infiltrating, oligoclonal CD8+ T cells that led to a diminished TCR repertoire. Our studies show that the combination of CTX and GITR agonism is a rational chemoimmunotherapeutic approach that warrants further clinical investigation.

Transcription factors ThPOK and Runx3 regulate the differentiation of “helper” CD4+ and “cytotoxic” CD8+ T cell lineages respectively, inducing single positive (SP) T cells that enter the periphery with the expression of either the CD4 or CD8 co-receptor. Despite the expectation that these cell fates are mutually exclusive and that mature CD4+CD8+ double positive (DP) T cells are present in healthy individuals and augmented in the context of disease, yet their molecular features and pathophysiologic role are disputed. Here, we show DP T cells in murine and human tumors as a heterogenous population originating from SP T cells which re-express the opposite co-receptor and acquire features of the opposite cell type’s phenotype and function following TCR stimulation. We identified distinct clonally expanded DP T cells in human melanoma and lung cancer by scRNA sequencing and demonstrated their tumor reactivity in cytotoxicity assays. Our findings indicate that antigen stimulation induces SP T cells to differentiate into DP T cell subsets gaining in polyfunctional characteristics.

Background Lineage plasticity, the ability to transdifferentiate among distinct phenotypic identities, facilitates therapeutic resistance in cancer. In lung adenocarcinomas (LUADs), this phenomenon includes small cell and squamous cell (LUSC) histologic transformation in the context of acquired resistance to targeted inhibition of driver mutations. LUAD-to-LUSC transdifferentiation, occurring in up to 9% of EGFR-mutant patients relapsed on osimertinib, is associated with notably poor prognosis. We hypothesized that multi-parameter profiling of the components of mixed histology (LUAD/LUSC) tumors could provide insight into factors licensing lineage plasticity between these histologies. Methods We performed genomic, epigenomics, transcriptomics and protein analyses of microdissected LUAD and LUSC components from mixed histology tumors, pre-/post-transformation tumors and reference non-transformed LUAD and LUSC samples. We validated our findings through genetic manipulation of preclinical models in vitro and in vivo and performed patient-derived xenograft (PDX) treatments to validate potential therapeutic targets in a LUAD PDX model acquiring LUSC features after osimertinib treatment. Results Our data suggest that LUSC transdifferentiation is primarily driven by transcriptional reprogramming rather than mutational events. We observed consistent relative upregulation of PI3K/AKT, MYC and PRC2 pathway genes. Concurrent activation of PI3K/AKT and MYC induced squamous features in EGFR-mutant LUAD preclinical models. Pharmacologic inhibition of EZH1/2 in combination with osimertinib prevented relapse with squamous-features in an EGFR-mutant patient-derived xenograft model, and inhibition of EZH1/2 or PI3K/AKT signaling re-sensitized resistant squamous-like tumors to osimertinib. Conclusions Our findings provide the first comprehensive molecular characterization of LUSC transdifferentiation, suggesting putative drivers and potential therapeutic targets to constrain or prevent lineage plasticity.

Summary Small cell lung cancer (SCLC) is an aggressive malignancy that includes subtypes defined by differential expression of ASCL1, NEUROD1, and POU2F3 (SCLC-A, -N, and -P, respectively). To define the heterogeneity of tumors and their associated microenvironments across subtypes, we sequenced 155,098 transcriptomes from 21 human biospecimens, including 54,523 SCLC transcriptomes. We observe greater tumor diversity in SCLC than lung adenocarcinoma, driven by canonical, intermediate, and admixed subtypes. We discover a PLCG2-high SCLC phenotype with stem-like, pro-metastatic features that recurs across subtypes and predicts worse overall survival. SCLC exhibits greater immune sequestration and less immune infiltration than lung adenocarcinoma, and SCLC-N shows less immune infiltrate and greater T cell dysfunction than SCLC-A. We identify a profibrotic, immunosuppressive monocyte/macrophage population in SCLC tumors that is particularly associated with the recurrent, PLCG2-high subpopulation.

Paired T cell receptor and RNA single cell sequencing (scTCR/RNA-seq) has allowed for enhanced resolution of clonal T cell dynamics in cancer. Here, we report a scTCR/RNA-seq dataset of 162,062 single T cells from 31 tissue regions, including tumor, adjacent normal tissues, and lymph nodes (LN), from three patients who underwent resections for progressing lung cancers after immune checkpoint blockade (ICB). We found marked regional heterogeneity in tumor persistence that was associated with heterogeneity in CD4 and CD8 T cell phenotypes; regions with persistent cancer cells were enriched for follicular helper CD4 T cells (TFH), regulatory T cells (Treg), and exhausted CD8 T cells. Clonal analysis demonstrated that highly-expanded T cell clones were predominantly of the CD8 subtype, were ubiquitously present across all sampled regions, found in the peripheral circulation, and expressed gene signatures of ‘large’ and ‘dual-expanded’ clones that have been predictive of response to ICB. Longitudinal tracking of CD8 T cell clones in the peripheral blood revealed that the persistence of ubiquitous CD8 T cell clones, as well as phenotypically distinct clones with tumor-reactive features, correlated with systemic tumor control. Finally, tracking CD8 T cell clones across tissues revealed the presence of TCF-1+precursor exhausted CD8 T cells in tumor draining LNs that were clonally linked to expanded exhausted CD8 T cells in tumors. Altogether, this comprehensive scTCR/RNA-seq dataset with regional, longitudinal, and clonal resolution provides fundamental insights into the tissue distribution, persistence, and differentiation trajectories of ICB-responsive T cells that underlie clinical responses to ICB.

Although cancer immunotherapy with PD-(L)1 blockade is now routine treatment for patients with lung cancer, remarkably little is known about acquired resistance. We examined 1,201 patients with NSCLC treated with PD-(L)1 blockade to clinically characterize acquired resistance, finding it to be common (occurring in more than 60% of initial responders), with persistent but diminishing risk over time, and with distinct metastatic and survival patterns compared to primary resistance. To examine the molecular phenotype and potential mechanisms of acquired resistance, we performed whole transcriptome and exome tumor profiling in a subset of NSCLC patients (n=29) with acquired resistance. Systematic immunogenomic analysis revealed that tumors with acquired resistance generally had enriched signals of inflammation (including IFNγ signaling and inferred CD8+ T cells) and could be separated into IFNγ upregulated and stable subsets. IFNγ upregulated tumors had putative routes of resistance with signatures of dysfunctional interferon signaling and mutations in antigen presentation genes. Transcriptomic profiling of cancer cells from a murine model of acquired resistance to PD-(L)1 blockade also showed evidence of dysfunctional interferon signaling and acquired insensitivity to in vitro interferon gamma treatment. In summary, we characterized clinical and molecular features of acquired resistance to PD-(L)1 blockade in NSCLC and found evidence of ongoing but dysfunctional IFN response. The persistently inflamed, rather than excluded or deserted, tumor microenvironment of acquired resistance informs therapeutic strategies to effectively reprogram and reverse acquired resistance.

Canonical p53-activated pathways can influence a microenvironment that promotes antitumor immune surveillance via tumor-associated macrophages (TAMs). We examined whether p53 activity in the tumor microenvironment (TME) influences antitumor immunity and show that p53 signaling induced pharmacologically with APR-246 (eprenetapopt) can augment the efficacy of immune checkpoint blockade (ICB) in preclinical models, a strategy that is also being tested in patients (NCT04383938). We first investigated the effects of combining APR-246 with ICB in wildtype C57BL6 (B6) mice bearing syngeneic p53 wildtype MC38 colon cancer and B16 melanoma tumors. The combination of an anti-PD-1 antibody (RMP1-14) with APR-246 in mice significantly delayed tumor growth (p < 0.001) and improved survival of tumor-bearing mice, compared to monotherapies (p < 0.01). To further dissect the effects of APR-246 on myeloid and T cells in the TME, we used a conditional knockout of p53 in CSF1R+myeloid cells (CSF1Rcre/p53fl mice), or T cells (CD8cre/p53fl mice). CSF1Rcre/p53fl had loss of tumor control and worse survival with APR-246+anti-PD-1. CD8cre/p53fl had intact tumor control. To study enhanced p53 activity in the TME, we performed flow cytometry, cytokine multiplex and global transcriptional profiling by RNA seq. We found enhanced p53-activity led to increased infiltration of T cells, increased MHC-II expression in TAMs and downregulation of M2-associated cytokines. This was associated with cellular senescence in TAMs and induction of canonical p53-induced senescence-associated secretory phenotype (SASP). Our preclinical findings informed the development of a phase I/II clinical trial using APR-246 with pembrolizumab for patients with advanced solid tumors (NCT04383938). We studied peripheral blood samples from two of the patients with tumor regression and two patients in whom tumors progressed on therapy. We analyzed peripheral blood mononuclear cells (PBMCs) and serum prior to therapy, and at the beginning of cycle 2 and 5 for the patients with tumor control, and at the end of therapy for patients who had progression. Single cell RNA-seq of PBMCs demonstrated a signature consistent with T cell activation and proliferation, and SASP-associated changes in the myeloid compartment as seen in mice. T cell profiling of PBMCs by flow cytometry demonstrated strong proliferation of T cells in patients with tumor control. Serum cytokine analysis demonstrated robust in IL-12, IFN-gamma and Eotaxin-1 in the two responders, which was not seen in the patients whose tumors progressed. Our study illustrates p53-induced SASP in TAMs as a mechanism to reprogram the TME and augment responses to ICB. Ongoing studies will help determine biomarkers that are predictive of response to APR-246+ICB therapy. Citation Format: Arnab Ghosh, Judith Michel, Divya Venkatesh, Riccardo Mezzadra, Lauren Dong, Fadi Samaan, Ricardo Gomez, Nathan Suek, Aliya Holland, Yu-Jui Ho, Mohsen Abu-Akeel, Luis Felipe Campesato, Levi Mark Bala Mangarin, Cailian Liu, Hong Zhong, Sadna Budhu, Andrew Chow, Roberta Zappasodi, Marcus Ruscetti, Scott W. Lowe, Taha Merghoub, Jedd D. Wolchok. Activating canonical p53 functions in tumor-associated macrophages improves immune checkpoint blockade efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 250.

Response to immune checkpoint blockade (ICB) in non-small cell lung cancers (NSCLC) is associated with recurring mutations in tumor suppressor genes STK11 and TP53. Whereas STK11-mutated patients are mostly insensitive, TP53-mutated patients commonly respond to ICB. Previous studies have linked mutational status in these genes to differences in cell type composition of the tumor microenvironment (TME). However, it remains unclear if differences in cell type compositions as well as cell-cell interactions in turn could account for the observed differences in treatment response and overall survival in NSCLC. Here, we perform spatial profiling of immune and stromal phenotypes in the TME of 119 NSCLC patients using imaging mass cytometry (IMC) on tissue microarrays (TMA). Matching data from MSK IMPACT (clinical sequencing) was used to establish mutation profiles and therapeutic response was included in the analysis. We find that STK11-mutated NSCLC is characterized by decreased CD4 T cell and increased neutrophil abundance, while TP53-mutated NSCLC is associated with increased CD8 T cell and decreased endothelial cell abundance. Accordingly, we stratified the patient population into TME classes by cell type composition. We found that while mutational status does not inform overall survival in our cohort, stratification by cell type abundance strongly associates with patient outcome (p-value: 0.000146, logRank test). Patients with neutrophil-rich TMEs show worse overall survival (25% 5-year survival), while patients with increased endothelial cell and macrophage abundance have a tendency to live longer (80% and 75% 5-year survival respectively). Furthermore, we interrogate pairwise proximity of immune cell types and states to construct cellular networks in NSCLC. Together, our findings suggest that TME cell type composition and cellular networks are potential molecular determinants for ICB therapeutic response in NSCLC patients. Citation Format: Florian Uhlitz, Douglas Linn, Elsa Beyer Krall, Jacklynn Egger, Hira Rizvi, Jason Chang, Benjamin Nicholson, Rami Vanguri, Andrew Chow, Matthew Hellmann, Sohrab Shah. Spatial immune determinants of ICB response in STK11-mutated non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB049.

Small cell lung cancer (SCLC) is an aggressive disease characterized by early metastasis and exceptional lethality, comprising 13% of all lung cancer cases. With few treatment options, typically resulting in only transient responses, SCLC is responsible for approximately 250,000 deaths globally per year. The backbone of SCLC treatment over the past several decades has been platinum-based doublet chemotherapy, with the recent addition of immunotherapy to first-line chemotherapy showing limited benefit in a small subset of patients. Major hurdles to improving SCLC treatment include development of rapid chemoresistance and ineffective second line therapies. The identification of more durably effective therapeutic strategies is a major unmet clinical need. Here, we performed an in vitro CRISPR screen in SCLC cell lines from all major SCLC subtypes, including short-term cultured cells from patient-derived xenografts (PDXs), to identify potential therapeutic targets to enhance sensitivity to chemotherapy. Candidate hits were validated genetically and pharmacologically with in vitro synergy assays, in vivo clonal competition assays and pharmacologic assessments in PDX models. Signaling pathways were studied by RNA sequencing and western blot, and toxicity studies were performed in vivo to assess the safety of the agents at pharmacologically effective doses. We performed immunohistochemistry (IHC) to assess expression of candidate targets in tissue microarrays (TMAs). Our CRISPR screen revealed the nuclear exporter exportin 1 (encoded by the XPO1 gene) as a promising target sensitizing to chemotherapy, independently of the SCLC subtype. We found that XPO1 mRNA expression was higher in SCLC than in any other solid tumor or hematological malignancy, and demonstrated consistently high protein expression by IHC in clinical TMAs. A potent and selective exportin 1 inhibitor, selinexor, is approved for use in hematological malignancies. Combination of selinexor with cisplatin or irinotecan demonstrated synergy in vitro and efficacy in vivo in an array of chemonäive and chemoresistant SCLC PDXs, including all major SCLC subtypes. The combinations were well tolerated in mice. The chemo-sensitizing effects of selinexor were associated with suppression of chemotherapy-induced AKT activation. In conclusion, exportin 1 inhibition strongly enhances sensitivity of SCLC tumors to cisplatin and irinotecan, used in first line and second line treatment of SCLC tumors, respectively, and these effects are independent of the SCLC subtype. These results provide preclinical rationale for the combination of selinexor with cisplatin or irinotecan in naïve and relapsed SCLC. The clinical availability of selinexor will allow rapid clinical translation of these results in a disease setting with extremely limited therapeutic options. Citation Format: Alvaro Quintanal-Villalonga, Hirokazu Taniguchi, Yuan Hao, Andrew Chow, Yingqian A. Zhan, Fathema Uddin, Viola Allaj, Parvathy Manoj, Nisargbhai S. Shah, Umesh K. Bhanot, Juan Qiu, Elisa de Stanchina, Richard P. Koche, Triparna Sen, John T. Poirier, Charles M. Rudin. Exportin 1 inhibition as a therapeutic strategy for small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3594.

Purpose: Small cell lung cancer (SCLC) is a highly aggressive cancer with early primary resistance and modest clinical benefit to immune checkpoint blockade (ICB). Mutation or transcriptional repression of the major histocompatibility complex class I (MHC-I) is a key mechanism driving resistance to T cell-based therapies. Lysine Demethylase 1 (LSD1) regulates gene expression through modulating mono- and di- methylated lysine 4 and 9 of histone H3. LSD1 is a therapeutic target of interests in SCLC due to its oncogenic requirement for tumor growth, and there has been growing evidence pointing to LSD1 as a repressor of tumor-intrinsic immunogenicity. Here investigated the role of LSD1 as a transcriptional regulator of antigen presentation in SCLC. Method: To perturb LSD1 function, we employed the pharmacological inhibitor ORY-1001 and shRNA-mediated knockdown. We then assessed changes in MHC-I expression on SCLC cell lines by flow cytometry and western blot. To analyze transcriptional changes following LSD1 inhibition, we performed RNA-seq on SCLC cells pre- and post-treatment with ORY-1001. To observe for antigen-specific T cell killing, we engineered SCLC cells to express endogenous antigens and co-cultured these cells with primary cognate CD8+ T cells. Finally, we treated genetically engineered mouse model (GEMM)-derived tumors on immunocompetent syngeneic mice with ORY-1001 with or without anti-PD-L1 blockade to assess for anti-tumor effects. Results: We discovered a significant and strong negative correlation between expression of LSD1 and genes encoding the MHC-I antigen presentation pathway. Inhibition of LSD1 induces expression of MHC-I genes and restores expression of genes encoding the antigen presentation machinery. Perturbation of LSD1 further activates interferon signaling and interferon-inducible expression of NLRC5, a well-characterized transcriptional activator of MHC-I genes. We further showed that targeting LSD1 sensitizes SCLC cells to MHC-I-restricted T cell-dependent cytolysis and enhances ICB efficacy in refractory SCLC tumors. Conclusion: Our data define a role for LSD1 as a potent negative regulator of MHC-I-mediated antigen presentation and provide rationale for the use of LSD1 inhibitors to augment response to immunotherapy in SCLC. Citation Format: Minh N. Nguyen, Hirokazu Taniguchi, Andrew Chow, Yingqian A. Zhan, Triparna Sen, Charles M. Rudin. Targeting LSD1 rescues MHC-I antigen presentation in small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1370.

e20613 Background: Small cell lung cancer (SCLC) is an extremely aggressive disease comprising around 13% of lung cancer cases and responsible for approximately 250,000 deaths globally per year. A major cause of SCLC poor prognosis is the sparse treatment options available, typically resulting in only transient responses. The backbone of SCLC treatment over the past several decades has been platinum-based doublet chemotherapy, with the recent addition of immunotherapy to first-line chemotherapy showing only limited benefit in a small subset of patients. Major hurdles to improving SCLC treatment include development of rapid chemoresistance and ineffective second line therapies. The identification of more durably effective therapeutic strategies is a major unmet clinical need. Methods: We performed an in vitro CRISPR screen in SCLC cell lines to identify potential therapeutic targets to sensitize to chemotherapy, including short-term cultured cell lines derived from patient-derived xenografts (PDXs). Candidate hits were validated genetically and pharmacologically with in vitro and in vivo. Signaling pathways involved in phenotypes observed were studied by RNA sequencing and western blot, and toxicity studies were performed in vivo to assess the safety of the agents at pharmacologically effective doses. We performed immunohistochemistry (IHC) to assess expression of candidate targets in tissue microarrays (TMAs). Results: Our CRISPR screen revealed the nuclear exporter XPO1 (Exportin 1) as a promising target sensitizing to chemotherapy, independently of the SCLC subtype. Importantly, exportin 1 is a therapeutic target in hematological malignancies, counting with a potent and selective inhibitor, selinexor, approved for clinical use. Combination of selinexor with cisplatin or irinotecan demonstrated high synergy in vitro and exquisite efficacy i n vivo in an array of chemonäive and chemoresistant SCLC PDXs, respectively, including all major SCLC subtypes. These chemotherapy-sensitizing effects were associated with the ability of Exportin 1 to impair chemotherapy-induced AKT overactivation, potentially occurring as a cytoprotective/anti-apoptotic mechanism in response to chemotherapy. The combinations were well tolerated in mice. We found that XPO1 mRNA expression was higher in SCLC than in any other solid tumor type or hematological malignancies, which we were able to confirm at the protein level in clinical TMAs. Conclusions: Exportin 1 inhibition strongly enhances sensitivity of SCLC tumors to cisplatin and irinotecan, used in first line and second line treatment of SCLC tumors, respectively. These results provide preclinical rationale for the combination of selinexor with first line and second line chemotherapy in SCLC. The clinical availability of selinexor will allow immediate clinical translation of these results in a disease setting with extremely limited therapeutic options.

e21178 Background: ICIs are cornerstones of therapy for advanced NSCLC. Despite dramatic and sometimes durable responses to therapy, most patients (pts) either (i) do not respond to therapy (intrinsic resistance), or (ii) subsequently progress after initial clinical benefit (acquired resistance). Currently, insights into the molecular mechanisms of resistance to ICIs in NSCLC are lacking. Methods: To investigate clinical and molecular features of pts progressing on ICIs, we identified pts who underwent repeat tumor biopsies on and/or after disease progression on ICIs and were included in the Stand Up 2 Cancer (SU2C)/Mark Foundation multi-institutional cohort. Biopsy specimens underwent whole-exome sequencing (WES) and/or whole transcriptome sequencing (RNAseq). Results: We identified 37 pts who underwent a total of 47 repeat biopsies on or after ICIs. Six pts underwent multiple post-ICI biopsies (range 2-4). Twenty-five pts (68%) received PD-(L)1 inhibitor monotherapy, 6 (16%) received PD-(L)1 plus CTLA-4 inhibitors, and 6 (16%) received other PD-1 inhibitor-based combinations. Overall, the objective response rate was 46% among pts undergoing repeat biopsies (complete response 2 [5%], partial response 15 [41%], stable disease 14 [38%], progressive disease 5 [14%] and not evaluable 1 [3%]). Median progression-free survival (PFS) was 8.1 months. In total, pre-ICI biopsy specimens were available in 20 pts. WES and RNAseq were performed on 67 and 44 specimens, respectively. Median tumor mutation burden (TMB) in pre-ICI specimens was 5.0 mutations/Mb versus 4.9 mutations/Mb in post-ICI specimens ( p= 0.3, Mann-Whitney U test). Among 20 paired pre/post-ICI specimens, there was no significant difference in TMB (pre-treatment median 3.9 mutations/Mb; post-treatment median 4.3 mutations/Mb; p= 0.7, Wilcoxon signed-rank test). One pt with a complete response acquired a nonsense mutation in B2M, and one pt with a partial response acquired a nonsense mutation in JAK1. Among 10 paired pre/post-ICI specimens that underwent RNAseq, we observed significant decreases in granzyme B and perforin in post-ICI specimens ( p= 4×10-5 and p= 2×10-3, respectively, limma-voom analysis). Conclusions: Genomic alterations impairing antigen presentation (e.g., B2M) or immune activation (e.g., JAK1) may enable resistance to ICIs in a small subset of cases. However, the majority of repeat biopsies obtained from pts progressing on ICIs lacked clear genetic mediators of resistance, suggesting the presence of additional tumor-intrinsic and/or tumor-extrinsic factors underlying resistance to ICIs in NSCLC.

BACKGROUND The Leila Rose Foundation ("the Foundation") was established in April 2011, to address financial toxicity as well as the gaps in knowledge and support for families affected by a rare childhood cancer diagnosis in Australia. AIM The aim of this brief report is to analyze the diagnostic trends surrounding the rare cancer diagnoses for patients referred to the Foundation over the past decade and to present case studies evaluating the role of the Foundation's Family Support Coordinator in providing tailored, individualized support for families. METHODS Eligibility for family support is restricted to children ≤ 14 years of age at diagnosis with a cancer that has an incidence less than 5% of all childhood cancers in Australia as reflected by national registry data. The analysis of diagnostic trends in this report, was based upon a systematic review of enrolment records. The role of the Family Support Coordinator is presented in four different case studies. RESULTS As at 1 November 2020, the Foundation has supported 197 families affected by rare childhood cancer. Financial support of $825,000 has been provided directly to these families. Enrollment records demonstrate that 35 patients representing 18% of all enrollments have had a unique diagnosis that has not been recorded for any other enrolled patient highlighting that these diagnoses are very rare. The most frequent diagnoses have included Medulloblastoma, Ewing's Sarcoma and Wilm's Tumor (20, 19, 19 patients respectively). The Family Support Coordinator role has provided individualized support for families which has been greatly appreciated based upon ad hoc family feedback. CONCLUSIONS Challenges remain in terms of improving outcomes for families affected by rare childhood cancer. The Foundation is committed to leaving no stone unturned and delivering its unique support services to families in order to reduce the burden caused by a rare childhood cancer diagnosis both now and in the future.

Purpose of review To describe the key features and epidemiology of traumatic brain injury (TBI) and how they may be changing, with an emphasis on how this may affect care in the intensive care unit. Recent findings TBI has been traditionally perceived as occurring mainly in a younger, predominantly male population injured in high velocity motor vehicle crashes or assaults. However, there are an increasing number of patients over 65 years who have sustained a TBI secondary to low velocity falls. Considering the effects of frailty, comorbidities and extracranial injuries is important when making management decisions. Mild TBI comprises a third of those admitted and as a significant proportion may have poor outcomes secondary to their TBI they should be assessed to ensure appropriate follow-up. Multimodal monitoring may offer a way in the future to offer more personalised management to this very complex and heterogeneous patient group. Summary This review highlights the urgent need to develop more age-inclusive TBI consensus management guidelines aimed at improving short- and long-term outcomes for the large and growing TBI population. Being elderly does not necessarily portend a poor outcome, and more research is needed to better triage, guide management and prognosticate on these patients.

Summary Although mutations in DNA are the best-studied source of neoantigens that determine response to immune checkpoint blockade, alterations in RNA splicing within cancer cells could similarly result in neoepitope production. However, the endogenous antigenicity and clinical potential of such splicing-derived epitopes have not been tested. Here, we demonstrate that pharmacologic modulation of splicing via specific drug classes generates bona fide neoantigens and elicits anti-tumor immunity, augmenting checkpoint immunotherapy. Splicing modulation inhibited tumor growth and enhanced checkpoint blockade in a manner dependent on host T cells and peptides presented on tumor MHC class I. Splicing modulation induced stereotyped splicing changes across tumor types, altering the MHC I-bound immunopeptidome to yield splicing-derived neoepitopes that trigger an anti-tumor T cell response in vivo. These data definitively identify splicing modulation as an untapped source of immunogenic peptides and provide a means to enhance response to checkpoint blockade that is readily translatable to the clinic.

Lineage plasticity, a capacity to reprogram cell phenotypic identity under evolutionary pressure, is implicated in treatment resistance and metastasis in multiple cancers. In lung adenocarcinomas (LUADs) amenable to treatment with targeted inhibitors, transformation to an aggressive neuroendocrine (NE) carcinoma resembling small cell lung cancer (SCLC) is a recognized mechanism of acquired resistance. Defining molecular mechanisms of NE transformation in lung cancer has been limited by a paucity of well annotated pre- and post-transformation clinical samples. We hypothesized that mixed histology LUAD/SCLC tumors may capture cancer cells proximal to, and on either side of, histologic transformation. We performed detailed genomic, epigenomic, transcriptomic and proteomic characterization of combined LUAD/SCLC tumors as well as pre- and post-transformation clinical samples. Our data support that NE transformation is primarily driven by transcriptional reprogramming rather than mutational events. We identify genomic contexts in which NE transformation is favored, including frequent loss of the 3p chromosome arm in pre-transformation LUADs. Consistent shifts in gene expression programs in NE transformation include induction of several stem/progenitor cell regulatory pathways, including upregulation of PRC2 and WNT signaling, and suppression of Notch pathway activity. We observe induction of PI3K/AKT and an immunosuppressive phenotype in NE transformation. Taken together our findings define a novel landscape of potential drivers and therapeutic vulnerabilities of NE transformation in lung cancer.

Small cell lung cancer (SCLC) is an aggressive malignancy that includes subtypes defined by differential expression of ASCL1, NEUROD1, and POU2F3 (SCLC-A, -N, and -P, respectively), which are associated with distinct therapeutic vulnerabilities. To define the heterogeneity of tumors and their associated microenvironments across subtypes, we sequenced 54,523 cellular transcriptomes from 21 human biospecimens. Our single-cell SCLC atlas reveals tumor diversity exceeding lung adenocarcinoma, driven by canonical, intermediate, and admixed subtypes. We discovered a PLCG2-high tumor cell population with stem-like, pro-metastatic features that recurs across subtypes and predicts worse overall survival, and manipulation of PLCG2 expression in cells confirms correlation with key metastatic markers. Treatment and subtype are associated with substantial phenotypic changes in the SCLC immune microenvironment, with greater T-cell dysfunction in SCLC-N than SCLC-A. Moreover, the recurrent, PLCG2-high subclone is associated with exhausted CD8+ T-cells and a pro-fibrotic, immunosuppressive monocyte/macrophage population, suggesting possible tumor-immune coordination to promote metastasis.

Purpose Small cell lung cancer (SCLC) is an aggressive tumor with modest clinical response to immune checkpoint blockade (ICB). Repression of major histocompatibility class I (MHC-I) molecules represents a key mechanism driving ICB resistance in SCLC. Recent studies have kindled interests in the lysine-specific demethylase 1 (LSD1) as an immunomodulatory target. Our study investigated the potential functions of LSD1 in regulating MHC-I antigen presentation in SCLC. Method We employed the inhibitor ORY-1001 and RNA interference to assess changes in MHC-I expression in SCLC cell lines by flow cytometry. We then performed RNA-seq to characterize whole transcriptomic changes in SCLC cells following LSD1 inhibition. To explore effects of targeting LSD1 on T cell cytolysis, we co-cultured SCLCs engineered to present endogenous peptides with pre-activated cognate CD8+ T cells. Finally, we treated immunocompetent mice bearing syngeneic SCLC tumors with ORY-1001 and/or anti-PD-L1 to evaluate tumor growth and characterize intratumor immune activities. Result We first demonstrated that targeting LSD1 restores MHC-I cell surface expression, transcriptionally activates APP-regulatory genes, and activates tumor intrinsic immunity. We further show that LSD1 inhibition of SCLC cells enables for efficient MHC-I-restricted T cell-mediated cytolysis. Finally, the addition of LSD1 inhibitor to anti-PD-L1 therapy significantly augments intratumor CD8+ T cell infiltrates and sensitizes refractory SCLC model to ICB response. Conclusion Our data define a potent regulatory role of LSD1 in MHC-I antigen presentation and provide support for targeting LSD1 to overcome immune evasion in SCLC. Supported by NIH NCI R01 CA197936 (CMR); U24 CA213274 (CMR); the Druckenmiller Center for Lung Cancer Research (CMR, TS); NIH/NCI R01 CA258784 (TS); Congressionally Directed Medical Research Programs (DOD-IITRA) LC190161 (TS); Parker Institute for Cancer Immunotherapy grant (TS); LCFA-BMS/ILC Foundation Young Investigator Research Awards in Translational Immuno-oncology (TS); the Geoffrey Beene Foundation (EMN); The Yasuda Medical Foundation (HT); NIH K08 CA-248723 (AC); and the Van Andel Institute – Stand Up to Cancer Epigenetics Dream Team grant (CMR). Stand Up to Cancer is a division of the Entertainment Industry Foundation. Research grants are administered by the American Association for Cancer Research, the Scientific Partner of SU2C. We also acknowledge the use of the MSKCC Flow Cytometry Core Facility, the MSKCC Antitumor Assessment Core, and the Integrated Genomics Core, which are funded by MSKCC Support Grant/Core Grant (P30 CA008748).

Background CD4 and CD8 T cells are genetically and functionally distinct cell subsets of the adaptive immune system that play pivotal roles in immune surveillance and disease control. During development in the thymus, transcription factors ThPOK and Runx3 regulate the differentiation and maturation of these two lineages into single positive T cells that enter the periphery with mutually exclusive expression of either the CD4 or CD8 co-receptor.1–2 Despite our expectation that these two cell fates are fixed, mature CD4+CD8+ double positive (DP) T cells have been described in the context of numerous immunological responses, including cancer, but their molecular and functional properties and therapeutic relevance remain controversial and largely unknown.3–5 Methods Our lab has identified and characterized a heterogenous DP T cell population in murine and human melanoma tumors comprised of CD4 and CD8 T cells re-expressing the opposite co-receptor and a parallel uptake in the opposite cell type’s phenotype and function. Using CD4 (Trp1) and CD8 (Pmel) transgenic TCR T cells specific to B16 melanoma antigens gp75 and gp100 respectively, we demonstrate the re-expression of the opposite co-receptor following adoptive T cell transfer in B16 melanoma tumor bearing mice. Results Specifically, up to 50% of transferred CD4 Trp1 T cells will re-express CD8 to become a DP T cell in the tumor microenvironment. Further, these CD4 derived DP T cells upregulate CD8 lineage regulator Runx3 and cytolytic genes Gzmb, Gzmk, and Prf1 to become potent cytotoxic T cells. Alternatively, a subset of CD8 Pmel T cells differentiate into DP T cells characterized by the increased expression of CD4, ThPOK, and regulatory marker FoxP3 (figure 1). In addition, we utilized 10x single cell and ATAC sequencing to further characterize these divergent DP T cell populations among open repertoire T cells isolated from murine and human melanoma tumors. Conclusions Our findings highlight the capability of single positive T cells to differentiate in response to antigen and local stimuli into novel T cell subsets with polyfunctional characteristics. The resulting cell subsets will potentially affect the tumor microenvironment in distinct ways. Our studies may inform therapeutic approaches to identify antigen specific T cells as well as innovative signaling pathways to target when genetically engineering T cells to optimize cytotoxic function in the setting of adoptive cell therapy. Ethics Approval The human biospecimen analyses were approved by Memorial Sloan Kettering Cancer Center IRB #06-107 References Ellmeier W, Haust L & Tschismarov R. Transcriptional control of CD4 and CD8 coreceptor expression during T cell development. Cell Mol Life Sci 2013;70:4537–4553. Luckey MA, et al. The transcription factor ThPOK suppresses Runx3 and imposes CD4+ lineage fate by inducing the SOCS suppressors of cytokine signaling. Nature Immunology 2014; 15, 638–645. Bohner P, et al. Double positive CD4(+)CD8(+) T Cells are enriched in urological cancers and favor T Helper-2 polarization. Front Immunol 2019; 10, 622. Nascimbeni M, Shin E-C, Chiriboga L, Kleiner DE & Rehermann B. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions. Blood 2004;104:478–486. Nishida K, et al. Clinical importance of the expression of CD4+CD8+ T cells in renal cell carcinoma. Int Immunol 2020;32:347–357.

Human clinical samples pose a challenge for single-cell RNA-seq (scRNA-seq) and single-nucleus ATAC-seq (snATAC-seq) analysis, due to their heterogeneity in cell type composition and degree of degradation or necrosis. Moreover, although some tissues can be sampled by surgical resection, most biospecimens are derived from core needle biopsies or fine needle aspirates, and must be allocated to pressing needs such as pathological analysis, thereby severely limiting the number of cells available for analysis. We have developed a protocol for obtaining robust, high-quality single-cell sequencing data from human biospecimens from a variety of biopsy types, enabling greater access to clinical cohorts. A critical factor is to limit ischemic time and transport to the lab to under an hour, and to restrict subsequent processing time to under 3 hours. This protocol uses a commercial tissue disruptor for dissociation. It was optimized on diverse human lung tumor samples, including pleural effusions, but is widely applicable to normal and diseased human clinical tissues from different organ sites.

Background Long-term clinical registries are essential tools to evaluate new therapies in a patient population that differs from those in randomized clinical trials. The objectives are to describe the profile of rheumatoid arthritis (RA) patients treated with anti-TNF agents in Canadian routine care. Methods RA patients eligible for treatment with Infliximab (IFX), golimumab (GLM) or intravenous golimumab (GLM-IV) as per their respective Canadian product monographs were enrolled into the BioTRAC registry between 2002 and 2017. Study visits occurred at baseline and every 6 months thereafter. Effectiveness was assessed by changes in disease activity. Safety was evaluated by the incidence of adverse events (AEs) and drug survival. Results Of the 890 IFX-, 530 GLM- and 157 GLM-IV-treated patients, the proportion of females ranged from 77.0–86.6%, the mean ages from 55.8–57.7 and the mean disease duration from 6.5–8.6 years. A significant decrease in baseline disease duration and disease activity parameters (DAS, TJC, SJC, HAQ, AM stiffness, MDGA, PtGA, CRP, ESR) was observed over time. Treatment with IFX, GLM- and GLM-IV significantly improved all disease parameters over time. The incidence of AEs was 105, 113 and 82.6 /100 PYs and the incidence of SAEs was 11.7, 11.2 and 4.68 /100 PYs for IFX, GLM- and GLM-IV-treated patients, respectively. Conclusion Differences in baseline characteristics between patients treated with an anti-TNFs over time shows the evolution of treatment modalities over time. All treatments significantly reduced disease activity and improved functionality in a similar fashion. The incidence of adverse events was consistent with the safety profiles of IFX and GLM. Trial registration ClinicalTrials.gov Identifier: NCT00741793 (Retrospectively registered on August 26, 2008).

Diaphorina citri (Hemiptera: Liviidae) is an invasive citrus pest that colonizes young flush shoots and spreads huanglongbing, a lethal citrus disease. Effects of D. citri colony size (nymphs per shoot) and instar composition on parasitism rates by the nymphal ectoparasitoid, Tamarixia radiata (Hymenoptera: Eulophidae), were evaluated on residential citrus in South Texas. From 2016 to 17, D. citri colony sizes and apparent parasitism (T. radiata adult emergence) were monitored monthly on grapefruit, lemon, lime, and orange trees at 12 residential sites. In 2019, size and instar composition of colonies and actual parasitism (mummies and nymphs with parasitoid larvae or eggs) were monitored biweekly on citrus trees at a residential park. Psyllid nymphs were found year-round at these sites with highest densities from late summer to fall and lowest densities in winter. Mean apparent parasitism was independent of citrus species and ranged from 23% in April 2016 to 4% in February 2017. Mean actual parasitism ranged from 1.5% in August to 33.4% in November 2019. Because actual parasitism of 3rd or younger instars was very rare, a ‘host patch’ was defined as the cluster(s) of 4th to 5th instars within a colony infesting a shoot. Based on apparent or actual parasitism, host density was positively related to discovery of D. citri colonies but inversely related to percent parasitism by T. radiata. The inability of T. radiata to achieve high rates of field parasitism under a wide range of host densities could explain, in part, its low impact against D. citri on residential citrus.

BackgroundTargeted immune-based therapies such as adoptive T cell transfer (ACT) are often ineffective because tumors evolve over time and under selective pressure display antigen loss variant clones. A classic example in melanoma is de-differentiation and loss of expression of antigenic proteins. Therapies that activate multiple branches of the immune system may eliminate such escape variantsMethodsHere we show that melanoma-specific CD4+ ACT therapy in combination with OX40 co-stimulation or CTLA-4 blockade can eradicate large melanoma tumors with clonal escape variants.ResultsEarly on-target recognition of melanoma antigens by adoptively transferred tumor-specific CD4+ T cells was required. Surprisingly, however, complete tumor eradication was partially dependent on neutrophils. Supporting these findings, extensive neutrophil activation and neutrophil extracellular traps were found in mouse tumors and in biopsies of melanoma patients treated with immune checkpoint blockade.ConclusionsOur findings uncover a novel interplay between T cells mediating the initial tumor- and tissue-specific immune response, and neutrophils mediating tumor destruction of antigen loss variants.Ethics ApprovalAll tissues were collected at MSKCC following study protocol approval by the MSKCC Institutional Review Board. All mouse procedures were performed in accordance with institutional protocol guidelines at Memorial Sloan-Kettering Cancer Center (MSKCC) under an approved protocol.

To describe the characteristics of patients receiving belimumab, overall patterns of systemic lupus erythematosus (SLE) care, clinical outcomes, and changes in glucocorticoid dose following 6 months of therapy with belimumab, and healthcare resource utilization in belimumab users in Canadian clinical practice settings. Retrospective multicenter medical chart review study of adult patients with SLE who were prescribed belimumab as part of usual care and who received ≥8 infusions or 6 months of treatment. Primary endpoints included physician-determined overall clinical improvement from baseline, glucocorticoid use, and physician-determined SLE disease severity at Month 6. In total, 52 patients were included in the study. At belimumab initiation, 5.8/76.9/17.3% of patients had mild/moderate/severe SLE, respectively. Oral glucocorticoids were discontinued in 11.4% of patients and 59.1% received a lower dose at Month 6. At Month 6, 80.8/57.7/17.3% of patients had a physician-determined clinical improvement of ≥20/≥50/≥80%, respectively. Sixteen patients had a SLE Disease Activity Index-2K score at both baseline and Month 6, with a mean improvement of 2.6 ± 5.3 from 8.1 ± 3.2 at baseline. No formal disease assessment tool was utilized for 42.3% of study patients at baseline. This study provides the first real-world insights into belimumab use in Canada. It demonstrates significant reduction or discontinuation of glucocorticoid dose in 70.5% of patients and clinically significant improvement following 6 months' belimumab therapy. The high number of patients with no formal disease activity assessments highlights a key care gap in SLE treatment in the real-world setting.

Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB; Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case–fatality ratio happened in 2005 in Angola, where direct spillover from bats was not shown. Here, collaborative studies by the Centers for Disease Control and Prevention, Njala University, University of California, Davis USAID-PREDICT, and the University of Makeni identify MARV circulating in ERBs in Sierra Leone. PCR, antibody and virus isolation data from 1755 bats of 42 species shows active MARV infection in approximately 2.5% of ERBs. Phylogenetic analysis identifies MARVs that are similar to the Angola strain. These results provide evidence of MARV circulation in West Africa and demonstrate the value of pathogen surveillance to identify previously undetected threats., Egyptian rousette bats (ERBs) are natural reservoirs for Marburg virus (MARV), but these bats have not been linked to the MARV Angola strain that caused the largest and deadliest outbreak on record. Here, Amman et al., in a multi-institutional surveillance effort, identify and isolate Angola-like MARV in ERBs in West Africa.

Background Long-term registries are essential to evaluate new therapies in a patient population that differs from clinical trials and usually varies over time. Objectives To describe the profile of psoriatic arthritis (PsA) patients selected for treatment with infliximab (IFX), golimumab (GLM) or ustekinumab (UST) treatment in Canadian routine care and to describe the long-term real-world effectiveness and safety of these agents. Methods 462 PsA patients treated with IFX, GLM or UST were enrolled into the Biologic Treatment Registry Across Canada (BioTRAC) registry between 2006-2015, 2010-2017 and 2014-2017, respectively. Study visits occurred at baseline and every 6 months thereafter. Effectiveness was assessed with changes in TJC28, SJC28, skin, enthesitis, dactylitis, pain, HAQ, acute phase reactants. Safety was evaluated with the incidence of adverse events (AEs) and drug survival rates. Results Of the 111 IFX-, 281 GLM- and 70 UST-treated patients, the proportion of males were 52.3%, 46.3% and 37.1%, the mean age was 48.4, 52.8 and 53.1 years and the mean disease duration was 5.8, 6.1 and 5.7 years, respectively. Most patients were bio-naive (85.6%, 77.9% and 55.7% for IFX, GLM and UST, respectively (p Treatment with IFX, GLM and UST was associated with significant improvements in all disease parameters over time (P AEs were reported for 74.8%, 69.8% and 52.9% (138, 114 and 115 events/100 PYs) and SAEs for 19.8%, 8.5% and 5.7% (8.8, 19.6 and 28.6 events/100 PYs) covering 325, 567 and 87 years of exposure for IFX-, GLM- and UST-treated patients, respectively. One, one and no death occurred IFX-, GLM- and UST-treated patients, respectively. The proportion of patients who discontinued treatment were 63.1%, 50.9% and 50.0% over a mean exposure of 2.9, 1.9 and 1.2 years to IFX, GLM and UST, respectively. Conclusion Differences in baseline characteristics between patients treated with an anti-TNF over an anti-IL12/23 agent suggest that the level of joint to skin involvement might be driving physician choice when the time comes to choose a biologic agent. IFX, GLM and UST treatment significantly reduced disease activity and improved functionality in a similar fashion and were well tolerated in patients with PsA. Disclosure of Interests Proton Rahman: None declared, Regan Arendse Grant/research support from: Janssen Sponsored Study, Isabelle Fortin Grant/research support from: ABBVIE, AMGEN, ASTRAZENECA, BMS, CELGENE, GSK, JANSSEN, PFIZER, SANOFI, UCB, Consultant for: LILLY, NOVARTIS, SANOFI, Speakers bureau: NOVARTIS, PFIZER, Andrew Chow Grant/research support from: Abbvie, Celgene, EliLilly, GSK, Janssen, Novartis, Pfizer, UCB, Consultant for: Abbvie, BMS, Celgene, EliLilly, GSK, Janssen, Novartis, Pfizer, Roche,UCB, Speakers bureau: Abbvie, BMS, EliLilly, Janssen, Novartis, Pfizer, Majed Khraishi Grant/research support from: Novartis, Consultant for: Amgen, Celgene, Gebro, Janssen, Novartis, Pfizer, Lilly, Merck, Suneil Kapur Grant/research support from: Abbvie, Merck, Janssen, Novartis, Eli Lilly, Amgen, Michel Zummer: None declared, Jon Chan Grant/research support from: Janssen, UCB, Novartis, Pfizer, Celgene, Consultant for: Amgen, Celgene, Eli Lilly, Janssen, Amgen, Abbvie, Novartis, Pfizer, UCB, Sandoz, Merck, Larissa Lisnevskaia Grant/research support from: Janssen Sponsored Study, Raheem Kherani Grant/research support from: Janssen, BMS, Abbvie, Consultant for: Abbvie, Amgen, BMS, Janssen, Lilly, Merck, Pfizer, Roche, Speakers bureau: Jannsen, BMS, Emmanouil Rampakakis : None declared, Odalis Asin MIilan Employee of: Employee of Janssen, Allen Lehman Employee of: Employee of Janssen, Meagan Rachich Shareholder of: Janssen, Employee of: Employee of Janssen, Francois Nantel Shareholder of: Janssen, Employee of: Employee of Janssen

Background Treatment selection in routine clinical care is driven by treatment guidelines, physician judgment, patient preferences, and regional reimbursement policies, which may vary over time and among geographic regions. Objectives The objective of this analysis is to investigate the regional and temporal variability of the profile of anti-TNF naive psoriatic arthritis (PsA) patients at initiation of adalimumab (ADA) treatment following failure of initial non-biologic treatment. Methods COMPLETE-PsA is an ongoing Canadian observational study of anti-TNFα naive adults with active PsA who require change in their current treatment as per the judgement of their treating physician. Patients are followed for up to 2 years. Regional variation was assessed for the following regions: British Columbia/Manitoba (BC/MB), Newfoundland/Nova Scotia (NL/NS), ontario (ON), and Quebec (QC). Temporal variation was assessed for the following periods: 2012-2014 and 2015-2017. Multivariate linear regression was used to evaluate the independent impact of region and time period on disease activity (DAS28) and patient function (HAQ). Results A total of 278 patients were included, of whom 68 (24.5%) were from BC/MB, 25 (9%) from NL/NS, 104 (37.4%) from on, and 81 (29.1%) from QC. One hundred fifty-three patients (55%) were enrolled in 2012-2014 and 125 (45%) in 2015-2017. Using univariate analysis, significant regional variation at aDA initiation was observed for the following disease parameters: BSA Conclusion The results of this analysis demonstrate that there is significant regional and temporal variation in the profile of PsA patients initiated on aDA treatment in Canadian routine care. The impact of this profile variation on treatment outcomes requires further investigation. Acknowledgement The authors wish to acknowledge JSS Medical Research, Montreal (QC) Canada for statistical analysis, medical writing and editorial assistance during the preparation of this abstract, and Nathalie Ross, PhD, for editorial assistance. AbbVie provided funding to JSS Medical Research and Nathalie Ross for this work. Disclosure of interests Majed Khraishi Consultant for: abbVie, Speakers bureau: abbVie, Louis Bessette Grant/research support from: amgen, BMS, Janssen, Roche, UCB, abbVie, Pfizer, Merck, Celgene, Sanofi, Lilly, Novartis, Consultant for: amgen, BMS, Janssen, Roche, UCB, abbVie, Pfizer, Merck, Celgene, Sanofi, Lilly, Novartis, Speakers bureau: amgen, BMS, Janssen, Roche, UCB, abbVie, Pfizer, Merck, Celgene, Sanofi, Lilly, Novartis, Samuel Silverberg Consultant for: abbVie, Janssen, Boulos Haraoui Consultant for: abbVie, amgen, Eli Lilly, Merck, Pfizer, Sandoz, UCB, BMS, Janssen, Pfizer, Speakers bureau: amgen, Pfizer, and UCB, andrew Chow Consultant for: abbVie, amgen, BMS, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Speakers bureau: abbVie, BMS, Janssen, Pfizer, Takeda, Yatish Setty Consultant for: abbVie, Valencia P. Remple Shareholder of: abbVie, Employee of: abbVie

An ‘attract-and-kill’ (AK) device was evaluated for suppression of adult Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), on residential citrus. The AK device, made from weather-resistant plasticized PVC, lured D. citri adults by simulating the color of citrus flush and killed them with beta-cyfluthrin. This study evaluated: 1) lethality of AK devices weathered up to 8 wk on residential citrus; 2) survival of psyllids caged with potted plants and AK devices; 3) psyllid suppression achieved by AK devices on individual dooryard trees. AK devices weathered for up to 8 wk remained lethal to psyllids. Greenhouse trials evaluated survival of adult psyllids caged for 4 d with orange jasmine plants that were: 1) treated with an (beta-cyfluthrin-infused) AK device; 2) treated with a blank (no insecticide) AK device; or 3) ‘untreated’ with no AK device. After 4 d, psyllid survival was on average 95% lower among adults exposed to plants with AK devices than adults exposed to untreated plants or plants with blank AK devices. Less than half of the adults exposed to plants with AK devices were alive after 1 d and nearly all were dead after 4 d. Deployment of 20 AK devices per tree provided significant psyllid suppression on infested lemon trees from winter to summer and reduced mean reproduction (cumulative eggs) by 91% and mean attack intensity (cumulative psyllid-days) of adults by 59% and nymphs by 53%. AK devices could be an effective control option for D. citri in urban areas.

8509 Background: Small cell lung cancer (SCLC) is an aggressive malignancy that includes subtypes defined by differential expression of ASCL1, NEUROD1, and POU2F3 (SCLC-A, -N, and -P, respectively), which are associated with distinct therapeutic vulnerabilities. The emerging consensus on SCLC subtypes has led to new questions, such as whether subtypes are associated with different disease stages, metastatic potential, or immune microenvironments; whether there is plasticity between subtypes; and whether novel SCLC phenotypes exist. Single cell RNA sequencing (scRNA-seq) offers a unique opportunity to address these questions by dissecting intratumoral transcriptional heterogeneity and the surrounding tumor microenvironment (TME). However, efforts to apply this technology to human SCLC tumors have been limited, as these tumors are infrequently resected. Methods: We have optimized protocols to process both surgical resections and biopsies to construct the first single-cell atlas of SCLC patient tumors (N = 21), with comparative lung adenocarcinoma (LUAD) and normal lung data. We leverage computational methods including diffusion maps and non-negative matrix factorization to perform a deep annotation of SCLC phenotypes and the surrounding immune TME. We perform validation experiments using flow cytometry, Vectra, and immunohistochemistry in independent SCLC cohorts, as well as genetic manipulation in preclinical SCLC models. Results: Our data reveals substantial transcriptional heterogeneity in SCLC both within and across tumors and confirms a pro-metastatic gene program in SCLC-N subtype characterized by epithelial-mesenchymal transformation and axonogenesis. Beyond known subtypes, we discover a PLCG2-high tumor cell population with stem-like, pro-metastatic features that recurs across subtypes and predicts significantly worse overall survival. Manipulation of PLCG2 expression in cells confirms correlation with key metastatic markers. Treatment and subtype are associated with substantial phenotypic changes in the SCLC immune microenvironment, with greater T-cell dysfunction in SCLC-N than SCLC-A. Moreover, the recurrent, PLCG2-high subclone is associated with exhausted CD8+ T-cells and a pro-fibrotic, immunosuppressive monocyte/macrophage population, suggesting possible tumor-immune coordination to promote metastasis. Conclusions: This atlas of SCLC illustrates how canonical subtypes and a novel PLCG2-high recurrent tumor subclone enlist diverse gene programs to create tumor heterogeneity and facilitate metastasis in a profoundly immunosuppressed TME. Our dataset provides further insight into tumor and immune biology in SCLC at single-cell resolution, with potential implications for design of novel targeted therapies and immunotherapeutic approaches.

Background:COMPLETE-AS was an observational study among Canadian biologic-naïve adults with active ankylosing spondylitis (AS) treated with either adalimumab or subsequent non-biologic disease-modifying anti-rheumatic drugs and/or non-steroidal anti-inflammatory drugs (nbDMARD/NSAID) after having switched from initial treatment with a preceding nbDMARD and/or NSAID due to lack of response or intolerance, as per treating physician judgement.Objectives:To assess the impact of adalimumab on disease activity and patient-reported outcomes among adalimumab- vs. nbDMARD/NSAID-treated patients over 24 months.Methods:Patients were enrolled between July 2011 and December 2017 and followed for up to 24 months. Treatment was per routine care and all analyses were perfomed using the intent-to-treat (ITT) approach. Between-group differences for change in patient-reported disease activity (BASDAI), morning stiffness (minutes/day), functional limitation (BASFI), quality of life (QoL: SF-12), depression (BDI-II), and work productivity (WLQ) were assessed with repeated measures models for overall treatment effect; baseline-adjusted estimates (least square means [LSM]) for each visit were produced. Achievement of, and time to the following endpoints were assessed: 50% improvement from baseline in BASDAI (BASDAI50); minimum clinically important improvements (MCIIs) in BASDAI (Δ≥1.1); BASFI (Δ≥0.6); SF-12 physical component score (PCS; Δ≥4.4) and mental component score (MCS; Δ≥3.1); and low disease activity for BASDAI (Results:A total of 452 adalimumab-treated patients and 187 nbDMARD/NSAID-treated patients were enrolled in the study and included in the analyses. At baseline, mean (SD) BASDAI [6.4 (1.8) vs. 5.0 (1.8); pOver 24 months, adalimumab-treated patients had significantly lower overall BASDAI scores compared to nbDMARD/NSAID-treated patients [estimate (95% CI): -0.7 (-1.2, -0.3); p=0.007]. BASFI scores were also significantly lower among adalimumab-treated patients over the course of the study [estimate (95% CI): -0.4 (-0.8, 0.0); p=0.013]. Both groups had statistically comparable outcomes for morning stiffness, BDI-II, WLQ, and SF-12.Adalimumab-treated patients were also at significantly higher odds of achieving therapeutic response thresholds, including BASDAI50 [OR (95% CI): 1.7 (1.2-2.3)], BASDAIAt month 24, baseline-adjusted BASDAI and BASFI was comparable (p>0.05): LSM (95%CI) 3.5 (3.3, 3.8) vs. 3.6 (3.2-4.0), and 2.9 (2.6-3.1) vs. 3.3 (2.9-3.7), respectively, for adalimumab-treated vs. nbDMARD/NSAID-treated patients.Conclusion:Among Canadian patients with active AS, adalimumab-treated patients reported a greater overall reduction in disease burden related to both self-reported disease activity and functional capacity compared to nbDMARD/NSAID-treated patients, along with higher odds and shorter time to achieving therapeutic response thresholds. Despite the overall beneficial effects observed with adalimumab, residual disease burden, however, is observed for Canadian AS patients even after 24 months of treatment.Acknowledgements:The authors wish to acknowledge JSS Medical Research for their contribution to the statistical analysis, medical writing, and editorial support during the preparation of this abstract. AbbVie provided funding to JSS Medical Research for this work.Disclosure of Interests:Louis Bessette Speakers bureau: Speaker for Amgen, BMS, Janssen, UCB, AbbVie, Pfizer, Merck, Celgene, Lilly, Novartis, Gilead, Sandoz, Fresenius Kabi, Consultant of: Consultant for Amgen, BMS, Janssen, UCB, AbbVie, Pfizer, Celgene, Lilly, Novartis, Gilead, Sandoz, Samsung Bioepis, Fresenius Kabi, Grant/research support from: Investigator for Amgen, BMS, Janssen, UCB, AbbVie, Pfizer, Merck, Celgene, Sanofi, Lilly, Novartis, Gilead, Andrew Chow Speakers bureau: Speaker for AbbVie, BMS, Janssen, Pfizer, Consultant of: Consultant for AbbVie, Amgen, BMS, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Grant/research support from: Investigator for AbbVie, Amgen, BMS, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Viktoria Pavlova Speakers bureau: Speaker for Amgen, Abbvie, BMS, Jenssen, Lilly, Merk, Novartis, Roche, UCB, and Pfizer, Consultant of: Consultant for Amgen, Abbvie, BMS, Jenssen, Lilly, Merk, Novartis, Roche, UCB, and Pfizer, Grant/research support from: Investigator for Janssen, UCB, Abbvie, and Pfizer; and received research grants from UCB, Marie-Claude Laliberté Employee of: Employee of AbbVie, Majed Khraishi Speakers bureau: Speaker for AbbVie, Consultant of: Consultant for AbbVie, Grant/research support from: Principal Investigator for AbbVie

Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata, if both natural enemies are simultaneously deployed for biological control of D. citri However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri.

Background: The aim of this study was to assess the real-world effectiveness and safety of certolizumab pegol (CZP) in rheumatoid arthritis (RA) patients, and the impact on patients’ productivity, pain, and fatigue, in Canadian practice. Methods: FαsT-CAN, a 2-year prospective, observational study, evaluated CZP use in Canadian adults with moderate to severe, active RA. The primary objective was to assess the proportion of patients achieving 28-joint Disease Activity Scores (DAS28) Results: The full analysis set (baseline DAS28 ⩾ 2.6, ⩾1 dose of CZP and ⩾1 valid post-baseline DAS28 measurement) included 451 of the 546 patients recruited into the study; a total of 229/451 (50.8%) patients completed Week 104. At Week 104, 90/451 (20.0%) patients achieved DAS28 < 2.6. Rapid improvements in disease activity, pain, and fatigue were observed. At Week 104, 66.2% of patients achieved HAQ-DI MCID. Patients employed at Week 104, reported reduced absenteeism, and improved productivity. CZP-related TEAEs were consistent with the known CZP safety profile. Conclusions: CZP was an effective RA treatment in Canadian practice, and no new CZP-related safety signals were identified. The improvements in household and workplace productivity are the first observations in a real-world Canadian setting.

Background To date, observational studies comparing the effectiveness of adalimumab (ADA) to non-biologic DMARDs (nbDMARD) in psoriatic arthritis (PsA) patients failing prior treatment are scarce. COMPLETE-PSA is a Canadian post-marketing observational study which assessed real-life effectiveness of ADA and non-biological therapies (NSAIDs and DMARDs) in PsA management following initial treatment failure. Objectives This analysis aimed to describe the baseline demographic and disease parameters of patients initiating nbDMARD or ADA and compare the 12 month real-life effectiveness of both treatments. Methods Patients eligible for COMPLETE PsA are anti-TNFα naive adults, with active PsA who require change in their treatment regimen, per the judgment of the treating physician. In the current analysis patients enrolled during Jul/2011–Jun/2016 were included. Outcome measures analysed were: DAS28, SF-12, DLQI, presence of extra-articular manifestations (EAMs; enthesitis and dactylitis), psoriasis BSA, achievement of modified MDA (defined as achievement of [i] 4 of 6 (MDA 1) and [ii] 5 of the following 6 criteria (MDA 2): TJC ≤1, SJC ≤1, BSA ≤3%, pain VAS≤15 mm, PtGA ≤20 and HAQ ≤0.5), modified remission (defined as SJC=0, TJC=0, absence of enthesitis and dactylitis, BSA ≤3% and HAQ ≤0.5), DAPSA LDA (≤14), and DAPSA remission (REM;≤4). Analyses were conducted by initial group assignment (intent-to-treat approach). Results 406 patients were included (nbDMARD n=146, ADA n=260). Baseline demographics were comparable between treatment groups. However, patients initiating ADA were more likely to be unemployed (47.3% ADA vs 34.9% nbDMARD, p=0.015), had higher DAS28 (4.8 vs 4.4, p=0.002) and total DLQI score (6.1 vs 4.3, p=0.007), and were more likely to have BSA ≥3% (44.6% vs 35.0%, p=0.063) and high DAPSA disease activity (50.8% vs 32.3%, p=0.015). A higher proportion of nbDMARD patients had dactylitis (36.1% vs 25.3%, p=0.023). No differences were observed between groups in enthesitis, overall EAMs, or QoL at baseline. Upon 12 months of treatment, mean adjusted DAS28 (2.6 vs 3.4, p Over time, 9.6% of ADA patients initiated another biologic and 32.2% of patients in the nbDMARD group initiated biologic treatment (p Conclusions PsA patients initiating ADA in Canadian routine clinical care have significantly greater baseline disease severity compared with those initiating nbDMARDs. However, 12 month ADA treatment improved disease control and EAMs. DAPSA-REM evaluation seems more sensitive than mMDA in differentiating both populations. Acknowledgements JSS Medical Research, Montreal, Canada Disclosure of Interest M. Khraishi Consultant for: AbbVie, Speakers bureau: AbbVie, L. Bessette Consultant for: Amgen, BMS, Janssen, Roche, UCB, AbbVie, Pfizer, Celgene, Lilly, Novartis, Speakers bureau: Amgen, BMS, Janssen, Roche, UCB, AbbVie, Pfizer, Merck, Celgene, Lilly, Novartis, A. Chow Consultant for: AbbVie, Amgen, BMS, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Speakers bureau: AbbVie, BMS, Janssen, Pfizer, Takeda, B. Haraoui Grant/research support from: AbbVie, Amgen, BMS, Janssen, Pfizer, Roche, and UCB, Consultant for: AbbVie, Amgen, BMS, Celgene, Eli Lilly, Janssen, Merck, Pfizer, Roche, and UCB, Speakers bureau: Amgen, BMS, Janssen, Pfizer, and UCB, V. Pavlova Consultant for: Amgen, Abbvie, BMS, Janssen, Lilly, Merk, Novartis, Roche, UCB, Pfizer, Speakers bureau: Amgen, Abbvie, BMS, Janssen, Lilly, Merk, Novartis, Roche, UCB, Pfizer, J. Stewart Consultant for: Pfizer, Abbvie, Amgen, Celgene, Roche, Novartis, V. Remple Shareholder of: AbbVie, Employee of: AbbVie

Background The Biologic Trial Registry Across Canada (BioTRAC) was a multi-centre, prospective, longitudinal, observational program that gathered and analysed data on inflammatory arthritis patients treated with infliximab (IFX), golimumab and ustekinumab. Patients specifically treated with IFX were recruited from July 2002 to June 2015 and followed up to June 2017. Objectives The objective of this abstract is to document the final consolidated safety data from the BioTRAC IFX cohort. Methods Treatment was prescribed by the physician per actual clinical practice or standard of care for rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA); there was no randomised assignments to treatment. There were no restrictions on the use of concomitant medications. At enrolment (baseline) and approximately every 6 months thereafter, information was collected to assess safety, clinical outcomes, quality of life, comorbidities, pharmaco-economics and treatment regimens. Results A total of 1390 patients were enrolled and used for this analysis. The proportion of patients by indication was 59.2% for RA (n=890), 25.9% for AS (n=389) and 7.4% for PsA (n=111). The mean (SD) exposure was 3.10 (3.26) years for a sum of 4290.25 patient-years. Treatment with IFX was generally safe, with AEs and SAEs being reported for 64.3% and 19.5% of patients, respectively. The incidence rate of AEs and SAEs was 116.0 and 11.2 events per 100 pt-years, respectively. More specifically, 338 SAEs were reported by 189 (21.2%) RA patients [SAEs/100 pt-yrs: 11.7], 130 SAEs were reported by 60 (15.4%) AS patients [SAEs/100 pt-yrs: 10.5] and 28 SAEs were reported by 22 (19.8%) PsA patients [SAEs/100 pt-yrs: 8.82]. The most commonly reported AE identified was arthralgia, viral upper respiratory tract infection, upper respiratory tract infection and nausea. For SAEs, the most commonly reported SOC (≥3% of patients) was “Infections and infestations” [5.3% (n=73); 2.16 SAEs/100 pt-yrs] and “Neoplasms benign, malignant and unspecified” [3.5% (n=49); 1.24 SAEs/100 pt-yrs] which occurred at similar rates to the general RA patient population1 and included two lymphomas [0.1%; 0.05/100 pt-yrs]. Across 3 closely monitored categories of AEs, a total of 302 closely monitored AEs were reported by 293 (21.1%) patients, including cancer (3.7%), lack of efficacy (17.1%) and tuberculosis (0.2%). A total of 21 deaths were reported during the study in 18 RA, 1 AS and 2 PsA patients. Cause of death included MACE (x5), lung cancer (x2), pulmonary fibrosis (x2), pneumonia (x2), respiratory failure, bronchitis, intestinal cancer, throat cancer, intestinal gangrene, disseminated TB, septic shock, procedural complication and drowning. The cause of death was not known for one patient. Conclusions The results of this longitudinal observational study showed that treatment with IFX was well tolerated in people living with AS, PsA and RA over a 15 year period in a real-world setting. Reference [1] Askling, et al. Arthritis & Rheum2009;60:3180–9. Disclosure of Interest D. Choquette Grant/research support from: Janssen Inc., P. Rahman Grant/research support from: Janssen Inc., Consultant for: Janssen Inc., Speakers bureau: Janssen Inc., A. Chow: None declared, R. Faraawi Consultant for: Janssen Inc., Speakers bureau: Janssen Inc., W. Olszynski Consultant for: Janssen Inc., E. Rampakakis: None declared, O. Asin-Milan Employee of: Janssen Inc., B. Osborne Employee of: Janssen Inc., A. Lehman Employee of: Janssen Inc., F. Nantel Shareholder of: Johnson and Johnson, Employee of: Janssen Inc.

Background COMPLETE-AS is an ongoing Canadian observational study of anti-TNFα naive adults with active AS per the judgment of the treating physician, who require change in current AS treatment to either 1 a subsequent NSAID or non-biologic disease modifying antirheumatic drug (nbDMARD group), or 2 to adalimumab (ADA group). Objectives The aim of this analysis was to describe and compare the baseline demographic and disease parameters of patients in the nbDMARD and ADA groups and to compare the 12 month effectiveness of the two treatment methods. Methods In the current analysis patients enrolled between July/2011 – Jun/2016 were included. Outcome measures analysed were extra articular manifestations (EAM 1: IBD, psoriasis, uveitis, enthesitis; EAM 2: IBD, uveitis, enthesitis), disease activity (BASDAI), functional status (BASFI), and quality of life (QoL; SF-12). Between-group differences in baseline parameters were assessed with the Chi-square test for categorical variables and the independent samples t-test for continuous variables. Baseline-adjusted changes in BASDAI and BASFI over time were compared between the two groups using linear mixed models. Results A total of 609 patients (nbDMARD n=177, ADA n=432) were included in the current analysis. No significant differences in baseline demographics were observed between the two groups. However, at baseline, patients initiating ADA were more likely to be unemployed (38% ADA vs. 27.1% nbDMARD, p = 0.009), had higher mean BASDAI (6.4 vs. 5.0; p After 12 months of treatment the prevalence of EAMs decreased significantly in the ADA group (EAM 1: p=0.004; EAM 2: p=0.033) but not in the nbDMARD group. After adjusting for baseline values, patients treated with ADA had numerically lower BASDAI score (least square means – LSM: 3.7 vs. 4.3, p=0.171) significantly lower BASFI score (2.9 vs. 3.6, p=0.031) scores, and comparable SF12-PCS (24.9 vs. 24.7, p=0.210) and SF12-MCS (19.1 vs. 18.9, p=0.532) scores at 12 months. During follow-up, 7.4% of ADA patients initiated another biologic and 23.7% of patients in the nbDMARD group initiated biologic treatment (p Conclusions AS patients initiating ADA in Canadian routine clinical care have significantly greater disease severity and impaired quality of life at baseline compared with those initiating non-biologic treatment. Treatment with ADA for 12 months resulted in greater reduction in the prevalence of EAMs and a greater reduction in disease severity scores compared to treatment with non-biologic agents. Acknowledgements JSS Medical Research, Montreal, Canada Disclosure of Interest L. Bessette Consultant for: Amgen, BMS, Janssen, Roche, UCB, AbbVie, Pfizer, Celgene, Lilly, Novartis, Speakers bureau: Amgen, BMS, Janssen, Roche, UCB, AbbVie, Pfizer, Merck, Celgene, Lilly, Novartis, M. Khraishi Consultant for: AbbVie, Speakers bureau: AbbVie, A. Chow Consultant for: AbbVie, Amgen, BMS, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Speakers bureau: AbbVie, BMS, Janssen, Pfizer, Takeda, V. Pavlova Grant/research support from: UCB, Consultant for: Amgen, Abbvie, BMS, Janssen, Lilly, Merk, Novartis, Roche, UCB, Pfizer, Speakers bureau: Amgen, Abbvie, BMS, Janssen, Lilly, Merk, Novartis, Roche, UCB, Pfizer, S. Silverberg Consultant for: AbbVie, Janssen, J. Stewart Consultant for: Pfizer, Abbvie, Amgen, Celgene, Roche, Novartis, V. Remple Shareholder of: AbbVie, Employee of: AbbVie

Autodissemination and foliar sprays of PFR-97 (Certis Inc., Columbia, MD) microbial insecticide, a blastospore formulation of Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), were evaluated for control of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), on residential citrus. Seasonal trials on dooryard trees in South Texas evaluated: 1) pathogenicity of I. fumosorosea (Ifr) spores on autodisseminators (dispensers) deployed up to 3 wk on grapefruit trees; 2) psyllid control on several citrus species by dispensers and sprays; 3) infection range of the dispenser. Decline in spore pathogenicity over time was similar among dispensers during fall, winter, or spring and decreased by 30% after 1 d, 59% after 7 d, 81% after 14 d, and 100% after 21 d. Dispensers or sprays were equally effective for psyllid control on heavily infested lime trees from fall to spring and reduced mean reproduction (cumulative eggs) by 90% and mean attack intensity (cumulative psyllid-days) of adults by 76% and nymphs by 82%. Dispensers or sprays were also equally effective for psyllid control on lightly infested lime trees from spring to mid-summer and on orange or grapefruit trees from fall to winter. Very light infestations on grapefruit trees from spring to mid-summer were not significantly reduced by dispensers or sprays. Psyllid control was not improved by combining dispensers and sprays. Adult psyllids infected by Ifr were recovered in trees located 3-4 m away from trees with dispensers but not at greater distances. PFR-97 dispensers could be a treatment option for D. citri in settings where chemical control is problematic.

We are developing an autodisseminator (‘dispenser’) to inoculate Asian citrus psyllid with entomopathogens for the purpose of inducing epizootics in residential trees and abandoned groves, areas where chemical control is problematic. The dispenser prototype consisted of a bright yellow pleated tube coated with a spore formulation made from pulverized cotton burrs and blastospores of Isaria fumosorosea . Adult psyllids were released within an array of dispensers and potted citrus saplings in a greenhouse. After 24 h, they were collected from the foliage, surface sterilized, and placed in an incubator. A mean of 55% of the adults developed mycosis ( n = 3 tests), demonstrating that the dispensers could cause primary infection. The potted plants used in the horizontal transmission tests were infested with immature psyllids; 27–35% of which became infected following contact with adults that had visited the dispensers ( n = 2 tests). When mycosed adult cadavers with mature conidia were placed near immatures on the potted plants, over 90% of the immatures mycosed, indicating that conidia from the cadavers were highly contagious. On dispensers left in the greenhouse for three weeks, the infectivity of blastospores exposed to direct sunlight decreased by 46% after 7 d and by 60% after 20 d, while infectivity levels remained high in blastospores that were shaded. These results confirmed that that the basic dispenser design was sound with respect to attracting and infecting psyllids. It requires further modification to work effectively under ambient conditions, since exposure to direct sunlight decreased blastospore infectiveness over time.

AIM: The objective of the present study was to use pharmacokinetic–pharmacodynamic modelling to characterize the effects of chemotherapy on the granulopoietic system and to predict the absolute neutrophil counts (ANCs) for patients with chemotherapy‐induced neutropenia treated with filgrastim and pegfilgrastim. METHODS: Data were extracted from 10 phase I–III studies conducted in 110 healthy adults, and 618 adult and 52 paediatric patients on chemotherapy following administration of filgrastim or pegfilgrastim. The structural model accounted for ANC dynamics and the effects of filgrastim and pegfilgrastim, chemotherapy and corticosteroids. The impact of neutrophils on drug disposition was based on a drug receptor–binding model that assumed quasi‐equilibrium and stimulation of the production and maturation of neutrophils upon treatment. The chemotherapy and corticosteroid effects were represented by kinetic–pharmacodynamic‐type models, where chemotherapy stimulated elimination of neutrophil precursors at the mitotic stage, and corticosteroids stimulated neutrophil production. RESULTS: The systemic half‐lives of filgrastim (2.6 h) and pegfilgrastim (10.1 h) were as expected. The effective half‐life of chemotherapy was 9.6 h, with a 2‐day killing effect. The rate of receptor elimination from mitotic compartments exhibited extreme interindividual variability (% coefficient of variation >200), suggesting marked differences in sensitivity to chemotherapy effects on ANCs. The stimulatory effects of pegfilgrastim were significantly greater than those of filgrastim. Model qualification confirmed the predictive capability of this model. CONCLUSION: This qualified model simulates the time course of ANC in the absence or presence of chemotherapy and predicts nadir, time to nadir and time of recovery from different grades of neutropenia upon treatment with filgrastim and pegfilgrastim.

Objective: To compare anti-TNF dose escalation, DMARD and/or glucocorticoid intensification, switches to another biologic, and drug and drug-related costs over 12 and 18 months for rheumatoid arthritis (RA) patients initiating etanercept (ETN), adalimumab (ADA), or infliximab (IFX) in routine clinical practice across Canada. Methods: A retrospective chart review of biologic-naïve adult RA patients newly initiating ADA, ETN, or IFX between January 01, 2006 and December 31, 2012 from 11 practices across Canada. Results: There were 314 patients in the 12-month analysis and 217 in the 18-month analysis. No dose escalation occurred with ETN over 12 and 18 months versus 38% and 32% for IFX (p Patients initiating ETN had lower total (drug and drug-related) costs over 12 and 18 months compared to IFX, and no difference compared to ADA when adjusted for potential confounders. Patients with dose escalation had higher costs compared to those with no dose escalation. Conclusion: Physicians were more likely to escalate the dose of IFX, but optimize co-therapy with ADA and ETN. ETN patients had no dose escalation and were less likely to have DMARD and/or glucocorticoid intensification than ADA patients. ETN-treated patients had lower costs compared to IFX patients.

A critical benchmark in the development of antibody-based therapeutics is demonstration of efficacy in preclinical mouse models of human disease, many of which rely on immunodeficient mice. However, relatively little is known about how the biology of various immunodeficient strains impacts the in vivo fate of these drugs. Here we used immunoPET radiotracers prepared from humanized, chimeric, and murine mAbs against four therapeutic oncologic targets to interrogate their biodistribution in four different strains of immunodeficient mice bearing lung, prostate, and ovarian cancer xenografts. The immunodeficiency status of the mouse host as well as both the biological origin and glycosylation of the antibody contributed significantly to the anomalous biodistribution of therapeutic monoclonal antibodies in an Fc receptor-dependent manner. These findings may have important implications for the preclinical evaluation of Fc-containing therapeutics and highlight a clear need for biodistribution studies in the early stages of antibody drug development. Significance: Fc/FcγR-mediated immunobiology of the experimental host is a key determinant to preclinical in vivo tumor targeting and efficacy of therapeutic antibodies. Cancer Res; 78(7); 1820–32. ©2018 AACR.

The RACAT (Rheumatoid Arthritis Comparison of Active Therapies) trial found triple therapy to be noninferior to etanercept-methotrexate in patients with active rheumatoid arthritis (RA).To determine the cost-effectiveness of etanercept-methotrexate versus triple therapy as a first-line strategy.A within-trial analysis based on the 353 participants in the RACAT trial and a lifetime analysis that extrapolated costs and outcomes by using a decision analytic cohort model.The RACAT trial and sources from the literature.Patients with active RA despite at least 12 weeks of methotrexate therapy.24 weeks and lifetime.Societal and Medicare.Etanercept-methotrexate first versus triple therapy first.Incremental costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).The within-trial analysis found that etanercept-methotrexate as first-line therapy provided marginally more QALYs but accumulated substantially higher drug costs. Differences in other costs between strategies were negligible. The ICERs for first-line etanercept-methotrexate and triple therapy were $2.7 million per QALY and $0.98 million per QALY over 24 and 48 weeks, respectively. The lifetime analysis suggested that first-line etanercept-methotrexate would result in 0.15 additional lifetime QALY, but this gain would cost an incremental $77 290, leading to an ICER of $521 520 per QALY per patient.Considering a long-term perspective, an initial strategy of etanercept-methotrexate and biologics with similar cost and efficacy is unlikely to be cost-effective compared with using triple therapy first, even under optimistic assumptions.Data on the long-term benefit of triple therapy are uncertain.Initiating biologic therapy without trying triple therapy first increases costs while providing minimal incremental benefit.The Cooperative Studies Program, Department of Veterans Affairs Office of Research and Development, Canadian Institutes for Health Research, and an interagency agreement with the National Institutes of Health-American Recovery and Reinvestment Act.

Objective To describe the profile of rheumatoid arthritis (RA) patients treated with infliximab in Canadian routine care and to assess the real-world effectiveness and safety of infliximab. Methods Biologics-naive RA patients from the Biologic Treatment Registry Across Canada were stratified based on their enrollment year. Effectiveness was assessed with the changes in clinical/laboratory parameters and patient-reported outcomes and the achievement of minimal disease activity and remission. Safety was assessed with the incidence of treatment-emergent adverse events (AEs). Results Among 628 patients, 45.9%, 34.6%, and 19.6% were enrolled between 2002–2005, 2005–2008, and 2008–2011, respectively. Patients recruited in more recent years had significantly lower Disease Activity Score with a 28-joint count using the C-reactive protein level (DAS28-CRP), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), swollen joint count in 28 joints, tender joint count in 28 joints, physician's global assessment of disease activity, patient's global assessment of disease activity, Health Assessment Questionnaire disability index, pain, erythrocyte sedimentation rate, and CRP level (P < 0.01 for all). Patient management also changed with a trend to initiate infliximab after failure of fewer disease-modifying antirheumatic drugs (DMARDs). Six-month treatment with infliximab resulted in statistically significant and clinically important improvements in all disease parameters examined, which were sustained over 36 months. The cumulative probability of achieving remission by 36 months, as defined by the DAS28, SDAI, and CDAI, was 56.2 (95% confidence interval [95% CI] 47.8–64.8), 31.0 (95% CI 23.8–39.8), and 36.2 (95% CI 28.5–45.3), respectively, which was significantly greater in patients with lower baseline disease activity. The profile and incidence of AEs were comparable to data previously reported for tumor necrosis factor α inhibitors. Conclusion RA patient characteristics at infliximab initiation changed over time toward lower disease activity. Furthermore, a trend to treat patients with fewer DMARDs before initiation of infliximab was observed. However, treatment with infliximab was effective in significantly reducing disease activity independent of the treatment initiation year.