Abatement of the Survival Cliff in Older Adolescents and Young Adults with Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma in the United States

Purpose: In 2018, a "survival cliff" in the United States was identified among older adolescent and young adult (AYA) patients with acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL). This study reassessed the cliff and associated putative causes. Methods: Survival data were obtained using the U.S. Surveillance Research Program, National Cancer Institute (NCI) SEER 22 Registries. Accrual data on cancer treatment trials conducted by the NCI cooperative groups and NCI-designated cancer centers were obtained from the NCI Cancer Therapy Evaluation Program. Trend and average percent changes and statistical significances were identified with the NCI Joinpoint Regression Program. Results: A previous cliff-like decrement in the survival of 17- to 20-year-olds is no longer apparent, overall and in all racial and ethnic groups. The "survival cliff" age range was coincident with a clinical trial accrual cliff, and both diminished when more clinical trials were available to, and participated in by, young adult patients. Older AYA patients of ages 30-39 had minimal improvement in clinical trial accrual and least survival gain among the AYA age group. Conclusion: The survival cliff has abated, resulting in thousands of fewer premature deaths and tens of thousands of years of life saved-a remarkable achievement. The survival improvement may be attributed to improved clinical trial availability for and recruitment and participation of AYAs on treatment trials, application of pediatric-inspired ALL treatment regimens to AYAs, expanded national health insurance for -18 to 25 year olds, improved AYA cancer services, and a national focus on AYA oncology.

Population-Based Data Linkage Describing Patterns of Cancer Clinical Trial Enrollment Among Children and Adolescents

PURPOSE

Database linkage between cancer registries and clinical trial consortia has the potential to elucidate referral patterns of children and adolescents with newly diagnosed cancer, including enrollment into cancer clinical trials. This study's primary objective was to assess the feasibility of this linkage approach.

METHODS

Patients younger than 20 years diagnosed with incident cancer during 2012-2017 in the Kentucky Cancer Registry (KCR) were linked with patients enrolled in a Children's Oncology Group (COG) study. Matched patients between databases were described by sex, age, race and ethnicity, geographical location when diagnosed, and cancer type. Logistic regression modeling identified factors associated with COG study enrollment. Timeliness of patient identification by KCR was reported through the Centers for Disease Control and Prevention's Early Case Capture (ECC) program.

RESULTS

Of 1,357 patients reported to KCR, 47% were determined by matching to be enrolled in a COG study. Patients had greater odds of enrollment if they were age 0-4 years (v 15-19 years), reported from a COG-affiliated institution, and had renal cancer, neuroblastoma, or leukemia. Patients had lower odds of enrollment if Hispanic (v non-Hispanic White) or had epithelial (eg, thyroid, melanoma) cancer. Most (59%) patients were reported to KCR within 10 days of pathologic diagnosis.

CONCLUSION

Linkage of clinical trial data with cancer registries is a feasible approach for tracking patient referral and clinical trial enrollment patterns. Adolescents had lower enrollment compared with younger age groups, independent of cancer type. Population-based early case capture could guide interventions designed to increase cancer clinical trial enrollment.

Reducing Cancer Risk Through Primary Prevention Activities Among Children: A Demonstration Project

CONTEXT

Opportunities to reduce the risk of cancer, including cervical, liver, and skin cancer, start early in life. To encourage adoption of primary prevention activities in childhood to reduce cancer risk later in life, Centers for Disease Control and Prevention conducted a demonstration project with 3 National Comprehensive Cancer Control Program (NCCCP) recipients.

PROGRAM

Iowa, Northwest Portland Area Indian Health Board (NPAIHB), and Pennsylvania NCCCP recipients implemented evidence-based primary prevention activities for cervical, liver, and skin cancer among children using health care provider education, patient education, and policy development.

IMPLEMENTATION

Iowa implemented an announcement approach to improve provider education on human papillomavirus (HPV) vaccination. Pennsylvania focused on patient education for reducing skin cancer risk and both provider and patient education for liver cancer prevention. NPAIHB created a sun safety intervention for tribal organizations, including a policy guide, media materials, and patient education.

RESULTS

In Iowa, health care providers taking the announcement approach reported significantly higher mean scores on a posttest compared with a pretest regarding perceptions about HPV vaccination, self-efficacy, and behavioral intentions related to vaccination. Pennsylvania integrated sun safety education and sunscreen dispenser programs as a health and wellness initiative in 8 state parks and the Pennsylvania Department of Conservation and Natural Resources incorporated the program in its Pennsylvania Outdoor Recreation Plan. Pennsylvania also implemented health care provider education on the primary prevention of liver cancer through hepatitis B and hepatitis C screening and hepatitis B vaccination. The NPAIHB skin cancer policy guide was created and distributed for use to all 43 federally recognized tribes of Oregon, Washington, and Idaho served by NPAIHB.

DISCUSSION

The identification, dissemination, and implementation of these efforts can serve as best practices for future childhood primary prevention programs. NCCCP recipients and public health professionals can use health care provider education, patient education, and policy development to reduce future risk for cervical, liver, and skin cancer among children.

Counts, incidence rates, and trends of pediatric cancer in the United States, 2003-2019

BACKGROUND

Cancer is a leading cause of death by disease among children and adolescents in the United States. This study updates cancer incidence rates and trends using the most recent and comprehensive US cancer registry data available.

METHODS

We used data from US Cancer Statistics to evaluate counts, age-adjusted incidence rates, and trends among children and adolescents younger than 20 years of age diagnosed with malignant tumors between 2003 and 2019. We calculated the average annual percent change (APC) and APC using joinpoint regression. Rates and trends were stratified by demographic and geographic characteristics and by cancer type.

RESULTS

With 248 749 cases reported between 2003 and 2019, the overall cancer incidence rate was 178.3 per 1 million; incidence rates were highest for leukemia (46.6), central nervous system neoplasms (30.8), and lymphoma (27.3). Rates were highest for males, children 0 to 4 years of age, Non-Hispanic White children and adolescents, those in the Northeast census region, the top 25% of counties by economic status, and metropolitan counties with a population of 1 million people or more. Although the overall incidence rate of pediatric cancer increased 0.5% per year on average between 2003 and 2019, the rate increased between 2003 and 2016 (APC = 1.1%), and then decreased between 2016 and 2019 (APC = -2.1%). Between 2003 and 2019, rates of leukemia, lymphoma, hepatic tumors, bone tumors, and thyroid carcinomas increased, while melanoma rates decreased. Rates of central nervous system neoplasms increased until 2017, and then decreased. Rates of other cancer types remained stable.

CONCLUSIONS

Incidence of pediatric cancer increased overall, although increases were limited to certain cancer types. These findings may guide future public health and research priorities.

Influence of depression on breast cancer treatment and survival: A Kentucky population-based study

BACKGROUND

Depression is common among breast cancer patients and can affect concordance with guideline-recommended treatment plans. Yet, the impact of depression on cancer treatment and survival is understudied, particularly in relation to the timing of the depression diagnosis.

METHODS

The Kentucky Cancer Registry data was used to identify female patients diagnosed with primary invasive breast cancer who were 20 years of age or older in 2007-2011. Patients were classified as having no depression, depression pre-cancer diagnosis only, depression post- cancer diagnosis only, or persistent depression. The impact of depression on receiving guideline-recommended treatment and survival was examined using multivariable logistic regression and Cox regression, respectively.

RESULTS

Of 6054 eligible patients, 4.1%, 3.7%, and 6.2% patients had persistent depression, depression pre-diagnosis only, and depression post-diagnosis only, respectively. A total of 1770 (29.2%) patients did not receive guideline-recommended cancer treatment. Compared to patients with no depression, the odds of receiving guideline-recommended treatment were decreased in patients with depression pre-diagnosis only (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.54-1.04) but not in patients with post-diagnosis only or persistent depression. Depression post-diagnosis only (hazard ratio, 1.51; 95% CI, 1.24-1.83) and depression pre-diagnosis only (hazard ratio, 1.26; 95% CI, 0.99-1.59) were associated with worse survival. No significant difference in survival was found between patients with persistent depression and patients with no depression (p > .05).

CONCLUSIONS

Neglecting depression management after a breast cancer diagnosis may result in poorer cancer treatment concordance and worse survival. Early detection and consistent management of depression is critical in improving patient survival.

Emergency department visits among people with cancer: Frequency, symptoms, and characteristics

OBJECTIVE

People with cancer are increasingly more likely to visit an emergency department for acute care than the general population. They often have long wait times and more exposure to infection and receive treatment from staff less experienced with cancer-related problems. Our objective was to examine emergency department (ED) visits among people with cancer to understand how often and why they seek care.

METHODS

We conducted a retrospective study of ED visits using the National Syndromic Surveillance Program BioSense Platform. Cancer reported during an ED visit was identified using International Classification of Diseases, Tenth Revision codes for any cancer type, including bladder, breast, cervical, colorectal, kidney, liver, lung, ovary, pancreas, prostate, or uterine cancers. Symptoms prompting the visit were identified for people with cancer who visited EDs in the United States from June 2017 to May 2018 in ≈4500 facilities, including 3000 EDs in 46 states and the District of Columbia (66% of all ED visits during a 1-year period).

RESULTS

Of 97 million ED visits examined, 710,297 (0.8%) were among people with cancer. Percentages were higher among women (50.1%) than men (49.5%) and among adults aged ≥65 years (53.6%) than among those ≤64 years (45.7%). The most common presenting symptoms were pain (19.1%); gastrointestinal (13.8%), respiratory (11.5%), and neurologic (5.3%) complaints; fever (4.9%); injury (4.1%); and bleeding (2.4%). Symptom prevalence differed significantly by cancer type.

CONCLUSIONS

The Centers for Medicare & Medicaid Services encourages efforts to reduce acute care visits among people with cancer. We characterized almost 70% of ED visits among this population.

Glioma-Derived miRNA-Containing Extracellular Vesicles Induce Angiogenesis by Reprogramming Brain Endothelial Cells

Glioblastoma (GBM) is characterized by aberrant vascularization and a complex tumor microenvironment. The failure of anti-angiogenic therapies suggests pathways of GBM neovascularization, possibly attributable to glioblastoma stem cells (GSCs) and their interplay with the tumor microenvironment. It has been established that GSC-derived extracellular vesicles (GSC-EVs) and their cargoes are proangiogenic in vitro. To further elucidate EV-mediated mechanisms of neovascularization in vitro, we perform RNA-seq and DNA methylation profiling of human brain endothelial cells exposed to GSC-EVs. To correlate these results to tumors in vivo, we perform histoepigenetic analysis of GBM molecular profiles in the TCGA collection. Remarkably, GSC-EVs and normal vascular growth factors stimulate highly distinct gene regulatory responses that converge on angiogenesis. The response to GSC-EVs shows a footprint of post-transcriptional gene silencing by EV-derived miRNAs. Our results provide insights into targetable angiogenesis pathways in GBM and miRNA candidates for liquid biopsy biomarkers.

Transcriptomic Analysis of Laser Capture Microdissected Tumors Reveals Cancer- and Stromal-Specific Molecular Subtypes of Pancreatic Ductal Adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) lethality is multifactorial; although studies have identified transcriptional and genetic subsets of tumors with different prognostic significance, there is limited understanding of features associated with the minority of patients who have durable remission after surgical resection. In this study, we performed laser capture microdissection (LCM) of PDAC samples to define their cancer- and stroma-specific molecular subtypes and identify a prognostic gene expression signature for short-term and long-term survival.

EXPERIMENTAL DESIGN

LCM and RNA sequencing (RNA-seq) analysis of cancer and adjacent stroma of 19 treatment-naïve PDAC tumors was performed. Gene expression signatures were tested for their robustness in a large independent validation set. An RNA-ISH assay with pooled probes for genes associated with disease-free survival (DFS) was developed to probe 111 PDAC tumor samples.

RESULTS

Gene expression profiling identified four subtypes of cancer cells (C1-C4) and three subtypes of cancer-adjacent stroma (S1-S3). These stroma-specific subtypes were associated with DFS (P = 5.55E-07), with S1 associated with better prognoses when paired with C1 and C2. Thirteen genes were found to be predominantly expressed in cancer cells and corresponded with DFS in a validation using existing RNA-seq datasets. A second validation on an independent cohort of patients using RNA-ISH probes to six of these prognostic genes demonstrated significant association with overall survival (median 17 vs. 25 months; P < 0.02).

CONCLUSIONS

Our results identified specific signatures from the epithelial and the stroma components of PDAC, which add clarity to the nature of PDAC molecular subtypes and may help predict survival.

Comparison of transarterial bland and chemoembolization for neuroendocrine tumours: a systematic review and meta-analysis

Background

Treatment of hepatic metastases from neuroendocrine tumours improves survival and symptom relief. Hepatic arterial embolotherapy techniques include transarterial chemoembolization (tace) and bland embolization (tae). The relative efficacy of the techniques is controversial. The purpose of the present study was to use a meta-analysis and systematic review to compare tace with tae in the treatment of hepatic metastases.

Methods

A literature search identified studies comparing tace and tae for treatment of hepatic metastases. Outcomes of interest included overall survival (os), progression-free survival (pfs), radiographic response, complications, and symptom control. The hazard ratios (hrs) and odds ratios (ors) were estimated and pooled.

Results

Eight studies and 504 patients were included. No statistically significant differences between tace and tae were observed for os at 1, 2, and 5 years or for hrs [1-year or: 0.72; 95% confidence interval (ci): 0.27 to 1.94; p < 0.52; 2-year or: 0.69; 95% ci: 0.43 to 1.11; p < 0.12; 5-year or: 0.91; 95% ci: 0.37 to 2.24; p < 0.85; hr: 0.96; 95% ci: 0.73 to 1.24; p < 0.74]. No statistically significant differences between tace and tae were observed for pfs at 1, 2, and 5 years or for hrs (1-year or: 0.71; 95% ci: 0.38 to 1.55; p < 0.30; 2-year or: 0.83; 95% ci: 0.33 to 2.06; p < 0.69; 5-year or: 0. 91; 95% ci: 0.37 to 2.24; p < 0.85; hr: 0.99-1.74; 95% ci: 0.74 to 1.73; p < 0.97). Both techniques are safe and effective for symptom control.

Conclusions

No statistically significant differences between tace and tae were observed for os and pfs.

Glioblastoma-Associated Microglia Reprogramming Is Mediated by Functional Transfer of Extracellular miR-21

Gliomas are primary, diffusely infiltrating brain tumors. Microglia are innate immune cells in the CNS and make up a substantial portion of the tumor mass. Glioma cells shape their microenvironment, communicating with and reprogramming surrounding cells, resulting in enhanced angiogenesis, immune suppression, and remodeling of the extracellular matrix. Glioma cells communicate with microglia, in part by releasing extracellular vesicles (EVs). Mouse glioma cells stably expressing a palmitoylated GFP to label EVs were implanted intracranially into syngeneic miR-21-null mice. Here, we demonstrate functional delivery of miR-21, regulating specific downstream mRNA targets in microglia after uptake of tumor-derived EVs. These findings attest to EV-dependent microRNA delivery as studied in an in vivo-based model and provide insight into the reprograming of microglial cells by tumor cells to create a favorable microenvironment for cancer progression.

Neoplastic-Stromal Cell Cross-talk Regulates Matrisome Expression in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warranting intense cancer-stroma communication. In this study, we interrogated the contribution of the BET family of chromatin adaptors to the cross-talk between PDAC cells and the tumor stroma. Short-term treatment of orthotopic xenograft tumors with CPI203, a small-molecule inhibitor of BET proteins, resulted in broad changes in the expression of genes encoding components of the extracellular matrix (matrisome) in both cancer and stromal cells. Remarkably, more than half of matrisome genes were expressed by cancer cells. In vitro cocultures of PDAC cells and cancer-associated fibroblasts (CAF) demonstrated that matrisome expression was regulated by BET-dependent cancer-CAF cross-talk. Disrupting this cross-talk in vivo resulted in diminished growth of orthotopic patient-derived xenograft tumors, reduced proliferation of cancer cells, and changes in collagen structure consistent with that of patients who experienced better survival. Examination of matrisome gene expression in publicly available data sets of 573 PDAC tumors identified a 65-gene signature that was able to distinguish long- and short-term PDAC survivors. Importantly, the expression of genes predictive of short-term survival was diminished in the cancer cells of orthotopic xenograft tumors of mice treated with CPI203. Taken together, these results demonstrate that inhibiting the activity BET proteins results in transcriptional and structural differences in the matrisome are associated with better patient survival. IMPLICATIONS: These studies highlight the biological relevance of the matrisome program in PDAC and suggest targeting of epigenetically driven tumor-stroma cross-talk as a potential therapeutic avenue.

Outcomes among pediatric patients with cancer who are treated on trial versus off trial: A matched cohort study

BACKGROUND

Approximately 50% of children with cancer in the United States who are aged <15 years receive primary treatment on a therapeutic clinical trial. To the authors' knowledge, it remains unknown whether trial enrollment has a clinical benefit compared with the best alternative standard therapy and/or off trial (ie, clinical trial effect). The authors conducted a retrospective matched cohort study to compare the morbidity and mortality of pediatric patients with cancer who are treated on a phase 3 clinical trial compared with those receiving standard therapy and/or off trial.

METHODS

Subjects were aged birth to 19 years; were diagnosed between 2000 and 2010 with acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), rhabdomyosarcoma, or neuroblastoma; and had received initial treatment at the Children's Hospital of Philadelphia. On-trial and off-trial subjects were matched based on age, race, ethnicity, a diagnosis of Down syndrome (for patients with ALL or AML), prognostic risk level, date of diagnosis, and tumor type.

RESULTS

A total of 428 participants were matched in 214 pairs (152 pairs for ALL, 24 pairs for AML, 32 pairs for rhabdomyosarcoma, and 6 pairs for neuroblastoma). The 5-year survival rate did not differ between those treated on trial versus those treated with standard therapy and/or off trial (86.9% vs 82.2%; P = .093). On-trial patients had a 32% lower odds of having worse (higher) mortality-morbidity composite scores, although this did not reach statistical significance (odds ratio, 0.68; 95% confidence interval, 0.45-1.03 [P = .070]).

CONCLUSIONS

There was no statistically significant difference in outcomes noted between those patients treated on trial and those treated with standard therapy and/or off trial. However, in partial support of the clinical trial effect, the results of the current study indicate a trend toward more favorable outcomes in children treated on trial compared with those treated with standard therapy and/or off trial. These findings can support decision making regarding enrollment in pediatric phase 3 clinical trials.

Pancreatic circulating tumor cell profiling identifies LIN28B as a metastasis driver and drug target

Pancreatic ductal adenocarcinoma (PDAC) lethality is due to metastatic dissemination. Characterization of rare, heterogeneous circulating tumor cells (CTCs) can provide insight into metastasis and guide development of novel therapies. Using the CTC-iChip to purify CTCs from PDAC patients for RNA-seq characterization, we identify three major correlated gene sets, with stemness genes LIN28B/KLF4, WNT5A, and LGALS3 enriched in each correlated gene set; only LIN28B CTC expression was prognostic. CRISPR knockout of LIN28B-an oncofetal RNA-binding protein exerting diverse effects via negative regulation of let-7 miRNAs and other RNA targets-in cell and animal models confers a less aggressive/metastatic phenotype. This correlates with de-repression of let-7 miRNAs and is mimicked by silencing of downstream let-7 target HMGA2 or chemical inhibition of LIN28B/let-7 binding. Molecular characterization of CTCs provides a unique opportunity to correlated gene set metastatic profiles, identify drivers of dissemination, and develop therapies targeting the "seeds" of metastasis.

OP0046 TARGETING IRAK1 AND 4 SIGNALING WITH R835, A NOVEL ORAL SMALL MOLECULE INHIBITOR: A POTENTIAL NEW TREATMENT FOR SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by loss of immunological tolerance, hyperactivation of immune cells, proinflammatory cytokine production and, ultimately, end organ damage due to immune complex deposition. Toll-like receptors (TLRs), which are essential to the innate immune response to microbes and other danger signals, play a key role in the pathogenesis of SLE by recognition of self-molecules (1). Interleukin receptor associated kinases (IRAK)1 and 4 are responsible for initiating MyD88-dependent signaling from most TLRs and Interleukin-1 Receptors (IL-1R) and represent attractive targets for the therapeutic treatment of SLE (2). We have identified a potent and selective IRAK1/4 inhibitor, R835, that substantially suppressed the elevation of LPS (TLR4 agonist)-induced serum cytokines in healthy human volunteers in a recently completed phase 1 study.

Objectives:

The aim of our study was to investigate the effect of IRAK1/4 selective inhibition as potential therapeutic approach for SLE. We evaluated the effect of our clinical candidate R835 on TLR7 signaling and in a mouse model of lupus-like disease.

Methods:

Human primary dendritic cells and whole blood were stimulated with gardiquimod (TLR7 agonist) to evaluate the effect of R835 on Interferon-alpha (IFN-α) production. R835 was further evaluated for its efficacy on survival and disease progression in lupus-prone NZB/W F1 mice with early or active signs of disease.

Results:

R835 inhibited TLR7-induced cytokine production in human dendritic cells and whole blood. Given orally to mice, R835 dose-dependently decreased serum IFN-α in response to administration of a TLR7 agonist. Furthermore, treatment of NZB/W F1 lupus-prone mice with R835 reversed the progression of lupus-like disease and the establishment of a pro-inflammatory environment, as demonstrated by decreased levels of proteinuria, blood urea nitrogen and autoantibodies, and reversal of renal pathology.

Conclusion:

To our knowledge, R835 is the first dual IRAK1/4 inhibitor to enter clinical development and provides an attractive approach to treat a range of autoimmune and rheumatic diseases, including lupus.

References:

[1]Signals via the Adaptor MyD88 in B cells and DCs Make Distinct and Synergistic Contributions to Immune Activation and Tissue Damage in Lupus. Lino L. Teichmann, Dominik Schenten, Ruslan Medzhitov, Michael Kashgarian, and Mark J. Shlomchik. Immunity. 2013 March 21; 38(3): 528–540.

[2]Suppression of IRAK1 or IRAK4 Catalytic Activity, but Not Type 1 IFN Signaling, Prevents Lupus Nephritis in Mice Expressing a Ubiquitin Binding-Defective Mutant of ABIN1. Nanda SK, Lopez-Pelaez M, Arthur JS, Marchesi F, Cohen P. J Immunol. 2016 Dec 1;197(11):4266-4273.

Disclosure of Interests:

Chrystelle Lamagna Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Meagan Chan Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Art Bagos Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Ernest Tai Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Chi Young Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Yan Chen Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Lu Chou Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Gary Park Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Esteban Masuda Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Vanessa Taylor Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals

AB0058 CELL-TYPE SPECIFIC REGULATION OF IL-1R SIGNALING BY R835, A DUAL IRAK1/4 INHIBITOR

Background:

Interleukin-1 beta (IL-1b) is a key mediator of the inflammatory response and is known to exacerbate damage during chronic disease and acute tissue injury. Through association with the adaptor protein Myd88, interleukin receptor associated kinases (IRAK)1 and 4 initiate signaling downstream of IL-1Rs resulting in the activation of the NFkB and MAPK pathways and the production of proinflammatory cytokines (1). IL-1Rs are broadly expressed across cell types and little is known about differences in signaling between cell types and the role of IRAK1 and IRAK4 kinase activity.

Objectives:

We have identified a potent and selective IRAK1/4 inhibitor, R835, that substantially suppressed the elevation of LPS (TLR4 agonist)-induced serum cytokines in healthy human volunteers in a recent phase 1 study. The aim of this study was to evaluate the effect of R835 on IL-1R signaling in primary human fibroblasts and endothelial cells.

Methods:

Human dermal fibroblasts, lung fibroblasts or endothelial cells were stimulated with IL-1b and the effect of R835 on the signaling pathway was evaluated by western blotting. Human dermal fibroblasts were stimulated with different amounts of IL-1b to evaluate both the signaling pathways activated and the cytokines produced. The ability of R835 to inhibit cytokine production induced by high or low amounts of IL-1b in dermal fibroblasts was assessed.

Results:

In human endothelial cells, inhibition of IRAK1/4 kinases with R835 resulted in a block of IL-1b-induced IRAK4 phosphorylation, IRAK1 degradation and downstream NFkB, p38 and JNK activation. In contrast, in both human primary dermal and lung fibroblasts stimulated with IL-1b, we observed potent inhibition of IRAK4 phosphorylation, IRAK1 degradation, and downstream JNK phosphorylation, but no inhibition of NFkB pathway proteins and only weak inhibition of p38. Upon titration of IL-1b we observed that dermal fibroblasts produced IL-8 and GRO in response to low levels of IL-1b (20pg/ml), and produced additional cytokines including G-CSF and GM-CSF with higher levels of IL-1b (400pg/ml). In the presence of low levels of IL-1b (20pg/ml), we observed a weak activation of NFkB pathway proteins and p38, compared to a very robust NFkB, p38 and additional JNK activation in the presence of higher levels of IL-1b (400pg/ml). Consistent with these results, in dermal fibroblasts, R835 showed little to no inhibition of IL-8 and GRO induced by low levels of IL-1b, but potently inhibited G-CSF and GM-CSF induced by high levels of IL-1b where JNK was activated.

Conclusion:

This study has elucidated signaling differences between cell types downstream of the IL-1R. In endothelial cells, as in myeloid cells, the kinase activity of IRAK1 and IRAK4 is required for the activation of all downstream signaling. Unexpectedly, in human fibroblasts, IRAK1/4 kinase activity appears to primarily regulate the JNK pathway, and not the NFkB pathway. Concomitant with that, only the cytokines induced by the additional activation of JNK in fibroblasts are regulated by a dual IRAK1/4 inhibitor. Clinically, an IRAK1/4 inhibitor may show select inhibition of IL-1b-induced cytokines depending on the tissue and cell type involved in inflammation.

References:

[1]Flannery S, Bowie A G. The interleukin-1 receptor-associated kinases: Critical regulators of innate immune signaling. Biochemical Pharmacology, Volume 80, Issue 12, 15 December 2010, Pages 1981-1991.

Disclosure of Interests:

Sylvia Braselmann Shareholder of: Shareholder of Rigel Pharmaceuticals, Employee of: Employee of Rigel Pharmaceuticals, Ernest Tai Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Roy Frances Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Chi Young Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Vadim Markovtsov Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Esteban Masuda Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Vanessa Taylor Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals

OP0133 PRECLINICAL EFFICACY OF R835, A NOVEL IRAK1/4 DUAL INHIBITOR, IN RODENT MODELS OF JOINT INFLAMMATION

Background:

Interleukin receptor associated kinases (IRAK) 1 and 4 are kinases involved in Toll-Like Receptor (TLR) and Interleukin-1 Receptor (IL-1R) signaling pathways, which regulate innate immunity and inflammation. Dysregulation of IRAK1/4 signaling can lead to a variety of inflammatory conditions including rheumatoid and gouty arthritis. As a result, IRAK1/4 are promising therapeutic targets for rheumatic diseases (1). We have identified a potent and selective IRAK1/4 inhibitor, R835, that substantially suppressed the elevation of LPS (TLR4 agonist)-induced serum cytokines in healthy human volunteers in a recently completed phase 1 study.

Objectives:

The aim of our study was to investigate the effect of IRAK1/4 selective inhibition as a potential therapeutic approach for rheumatological diseases. We evaluated the inhibition by our clinical candidate, R835, on TLR-, IL-1R- and NLRP3 inflammasome-induced cytokine production, as well as in preclinical models of arthritis.

Methods:

The effect of R835 on TLR- or IL-1R-induced cytokine production was evaluated in vitro using THP-1, human primary endothelial cells and human primary dendritic cells. The activity of R835 on the NLRP3 inflammasome was also tested in vitro using THP-1 cells. The pharmacokinetic-pharmacodynamic relationship of R835 was evaluated in a mouse model of IL-1b-induced cytokine release. Mice were pre-treated orally with vehicle or R835 prior to challenge; serum cytokine and plasma compound levels were determined. The efficacy of IRAK1/4 inhibition by R835 in rodent models of joint inflammation was evaluated in a mouse model monosodium (MSU)-induced peritonitis, in rat model of MSU-induced gouty arthritis and in a rat model of collagen-induced arthritis (CIA).

Results:

In human cells, R835 blocked proinflammatory cytokine production in response to TLR, IL-1R and NLRP3 inflammasome activation. In mice, R835 dose-dependently decreased serum cytokines in response to administration of IL-1b. Mice pre-treated with R835 demonstrated dose-dependent reductions in MSU crystal-induced serum and peritoneal cytokine levels, as well as neutrophil influx in the peritoneal cavity. Prophylactic and therapeutic treatment with R835 also resulted in significant inhibition of MSU crystal-induced knee edema and pain in a rat model of human gouty arthritis. In the rat model of CIA, R835 blocked both onset and progression of disease, by reducing inflammation, cartilage degeneration and synovial inflammation.

Conclusion:

R835 is a promising clinical candidate for the treatment of a range of cytokine-driven rheumatological diseases. R835 has proven to have desirable pharmacokinetic properties, was well tolerated and suppressed LPS-induced serum cytokines in healthy volunteers in a recent phase 1 study.

References:

[1]Bahia M S, Kaur M, Silakari P, Silakari O. Interleukin-1 receptor associated kinase inhibitors: Potential therapeutic agents for inflammatory- and immune-related disorders. Cellular Signalling 27 (2015) 1039–1055.

Disclosure of Interests:

Chrystelle Lamagna Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Meagan Chan Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Ernest Tai Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Stacey Siu Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Roy Frances Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Sothy Yi Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Chi Young Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Vadim Markovtsov Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Yan Chen Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Lu Chou Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Gary Park Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Esteban Masuda Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals, Vanessa Taylor Shareholder of: Rigel Pharmaceuticals, Employee of: Rigel Pharmaceuticals

Are uninsured women in a national screening program having longer intervals between cervical cancer screening tests?

With increased understanding of the natural history of cervical cancer, cervical cancer screening recommendations have evolved (Schiffman & Wentzensen, 2013). As research better quantified the balance of benefits and harms of screening, new recommendations called for longer intervals between screening tests. Adherence to longer screening intervals detects similar numbers of abnormalities and decreases harms associated with overscreening/overtreatment. In this descriptive study, we examined the cervical cancer screening intervals from 2010 to 2018 in the National Breast and Cervical Cancer Early Detection Program (NBCCEDP). There were 1,397,899 women aged 21-64 who were screened for cervical cancer from 2010 to 2018 and 556,743 rescreenings of average risk women were performed. The median cervical screening interval increased from 2.02 years in 2010 to 3.88 years in 2018. Providers serving uninsured women in a national screening program are following the recommendations of longer intervals between cervical cancer screenings.