Receptor-blocking Monoclonal Antibody Research Articles

Psychological stress triggers the accumulation of myeloid-derived suppressor cells in the liver through adrenergic receptor signaling

Abstract Chronic physiological stress affects tightly regulated crosstalk between the nervous and the immune system. However, the exact mechanism(s) of stress-induced immunomodulation is far from clear. Immature myeloid cells such as myeloid-derived suppressor cells (MDSCs) impair immune responses, which may in turn increase susceptibility to infections and cancer or their complications. In a mouse model of chronic psychological stress through physical restraint, we found mononuclear-MDSC (Mo-MDSC) cells, defined as CD11b +Ly6C highLy6G highcells, to accumulate in the liver. These cells expressed high levels of Mo-MDSC markers such as CD14, TLR4, IL-4Rα as well as markers indicative of anti-apoptotic and immunosuppressive functions (HIF-1α, G-CSFR, Bcl2, Arg2, iNOS). In addition, FACS sorted MDSCs suppressed production of IFN-ɣ by T cells in vitro. Increased levels of proinflammatory mediators were detectable in serum samples of stressed mice, with circulating levels of IL-6 and G-CSF being the most pronounced mediators. The observed intrahepatic accumulation of Mo-MDSC-like cells was mediated by IL-6 and G-CSF and could be reversed by treatment with corresponding receptor-blocking monoclonal antibodies. In addition, this phenomenon was driven by norepinephrine (NE), the main neurotransmitter released from sympathetic neurons, and could be recapitulated by in vivo administration of NE to non-stressed mice. Our work reveals a novel mechanism of immunosuppression that is governed by adrenergic and inflammatory cues and alters the cellular landscape of the liver with implications for immune surveillance against microbes and cancer. This work was funded by NSERC

P164 An emerging role of interferon targeted therapy in mucocutaneous SLE: a prospective real-world evaluation of anifrolumab for refractory cutaneous lupus

Abstract Background/Aims Advances in rational drug design and recent clinical trials are leading to emergence of a range of novel therapies for SLE and therapeutic options in clinical practice are expected to broaden rapidly. The optimal real-world place of emerging and established agents will be guided by understanding their differential efficacy on specific SLE manifestations as well as efficacy for more resistant disease. Anifrolumab, a type-I interferon receptor blocking monoclonal antibody, showed efficacy in SLE in phase III trials with a notable effect on mucocutaneous disease although specific lesion subtypes and chroncicity were not explored. Severe refractory mucocutaneous SLE such as scarring discoid lesions are an important and common clinical challenge in current practice. We therefore prospectively evaluated the real-world efficacy and quality of life impact of anifolumab for active mucocutaneous SLE, recalcitrant to multiple biologic and immunosuppressant therapies. Methods Seven patients commenced anifrolumab (300 mg by monthly iv infusion) following application to the manufacturer’s early access programme (NCT 04750057). Prior biologic therapies were discontinued at least 5 half-lives in advance. Mucocutaneous disease activity was captured by Cutaneous Lupus Disease Area and Severity Index (CLASI) activity score and medical photography. Patient reported health-related quality of life comprising the Dermatology Life Quality Index (DLQI); Lupus-QoL and EQ5D-5L were evaluated at baseline, three and six months. Results Seven female patients with active mucocutaneous SLE (Discoid LE n = 5, chilblain LE n = 1, subacute cutaneous LE n = 1) and median disease duration of 17 years were evaluated. Median baseline CLASI activity score was 17 (range 10-26; higher scores indicating severe disease). Median number of previously failed therapies was 7 and included rituximab in 6/7, belimumab in 2/7 and thalidomide in 4/7. Rapid resolution of scale and erythema in DLE was established within 1 month of anifrolumab treatment. Improvements to chilblain lupus were evident by three months. CLASI activity score was improved ≥75% in all patients at 3 months. Clinical responses were associated with significant improvements in DLQI (p < 0.001) and EQ5D-VAS (p = 0.002) by three months. Lupus-QoL trended toward improvement across all domains but most strongly for fatigue (p = 0.01) and pain (p = 0.002) by 6 months. One patient discontinued treatment after 4 months due to polydermatomal shingles complicated by sensorineural hearing loss. Infection coincided with background prednisolone dose >15 mg daily, recent COVID-19 infection and new on-treatment hypogammaglobulinaemia (IgG <5 g/L). Prolonged aciclovir treatment was required for lesion resolution. Conclusion We report rapid real-world efficacy and quality of life impact of anifrolumab on highly refractory mucocutaneous SLE, which exceeded that anticipated from existing clinical trial data. Findings suggest a unique role for emerging interferon targeting therapies in management of mucocutaneous SLE but emphasize need for enhanced VZV precautions among higher risk patients. Disclosure L. Carter: Consultancies; UCB. Z. Wigston: None. P. Laws: Consultancies; Amgen, Celgene, Janssen, Leo, Lilly and Sanofi. Member of speakers’ bureau; AbbVie, Actelion and BMS. Grants/research support; UCB, Almirall, and Novartis. E.M. Vital: Consultancies; Roche, GSK, AstraZeneca, Aurinia Pharmaceuticals, Lilly and Novartis. Grants/research support; Roche, AstraZeneca and Sandoz.

Anti-CSF-1R emactuzumab in combination with anti-PD-L1 atezolizumab in advanced solid tumor patients naïve or experienced for immune checkpoint blockade

BackgroundThis phase 1b study (NCT02323191) evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of colony-stimulating factor-1 receptor-blocking monoclonal antibody (mAb) emactuzumab in combination with the programmed cell death-1 ligand (PD-L1)-blocking...

Comparative evaluation of meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes and immunotherapy using an anti-canine IL-10 receptor-blocking monoclonal antibody on canine visceral leishmaniasis

This study compared the therapeutic potential of the chemotherapy using meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes (Nano Sbv) and immunotherapy with anti-canine IL-10 receptor-blocking monoclonal antibody (Anti IL-10R) on canine visceral leishmaniasis (CVL). Twenty mongrel dogs naturally infected by L. infantum, displaying clinical signs of visceral leishmaniasis were randomly divided in two groups. In the first one, nine dogs received six intravenous doses of a mixture of conventional and PEGylated liposomes containing meglumine antimoniate at 6.5 mg Sb/kg/dose. In the second one, eleven dogs received two intramuscular doses of 4 mg of anti-canine IL-10 receptor-blocking monoclonal antibody. The animals were evaluated before (T0) and 30, 90, and 180 days after treatments. Our major results demonstrated that both treatments were able to maintain hematological and biochemical parameters, increase circulating T lymphocytes subpopulations, increase the IFN-γ producing T-CD4 lymphocytes, restore the lymphoproliferative capacity and improve the clinical status. However, although these improvements were observed in the initial post-treatment times, they did not maintain until the end of the experimental follow-up. We believe that the use of booster doses or the association of chemotherapy and immunotherapy (immunochemotherapy) is promising to improve the effectiveness of treating CVL for improving the clinical signs and possibly reducing the parasite burden in dogs infected with Leishmania infantum.

IL-10 receptor blockade controls the in vitro infectivity of Leishmania infantum and promotes a Th1 activation in PBMC of dogs with visceral leishmaniasis

An important strategy to reduce the risk of visceral leishmaniasis (VL) in humans is to control the infection and disease progression in dogs, the domestic reservoir of Leishmania infantum parasites. Certain therapeutic strategies that modulate the host immune response show great potential for the treatment of experimental VL, restoring the impaired effector functions or decreasing host excessive responses. It is known that the overproduction of interleukin-10 (IL-10) promotes parasite replication and disease progression in human VL as well as in canine visceral leishmaniasis (CVL). Thus, in the present study we investigated the potential of the anti-canine IL-10 receptor-blocking monoclonal antibody (Bloq IL-10R) to control and reduce in vitro infectivity of L. infantum and improve the ability of PBMC isolated from VL dogs to alter the lymphoproliferative response and intracytoplasmic cytokines. Overall, GFP+Leishmania showed lower capacity of in vitro infectivity in the presence of Bloq IL-10R. Moreover, addition of Bloq IL-10R in cultured PBMC enhanced T-CD4 and CD8 proliferative response and altered the intracytoplasmic cytokine synthesis, reducing CD4+IL-4+ cells and increasing CD8+IFN-γ+ cells after specific antigen stimulation in PBMC of dogs. Furthermore, we observed an increase of TNF-α levels in supernatant of cultured PBMC under IL-10R neutralizing conditions. Together, our findings are encouraging and reaffirm an important factor that could influence the effectiveness of immune modulation in dogs with VL and suggest that blocking IL-10R activity has the potential to be a useful approach to CVL treatment.

Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination

BackgroundSeveral cases of unusual thrombotic events and thrombocytopenia have developed after vaccination with the recombinant adenoviral vector encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (ChAdOx1 nCov-19, AstraZeneca). More data were needed on the pathogenesis of this unusual clotting disorder.MethodsWe assessed the clinical and laboratory features of 11 patients in Germany and Austria in whom thrombosis or thrombocytopenia had developed after vaccination with ChAdOx1 nCov-19. We used a standard enzyme-linked immunosorbent assay to detect platelet factor 4 (PF4)–heparin antibodies and a modified (PF4-enhanced) platelet-activation test to detect platelet-activating antibodies under various reaction conditions. Included in this testing were samples from patients who had blood samples referred for investigation of vaccine-associated thrombotic events, with 28 testing positive on a screening PF4–heparin immunoassay.ResultsOf the 11 original patients, 9 were women, with a median age of 36 years (range, 22 to 49). Beginning 5 to 16 days after vaccination, the patients presented with one or more thrombotic events, with the exception of 1 patient, who presented with fatal intracranial hemorrhage. Of the patients with one or more thrombotic events, 9 had cerebral venous thrombosis, 3 had splanchnic-vein thrombosis, 3 had pulmonary embolism, and 4 had other thromboses; of these patients, 6 died. Five patients had disseminated intravascular coagulation. None of the patients had received heparin before symptom onset. All 28 patients who tested positive for antibodies against PF4–heparin tested positive on the platelet-activation assay in the presence of PF4 independent of heparin. Platelet activation was inhibited by high levels of heparin, Fc receptor–blocking monoclonal antibody, and immune globulin (10 mg per milliliter). Additional studies with PF4 or PF4–heparin affinity purified antibodies in 2 patients confirmed PF4-dependent platelet activation.ConclusionsVaccination with ChAdOx1 nCov-19 can result in the rare development of immune thrombotic thrombocytopenia mediated by platelet-activating antibodies against PF4, which clinically mimics autoimmune heparin-induced thrombocytopenia. (Funded by the German Research Foundation.)

Abstract S04-02: Treatment with tocilizumab does not inhibit induction of anti-COVID-19 antibodies in patients with severe SARS-CoV-2 infection

Abstract Tocilizumab (TCZ), an interleukin-6 (IL-6) receptor-blocking monoclonal antibody, is used to treat various rheumatologic conditions and cytokine release syndrome in CAR-T cell therapy and has been repurposed to treat COVID-19-related hyperinflammation. There are limited data available reporting how TCZ affects the immune response in the context of COVID-19. To investigate this question, we recruited patients treated with TCZ as part of a COVID-19 biobanking protocol (A-28063295) to study immune parameters that might be affected. We enrolled 19 patients who were treated with a range of 40-200mg TCZ as part of a low-dose TCZ trial (COVIDOSE, reported separately as abstract A-94803796), and 11 patients who received 400mg TCZ on a standard-of-care expanded-access basis. As IL-6 acts as a stimulant of B-cell proliferation, plasma cell maturation, and antibody responses, we evaluated whether blocking the IL-6 receptor with TCZ therapy impairs antibody generation to SARS-CoV-2. To evaluate antibody levels in these patients, we performed ELISAs against the SARS-CoV-2 spike glycoprotein and its receptor-binding domain (RBD). The spike glycoprotein, a structural protein of SARS-CoV-2, is a crucial component in the recognition, attachment, and entry of the virus into host cells. Specifically, the RBD is responsible for binding the ACE2 receptor on human cells, and likely serves as a major target for neutralizing antibodies. To establish if the formation and persistence of antibodies was affected by TCZ treatment, we analyzed serum and plasma samples longitudinally from 29 patients treated with TCZ and 26 control patients. To account for potential variability between plates, the measured optical density (OD) values were normalized to the OD for COVID-19-negative control serum at 1:50 dilution, and the same negative control was tested on each plate. Titers were calculated as the linear interpolation of the inverse dilution at which the normalized OD value crossed a threshold of 1, representing the maximum OD measured for the negative control. Anti-spike and anti-RBD antibodies increased significantly over time in both TCZ-treated patients and controls (p < 0.005 for both). Increasing antibody titers throughout the disease course followed a similar trajectory in TCZ-treated patients compared to control patients, suggesting that TCZ treatment does not impede the generation of antibodies to SARS-CoV-2. Additionally, TCZ-treated patients achieved comparable maximal observed antibody titers to control patients (average maximal log10 (titer) of 5.42 and 4.96 for spike and of 4.39 and 4.44 for RBD, respectively). These data suggest that TCZ does not impair the induction of anti-SARS-CoV-2 antibodies. Citation Format: Alexandra Cabanov, Blake A. Flood, Jeffrey Bloodworth, Emily F. Higgs, Jessica Fessler, Michael Y.K. Leung, Kyle R. Cron, Jonathan Trujillo, Athalia R. Pyzer, Sherin Rouhani, Garth Strohbehn, Brian Heiss, Mark Ratain, Pankti Reid, Kiang-Teck J. Yeo, Randy F. Sweis, Yuanyuan Zha, Thomas F. Gajewski. Treatment with tocilizumab does not inhibit induction of anti-COVID-19 antibodies in patients with severe SARS-CoV-2 infection [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S04-02.

COVID-19 and therapy with essential oils having antiviral, anti-inflammatory, and immunomodulatory properties.

Coronavirus disease of 2019 (COVID-19) has emerged as a global health threat. Unfortunately, there are very limited approved drugs available with established efficacy against the SARs-CoV-2 virus and its inflammatory complications. Vaccine development is actively being researched, but it may take over a year to become available to general public. Certain medications, for example, dexamethasone, antimalarials (chloroquine/hydroxychloroquine), antiviral (remdesivir), and IL-6 receptor blocking monoclonal antibodies (tocilizumab), are used in various combinations as off-label medications to treat COVID-19. Essential oils (EOs) have long been known to have anti-inflammatory, immunomodulatory, bronchodilatory, and antiviral properties and are being proposed to have activity against SARC-CoV-2 virus. Owing to their lipophilic nature, EOs are advocated to penetrate viral membranes easily leading to membrane disruption. Moreover, EOs contain multiple active phytochemicals that can act synergistically on multiple stages of viral replication and also induce positive effects on host respiratory system including bronchodilation and mucus lysis. At present, only computer-aided docking and few in vitro studies are available which show anti-SARC-CoV-2 activities of EOs. In this review, role of EOs in the prevention and treatment of COVID-19 is discussed. A discussion on possible side effects associated with EOs as well as anti-corona virus claims made by EOs manufacturers are also highlighted. Based on the current knowledge a chemo-herbal (EOs) combination of the drugs could be a more feasible and effective approach to combat this viral pandemic.

1894-P: Interruption of Glucagon Signaling Increases Pancreas Mass

Interruption of glucagon signaling by glucagon receptor gene inactivation or treatment with a glucagon receptor blocking monoclonal antibody (GCGR-Ab) stimulates alpha cell proliferation and expansion. Surprisingly, pancreas weight is also increased in mice with GCG gene inactivation. To investigate mechanisms linking glucagon signaling and pancreas size, we treated C57BL/6J mice with GCGR-Ab or a control IgG. Eight weeks of treatment (N=4-15 mice/treatment) increased absolute pancreas weight (0.42±0.013 vs. 0.32±0.008; p<0.0001), pancreas weight normalized to body weight (1.39±0.03% vs. 1.11±0.02%; p<0.0001), and serum levels of 15 amino acids (AA), including glutamine (1.7-4.67 fold, p<0.0001). GCGR-Ab treatment promoted acinar cell proliferation (Ki67+, 0.65±0.14% vs. 0.20±0.03%; p=0.0058), increased acinar cell size (peri-islet region: 438.4±12.77 vs. 341.7±22.05μm2; p=0.0045; peripheral region: 431.1±9.34 vs. 334.2±25μm2, p=0.0055; central region: 437.0±10.45 vs. 338.7±13.6 μm2, p=0.0006), and increased pancreas protein content (248.3±9.84 vs. 194±8.67μg/mg tissue; p=0.0003). By electron microscopy, GCGR-Ab treatment increased acinar cell zymogen granule number (129±9 vs. 49±6; p<0.0001; n=28-37 cells/treatment) and led to acinar cell ER dilatation, but did not induce pancreatitis or alter acinar cell apoptosis or pancreatic macrophage number. Serum cholecystokinin and total glucagon-like peptide-1, trophic hormones linked to exocrine growth, were not changed by GCGR-Ab treatment. GCGR-Ab treatment upregulated mRNA and protein levels of the glutamine transporter, Slc38a3, and increased mTOR-related ribosomal protein S6 phosphorylation in acinar cells. Together, these data indicate that interruption of glucagon signaling increases pancreas mass by inducing acinar cell hyperplasia and hypertrophy and activates protein synthesis and mTOR signaling; whether this is mediated by elevated glutamine or AA levels is not known. Disclosure C. Dai: None. A. Bradley: None. K.C. Coate: None. G. Poffenberger: None. E. Spears: None. J.J. Wright: None. S. Shrestha: None. D. Dean: None. M. Brissova: None. A.C. Powers: None. Funding National Institutes of Health (DK117147)

A first-in-human pharmacodynamic and pharmacokinetic study of a fully human anti-glucagon receptor monoclonal antibody in normal healthy volunteers.

AimsGlucagon receptor (GCGR) blockers are being investigated as potential therapeutics for type 1 and type 2 diabetes. Here we report the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of REGN1193, a fully human glucagon receptor blocking monoclonal antibody from a first‐in‐human healthy volunteer randomized double‐blinded trial.MethodsHealthy men and women received single ascending doses of REGN1193 ranging from 0.05 to 0.6 mg/kg (n = 42) or placebo (n = 14) intravenously. Safety, tolerability and PK were assessed over 106 days. The glucose‐lowering effect of REGN1193 was assessed after induction of hyperglycaemia by serial glucagon challenges.ResultsREGN1193 was generally well tolerated. There were small (<3× the upper limit of normal) and transient dose‐dependent increases in hepatic aminotransferases. No increase in LDL‐C was observed. Hypoglycaemia, assessed as laboratory blood glucose ≤70 mg/dL, occurred in 6/14 (43%) subjects on placebo and 27/42 (57%) on REGN1193 across all dose groups. All episodes of hypoglycaemia were asymptomatic, >50 mg/dL, and did not require treatment or medical assistance. Concentration‐time profiles suggest a 2‐compartment disposition and marked nonlinearity, consistent with target‐mediated clearance. REGN1193 inhibited the glucagon‐stimulated glucose increase in a dose‐dependent manner. The 0.6 mg/kg dose inhibited the glucagon‐induced glucose area under the curve for 0 to 90 minutes (AUC0‐90 minutes) by 80% to 90% on days 3 and 15, while blunting the increase in C‐peptide. REGN1193 dose‐dependently increased total GLP‐1, GLP‐2 and glucagon, with plasma levels returning to baseline by day 29 in all dose groups.ConclusionREGN1193, a GCGR‐blocking monoclonal antibody, produced a safety, tolerability and PK/PD profile suitable for further clinical development. The occurrence of transient elevations in serum hepatic aminotransferases observed here and reported with several small molecule glucagon receptor antagonists suggests an on‐target effect of glucagon receptor blockade. The underlying mechanism is unknown.

Early rheumatoid arthritis treated with tocilizumab, methotrexate, or their combination (U-Act-Early): a multicentre, randomised, double-blind, double-dummy, strategy trial

For patients with newly diagnosed rheumatoid arthritis, treatment aim is early, rapid, and sustained remission. We compared the efficacy and safety of strategies initiating the interleukin-6 receptor-blocking monoclonal antibody tocilizumab with or without methotrexate (a conventional synthetic disease-modifying antirheumatic drug [DMARD]), versus initiation of methotrexate monotherapy in line with international guidelines. We did a 2-year, multicentre, randomised, double-blind, double-dummy, strategy study at 21 rheumatology outpatient departments in the Netherlands. We included patients who had been diagnosed with rheumatoid arthritis within 1 year before inclusion, were DMARD-naive, aged 18 years or older, met current rheumatoid arthritis classification criteria, and had a disease activity score assessing 28 joints (DAS28) of at least 2·6. We randomly assigned patients (1:1:1) to start tocilizumab plus methotrexate (the tocilizumab plus methotrexate arm), or tocilizumab plus placebo-methotrexate (the tocilizumab arm), or methotrexate plus placebo-tocilizumab (the methotrexate arm). Tocilizumab was given at 8 mg/kg intravenously every 4 weeks with a maximum of 800 mg per dose. Methotrexate was started at 10 mg per week orally and increased stepwise every 4 weeks by 5 mg to a maximum of 30 mg per week, until remission or dose-limiting toxicity. We did the randomisation using an interactive web response system. Masking was achieved with placebos that were similar in appearance to the active drug; the study physicians, pharmacists, monitors, and patients remained masked during the study, and all assessments were done by masked assessors. Patients not achieving remission on their initial regimen switched from placebo to active treatments; patients in the tocilizumab plus methotrexate arm switched to standard of care therapy (typically methotrexate combined with a tumour necrosis factor inhibitor). When sustained remission was achieved, methotrexate (and placebo-methotrexate) was tapered and stopped, then tocilizumab (and placebo-tocilizumab) was also tapered and stopped. The primary endpoint was the proportion of patients achieving sustained remission (defined as DAS28 <2·6 with a swollen joint count ≤four, persisting for at least 24 weeks) on the initial regimen and during the entire study duration, compared between groups with a two-sided Cochran-Mantel-Haenszel test. Analysis was based on an intention-to-treat method. This trial was registered at ClinicalTrials.gov, number NCT01034137. Between Jan 13, 2010, and July 30, 2012, we recruited and assigned 317 eligible patients to treatment (106 to the tocilizumab plus methotrexate arm, 103 to the tocilizumab arm, and 108 to the methotrexate arm). The study was completed by a similar proportion of patients in the three groups (range 72-78%). The most frequent reasons for dropout were adverse events or intercurrent illness: 27 (34%) of dropouts, and insufficient response: 26 (33%) of dropouts. 91 (86%) of 106 patients in the tocilizumab plus methotrexate arm achieved sustained remission on the initial regimen, compared with 86 (84%) of 103 in the tocilizumab arm, and 48 (44%) of 108 in the methotrexate arm (relative risk [RR] 2·00, 95% CI 1·59-2·51 for tocilizumab plus methotrexate vs methotrexate, and 1·86, 1·48-2·32 for tocilizumab vs methotrexate, p<0·0001 for both comparisons). For the entire study, 91 (86%) of 106 patients in the tocilizumab plus methotrexate arm, 91 (88%) of 103 in the tocilizumab arm, and 83 (77%) of 108 in the methotrexate arm achieved sustained remission (RR 1·13, 95% CI 1·00-1·29, p=0·06 for tocilizumab plus methotrexate vs methotrexate, 1·14, 1·01-1·29, p=0·0356 for tocilizumab vs methotrexate, and p=0·59 for tocilizumab plus methotrexate vs tocilizumab). Nasopharyngitis was the most common adverse event in all three treatment groups, occurring in 38 (36%) of 106 patients in the tocilizumab plus methotrexate arm, 40 (39%) of 103 in the tocilizumab arm, and 37 (34%) of 108 in the methotrexate arm. The occurrence of serious adverse events did not differ between the treatment groups (17 [16%] of 106 patients in the tocilizumab plus methotrexate arm vs 19 [18%] of 103 in the tocilizumab arm and 13 [12%] of 108 in the methotrexate arm), and no deaths occurred during the study. For patients with newly diagnosed rheumatoid arthritis, strategies aimed at sustained remission by immediate initiation of tocilizumab with or without methotrexate are more effective, and with a similar safety profile, compared with initiation of methotrexate in line with current standards. Roche Nederland BV.

Biologic Therapy in Inflammatory and Immunomediated Arthritis: Safety Profile.

The increasing insights into the pathogenetic mechanisms of inflammatory autoimmune arthritis and the development of innovative systems of industrial production have led to discover molecules that are able to target/block other molecules that play a critical role in the immune system functioning, and that have been introduced in clinical practice alone and/or in addiction with other "old" disease-modifying anti-rheumatic drugs. For this reason, such drugs are currently known as "biological drugs" and include molecules that induce the immunosuppression acting on several immune pathways. However, though the biological drugs have been employed from more than a decade, there still exist some drawbacks of their use, in particular about the high costs of this therapy and their overall safety, including the route of administration for the intravenous use. In this review we provide an update on the correct use and current therapeutic indications of such drugs, including some of the new biologic therapies that will be soon available for the clinical use, focusing on these biological drugs: • Tumor necrosis factor-alpha (TNF-alpha) inhibitors (adalimumab, certolizumab-pegol, etanercept, golimumab and infliximab); • The T cell co-stimulation inhibitor, abatacept; • The anti-CD20 receptor monoclonal B cell agent, rituximab; • The interlukin-6 (IL-6) receptor-blocking monoclonal antibody, tocilizumab; • The interlukin-1 (IL-1) inhibitor, anakinra; • The interlukin-IL17 (IL-17) pathway inhibitors (ustekinumab, secukinumab, brodalumab).

Regulating against the dysregulation: new treatment options in autoinflammation.

In autoinflammatory disorders, dysregulation of the innate immune response leads to an excessive cytokine release. The disease course is often characterized by high morbidity and mortality, treatment is mostly difficult and therapeutic options are limited. In most cases, life-long control of ongoing inflammation is necessary in order to improve clinical symptoms and prevent development of damage. Steroids are helpful in many conditions, but the development of serious side effects often limits their long-term use. Other immunosuppressive, steroid-sparing medications are less effective than in the treatment of autoimmune diseases or do not show any effect. So far, anti-IL1α and/or β-blocking agents as well as an IL-6 receptor-blocking monoclonal antibody and, to a lesser extent, TNF-α blocking agents were applied in autoinflammatory disorders and significantly improved the outcome. Although these progresses were made in the last years, there are still numerous challenges in order to improve drug therapy in autoinflammation. This review summarizes the current state of new drug development and discusses advantages and disadvantages of possible targets.

Biological agents and respiratory infections: Causative mechanisms and practice management.

Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents.

Towards a stratified targeted approach with biologic treatments in rheumatoid arthritis: role of synovial pathobiology.

Rheumatoid Arthritis (RA) is a chronic, inflammatory, autoimmune disease affecting diarthrodial joints and extra-articular tissues; in the absence of an effective treatment, it is characterized by persistent symmetrical and erosive synovitis which leads to structural joint damage and lifelong disability. Several autoantibodies have been associated with RA such as rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). B cells have been shown to play a crucial role in the pathogenesis of RA by producing autoantibodies and promoting synovial inflammation through antigen presentation, T cells activation and cytokines production [1]. Although biologic agents have notably improved disease outcome and patients' quality of life, currently around 30-40% of subjects do not respond to treatment and the mechanisms leading to resistance are still not known [2]. For this reason, new prognostic biomarkers and predictors of response are needed. We and others have postulated that the development of biomarkers for patients' stratification prior therapeutic intervention may be possible through a better understanding of the different histopathological patterns present both in early and established individual RA patient and the related underlying cellular and molecular mechanisms. To date, Tumor Necrosis Factor (TNF)-α has been shown to be one of the master elements of inflammation in RA; however, even though therapies aimed at blocking this key cytokine have emerged as a major tool in the treatment of RA, a large proportion of patients (approximately 30-40%) do not achieve a meaningful clinical response assessed by either the American College of Rheumatology (ACR) or the European League Against Rheumatism (EULAR) criteria. The same limitation can be applied to the use of rituximab, a chimeric monoclonal antibody directed against CD20, which is uniquely expressed by all B-lymphocytes during the maturation process from late stage pro-B cells to memory cells. The clinical efficacy of rituximab has been proved by several clinical studies [3] but it is highly variable. Currently, NICE guidelines recommend rituximab in patients with inadequate response to a first-line biologic therapy, including at least one anti-TNFα agent independently of their pre-treatment chance to respond. In all cases, whether considering biologics used for several years in RA patients (anti-TNFα or rituximab) or relatively newer biologics in clinical use (i.e. tocilizumab, an anti-interleukin (IL) -6 receptor blocking monoclonal antibody or abatacept, a CTLA4 inhibitor fusion protein designed to target the T cell co-stimulatory signal mediated through the CD28-CD80/86 pathway), no validated biomarkers predictive of clinical response currently exist. Consequently, to date a "trial-and-error" approach is used in the prescription of biologics in RA, which has the obvious disadvantage of potentially exposing patients to drugs that they may not respond, with potential unnecessary side-effects, delaying use of an effective treatment and causing a significant economic burden to society. Therefore, identifying pre-treatment predictors of response with a customized stratification approach would be of invaluable importance in RA, also in consideration of the large number of biologics in development targeting novel pathways currently being tested in clinical trials. In this manuscript, we review existing data and provide future perspectives with regard to the role of synovial histopathology as a potential prognostic biomarker for patient stratification in RA, in particular regarding the use of specific biologic therapies.

In VitroCharacterization of the Anti-PD-1 Antibody Nivolumab, BMS-936558, andIn VivoToxicology in Non-Human Primates

The programmed death-1 (PD-1) receptor serves as an immunologic checkpoint, limiting bystander tissue damage and preventing the development of autoimmunity during inflammatory responses. PD-1 is expressed by activated T cells and downmodulates T-cell effector functions upon binding to its ligands, PD-L1 and PD-L2, on antigen-presenting cells. In patients with cancer, the expression of PD-1 on tumor-infiltrating lymphocytes and its interaction with the ligands on tumor and immune cells in the tumor microenvironment undermine antitumor immunity and support its rationale for PD-1 blockade in cancer immunotherapy. This report details the development and characterization of nivolumab, a fully human IgG4 (S228P) anti-PD-1 receptor-blocking monoclonal antibody. Nivolumab binds to PD-1 with high affinity and specificity, and effectively inhibits the interaction between PD-1 and its ligands. In vitro assays demonstrated the ability of nivolumab to potently enhance T-cell responses and cytokine production in the mixed lymphocyte reaction and superantigen or cytomegalovirus stimulation assays. No in vitro antibody-dependent cell-mediated or complement-dependent cytotoxicity was observed with the use of nivolumab and activated T cells as targets. Nivolumab treatment did not induce adverse immune-related events when given to cynomolgus macaques at high concentrations, independent of circulating anti-nivolumab antibodies where observed. These data provide a comprehensive preclinical characterization of nivolumab, for which antitumor activity and safety have been demonstrated in human clinical trials in various solid tumors.

Combination Of 4T's Score and Rapid Gel Centrifugation Assay Excludes HIT In a Prospective Cohort Study

The diagnosis of heparin-Induced thrombocytopenia (HIT) is based on the presence of a compatible clinical picture combined with laboratory evidence of heparin-dependent, platelet-activating IgG antibodies. The 4T's Score is a clinical prediction rule that determines the likelihood that a patient has HIT before laboratory testing is performed. A rapid assay (H/PF4-PaGIA, Diamed, Switzerland) uses gel centrifugation to measure binding of antibodies to antigen-coated polystyrene beads (15 min turnover time). The purpose of this study is to evaluate the clinical utility of a diagnostic strategy which combines the 4T's Score with a H/PF4-PaGIA result to guide management of patients with suspected HIT while awaiting results of the serotonin-release assay (SRA). MethodsProspective cohort study of 538 consecutive adult patients with suspected HIT at 4 Canadian hospitals. Physicians completed a standardized 4T's Score sheet and the H/PF4-PaGIA was performed using fresh plasma in a central lab by technologists blinded to the 4T's Score (frozen plasma was used for 85 patients due to disruptions in worldwide availability of the assay.) The SRA and an in-house IgG anti-PF4/H enzyme-immunoassay (EIA) were performed on all patients by blinded technologists. Serologically-confirmed HIT (“HIT positive”) was defined as >50% serotonin release (mean) at three reaction conditions (0.1 U/mL heparin; 0.3 U/mL heparin; enoxaparin, 0.1 U/ml), as well as inhibition (<20% release or >50% inhibition) at 100 U/mL heparin and in the presence of Fc receptor-blocking monoclonal antibody, and a positive EIA. Thrombotic events, major bleeding events, and mortality were captured at day 30.Recommendations for management of patients while awaiting the SRA: patients with a Low 4T's Score (irrespective of H/PF4-PaGIA result) and patients with an Intermediate 4T's Score and negative H/PF4-PaGIA were to receive low-dose danaparoid or fondaparinux. Therapeutic-dose non-heparin anticoagulation was recommended for all patients with an Intermediate 4T's Score and positive H/PF4-PaGIA and for all patients with a High 4T's Score irrespective of H/PF4-PaGIA result.The primary outcome measure was the frequency of management failures defined as a patient with serologically-confirmed HIT who had one of the following combinations of diagnostic testing (a) Low 4T's Score and negative H/PF4-PaGIA; (b) Low 4T's Score and positive H/PF4-PaGIA or (c) Intermediate 4T's Score and negative H/PF4-PaGIA. Results527 patients with mean age 66.5 yr (sd 15.4) were analyzed; 11 patients with missing diagnostic testing results were excluded. Clinical outcomes of the management of patients according to the diagnostic strategy will be reported separately. Results of diagnostic accuracy of the 4T's Score and H/PF4-PaGIA compared to the SRA are provided below.HIT Negative (i.e., SRA-)HIT Positive (i.e., SRA+)TotalH/PF4-PaGIA -H/PF4 PaGIA +H/PF4 PaGIA indeterminateH/PF4 PaGIA -H/PF4 PaGIA +4T's ScoreLow27833226321Intermediate137161010164High243001542Total439523231527The prevalence of serologically-confirmed HIT in the study population was 6.5%. Two patients with indeterminate SRAs but IgG>1.0 were reported as HIT Positive.A negative H/PF4-PaGIA result reduced the probability of HIT based on the 4T's Score from 2.5% to 0.7% (95% CI: 0.1-2.6%) in the Low group, from 6.1% to 0% (95% CI: 0-2.7%) in the Intermediate group and from 35.7% to 0% (95% CI: 0-14.3%) in the High group. A positive H/PF4-PaGIA result increased the probability of HIT based on the 4T's Score to 15.4% (Low 4T's), 38.5% (intermediate 4T's) and 83.3% (High 4T's).The proportion of management failures was 1.5% (95% CI : 0.7%-3.0%). Of the 8 patients who were identified as management failures, 2 (Low 4T's) had a negative H/PF4-PaGIA. Out of 33 HIT Positive patients, 8 (24.2%) would have been missed based on a Low 4T's Score alone and 2 (6.1%) based on negative H/PF4-PaGIA alone. The combination of a Low or Intermediate 4T's Score and a negative H/PF4-PaGIA result had a negative predictive value for HIT of 99.5% (95% CI: 98.3-99.9). ConclusionsThe proportion of management failures was low (1.5%) and within acceptable limits (95% CI : 0.7%-3.0%). Combining the 4T's Score with the result of H/PF4-PaGIA excludes the diagnosis of HIT in the majority of patients with a Low or Intermediate probability for HIT and raises the likelihood of HIT in patients with a High probability. Disclosures:Linkins:BioRad DiaMed: PaGIA assays purchased at cost for study Other. Bates:BioRad Diamed: provided assays for study at cost Other. Lee:BioRad Diamed: provided assays for study at cost Other. Warkentin:GSK: Research Funding; WL Gore: Consultancy; Immucor GTI Diagnostics: Research Funding; Paringenix: Consultancy; Pfizer Canada: Honoraria; BioRad Diamed: provided assays for study at cost, provided assays for study at cost Other.

Cetuximab Reverses the Warburg Effect by Inhibiting HIF-1–Regulated LDH-A

Hypoxia-inducible factor-1 (HIF-1) plays a critical role in reprogramming cancer metabolism toward aerobic glycolysis (i.e., the Warburg effect), which is critical to supplying cancer cells with the biomass needed for proliferation. Previous studies have shown that cetuximab, an EGF receptor-blocking monoclonal antibody, downregulates the alpha subunit of HIF-1 (HIF-1α) through the inhibition of EGF receptor downstream cell signaling and that downregulation of HIF-1α is required for cetuximab-induced antiproliferative effects. However, the mechanism underlying these actions has yet to be identified. In this study, we used the Seahorse XF96 extracellular flux analyzer to assess the effect of cetuximab treatment on changes in glycolysis and mitochondrial respiration, the two major energy-producing pathways, in live cells. We found that cetuximab downregulated lactate dehydrogenase A (LDH-A) and inhibited glycolysis in cetuximab-sensitive head and neck squamous cell carcinoma (HNSCC) cells in an HIF-1α downregulation-dependent manner. HNSCC cells with acquired cetuximab resistance expressed a high level of HIF-1α and were highly glycolytic. Overexpression of a HIF-1α mutant (HIF-1α/ΔODD) conferred resistance to cetuximab-induced G1 phase cell-cycle arrest, which could be overcome by knockdown of LDH-A expression. Inhibition of LDH-A activity with oxamate enhanced the response of cetuximab-resistant cells to cetuximab. Cetuximab had no noticeable inhibitory effect on glycolysis in nontransformed cells. These findings provide novel mechanistic insights into cetuximab-induced cell-cycle arrest from the perspective of cancer metabolism and suggest novel strategies for enhancing cetuximab response.

A phase III open-label study of nivolumab (anti-PD-1; BMS-936558; ONO-4538) versus investigator’s choice in advanced melanoma patients progressing post anti-CTLA-4 therapy.

TPS9105^ Background: Despite the recent approval of ipilimumab and vemurafenib for advanced melanoma, there is still a large unmet need for patients (pts) who have progressed on anti-CTLA-4 therapy and a BRAF inhibitor (depending on BRAF status). Programmed death-1 (PD-1) is a co-stimulation inhibitory receptor that negatively regulates T-cell activation and is upregulated in tumor-infiltrating lymphocytes. Upregulation of PD-1 is also associated with advanced disease in melanoma. Nivolumab, an anti-PD-1 receptor blocking monoclonal antibody, demonstrated durable antitumor activity in a phase 1 study in 106 pts with advanced melanoma with objective responses (OR) observed in 31% and stable disease ≥24 weeks in 6% with a manageable safety profile (Topalian SL et al; ESMO 2012 [Abstr 453P]). Here we describe a phase III study designed to compare the clinical benefit of nivolumab to chemotherapy of investigator’s choice in previously treated pts with unresectable or metastatic melanoma. Methods: In this two arm open-label study, approximately 390 pts will be randomized 2:1 to receive either nivolumab 3 mg/kg IV every two weeks (Arm A) or either dacarbazine 1000 mg/m2 IV or carboplatin AUC6/paclitaxel 175 mg/m2 IV every 3 weeks (Arm B) until disease progression or treatment discontinuation. Pts included are those with ≤2 regimens for advanced melanoma who have progressed on anti-CTLA-4 therapy as well as a BRAF inhibitor if BRAF V600-mutation positive. Pts without active brain metastases are eligible. All pts require baseline fresh biopsy to determine PD-L1 expression. Pts will be stratified by tumor PD-L1 expression, BRAF status, and prior anti-CTLA-4 best response. Tumor response per RECIST 1.1 will be assessed 9 weeks following randomization and every 6 weeks thereafter for the first year. After the first year, response will be assessed every 12 weeks until disease progression or treatment discontinuation. The co-primary endpoints are overall survival (OS) and OR rate. Secondary endpoints include progression-free survival, correlation of PD-L1 expression with clinical outcome, and health-related quality of life. Clinical trial information: NCT01721746.

An open-label, randomized, phase II study of nivolumab (anti-PD-1; BMS-936558; ONO-4538) given sequentially with ipilimumab in patients (pts) with advanced or metastatic melanoma (MEL).

TPS9107^ Background: Programmed death-1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) are immune checkpoint receptors that attenuate T-cell responses and contribute to immune evasion by tumor cells. Nivolumab is a PD-1 receptor blocking monoclonal antibody that has shown clinical activity in phase 1 trials with various tumor types including MEL. Ipilimumab is an anti-CTLA-4 monoclonal antibody approved for advanced or metastatic MEL. Preclinical data suggest that combined PD-1 and CTLA-4 receptor blockade may improve antitumor activity in MEL, with PD-1 blockade upregulating CTLA-4 expression and CTLA-4 blockade upregulating PD-1 expression on tumor-infiltrating T cells. We describe a phase II study evaluating nivolumab administered sequentially with ipilimumab in pts with advanced (unresectable stage III) or metastatic (stage IV) MEL. Methods: This open-label, phase II study will enroll approximately 80 pts. During the induction period, pts will be randomized 1:1 to either nivolumab (3 mg/kg, q2w) from Weeks (Wk) 1-13 followed by ipilimumab (3 mg/kg, q3w) from Wks 14-25, or ipilimumab followed by nivolumab at the same doses and schedules. All pts will then receive nivolumab (3 mg/kg, q2wk) during the continuation period until disease progression or unacceptable toxicity, for ≤2 years from initial study treatment. Pts may be treatment-naive or have disease recurrence or progression after one prior systemic therapy, excluding prior anti-PD-1, anti-CTLA-4, or a BRAF inhibitor. The primary endpoint is the incidence of treatment-related Grade 3–5 adverse events (AEs) during the induction period. Secondary endpoints are response rate at Wk 25 and progression rates at Wks 13 and 25. Exploratory endpoints include safety and tolerability; overall survival; pt-level time course of treatment-related grade 3–5 AEs, response, progression, treatment discontinuation, and death; the association of changes in pharmacodynamic immune markers from baseline to Wk 13 and Wk 25 and clinical response; the association between baseline immunological parameters and clinical response; and immune-related single nucleotide polymorphisms. Clinical trial information: NCT01783938.