Pharmacokinetics, pharmacodynamics and safety of a human anti-IL-6 monoclonal antibody (sirukumab) in healthy subjects in a first-in-human study

Systemic lupus erythematosus: pathogenesis and targeted therapy

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by dysregulated immune responses and autoantibody production, which affects multiple organs and varies in clinical presentation and disease severity. The development of SLE is intricate, encompassing dysregulation within the immune system, a collapse of immunological tolerance, genetic susceptibilities to the disease, and a variety of environmental factors that can act as triggers. This review provides a comprehensive discussion of the pathogenesis and treatment strategies of SLE and focuses on the progress and status of traditional and emerging treatment strategies for SLE. Traditional treatment strategies for SLE have mainly employed non-specific approaches, including cytotoxic and immunosuppressive drugs, antimalarials, glucocorticoids, and NSAIDs. These strategies are effective in mitigating the effects of the disease, but they are not a complete cure and are often accompanied by adverse reactions. Emerging targeted therapeutic drugs, on the other hand, aim to control and treat SLE by targeting B and T cells, inhibiting their activation and function, as well as the abnormal activation of the immune system. A deeper understanding of the pathogenesis of SLE and the exploration of new targeted treatment strategies are essential to advance the treatment of this complex autoimmune disease.

The IL-6 hypothesis in COVID-19: A phase 2, randomised, double-blind, placebo-controlled study to evaluate the efficacy and safety of free IL-6 sequestration by the monoclonal antibody sirukumab in severe and critical COVID-19

BACKGROUND

Upregulation of IL-6 has been associated with worse prognosis in COVID-19 patients. Impact on IL-6 signalling has mostly been limited to clinical outcomes in IL-6 receptor antagonist trials.

METHODS

We performed a phase 2, randomised, double-blind, placebo-controlled trial (NCT04380961) of US-based hospitalised adults (<85 years) with laboratory-confirmed SARS-CoV-2 infection and severe (low levels of supplemental oxygen) or critical disease (high levels of oxygen supplementation). Patients received sirukumab 5 mg/kg or placebo single dose IV on Day 1 plus standard of care. The primary endpoint was time to sustained clinical improvement up to Day 28 based on an ordinal scale. Secondary endpoints included clinical improvement, all-cause mortality, and safety. Following an interim analysis, the protocol was amended to only recruit patients with critical COVID-19.

FINDINGS

From May 2020 to March 2021, 209 patients were randomised; 112 had critical disease (72 sirukumab, 40 placebo) at baseline. Median time to sustained clinical improvement in critical patients was 17 and 23 days in the sirukumab and placebo groups (HR, 1∙1; 95% CI, 0∙66-1∙88; p > 0∙05). At Day 28, 59∙4% versus 55∙0% of patients achieved clinical improvement with sirukumab versus placebo and rates of all-cause mortality were 24∙6% versus 30∙0%, respectively. Rates of grade ≥3 adverse events were comparable between the sirukumab and placebo groups (25∙9% vs 32∙9%; all patients).

INTERPRETATION

In critical COVID-19 patients who received sirukumab, there was no statistically significant difference in time to sustained clinical improvement versus placebo despite objective sequestration of circulating IL-6, questioning IL-6 as a key therapeutic target in COVID-19.

Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

Comparison of the efficacy and safety of olokizumab at different dosages in patients with active rheumatoid arthritis: a network meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to assess the relative efficacy and safety of olokizumab at different dosages in patients with active rheumatoid arthritis (RA).

METHODS

We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of olokizumab administered intravenously to RA patients at 64 mg/kg every 2 or 4 weeks (Q2 or Q4W).

RESULTS

Five RCTs comprising 2609 patients met the inclusion criteria. Both olokizumab Q2 and Q4W treatments achieved a significant American College of Rheumatology 20% response (ACR20) compared with the placebo (odds ratio [OR] 3.21, 95% credible interval [CrI] 2.53-4.09; OR 3.05, 95% CrI 2.43-3.86). However, olokizumab Q2W was associated with the most favorable surface using the cumulative ranking curve (SUCRA) for the ACR20 response rate. The ranking probability based on the SUCRA indicated that olokizumab Q2W had the highest probability of being considered the best treatment option for achieving the ACR20 response rate, followed by olokizumab Q4W, adalimumab, and placebo. The ACR50 and 70 response rates showed a similar distribution pattern to the ACR20 response rate, except that olokizumab Q4W had a higher-ranking probability than olokizumab Q2W for ACR50. The SUCRA rating likelihood of adverse events (AEs) and withdrawal due to AEs showed that a placebo was likely to be the best intervention.

CONCLUSION

Both olokizumab Q2 and Q4W were efficacious and well-tolerated treatments for active RA.

The role of inflammation in autoimmune disease: a therapeutic target

Autoimmune diseases (AIDs) are immune disorders whose incidence and prevalence are increasing year by year. AIDs are produced by the immune system's misidentification of self-antigens, seemingly caused by excessive immune function, but in fact they are the result of reduced accuracy due to the decline in immune system function, which cannot clearly identify foreign invaders and self-antigens, thus issuing false attacks, and eventually leading to disease. The occurrence of AIDs is often accompanied by the emergence of inflammation, and inflammatory mediators (inflammatory factors, inflammasomes) play an important role in the pathogenesis of AIDs, which mediate the immune process by affecting innate cells (such as macrophages) and adaptive cells (such as T and B cells), and ultimately promote the occurrence of autoimmune responses, so targeting inflammatory mediators/pathways is one of emerging the treatment strategies of AIDs. This review will briefly describe the role of inflammation in the pathogenesis of different AIDs, and give a rough introduction to inhibitors targeting inflammatory factors, hoping to have reference significance for subsequent treatment options for AIDs.

Relative effectiveness and safety of interleukin-6 and Janus kinase inhibitors versus adalimumab in patients with rheumatoid arthritis: a network meta-analysis

OBJECTIVE

The relative efficacy and tolerability of interleukin‑6 (IL-6) and Janus kinase (JAK) inhibitor therapies were compared with those of adalimumab in patients with rheumatoid arthritis (RA) and inadequate responses to methotrexate (MTX).

METHODS

We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of IL‑6 inhibitors, JAK inhibitors, and adalimumab in patients with RA and inadequate responses to MTX.

RESULTS

Seven RCTs, which included 4428 patients (1066 for IL‑6 inhibitors and 3362 for JAK inhibitors), met the inclusion criteria. IL‑6 inhibitors were placed at the top left of the league table diagonal (Odds ratio, OR 1.43; 95% CrI 1.12-1.82) as these were correlated with the most beneficial ACR20 response rate. Conversely, the placebo was placed at the bottom right of the league table diagonal as it was correlated with the least desirable effects. IL‑6 and JAK inhibitors produced a substantial ACR20 response relative to adalimumab. The surface under the cumulative ranking curve (SUCRA) revealed that treatment with IL‑6 inhibitors had the greatest ability to reach the ACR20 response rate (SUCRA = 0.826), followed by treatment with JAK inhibitors (SUCRA = 0.672) and adalimumab (SUCRA = 0.001). The ACR50 and ACR70 rates displayed patterns similar to the ACR20 response rate. With regard to serious adverse events (SAEs), the SUCRA rating likelihood showed that adalimumab was likely to be the best intervention, followed by JAK and IL‑6 inhibitors.

CONCLUSION

Both IL‑6 and JAK inhibitors are more effective than adalimumab and have similar effects in patients with RA and an inadequate response to MTX. Adalimumab is likely to be safer than JAK and IL‑6 inhibitors.

Pharmacokinetics, pharmacodynamics, safety, and immunogenicity of Gerilimzumab (GB224), a recombinant humanized interleukin-6 monoclonal antibody, in healthy Chinese adults: A randomized controlled dose-escalation study

OBJECTIVES

This study aimed to investigate the safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of Gerilimzumab (GB224), a recombinant humanized IgG1λ monoclonal antibody against interleukin-6, in healthy Chinese adults.

METHODS

Fifty-eight subjects were randomly assigned to receive a single subcutaneous dose of 2, 5, 10, 15, 20, 30 mg GB224 or placebo. Safety assessments were performed, and blood samples were collected for PK, PD, and immunogenicity analyses during a follow-up of 112 days.

RESULTS

The most frequent adverse event was decreased fibrinogen (43.1%). GB224 was absorbed relatively fast with a median T_max of 48 h (24-168 h) but eliminated slowly with a long mean half-life (839.38-981.63 h). Dose proportionality was shown to be in the dose range of 10-30 mg. A dose-dependent increase in serum interleukin-6 concentration from baseline was observed in the subjects receiving GB224. Only two subjects tested positive for antidrug antibodies after administration of GB224.

CONCLUSION

GB224 had a well-tolerated safety profile, desirable PK, and a low immunogenicity following a single-dose subcutaneous administration in healthy Chinese subjects. These findings warrant further investigation.

Multiscale pharmacokinetic modeling of systemic exposure of subcutaneously injected biotherapeutics

Subcutaneously injected formulations have been developed for many biological products including monoclonal antibodies (mAbs). A knowledge gap nonetheless remains regarding the absorption and catabolism mechanisms and kinetics of a large molecule at the administration site. A multiscale pharmacokinetic (PK) model was thus developed by coupling multiphysics simulations of subcutaneous (SC) absorption kinetics with whole-body pharmacokinetic (PK) modeling, bridged by consideration of the presystemic clearance by the initial lymph. Our local absorption simulation of SC-injected albumin enabled the estimation of its presystemic clearance and led to the whole-body PK modeling of systemic exposure. The local absorption rate of albumin was found to be influential on the PK profile. Additionally, nineteen mAbs were explored via this multiscale simulation and modeling framework. The computational results suggest that stability propensities of the mAbs are correlated with the presystemic clearance, and electrostatic charges in the complementarity-determining region influence the local absorption rate. Still, this study underscores a critical need to experimentally determine various biophysical characteristics of a large molecule and the biomechanical properties of human skin tissues.

Identifying biophysical assays and in silico properties that enrich for slow clearance in clinical-stage therapeutic antibodies

Understanding the pharmacokinetic (PK) properties of a drug, such as clearance, is a crucial step for evaluating efficacy. The PK of therapeutic antibodies can be complex and is influenced by interactions with the target, Fc-receptors, anti-drug antibodies, and antibody intrinsic factors. A growing body of literature has linked biophysical properties of antibodies, particularly nonspecific-binding propensity, hydrophobicity and charged regions to rapid clearance in preclinical species and selected human PK studies. A clear understanding of the connection between biophysical properties and their impact on PK would allow for early selection and optimization of antibodies and reduce costly attrition during clinical trials due to sub-optimal human clearance. Due to the difficulty in obtaining large and unbiased human PK data, previous studies have focused mostly on preclinical PK. For this study, we obtained and curated the most comprehensive clinical PK dataset to date and calculated accurate estimates of linear clearance for 64 monoclonal antibodies ranging from investigational candidates in Phase 2 trials to marketed products. This allows for the first time a deep analysis of the influence of biophysical and sequence-based in silico properties directly on human clearance. We use statistical analysis and a Random Forest classifier to identify properties that have the greatest influence in our dataset. Our findings indicate that in vitro poly-specificity assay and in silico estimated isoelectric point can discriminate fast and slow clearing antibodies, extending previous observations on preclinical clearance. This provides a simple yet powerful approach to select antibodies with desirable PK during early-stage screening.

Mesenchymal stem cell-derived microvesicles improve intestinal barrier function by restoring mitochondrial dynamic balance in sepsis rats

BACKGROUND

Sepsis is a major cause of death in ICU, and intestinal barrier dysfunction is its important complication, while the treatment is limited. Recently, mesenchymal stem cell-derived microvesicles (MMVs) attract much attention as a strategy of cell-free treatment; whether MMVs are therapeutic in sepsis induced-intestinal barrier dysfunction is obscure.

METHODS

In this study, cecal ligation and puncture-induced sepsis rats and lipopolysaccharide-stimulated intestinal epithelial cells to investigate the effect of MMVs on intestinal barrier dysfunction. MMVs were harvested from mesenchymal stem cells and were injected into sepsis rats, and the intestinal barrier function was measured. Afterward, MMVs were incubated with intestinal epithelial cells, and the effect of MMVs on mitochondrial dynamic balance was measured. Then the expression of mfn1, mfn2, OPA1, and PGC-1α in MMVs were measured by western blot. By upregulation and downregulation of mfn2 and PGC-1α, the role of MMVs in mitochondrial dynamic balance was investigated. Finally, the role of MMV-carried mitochondria in mitochondrial dynamic balance was investigated.

RESULTS

MMVs restored the intestinal barrier function by improving mitochondrial dynamic balance and metabolism of mitochondria. Further study revealed that MMVs delivered mfn2 and PGC-1α to intestinal epithelial cells, and promoted mitochondrial fusion and biogenesis, thereby improving mitochondrial dynamic balance. Furthermore, MMVs delivered functional mitochondria to intestinal epithelial cells and enhanced energy metabolism directly.

CONCLUSION

MMVs can deliver mfn2, PGC-1α, and functional mitochondria to intestinal epithelial cells, synergistically improve mitochondrial dynamic balance of target cells after sepsis, and restore the mitochondrial function and intestinal barrier function. The study illustrated that MMVs might be a promising strategy for the treatment of sepsis.

Therapeutic Advances in Diabetes, Autoimmune, and Neurological Diseases

Since 2015, 170 small molecules, 60 antibody-based entities, 12 peptides, and 15 gene- or cell-therapies have been approved by FDA for diverse disease indications. Recent advancement in medicine is facilitated by identification of new targets and mechanisms of actions, advancement in discovery and development platforms, and the emergence of novel technologies. Early disease detection, precision intervention, and personalized treatments have revolutionized patient care in the last decade. In this review, we provide a comprehensive overview of current and emerging therapeutic modalities developed in the recent years. We focus on nine diseases in three major therapeutics areas, diabetes, autoimmune, and neurological disorders. The pathogenesis of each disease at physiological and molecular levels is discussed and recently approved drugs as well as drugs in the clinic are presented.

Modeling and Simulation to Support Phase Ib/IIa Dose Selection for WBP216, A Long Half-Life Fully Human Monoclonal Antibody Against Interleukin-6

WBP216 is an innovative IL-6 antibody, presenting high affinity to IL-6 and a long half-life (40–60 days). To optimize the dosage regimen for future clinical trials, pharmacokinetics (PK) and pharmacodynamics (PD) of WBP216 would be firstly characterized in Chinese rheumatoid arthritis (RA) patients. PK, CRP and DAS28 data of WBP216 were collected from 26 RA patients in a single ascending dose study. Non-linear mixed effects modeling was used for a population PK/PD analysis. A two-compartment model with a sequential zero-first order absorption and a first order elimination best described PK behavior of WBP216. Apparent systemic clearance was 0.015 L/h, central volume was 8.04 L. CRP as the fast-decreasing endpoint and DAS28 as the slow-reacting endpoint were both fitted well through an indirect response model. The baseline of ALT and free IL-6 were found associated with PK/PD parameters during covariates exploration. Simulation results confirmed that a loading dose regimen either of administration at weeks 0, 2, and 6 or doubling the maintenance dose level, followed by maintenance dosing of 75–150 mg every 8 weeks, was expected to provide a best risk/benefit ratio in future clinical studies. We hope this first PK/PD study of WBP216 in Chinese RA patients will help in the clinical development of WBP216 in future and provide a reference to the dosage optimization of similar antibodies with long half-life.

Clinical Trial Registration:CTR20170306

A Multicentre, Randomised, Double-Blind, Placebo-Controlled, Parallel-Group Study to Evaluate the Efficacy and Safety of Sirukumab in the Treatment of Giant Cell Arteritis

INTRODUCTION

To evaluate the efficacy and safety of sirukumab in giant cell arteritis (GCA).

METHODS

In this multicentre, randomised, double-blind, placebo-controlled, two-part phase 3 trial (NCT02531633; Part A [52-week double-blind treatment]; Part B [104-week follow-up]), patients with GCA were randomised (3:3:2:2:2) to sirukumab 100 mg every 2 weeks plus 6-month or 3-month prednisone taper, sirukumab 50 mg every 4 weeks plus 6-month prednisone taper, or placebo every 2 weeks plus 6-month or 12-month prednisone taper. The primary endpoint was the proportion of patients in sustained remission at week 52. Secondary endpoints included disease flare and safety. The study was terminated early (October 2017; sponsor decision).

RESULTS

Of 161 patients randomised (sirukumab: n = 107; placebo: n = 54), 28 (17.4%) completed week 52 (median treatment duration: 24-30 weeks). In a revised intent-to-treat (ITT) subgroup (completed week 52 or discontinued before study termination [n = 55]); six patients (all receiving sirukumab) achieved the primary endpoint. In the ITT population (n = 161), the proportion of patients with flares (week 2-52) was lower with sirukumab (18.4-30.8%) than placebo (37.0-40.0%). The proportion of patients with flares (week 2-12) was highest with sirukumab 100 mg every 2 weeks plus 3-month prednisone taper (23.1%). In Part A, 94.4% of patients reported ≥ 1 treatment-emergent adverse event (TEAE); 19.3% reported serious TEAEs. The proportions of patients with TEAEs were generally similar across treatment arms. No deaths occurred.

CONCLUSIONS

Although data were limited due to early termination and shortened treatment duration, sirukumab treatment resulted in numerically lower proportions of patients with flare by week 52 versus placebo, with no unexpected safety findings.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02531633.

Interleukin-6 in Rheumatoid Arthritis

The role of interleukin (IL)-6 in health and disease has been under a lot of scrutiny in recent years, particularly during the recent COVID-19 pandemic. The inflammatory pathways in which IL-6 is involved are also partly responsible of the development and progression of rheumatoid arthritis (RA), opening interesting perspectives in terms of therapy. Anti-IL-6 drugs are being used with variable degrees of success in other diseases and are being tested in RA. Results have been encouraging, particularly when anti-IL-6 has been used with other drugs, such as metothrexate (MTX). In this review we discuss the main immunologic aspects that make anti-IL-6 a good candidate in RA, but despite the main therapeutic options available to target IL-6, no gold standard treatment has been established so far.

Exploring pharmacological approaches for managing cytokine storm associated with pneumonia and acute respiratory distress syndrome in COVID-19 patients

Sars-CoV-2 complications include pneumonia and acute respiratory distress syndrome (ARDS), which require intensive care unit admission. These conditions have rapidly overwhelmed healthcare systems, with detrimental effects on the quality of care and increased mortality. Social isolation strategies have been implemented worldwide with the aim of reducing hospital pressure. Among therapeutic strategies, the use of immunomodulating drugs, to improve prognosis, seems promising. Particularly, since pneumonia and ARDS are associated with a cytokine storm, drugs belonging to therapeutic classes as anti-IL-6, anti-TNF, and JAK inhibitors are currently studied. In this article, we discuss the potential advantages of the most promising pharmacological approaches.

State of the art in immunotherapy of neuroblastoma

Neuroblastoma (NB) is a common and deadly malignancy mostly observed in children. Evolution of therapeutic options for NB led to the addition of immunotherapeutic modalities to the previously recruited chemotherapeutic options. Molecular studies of the NB cells resulted in the discovery of many tumor-associated genes and antigens such as MYCN gene and GD2. MYCN gene and GD2 surface antigen are two of the most practical discoveries regarding immunotherapy of neuroblastoma. The GD2 antigen has been targeted in many animal and human studies including Phase III clinical trials. Even though these antigens have changed the face of pediatric neuroblastoma, they do not take as much credit in immunotherapy of adult-onset neuroblastoma. Monoclonal antibodies have been designed to detect this antigen on the surface of NB tumor cells. Despite bettering the outcomes for NB patients, current therapies still fail in many cases. Studies are underway to discover more specific tumor-associated antigens and more effective treatment options. In the current narrative, immunotherapy of NB - from emerging of this therapeutic backbone in NB to the latest discoveries regarding this malignancy - has been reviewed.

Post-stroke inflammation-target or tool for therapy?

Inflammation is currently considered a prime target for the development of new stroke therapies. In the acute phase of ischemic stroke, microglia are activated and then circulating immune cells invade the peri-infarct and infarct core. Resident and infiltrating cells together orchestrate the post-stroke inflammatory response, communicating with each other and the ischemic neurons, through soluble and membrane-bound signaling molecules, including cytokines. Inflammation can be both detrimental and beneficial at particular stages after a stroke. While it can contribute to expansion of the infarct, it is also responsible for infarct resolution, and influences remodeling and repair. Several pre-clinical and clinical proof-of-concept studies have suggested the effectiveness of pharmacological interventions that target inflammation post-stroke. Experimental evidence shows that targeting certain inflammatory cytokines, such as tumor necrosis factor, interleukin (IL)-1, IL-6, and IL-10, holds promise. However, as these cytokines possess non-redundant protective and immunoregulatory functions, their neutralization or augmentation carries a risk of unwanted side effects, and clinical translation is, therefore, challenging. This review summarizes the cell biology of the post-stroke inflammatory response and discusses pharmacological interventions targeting inflammation in the acute phase after a stroke that may be used alone or in combination with recanalization therapies. Development of next-generation immune therapies should ideally aim at selectively neutralizing pathogenic immune signaling, enhancing tissue preservation, promoting neurological recovery and leaving normal function intact.

Cellular and Molecular Therapeutic Targets in Inflammatory Bowel Disease-Focusing on Intestinal Barrier Function

The human gut relies on several cellular and molecular mechanisms to allow for an intact and dynamical intestinal barrier. Normally, only small amounts of luminal content pass the mucosa, however, if the control is broken it can lead to enhanced passage, which might damage the mucosa, leading to pathological conditions, such as inflammatory bowel disease (IBD). It is well established that genetic, environmental, and immunological factors all contribute in the pathogenesis of IBD, and a disturbed intestinal barrier function has become a hallmark of the disease. Genetical studies support the involvement of intestinal barrier as several susceptibility genes for IBD encode proteins with key functions in gut barrier and homeostasis. IBD patients are associated with loss in bacterial diversity and shifts in the microbiota, with a possible link to local inflammation. Furthermore, alterations of immune cells and several neuro-immune signaling pathways in the lamina propria have been demonstrated. An inappropriate immune activation might lead to mucosal inflammation, with elevated secretion of pro-inflammatory cytokines that can affect the epithelium and promote a leakier barrier. This review will focus on the main cells and molecular mechanisms in IBD and how these can be targeted in order to improve intestinal barrier function and reduce inflammation.

Sirukumab for the treatment of rheumatoid arthritis: update on sirukumab, 2018

INTRODUCTION

Interleukin-6 (IL-6) is well-known for its pro-inflammatory properties, has been proven to target a wide range of cells in the joint, and has been implicated in extra-articular and articular manifestations in rheumatoid arthritis (RA). Tocilizumab (TCZ) is now widely used in patients with active RA and a number of additional agents that target the IL-6 pathways are under development, including sirukumab (SRK). Areas covered: SRK is an IgG1κ human anti-IL-6 monoclonal antibody which binds to IL-6 and prevents IL-6-mediated downstream effects. Initial trial results in phase-III studies in patients with RA seemed promising, showing improved results in patients with moderate-to-severe RA. Data derive from the phase-II study and the various SIRROUND studies (phase III). Expert commentary: The available data show that SRK50 mg every 4 weeks or 100 mg every 2 weeks will be effective in treating the RA population, with clinical improvements as early as week 2 and sustained over time. The adverse-event profile seems to be similar to TCZ, except for an increased mortality post open-label studies due to infections and cardiovascular events, our knowledge of which will be deepened with post-marketing surveillance and registry data.

Pharmacokinetics and C-reactive protein modelling of anti-interleukin-6 antibody (PF-04236921) in healthy volunteers and patients with autoimmune disease

AIMS

The purpose of this study was to characterize pharmacokinetics (PK) of PF-04236921, a novel anti-interleukin-6 monoclonal antibody, and its pharmacokinetic/pharmacodynamic (PK/PD) relationship on serum C-reactive protein (CRP) in healthy volunteers and patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and Crohn's disease (CD).

METHODS

Population modelling analyses were conducted using nonlinear mixed effects modelling. Data from two phase 1 healthy volunteer studies, a phase 1 RA study, a Phase 2 CD study and a Phase 2 SLE study were included.

RESULTS

A two-compartment model with first order absorption and linear elimination and a mechanism-based indirect response model adequately described the PK and PK/PD relationships, respectively. Central compartment volume of distribution (Vc) positively correlated with body weight. Clearance (CL) negatively correlated with baseline albumin concentration and positively correlated with baseline CRP and creatinine clearance, and was slightly lower in females. After correcting for covariates, CL in CD subjects was approximately 60% higher than other populations. Maximum inhibition of PF-04236921 on CRP production (I_max ) negatively correlated with baseline albumin. I_max positively correlated with baseline CRP and the relationship was captured as a covariance structure in the PK/PD model.

CONCLUSION

Integrated population PK and PK/PD models of PF-04236921 have been developed using pooled data from healthy subjects and autoimmune patients. The current model enables simulation of PF-04236921 PK and PD profiles under various dosing regimens and patient populations and should facilitate future clinical study of PF-04236921 and other anti-interleukin-6 monoclonal antibodies.

Exposure-Response Modeling Analyses for Sirukumab, a Human Monoclonal Antibody Targeting Interleukin 6, in Patients With Moderately to Severely Active Rheumatoid Arthritis

To characterize the dose-exposure-response relationship of sirukumab, an anti-interleukin 6 human monoclonal antibody, in the treatment of moderately to severely active rheumatoid arthritis (RA), we conducted exposure-response (E-R) modeling analyses based on data from two pivotal phase 3 placebo-controlled trials of sirukumab in patients with RA who were inadequate responders to nonbiologic disease-modifying antirheumatic drugs or anti-tumor necrosis factor α agents. A total of 2176 patients were included for the analyses and received subcutaneous administration of either placebo or sirukumab 50 mg every 4 weeks or 100 mg every 2 weeks. The clinical endpoints were 20%, 50%, and 70% improvement in the American College of Rheumatology response criteria (ie, ACR20, ACR50, and ACR70), and 28-joint Disease Activity Index Score (DAS28) using C-reactive protein. To provide a thorough assessment of the sirukumab E-R relationship, 2 pharmacokinetic/pharmacodynamic modeling approaches were implemented, including joint longitudinal modeling (ie, indirect response modeling of the time course of the 2 clinical endpoints) and landmark analyses (ie, direct linking of selected pharmacokinetic parameters to response at week 16 or 24). Results from both modeling analyses were generally consistent, and collectively suggested that the sirukumab subcutaneous dose of 50 mg every 4 weeks would produce near-maximal efficacy. No covariates identified in the E-R modeling analyses would have a significant impact on dose-response. Despite body weight and comorbid diabetes having significant effect on sirukumab exposure, simulations suggested that their effect on efficacy was small. Our work provides a comprehensive evaluation of sirukumab E-R to support dose recommendations in patients with RA.

Biological treatments in giant cell arteritis & Takayasu arteritis

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are the two main large vessel vasculitides. They share some similarities regarding their clinical, radiological and histological presentations but some pathogenic processes in GCA and TAK are activated differently, thus explaining their different sensitivity to biological therapies. The treatment of GCA and TAK essentially relies on glucocorticoids. However, thanks to major progress in our understanding of their pathogenesis, the role of biological therapies in the treatment of these two vasculitides is expanding, especially in relapsing or refractory diseases. In this review, the efficacy, the safety and the limits of the main biological therapies ever tested in GCA and TAK are discussed. Briefly, anti TNF-α agents appear to be effective in treating TAK but not GCA. Recent randomized placebo-controlled trials have reported on the efficacy and safety of abatacept and mostly tocilizumab in inducing and maintaining remission of GCA. Abatacept was not effective in TAK and robust data are still lacking to draw any conclusions concerning the use of tocilizumab in TAK. Furthermore, ustekinumab appears promising in relapsing/refractory GCA whereas rituximab has been reported to be effective in only a few cases of refractory TAK patients. If a biological therapy is indicated, and in light of the data discussed in this review, the first choice would be tocilizumab in GCA and anti-TNF-α agents (mainly infliximab) in TAK.

Efficacy and safety of sirukumab in Japanese patients with active rheumatoid arthritis who were refractory or intolerant to anti-tumor necrosis factor therapy: Subgroup analysis of a randomized, double-blind, multicenter, phase 3 study (SIRROUND-T)

OBJECTIVE

To evaluate the efficacy and safety of sirukumab, a human anti-interleukin six monoclonal antibody, in Japanese patients with rheumatoid arthritis who were refractory to anti-tumor necrosis factor therapy.

METHODS

This subgroup analysis, based on a double-blind, placebo-controlled, 52-week phase 3, global study (SIRROUND-T) assessed the American College of Rheumatology (ACR) 20 response at week 16 (primary endpoint). Secondary endpoints: ACR 50, Disease Activity Score in 28 joints-C reactive protein, Health Assessment Questionnaire-Disability Index and safety were assessed. Results 116/878 patients received sirukumab 50 mg/4 weeks (q4w, n = 35), 100 mg/2 weeks (q2w, n = 44) or placebo (n = 37) subcutaneously. Significantly more patients achieved ACR 20 response at week 16 with sirukumab (50 mg q4w:20 [57.1%]; p < .001, 100 mg q2w:24 [54.5%]; p = .001) versus placebo (7 [18.9%]); consistent significant improvement in secondary endpoints at week 24 and 52 was observed. At week 24, incidence of treatment-emergent adverse events (TEAEs) was numerically higher with sirukumab groups (50 mg q4w:29 [82.9%]; 100 mg q2w:38 [86.4%] versus placebo (28 [75.7%]); however, at week 52, sirukumab combined groups had comparable incidence of TEAEs.

CONCLUSION

Efficacy findings through 52 weeks were comparable between sirukumab doses in Japanese patients and consistent with primary SIRROUND-T study results. No new safety signals were observed.

Sirukumab in rheumatoid arthritis refractory to sulfasalazine or methotrexate: a randomized phase 3 safety and efficacy study in Japanese patients

Background

Sirukumab, a high-affinity human monoclonal antibody that selectively binds to interleukin-6, has demonstrated efficacy in the treatment of rheumatoid arthritis (RA) in global phase 1 and phase 2 studies. The present study evaluated the safety and efficacy of sirukumab, as monotherapy in Japanese patients with RA refractory to methotrexate or sulfasalazine.

Methods

In this phase 3, double-blind study, 122 patients (age ≥ 20 years) were randomized (1:1, 61 patients in each arm) to sirukumab administered subcutaneously: 50 mg once every 4 weeks (q4w) or 100 mg once every 2 weeks (q2w) through 52 weeks. Disease-modifying anti-rheumatic drugs were allowed after 24 weeks. Safety was assessed and efficacy was evaluated using American College of Rheumatology (ACR) responses, Disease Activity Score C-reactive protein (DAS28-CRP) and Health Assessment Questionnaire-Disability Index (HAQ-DI).

Results

Amongst the 122 randomized patients, 99 (81.1%) patients completed the study. Adverse events (AEs) were reported in 114/122 (93.4%) patients and serious AEs were reported in 9/122 (7.4%) patients. No deaths, major cardiovascular AEs, serious gastrointestinal perforations or tuberculosis cases were reported during this study period. Grade 3 hematologic abnormalities (neutropenia and leukopenia) were reported in seven patients and no grade 4 abnormalities were observed. ACR20 responses were observed within 2 weeks, achieved in 47/61 (77.0%, 50 mg q4w) patients and 44/61 (72.1%, 100 mg q2w) patients at week 16 and maintained through week 52. ACR50/70, DAS28-CRP and HAQ-DI responses were also maintained through week 52 in both groups.

Conclusions

Safety findings were comparable between the two treatment groups. The 52-week administration of sirukumab at 50 mg q4w and 100 mg q2w was generally tolerable and with measurable efficacy in Japanese patients with RA refractory to methotrexate and sulfasalazine.

Trial registration

NCT01689532. Registered 18 September 2012.

Comparison of the efficacy and tolerability of tocilizumab, sarilumab, and sirukumab in patients with active rheumatoid arthritis: a Bayesian network meta-analysis of randomized controlled trials

The relative efficacy and tolerability of tocilizumab, sarilumab, and sirukumab were assessed in patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX) or tumor necrosis factor (TNF) inhibitors. We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of tocilizumab, sarilumab, and sirukumab in RA patients and an inadequate MTX or TNF inhibitor response. Fourteen RCTs, comprising 9753 patients, met the inclusion criteria. Tocilizumab 8 mg combined with MTX or as monotherapy was the most effective treatment for active RA with an inadequate MTX or TNF antagonist response, followed by sarilumab and sirukumab, regardless of MTX combination. The ranking probability based on the surface under the cumulative ranking curve (SUCRA) indicated that tocilizumab 8 mg + MTX had the highest probability of being the best treatment to achieve the ACR50 response rate, followed by tocilizumab 8 mg, sarilumab 200 mg, sarilumab 200 mg + MTX, sirukumab 100 mg, tocilizumab 4 mg + MTX, sirukumab 100 mg + MTX, sirukumab 50 mg + MTX, sarilumab 150 mg + MTX, adalimumab 40 mg, and sirukumab 50 mg, and placebo + MTX. No significant differences were observed in withdrawals owing to adverse events after treatment with tocilizumab 8 mg + MTX, sirukumab 100 mg + MTX, or sarilumab 200 mg + MTX. In RA patients with an inadequate MTX or anti-TNF therapy response, tocilizumab 8 mg as monotherapy and combined with MTX showed acceptable tolerability and the highest performance based on the ACR50 response rate, followed by sarilumab and sirukumab.

Potential therapeutic implications of IL-6/IL-6R/gp130-targeting agents in breast cancer

Interleukin-6 (IL-6) is a pleiotropic cytokine with known multiple functions in immune regulation, inflammation, and oncogenesis. Binding of IL-6 to the IL-6 receptor (IL-6R) induces homodimerization and recruitment of glycoprotein 130 (gp130), which leads to activation of downstream signaling. Emerging evidence suggests that high levels of IL-6 are correlated with poor prognosis in breast cancer patients. IL-6 appears to play a critical role in the growth and metastasis of breast cancer cells, renewal of breast cancer stem cells (BCSCs), and drug resistance of BCSCs, making anti-IL-6/IL-6R/gp130 therapies promising options for the treatment and prevention of breast cancers. However, preclinical and clinical studies of the applications of anti-IL-6/IL-6R/gp130 therapy in breast cancers are limited. In this review, we summarize the structures, preclinical and clinical studies, mechanisms of action of chemical and biological blockers that directly bind to IL-6, IL-6R, or gp130, and the potential clinical applications of these pharmacological agents as breast cancer therapies.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

Sirukumab for rheumatoid arthritis: the phase III SIRROUND-D study

OBJECTIVES

Interleukin-6 (IL-6) is implicated in rheumatoid arthritis (RA) pathophysiology. Unlike IL-6 receptor inhibitors, sirukumab is a human monoclonal antibody that selectively binds to the IL-6 cytokine. The phase III, multicentre, randomised, double-blind, placebo-controlled, parallel-group SIRROUND-D study (ClinicalTrials.gov identifier NCT01604343) evaluated the efficacy and safety of sirukumab in patients with active RA refractory to disease-modifying antirheumatic drugs.

METHODS

Patients were randomised 1:1:1 to treatment with sirukumab 100 mg every 2 weeks, 50 mg every 4 weeks or placebo every 2 weeks subcutaneously. Results through week 52 are reported.

RESULTS

Of 1670 randomised patients, significantly more patients achieved American College of Rheumatology 20% (ACR20) response at week 16 (coprimary endpoint) with sirukumab 100 mg every 2 weeks (53.5%) or 50 mg every 4 weeks (54.8%) versus placebo (26.4%; both p<0.001). Mean (SD) change from baseline in modified Sharp/van der Heijde score at week 52 (coprimary endpoint) was significantly lower with sirukumab (100 mg every 2 weeks: 0.46 (3.26); 50 mg every 4 weeks: 0.50 (2.96)) versus placebo (3.69 (9.25); both p<0.001). All major secondary endpoints (week 24 Health Assessment Questionnaire-Disability Index change from baseline, ACR50 response, 28-joint Disease Activity Score based on C reactive protein and major clinical response (ACR70 for six continuous months by week 52)) were met. The most common adverse events with sirukumab were elevated liver enzymes, upper respiratory tract infection, injection site erythema and nasopharyngitis.

CONCLUSIONS

Sirukumab 100 mg every 2 weeks and 50 mg every 4 weeks led to significant reductions in RA symptoms, inhibition of structural damage progression and physical function and quality of life improvements, with an expected safety profile.

TRIAL REGISTRATION NUMBER

NCT01604343; Results.

Investigational drugs in systemic vasculitis

INTRODUCTION

Treatment of systemic vasculitis is based on glucocorticoids (GC) in association with immunosuppressive therapy. There are still unmet needs, including earlier onset of response, more targeted therapies, reduction of relapse-risk and decrease of long-term GC and classic immunosuppressants toxicities. Areas covered: In this review, we discuss investigational drugs in early phase clinical trials for induction of remission in vasculitis. We focus on ANCA-associated vasculitis, Behçet's disease, giant cell arteritis, Takayasu arteritis, and cryoglobulinemic vasculitis. We performed a comprehensive review of articles published on pubmed and a review of clinical trials registered online ( https://clinicaltrials.gov ) for each vasculitis. Expert opinion: Recent progress in the pathogenesis identifies new therapeutic targets. Some of these therapies are promising in GC sparing effects, in reducing relapse rate, and for their safety profile. These results need to be confirmed in large-scale phase III studies.

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Treatment With Sirukumab (CNTO 136) in Patients With Active Lupus Nephritis

Objective

To assess the efficacy and safety of sirukumab, an anti–interleukin‐6 monoclonal antibody, for the treatment of patients with active lupus nephritis (LN).

Methods

Patients with class III or class IV LN (as determined by renal biopsy within 14 months of randomization) who had persistent proteinuria (>0.5 gm/day) despite receiving immunosuppressive therapy and who were being treated with stable doses of a renin‐angiotensin system blocker were randomized (5:1) to receive treatment with sirukumab at a dose of 10 mg/kg intravenously (n = 21) or placebo (n = 4) every 4 weeks through week 24. The primary end point was the percent reduction in proteinuria (measured as the protein‐to‐creatinine [P:C] ratio in a 12‐hour urine collection) from baseline to week 24.

Results

Twenty‐five patients were enrolled, of whom 19 (76.0%) completed treatment through week 24 and 6 (24.0%) discontinued the study agent early, with 5 of the 6 discontinuing due to adverse events. At week 24, the median percent change in proteinuria from baseline to week 24 in sirukumab‐treated patients was 0.0% (95% confidence interval −61.8, 39.6). In contrast, the 4 placebo‐treated patients showed an increase in proteinuria (median percent reduction −43.3%) at week 24. Of note, a subset of 5 sirukumab‐treated patients had ≥50% improvement in their P:C ratio through week 28. In the sirukumab group, 47.6% of patients experienced ≥1 serious adverse event through week 40; most were infection‐related. No deaths or malignancies occurred. No serious adverse events were observed in the 4 placebo‐treated patients.

Conclusion

This proof‐of‐concept study did not demonstrate the anticipated efficacy nor did it demonstrate an acceptable safety profile for sirukumab treatment in this population of patients with active LN receiving concomitant immunosuppressive treatment.

Research and therapeutics-traditional and emerging therapies in systemic lupus erythematosus

This review summarizes traditional and emerging therapies for SLE. Evidence suggests that the heterogeneity of SLE is a crucial aspect contributing to the failure of large clinical trials for new targeted therapies. A clearer understanding of the mechanisms driving disease pathogenesis combined with recent advances in medical science are predicted to enable accelerated progress towards improved SLE diagnosis and personalized approaches to treatment.

Efficacy and safety of sirukumab in patients with active rheumatoid arthritis refractory to anti-TNF therapy (SIRROUND-T): a randomised, double-blind, placebo-controlled, parallel-group, multinational, phase 3 study

BACKGROUND

Sirukumab, a human monoclonal antibody that selectively binds to the interleukin-6 cytokine with high affinity, is under development for the treatment of rheumatoid arthritis and other diseases. We aimed to assess the efficacy and safety of sirukumab for rheumatoid arthritis in a phase 3 study (SIRROUND-T).

METHODS

We did a randomised, double-blind, placebo-controlled, parallel-group, multicentre study at 183 hospitals and private rheumatology clinics in 20 countries (Argentina, Australia, Austria, Belgium, Canada, France, Germany, Italy, Japan, Lithuania, Mexico, Netherlands, Poland, Portugal, Russia, South Korea, Spain, Taiwan, UK, and USA). Eligible participants were patients with active rheumatoid arthritis aged at least 18 years, with four or more of 68 tender joints and four or more of 66 swollen joints, who were refractory or intolerant to previous treatment with at least one anti-TNF drug. We randomly assigned patients (1:1:1) via a central interactive voice or web response system to either placebo every 2 weeks, 50 mg sirukumab every 4 weeks, or 100 mg sirukumab every 2 weeks, all given for 52 weeks or less. We allowed participants to continue using any concomitant disease-modifying antirheumatic drugs (DMARDs). We based the randomisation on a computer-generated, permuted-block schedule stratified by use of methotrexate at baseline (0, >0 to <12·5 mg/week, or ≥12·5 mg/week). Masking was achieved with the use of multipart labels on the study drug containers which contained directions for use and other information, but not the drug's identity. Treatments were administered by subcutaneous injection; patients assigned to 50 mg sirukumab given every 4 weeks also received a placebo injection every 2 weeks to maintain masking. At week 18, placebo-treated patients meeting early escape criteria (<20% improvement in swollen and tender joint counts) were randomly reassigned to either 50 mg or 100 mg of sirukumab. All remaining placebo-treated patients were subsequently randomly reassigned at week 24 to either sirukumab dose (crossover). The primary outcome was the proportion of patients who achieved a response of at least 20% improvement at week 16 according to American College of Rheumatology criteria (ACR20) in the intention-to-treat population (all randomly assigned participants). Safety analyses included all participants who received at least one dose (partial or complete) of study drug. This study is registered at EudraCT (number: 2010-022243-38) and ClinicalTrials.gov (number: NCT01606761).

FINDINGS

Between July 25, 2012, and Jan 12, 2016, we randomly assigned 878 patients to treatment: 294 to placebo, 292 to 50 mg sirukumab every 4 weeks, and 292 to 100 mg sirukumab every 2 weeks. 523 (60%) of 878 patients had previously received two or more biological treatments including non-TNF drugs, and 166 (19%) of 878 were not taking a DMARD at baseline. The proportions of patients who achieved an ACR20 response at week 16 were 117 (40%) of 292 with 50 mg sirukumab every 4 weeks, and 132 (45%) of 292 with 100 mg sirukumab every 2 weeks versus 71 (24%) of 294 with placebo; differences compared with placebo were 0·16 (95% CI 0·09-0·23) for 50 mg sirukumab every 4 weeks and 0·21 (0·14-0·29) for 100 mg sirukumab every 2 weeks (both p<0·0001). Adverse event incidences in the 24-week placebo-controlled period were similar across groups (at least one event occurred for 182 patients assigned to placebo [62%, including early escape patients switched to sirukumab at week 18] of 294; 194 [66%] of 292 with 50 mg sirukumab every 4 weeks; and 207 [71%] of 292 with 100 mg sirukumab every 2 weeks). The most common adverse events in this period were injection-site erythema (four [1%] with placebo, 22 [8%] with 50 mg sirukumab every 4 weeks, and 41 [14%] with 100 mg sirukumab every 2 weeks). At week 52, of all patients receiving sirukumab including those reassigned from placebo, the most common adverse events were again injection-site erythema (33 [8%] of 416 with 50 mg sirukumab every 4 weeks and 66 [16%] of 418 with 100 mg sirukumab every 2 weeks).

INTERPRETATION

In patients with active rheumatoid arthritis who were refractory or intolerant to anti-TNF drugs and other biological treatments, both dosing regimens of sirukumab were well tolerated and significantly improved signs and symptoms of the disease, compared with placebo, in this difficult-to-treat population.

FUNDING

Janssen Research & Development, LLC, and GlaxoSmithKline.

Advances in the treatment of cutaneous lupus erythematosus

Lupus erythematosus (LE) is a multifactorial autoimmune disease with clinical manifestations of differing severity which may present with skin manifestations as primary sign of the disease (cutaneous lupus erythematosus, CLE) or as part of a disease spectrum (systemic lupus erythematosus, SLE). To date, no drugs are approved specifically for the treatment of CLE and only single agents have been applied in randomized controlled trials. Therefore, topical and systemic agents are used "off-label", primarily based on open-label studies, case series, retrospective analyses, and expert opinions. In contrast, several agents, such as hydroxychloroquine, chloroquine, cyclophosphamide, azathioprine, and belimumab, are approved for the treatment of SLE. Recent approaches in the understanding of the molecular pathogenesis of LE enabled the development of further new agents, which target molecules such as interleukin 6 (IL-6) and interferon (IFN). Only single trials, however, applied these new agents in patients with cutaneous involvement of the disease and/or included endpoints which evaluated the efficacy of these agents on skin manifestations. This article provides an updated review on new and recent approaches in the treatment of CLE.

Absolute Bioavailability and Pharmacokinetic Comparability of Sirukumab Following Subcutaneous Administration by a Prefilled Syringe or an Autoinjector

This phase 1, randomized, open-label study assessed the absolute bioavailability and pharmacokinetic comparability of sirukumab, a human anti-interleukin-6 monoclonal antibody, following subcutaneous (SC) administration via Prefilled Syringe-UltraSafe Passive® Delivery System (PFS-U) or Prefilled Syringe-SmartJect® Autoinjector (PFS-AI; Janssen Research & Development, LLC, Spring House, Pennsylvania). A total of 144 healthy male subjects were randomized to 5 single-dose treatment groups: sirukumab 50 mg and 100 mg (each by PFS-U and PFS-AI) and sirukumab 100 mg intravenous (IV) infusion. Pharmacokinetic parameters were calculated using noncompartmental analysis. Following SC administration, maximum serum concentrations (C_max ) and area under the concentration-vs-time curve (AUC) increased in an approximately dose-proportional manner. Median time to reach C_max was 5 days, and mean half-life ranged from 16 to 19 days. Mean absolute bioavailability of sirukumab by PFS-AI and PFS-U, respectively, was estimated at 92.4% and 81.4% with 100 mg and 88.4% and 94.7% with 50 mg. Ratios of geometric means (90% confidence intervals) of C_max and AUC_0-77d for PFS-AI:PFS-U were 1.13 (1.03, 1.25) and 1.14 (1.05, 1.24), respectively, indicating comparable systemic exposures of sirukumab following a single 100-mg SC dose by PFS-U or PFS-AI. The incidence of antibodies to sirukumab was low (1.4%). No new safety concerns associated with sirukumab were identified at either dose.

Sirukumab: A Potential Treatment for Mood Disorders?

Convergent evidence indicates that abnormalities in the innate immune system may be pertinent to the pathogenesis, phenomenology, and possible treatment of several mental disorders. In keeping with this view, the targeting of interleukin-6 with the human monoclonal antibody sirukumab may represent a possible treatment and disease modification approach, for adults with brain-based disorders (e.g., major depressive disorder). A PubMed/Medline database search was performed using the following search terms: sirukumab; anti-IL-6; IL-6; major depressive disorder; inflammation. A systematic review was conducted of both preclinical and clinical trials reporting on the pharmacology of sirukumab or investigating the efficacy of targeting IL-6 signaling. Overall, sirukumab has been reported to be a safe and well-tolerated agent, capable of modulating the immune response in healthy populations as well as in subjects with inflammatory disorders (e.g., rheumatoid arthritis). Sirukumab's effects on cytokine networks as part of the innate immune system provide a coherent rationale for possible application in neuropsychiatric disorders with possible benefits across several domains of the biobehavioral Research Domain Criteria matrix (e.g., general cognitive processes, positive valence systems). Amongst individuals with complex brain-based disorders (e.g., mood disorders), the dimensions/domains most likely to benefit with sirukumab are negative valence disturbances (e.g., anxiety, depression, rumination), positive valence disturbances (e.g., anhedonia) as well as general cognitive processes. We suggest that sirukumab represents a prototype and possibly a proof-of-concept that agents that engage IL-6 targets have salutary effects in psychiatry.

Determination of the starting dose in the first-in-human clinical trials with monoclonal antibodies: a systematic review of papers published between 1990 and 2013

A systematic review was performed to evaluate how the maximum recommended starting dose (MRSD) was determined in first-in-human (FIH) studies with monoclonal antibodies (mAbs). Factors associated with the choice of each MRSD determination method were also identified. PubMed was searched for FIH studies with mAbs published in English between January 1, 1990 and December 31, 2013, and the following information was extracted: MRSD determination method, publication year, therapeutic area, antibody type, safety factor, safety assessment results after the first dose, and number of dose escalation steps. Seventy-nine FIH studies with mAbs were identified, 49 of which clearly reported the MRSD determination method. The no observed adverse effects level (NOAEL)-based approach was the most frequently used method, whereas the model-based approach was the least commonly used method (34.7% vs 16.3%). The minimal anticipated biological effect level (MABEL)- or minimum effective dose (MED)-based approach was used more frequently in 2011–2013 than in 1990–2007 (31.6% vs 6.3%, P=0.036), reflecting a slow, but steady acceptance of the European Medicines Agency’s guidance on mitigating risks for FIH clinical trials (2007). The median safety factor was much lower for the MABEL- or MED-based approach than for the other MRSD determination methods (10 vs 32.2–53). The number of dose escalation steps was not significantly different among the different MRSD determination methods. The MABEL-based approach appears to be safer and as efficient as the other MRSD determination methods for achieving the objectives of FIH studies with mAbs faster.

Spotlight on sirukumab for the treatment of rheumatoid arthritis: the evidence to date

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease primarily affecting synovial joints and is characterized by persistent high-grade systemic inflammation. Proinflammatory cytokines, particularly interleukin-6 (IL-6), are of crucial importance in the pathogenesis of the disease, driving both joint inflammation and extra-articular comorbidities. Tocilizumab, a humanized IL-6 receptor-inhibiting monoclonal antibody, has been the first, and, to date, the only, IL-6 inhibitor approved for the treatment of RA. Many studies have demonstrated the potency and effectiveness of tocilizumab in controlling disease activity and radiological progression of RA. These successful results have encouraged the development of novel IL-6 inhibitors, among which a promising agent is sirukumab (SRK), a human anti-IL-6 monoclonal antibody currently under evaluation in Phase II/III studies in patients with RA, systemic lupus erythematosus, giant-cell arteritis, and major depressive disorder. The evidence to date indicates SRK as an effective and well-tolerated new therapeutic tool for patients with active RA, with some preliminary data suggesting a specific beneficial impact on relevant systemic complications associated with the disease, such as depression and cardiovascular disease. Conversely, although pathophysiological considerations make plausible the hypothesis that IL-6 blockade with SRK may also be beneficial in the treatment of many diseases other than RA (either autoimmune or not), available clinical data in patients with systemic lupus erythematosus do not seem to support this view, also giving rise to potentially relevant concerns about drug safety. If large Phase III clinical trials currently in progress in patients with RA confirm the efficacy and tolerability of SRK, then in the long term, this drug could, in the near future, occupy a place in the treatment of the disease, potentially also opening the doors to a more extended use of SRK in a wide range of disorders in which IL-6 plays a key pathogenic role.

Functions of interleukin-34 and its emerging association with rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic, synovial inflammation affecting multiple joints, finally leading to extra-articular lesions for which limited effective treatment options are currently available. Interleukin-34 (IL-34), recently discovered as the second colony-stimulating factor-1 receptor (CSF-1R) ligand, is a newly discovered cytokine. Accumulating evidence has disclosed crucial roles of IL-34 in the proliferation and differentiation of mononuclear phagocyte lineage cells, osteoclastogenesis and inflammation. Recently, IL-34 was detected at high levels in patients with active RA and in experimental models of inflammatory arthritis. Blockade of functional IL-34 with a specific monoclonal antibody can reduce the severity of inflammatory arthritis, suggesting that targeting IL-34 or its receptors may constitute a novel therapeutic strategy for autoimmune diseases such as RA. Here, we have comprehensively discussed the structure and biological functions of IL-34, and reviewed recent advances in our understanding of the emerging role of IL-34 in the development of RA as well as its potential utility as a therapeutic target.

Recent advances in the biologic therapy of lupus: the 10 most important areas to look for common pitfalls in clinical trials

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting different organs. The improved knowledge of the disease's pathogenesis has contributed to the emergence of immune targets and new biologic drugs directed at them. Although rheumatologists continue to use off-label biologics in SLE resistant to other immunosuppressants, only belimumab has been approved as a biological therapy since 2011.

AREAS COVERED

In this review, an overview is provided on: 1) the classification of the biologic drugs in clinical trials and of those under research; 2) the results of clinical trials of biologic therapy with an interpretation of pitfalls and syntheses of potential approaches to overcome these pitfalls and, 3) the commonly used disease activity metrics and composite indices for assessing response to drugs.

EXPERT OPINION

Some drugs that have failed in previous drug trials have shown to be efficacious in the treatment of lupus in observational studies. Moreover, the post-hoc analyses of the data of negative drug trials have shown that results of the same trials could be altered with the modification of some pitfalls. For future clinical trials, the consideration of these pitfalls is crucial when designing clinical trials. This could potentially enhance the approval of novel drugs for SLE.

The safety of pharmacological treatment options for lupus nephritis

INTRODUCTION

The management of lupus nephritis (LN) has changed significantly over the last 10 years due to emerging evidence from large randomised clinical trials that produced good quality data and guided the formulation of two key concepts: the induction of remission and the maintenance phase of immunosuppressive therapy.

AREAS COVERED

Optimizing cyclophosphamide and glucocorticoid regimens and the introduction of mycophenolate mofetil for proliferative and membranous LN has been pivotal. Nevertheless, concerns remain about treatment toxicity especially long term glucocorticoid use and exposure to cumulative cyclophosphamide doses. Here we discuss the conventional and newer pharmacological options for managing LN focusing on drug safety and toxicity issues.

EXPERT OPINION

The need for effective and less toxic treatments led to the development of the role of targeted biologic therapies in LN. However, evidence from the initial randomized controlled trials has been disappointing, although this reflects inadequate trial design rather than true lack of efficacy.

Predicting pharmacokinetic profile of therapeutic antibodies after iv injection from only the data after sc injection in cynomolgus monkey

1. The number of developed therapeutic monoclonal antibodies (mAbs) has increased in this decade. This study aims to predict their pharmacokinetic profiles after intravenous (iv) injection using only the data taken after subcutaneous (sc) injection in cynomolgus monkey. 2. Two-compartment model parameters, Q, V_c and V_p, were collected from the published data after iv injection in cynomolgus monkey for 21 mAbs (Group A). Bioavailability after sc injection (F), CL and serum/plasma concentration after iv injection of other published 19 mAbs (Group B) were predicted using the estimated geometric means of Q, V_c and V_p in Group A and the serum/plasma concentration after sc injection in Group B. 3. F and CL of 18 out of 19 mAbs in Group B were successfully predicted within 30% difference of observed value. Moreover, most of the observed serum/plasma concentrations after iv injection of mAbs in Group B were successfully predicted within 2-fold difference. Our approach suggests that iv injection might not be required to evaluate absorption of mAbs after sc injection in cynomolgus monkey. Therefore, our approach might reduce the time and cost of drug development, reduce the burden on resources, and also contribute to animal welfare.

Development of a Physiologically Based Pharmacokinetic Model to Predict Disease-Mediated Therapeutic Protein-Drug Interactions: Modulation of Multiple Cytochrome P450 Enzymes by Interleukin-6

Disease-mediated therapeutic protein-drug interactions have recently gained attention from regulatory agencies and pharmaceutical industries in the development of new biological products. In this study, we developed a physiologically based pharmacokinetic (PBPK) model using SimCYP to predict the impact of elevated interleukin-6 (IL-6) levels on cytochrome P450 (CYP) enzymes and the treatment effect of an anti-IL-6 monoclonal antibody, sirukumab, in patients with rheumatoid arthritis (RA). A virtual RA patient population was first constructed by incorporating the impact of systemic IL-6 level on hepatic and intestinal expression of multiple CYP enzymes with information from in vitro studies. Then, a PBPK model for CYP enzyme substrates was developed for healthy adult subjects. After incorporating the virtual RA patient population, the PBPK model was applied to quantitatively predict pharmacokinetics of multiple CYP substrates in RA patients before and after sirukumab treatment from a clinical cocktail drug interaction study. The results suggested that, compared with observed clinical data, changes in systemic exposure to multiple CYP substrates by anti-IL-6 treatment in virtual RA patients have been reasonably captured by the PBPK model, as manifested by modulations in area under plasma concentration versus time curves for midazolam, omeprazole, S-warfarin, and caffeine. This PBPK model reasonably captured the modulation effect of IL-6 and sirukumab on activity of CYP3A, CYP2C9, CYP2C19, and CYP1A2 and holds the potential to be utilized to assess the modulation effect of sirukumab on the metabolism and pharmacokinetics of concomitant small-molecule drugs in RA patients.

IL-6 blockers in systemic onset juvenile idiopathic arthritis

IL-6 has a key role in the pathogenesis, clinical manifestations and activity of Systemic Onset Idiopathic Arthritis (sJIA). Tocilizumab (TCZ), the first humanized antihuman IL-6 receptor antibody, inhibits the activity of IL-6. In this review, we summarize the main studies performed, to date, about the use of TCZ in children affected by sJIA refractory to conventional treatment. Nowadays TCZ can be used, alone or in association with Metotrexate, in children older than 2 years. Its use in children younger than 2 years is being investigated. Further study about its use in sJIA and other type of idiopathic arthritis should be done.

Deciphering the In Vivo Performance of a Monoclonal Antibody to Neutralize Its Soluble Target at the Site of Action in a Mouse Collagen-Induced Arthritis Model

PURPOSE

Study the disposition and target-neutralization capability of an anti-interleukin-6 (IL-6) monoclonal antibody (mAb) at the joint in a mouse collagen-induced arthritis (CIA) model.

METHODS

A mechanistic pharmacokinetic/pharmacodynamic study was conducted in a mouse CIA model using CNTO 345, a rat anti-mouse IL-6 mAb, as model compound. The drug, total/free IL-6 concentrations in both serum and joint lavage fluid were quantitatively assessed and compared to those in the normal control mice.

RESULTS

CNTO 345 exhibited higher clearance and significantly higher joint lavage/serum ratio in the CIA mice than in the normal control mice. The mAb concentrations in the joint lavage are approximately proportional to the serum concentrations at all the time points being examined. Dosing of CNTO 345 led to sustained free IL-6 suppression in both serum and joint lavage in a dose-dependent manner. A dose-dependent increase in total IL-6 was observed in serum, but not in the joint lavage fluid. Though no change in disease activity was observed following a single dose of anti-IL-6 mAb at peak of the disease, a dose-dependent decrease in serum amyloid A, a downstream biomarker of IL-6, was observed.

CONCLUSIONS

This study provided quantitative assessments of the distribution and target-neutralization capability of an anti-IL-6 mAb at the site of action in an animal disease model.