In this review, through the effort of unraveling the complex pathophysiological pathways, we will depict drugs used throughout the years for the treatment of RA, the current and future biological therapies and their molecular or cellular targets and finally will suggest therapeutic algorithms for RA management. With multiple biologic options, there is still a need for strong predictive biomarkers to determine which drug is most likely to be effective, safe, and durable in a given individual. The fact that available biologics are not effective in all patients attests to the heterogeneity of RA, yet over the long term, as research and treatment become more aggressive, efficacy, toxicity, and costs must be balanced within the therapeutic equation to enhance the quality of life in patients with RA.

The aim of the review is to highlight the current knowledge about established and new biologicals and to summarise recent advances by focusing on comparative efficacy, safety and possible discontinuation of treatment in patients with rheumatoid arthritis (RA). Up to now, comparative analyses showed only minor differences with respect to efficacy and safety among the established biologicals. Studies confirmed the excellent drug retention rate as well as efficacy and safety of approved biologicals including their use in monotherapy. Tapering and in some instances discontinuation of biologicals is possible in disease remission. In case of relapse, patients usually show full response after reintroduction of the same compound. The development of biologicals continues fast with several new biologicals targeting different or established cytokines or cellular subsets of the immune system. With several new biologicals in the pipeline and different formulations for established compounds, treatment options for RA will become even more versatile and sophisticated. Although we get closer to the aim of decreasing the proportion of refractory patients, many questions have to be addressed in the near future regarding emerging biosimilars and biologicals with new modes of action.

Rheumatoid arthritis (RA), as a common chronic disease leading to severe disability, requires early diagnosis and introduction of proper treatment. Deregulation in the cytokine network plays an undoubtedly crucial role in the pathogenesis of RA. The understanding of the role of cytokines in RA can be used for patients鈥 benefit. Technological advances had already allowed introduction of the tailor-made cytokine-targeted therapies (so far anti-TNF, anti-IL-1 and anti-IL-6) into clinical practice. This type of treatment is currently developing very fast. Moreover, cytokines are considered to be potential powerful biomarkers of RA with roles predicted to grow in the future. Detailed understanding of the cytokine balance in RA may assist both the diagnostic process and therapy.

Abstract Few, if any, areas of medical therapeutics have witnessed such dramatic changes as those that have occurred in the therapy of rheumatoid arthritis (RA) during the past two decades. Improvements in clinical trials methodologies, the introduction of no fewer than nine biologic agents with distinct mechanisms of action, and the development of better strategies for the use of such agents have all contributed to the new age in RA therapeutics. Here, we review these developments and attempt to describe the current landscape of RA therapy in terms of available treatments, agreed-upon principles of RA management, as well as some important controversies in this field. Despite the great pace at which developments are moving, a treatment-free remission for patients with RA remains an elusive goal and unmet medical needs remain. The quest for better therapies for this potentially devastating disease is still as important as ever; research in this exciting area is ongoing, and it is reasonable to hope that, during the next decade, developments will lead to improved, rationally designed, targeted therapies for RA.

Abstract Tocilizumab (RoActemra(03); Actemra(03)) is a recombinant humanized monoclonal antibody that acts as an interleukin-6 receptor antagonist. Both in the US and EU, tocilizumab has been approved for the treatment of two subtypes of juvenile idiopathic arthritis (JIA), namely systemic JIA (sJIA) and polyarticular JIA (pJIA), in patients aged ≥202years. These approvals are based on favorable results from two randomized, double-blind, placebo-controlled, multinational, phase III trials in which patients aged 2-1702years with active sJIA (TENDER) or pJIA (CHERISH) received an intravenous dose of tocilizumab based on bodyweight every 2 or 402weeks, respectively. Tocilizumab met the primary endpoint in both of these ongoing, multi-part studies. That is, in TENDER, significantly more tocilizumab recipients than placebo recipients achieved a JIA American College of Rheumatology (ACR) 30 response plus absence of fever, as assessed at the end of a 12-week double-blind treatment period, while in CHERISH, significantly fewer tocilizumab recipients than placebo recipients experienced a JIA ACR 30 flare during a 24-week double-blind withdrawal period (all patients had previously received open-label tocilizumab in a 16-week lead-in phase). Tocilizumab was generally well tolerated in the TENDER trial. Infections (e.g. upper respiratory tract infection and pharyngitis or nasopharyngitis) accounted for just over one-third of all reported adverse events in this trial; tocilizumab-treated patients appeared to have an approximately 1102% risk of a serious infection per year of treatment. Clinical laboratory abnormalities included neutropenia and elevated aminotransferase levels. The tolerability profile of tocilizumab in CHERISH was generally consistent with that of the drug in TENDER.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by polyarthritis. Numerous agents with varying mechanisms are used in the treatment of RA, including non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs, and some biological agents. Studies to uncover the cause of RA have recently ended up scrutinizing the importance of pro-inflammatory cytokine such as tumor necrosis factor 伪 (TNF-伪) and interleukin (IL)-6 in the pathogenesis of RA. TNF-伪 inhibitors are increasingly used to treat RA patients who are non-responsive to conventional anti-arthritis drugs. Despite its effectiveness in a large patient population, up to two thirds of RA patients are found to be partially responsive to anti-TNF therapy. Therefore, agents targeting IL-6 such as tocilizumab (TCZ) attracted significant attention as a promising agent in RA treatment. In this article, we review the mechanism of anti-IL-6 in the treatment of RA, provide the key efficacy and safety data from clinical trials of approved anti-IL-6, TCZ, as well as six candidate IL-6 blockers including sarilumab, ALX-0061, sirukumab, MEDI5117, clazakizumab, and olokizumab, and their future perspectives in the treatment of RA.

Pelvic girdle pain during and after pregnancy is the clinical syndrome of persistent musculoskeletal pain localized in the posterior and/or anterior aspect of the pelvis originating from sacroiliac joints and/or pubic symphysis due to dynamic instability. We report the case of severe and disabling postpartum pelvic girdle pain caused by unilateral noninfectious sacroiliitis which resolved after 2 months by nonsteroidal anti-inflammatory drug and physical therapy. A short literature review is given on epidemiology, etiology, clinical presentation, therapy, and prognosis of pregnancy-related pelvic girdle pain.

Abstract OBJECTIVES: To investigate the duration of remission and low disease activity (LDA) after cessation of tocilizumab (TCZ) treatment in rheumatoid arthritis patients who showed remission or LDA as assessed by DAS28 in response to preceding TCZ monotherapy, and to explore the factors contributing to prolonged efficacy duration. METHODS: Disease activity was monitored for 56 weeks. The rate of continued efficacy was estimated by Kaplan-Meier curves. RESULTS: A total of 187 patients were eligible. At baseline of this study, median disease duration was 7.8 years, preceding TCZ treatment period was 4.0 years and DAS28 was 1.5. The rate of continued LDA at 52 weeks was 13.4 % according to the Kaplan-Meier estimate. 19 patients (10 %) were completely drug-free and 17 patients (9.1 %) fulfilled DAS28 remission at 52 weeks. Multivariate Cox regression analysis identified low serum IL-6 and normalisation of MMP-3 levels at cessation of TCZ as independent predictive markers for longer duration of LDA. In patients with low serum IL-6 (<12.9 pg/mL) and normal MMP-3 levels, the rate of continued LDA reached 38.0 % at 52 weeks. CONCLUSIONS: TCZ monotherapy may induce biologics-free remission or LDA without concomitant use of synthetic DMARDs. Serum levels of IL-6 and MMP-3 are useful markers for identifying patients who could discontinue TCZ without acute disease flare.

Roughly a third of patients with rheumatoid arthritis treated with biological treatments receive them as monotherapy. Tocilizumab--an inhibitor of interleukin 6 receptor signalling--has been studied as monotherapy in several clinical trials. We assessed the efficacy and safety of tocilizumab monotherapy compared with adalimumab monotherapy for patients with rheumatoid arthritis.We did this randomised, double-blind, parallel-group, phase 4 superiority study in 76 centres in 15 countries in North and South America, Australasia, and Europe. We enrolled patients who were aged at least 18 years, had severe rheumatoid arthritis for 6 months or more, and were intolerant to methotrexate or were inappropriate for continued methotrexate treatment. Patients were randomly assigned (1:1; block size of four) to receive tocilizumab 8 mg per kg bodyweight intravenously every 4 weeks plus placebo subcutaneously every 2 weeks or adalimumab 40 mg subcutaneously every 2 weeks plus placebo intravenously every 4 weeks for 24 weeks. Investigators, patients, and sponsor personnel were masked to assignment. The primary endpoint was change in disease activity score using 28 joints (DAS28) from baseline to week 24. This trial is registered with ClinicalTrials.gov, number NCT01119859.We screened 452 patients and enrolled 326 patients. The intention-to-treat population contained 325 patients (163 assigned to tocilizumab, 162 assigned to adalimumab). Week 24 mean change from baseline in DAS28 was significantly greater in the tocilizumab group (-3路3) than in the adalimumab group (-1路8) patients (difference -1路5, 95% CI -1路8 to -1路1; p<0路0001). 16 of 162 (10%) patients in the adalimumab group versus 19 of 162 (12%) in the tocilizumab group had serious adverse events. More patients in the tocilizumab group than in the adalimumab group had increased LDL-cholesterol, increased alanine aminotransferase concentrations, and reduced platelet and neutrophil counts.Tocilizumab monotherapy was superior to adalimumab monotherapy for reduction of signs and symptoms of rheumatoid arthritis in patients for whom methotrexate was deemed inappropriate. The adverse event profiles of tocilizumab and adalimumab were consistent with previous findings.F Hoffmann-La Roche.

ABSTRACT AimTo evaluate safety and efficacy of tocilizumab (TCZ) in a post-approval pilot study among selected Iranian patients with moderate to severe rheumatoid arthritis (RA) and inadequate responses to disease-modifying antirheumatic drugs (DMARDs).Methods Twenty-four weeks monitoring of adverse events and efficacy of TCZ plus previously used DMARD(s) and steroids, as well as investigating durability of TCZ effects within a year after the drug cessation. The efficacy end-points included 28-joint Disease Activity Score (DAS28) and an annual change in radiographic Sharp鈥搗an der Heijde score (SHS).ResultsWith no withdrawal from the study due to adverse events (AE) or unsatisfactory responses in the 21 treated patients, the most common drug-related AEs were dermatologic and the most common serious AEs were infectious in origin (all of the latter occurring after the last drug dose). The only case of TCZ dose alteration was due to increased transaminase levels. Changes in lipid and hemoglobin levels were within the expected ranges. At week 24, cumulative frequencies for significant clinical response, low disease activity and remission were 100%, 90.5% and 76.2%, respectively. The mean SHS in both hands showed no significant change a year after the first TCZ dose. Mean DAS28 levels gradually increased through 1 year post-cessation follow-up, with a somewhat slower rate compared to the initial mean DAS28 reduction.Conclusion In our DMARD-resistant RA patients, TCZ plus DMARD provided a predicted rapid clinical improvement and inhibited structural joint damage, but with some unexpected safety concerns and an expected vanishing of post-cessation efficacy.

The commercial pipeline of recombinant antibody therapeutics is robust and dynamic. As of early December 2014, a total of 6 such products (vedolizumab, siltuximab, ramucirumab, pembrolizumab, nivolumab, blinatumomab) were granted first marketing approvals in 2014. As discussed in this perspective on antibodies in late-stage development, the outlook for additional approvals, potentially still in 2014 and certainly in 2015, is excellent as marketing applications for 7 antibody therapeutics (secukinumab, evolocumab, mepolizumab, dinutuximab, nivolumab, blinatumomab, necitumumab) are undergoing a first regulatory review in the EU or US. Of the 39 novel mAbs currently in Phase 3 studies, a marketing application for one (alirocumab) may be submitted in late 2014, and marketing application submissions for at least 4 (reslizumab, ixekizumab, ocrelizumab, obiltoxaximab) are expected in 2015. Other 'antibodies to watch' are those in Phase 3 studies with estimated primary completion dates in late 2014 or 2015, which includes 13 for non-cancer indications (brodalumab, bimagrumab, bococizumab, MABp1, gevokizumab, dupilumab, sirukumab, sarilumab, tildrakizumab, guselkumab, epratuzumab, combination of actoxumab + bezlotoxumab, romosozumab) and 2 (racotumomab and clivatuzumab tetraxetan) undergoing evaluation as treatments for cancer. In addition to the novel antibody therapeutics mentioned, biosimilar infliximab and biosimilar trastuzumab are 'antibodies to watch' in 2015 because of their potential for entry into the US market and regulatory review, respectively.

ABSTRACT Background Sarilumab is the first fully human monoclonal antibody (mAb) directed against the interleukin-6 receptor alpha (IL-6R伪). Sarilumab was developed using VelocImmune庐; mice immunized with the human IL-6 (hIL-6) receptor. VelocImmune mice are genetically-engineered to express human antibody variable domain genes in the same robust fashion that the replaced mouse genes are typically expressed. Sarilumab is currently being explored as a new therapeutic modality for the treatment of rheumatoid arthritis. Objectives To evaluate the kinetic binding parameters and in vitro functional activity of two monoclonal antibodies directed against IL-6R伪: the fully human mAb sarilumab and the humanized mAb tocilizumab. Methods Kinetic binding parameters were measured using Surface Plasmon Resonance (SPR) technology. The ability to block hIL-6 induced activation of the human IL-6R伪 was investigated using several bioassays; a human hepatocellular carcinoma cell line HepG2, transfected with a STAT3-luciferase reporter plasmid, as well as a proliferation assay using the human B-lymphoma cell line, DS-1. Results Sarilumab bound with high affinity to recombinant monomeric human and monkey IL-6 receptor with a KD value of 61.9 pM and 71.9 pM, respectively. The binding affinity of sarilumab to the dimeric human IL-6 receptor Fc-fusion was 12.8 pM. Cross-reactivity to mouse IL-6 receptor was not observed using SPR, indicating that sarilumab is specific to human and monkey IL-6 receptor. In contrast, tocilizumab bound to monomeric and dimeric forms of the human IL-6 receptor with a 15-22 fold weaker affinity than that of sarilumab as determined by SPR. In the HepG2 cell luciferase reporter assay, sarilumab effectively blocked luciferase activity induced by 50 pM hIL-6 with an IC50 of 146 pM and was 鈭4 fold more potent than tocilizumab. Similarly, in the DS-1 cell proliferation assay, sarilumab effectively blocked growth induced by 1.0 pM hIL-6 with an IC50 of 226 pM and was several fold more potent than tocilizumab. Conclusions Based on these in vitro assay data, sarilumab has both a higher relative binding affinity for IL-6R伪, blocks IL-6R伪 activation, and inhibits IL-6-induced cellular responses such as cell proliferation at lower concentrations than tocilizumab. Acknowledgements VelocImmune庐; is a registered trademark of Regeneron Pharmaceuticals, Inc. Disclosure of Interest A. Rafique Shareholder of: Regeneron Pharmaceuticals, Inc., Employee of: Regeneron Pharmaceuticals, Inc., J. Martin Shareholder of: Regeneron Pharmaceuticals, Inc., Employee of: Regeneron Pharmaceuticals, Inc., M. Blome Shareholder of: Regeneron Pharmaceuticals, Inc., Employee of: Regeneron Pharmaceuticals, Inc., T. Huang Shareholder of: Regeneron Pharmaceuticals, Inc., Employee of: Regeneron Pharmaceuticals, Inc., A. Ouyang Shareholder of: Regeneron Pharmaceuticals, Inc., Employee of: Regeneron Pharmaceuticals, Inc., N. Papadopoulos Employee of: Regeneron Pharmaceuticals, Inc.

Abstract Top of page Abstract PATIENTS AND METHODS RESULTS DISCUSSION ACKNOWLEDGMENTS AUTHOR CONTRIBUTIONS ROLE OF THE STUDY SPONSOR REFERENCES Supporting Information Objective To evaluate the efficacy and safety of sarilumab in combination with methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). Methods Adults with moderate-to-severe RA and an inadequate response to MTX were randomized (1:1:1) to receive sarilumab (doses of 150 mg or 200 mg) or placebo every 2 weeks in conjunction with weekly MTX for 52 weeks. Co–primary end points were the proportion of patients achieving American College of Rheumatology 20% (ACR20) improvement responses at week 24, change from baseline in the Health Assessment Questionnaire (HAQ) disability index (DI) at week 16, and change from baseline in the modified Sharp/van der Heijde score (SHS) of radiographic damage at week 52. Results Baseline characteristics were similar among the groups. For all 3 co–primary end points, the sarilumab 150 mg and 200 mg groups demonstrated statistically significant improvements as compared with the placebo group (ACR20 response rate at week 24, 58.0%, 66.4%, and 33.4%, respectively [ P 653-fold the upper limit of normal occurred in 9.5%, 8.0%, and 2.1% of patients, respectively; in 24 patients, this led to discontinuation of treatment. Elevated total cholesterol levels were observed in 36.8%, 43.0%, and 18.3% of patients, respectively. In patients receiving 150 mg and 200 mg sarilumab, neutrophil counts of 0.5 to <1.0 × 10 9 /liter were observed in 5.1% and 7.8% of patients, respectively, while neutrophil counts of <0.5 × 10 9 /liter were observed in 0.9% and 0.7% of patients, respectively; none of the patients receiving placebo experienced changes in neutrophil counts. Conclusion In RA patients treated with sarilumab (150 mg or 200 mg every 2 weeks) in combination with MTX, both doses provided sustained clinical efficacy, as shown by significant improvements in symptomatic, functional, and radiographic outcomes. Sarilumab was generally well tolerated. The adverse events observed in this study were consistent with the effects of interleukin-6 signaling blockade.

Objective: Sirukumab (CNTO 136) is a human mAb with high affinity and specificity for binding to interleukin-6. This Phase 1 study evaluated the pharmacokinetics, immunogenicity, safety, and tolerability of sirukumab following a single subcutaneous (s.c.) administration in healthy male Japanese and Caucasian subjects. Methods: Japanese and Caucasian subjects were randomized to placebo or 25, 50, or 100 mg sirukumab. Blood samples were collected to measure serum sirukumab concentration and antibodies to sirukumab. Noncompartmental analysis and population pharmacokinetic modeling were conducted to characterize sirukumab pharmacokinetics. Adverse events were monitored at each visit. Results: 25 Japanese and 24 Caucasian subjects received sirukumab and were included in the pharmacokinetic evaluation. Mean C

Abstract INTRODUCTION: Lupus nephritis (LN) is a significant contributor to morbidity and mortality in systemic lupus erythematosus (SLE). Current therapies for LN are limited by significant toxicities and high rates of relapse. A clear and present need exists for the development of effective, targeted and well-tolerated treatment strategies for LN. AREAS COVERED: In this review, the authors examine sirukumab , a monoclonal antibody with high affinity for IL-6, as a novel agent with potential for use in the treatment of SLE and LN in particular. Their review focuses on the available data on the use of sirukumab in patients. Data from Phase I trials would indicate that sirukumab is generally safe and well tolerated. This review also reports the dose-dependent decreases in absolute neutrophil count and platelet count. To date, data for sirukumab in the treatment of SLE and LN are limited, but preliminary data suggest improvement in patient-reported outcomes, and transient improvement in clinical parameters. EXPERT OPINION: Considering scientific literature regarding IL-6 and the IL-6 receptor antagonist tocilizumab, one could extrapolate that sirukumab has the potential to treat LN by acting acutely and locally at the site of renal injury, as well as chronically by modulating the abnormal B- and T-cell subsets observed in SLE patients. However, the clinical efficacy of sirukumab in SLE and LN, in particular, remains to be seen in Phase III trials, and efficacy data in both the induction and maintenance phases of LN treatment will be of interest.

In this article, the 2010 European League against Rheumatism (EULAR) recommendations for the management of rheumatoid arthritis (RA) with synthetic and biological disease-modifying antirheumatic drugs (sDMARDs and bDMARDs, respectively) have been updated. The 2013 update has been developed by an international task force, which based its decisions mostly on evidence from three systematic literature reviews (one each on sDMARDs, including glucocorticoids, bDMARDs and safety aspects of DMARD therapy); treatment strategies were also covered by the searches. The evidence presented was discussed and summarised by the experts in the course of a consensus finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) were determined. Fourteen recommendations were developed (instead of 15 in 2010). Some of the 2010 recommendations were deleted, and others were amended or split. The recommendations cover general aspects, such as attainment of remission or low disease activity using a treat-to-target approach, and the need for shared decision-making between rheumatologists and patients. The more specific items relate to starting DMARD therapy using a conventional sDMARD (csDMARD) strategy in combination with glucocorticoids, followed by the addition of a bDMARD or another csDMARD strategy (after stratification by presence or absence of adverse risk factors) if the treatment target is not reached within 6months (or improvement not seen at 3months). Tumour necrosis factor inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab, biosimilars), abatacept, tocilizumab and, under certain circumstances, rituximab are essentially considered to have similar efficacy and safety. If the first bDMARD strategy fails, any other bDMARD may be used. The recommendations also address tofacitinib as a targeted sDMARD (tsDMARD), which is recommended, where licensed, after use of at least one bDMARD. Biosimilars are also addressed. These recommendations are intended to inform rheumatologists, patients, national rheumatology societies and other stakeholders about EULAR's most recent consensus on the management of RA with sDMARDs, glucocorticoids and bDMARDs. They are based on evidence and expert opinion and intended to improve outcome in patients with RA.

In light of the recent emergence of new therapeutics for rheumatoid arthritis, such as kinase inhibitors and biosimilars, a new nomenclature for disease-modifying antirheumatic drugs (DMARDs), which are currently often classified as synthetic (or chemical) DMARDs (sDMARDS) and biological DMARDs (bDMARDs), may be needed. We propose to divide the latter into biological original and biosimilar DMARDs (boDMARDs and bsDMARDs, respectively, such as abatacept, adalimumab, anakinra, certolizumab pegol, etanercept, golimumab, infliximab, rituximab or tocilizumab, but also emerging ones like clazakizumab, ixekizumab, sarilumab, secukinumab or sirukumab) and the former into conventional synthetic and targeted synthetic DMARDs (csDMARDs and tsDMARDs, respectively). tsDMARDs would then constitute only those that were specifically developed to target a particular molecular structure (such as tofacitinib, fostamatinib, baricitinib or apremilast, or agents not focused primarily on rheumatic diseases, such as imatinib or ibrutinib), while csDMARDs would comprise the traditional drugs (such as methotrexate, sulfasalazine, leflunomide, hydroxychloroquine, gold salts and others). The proposed nomenclature may provide means to group and distinguish the different types of DMARDs in clinical studies and review articles.

The differentiation of therapeutic monoclonal in an increasingly competitive landscape requires optimization of clinical efficacy combined with increased patient convenience. We describe here the generation of MEDI5117, a anti-interleukin (IL)-6 generated by variable domain engineering, to achieve subpicomolar affinity for , combined with Fc (fragment crystallizable) engineering to enhance pharmacokinetic half-life. MEDI5117 was shown to be highly potent in disease-relevant cellular assays. The pharmacokinetics of MEDI5117 were evaluated and compared to those of its progenitor, CAT6001, in a single-dose study in . The were administered, either subcutaneously or intravenously, as a single dose of 5 mg/kg. The half-life of MEDI5117 was extended by approximately 3-fold, and clearance was reduced by approximately 4-fold when compared to CAT6001. MEDI5117 therefore represents a potential 'next-generation' ; future studies are planned to determine the potential for affinity-driven efficacy and/or less frequent administration.

ABSTRACT Interleukin-6 (IL-6) is a critical regulator of the immune system and has been widely implicated in autoimmune disease. Here, we describe the discovery and characterization of olokizumab, a humanized antibody to IL-6. Data from structural biology, cell biology, and primate pharmacology demonstrate the therapeutic potential of targeting IL-6 at "Site 3," blocking the interaction with the signaling co-receptor gp130.

ABSTRACT Objectives: This phase II, dose-ranging, double-blind, placebo-controlled, randomized study (NCT01463059) evaluated efficacy and safety of olokizumab (OKZ), a humanized anti-interleukin 6 monoclonal antibody, in Asian patients with moderately-to-severely active rheumatoid arthritis (RA) who had previously failed anti-TNF therapy. Methods: Patients were randomized to one of six treatment arms: placebo or OKZ (60 mg/120 mg/240 mg every four weeks [Q4W]; or 60 mg/120 mg every two weeks [Q2W]); stratified by country and number of prior anti-TNFs. Primary efficacy variable was Week 12 change from baseline (CFB) in DAS28 CRP for 4-week cumulative dose groups of OKZ and placebo; secondary efficacy variables were Week 12 ACR20/ACR50/ACR70 response rates. Patients continued MTX treatment from baseline, without additional csDMARDs. Results: Of 119 randomized patients, 88.2% completed the study. Greater improvements in DAS28(CRP) mean CFB at Week 12 were observed in all OKZ 4-week cumulative dose groups (60 mg/120 mg/240 mg) versus placebo (p < 0.0001). Week 12 ACR20/ACR50 response rates were higher in all OKZ cumulative dose groups versus PBO (p < 0.05). Incidences of adverse events were similar across OKZ 4-week cumulative dose groups (76.9-84.4%) and placebo (82.8%) with no deaths. Conclusions: OKZ demonstrated improvements in efficacy variables versus placebo in Asian patients with moderately-to-severely active RA who had previously failed anti-TNF therapy. The safety profile was as expected for this class of drug.

Introduction: The pleiotropic cytokine interleukin-6 (IL-6) plays an important role in the pathogenesis of different diseases, including rheumatoid arthritis (RA). ALX-0061 is a bispecific Nanobody (R) with a high affinity and potency for IL-6 receptor (IL-6R), combined with an extended half-life by targeting human serum albumin. We describe here the relevant aspects of its in vitro and in vivo pharmacology. Methods: ALX-0061 is composed of an affinity-matured IL-6R-targeting domain fused to an albumin-binding domain representing a minimized two-domain structure. A panel of different in vitro assays was used to characterize the biological activities of ALX-0061. The pharmacological properties of ALX-0061 were examined in cynomolgus monkeys, using plasma levels of total soluble (s)IL-6R as pharmacodynamic marker. Therapeutic effect was evaluated in a human IL-6-induced acute phase response model in the same species, and in a collagen-induced arthritis (CIA) model in rhesus monkeys, using tocilizumab as positive control. Results: ALX-0061 was designed to confer the desired pharmacological properties. A 200-fold increase of target affinity was obtained through affinity maturation of the parental domain. The high affinity for sIL-6R (0.19 pM) translated to a concentration-dependent and complete neutralization of sIL-6R in vitro. In cynomolgus monkeys, ALX-0061 showed a dose-dependent and complete inhibition of hIL-6-induced inflammatory parameters, including plasma levels of C-reactive protein (CRP), fibrinogen and platelets. An apparent plasma half-life of 6.6 days was observed after a single intravenous administration of 10 mg/kg ALX-0061 in cynomolgus monkeys, similar to the estimated expected half-life of serum albumin. ALX-0061 and tocilizumab demonstrated a marked decrease in serum CRP levels in a non-human primate CIA model. Clinical effect was confirmed in animals with active drug exposure throughout the study duration. Conclusions: ALX-0061 represents a minimized bispecific biotherapeutic of 26 kDa, nearly six times smaller than monoclonal antibodies. High in vitro affinity and potency was demonstrated. Albumin binding as a half-life extension technology resulted in describable and expected pharmacokinetics. Strong IL-6R engagement was shown to translate to in vivo effect in non-human primates, demonstrated via biomarker deregulation as well as clinical effect. Presented results on preclinical pharmacological properties of ALX-0061 are supportive of clinical development in RA.