A high circulating concentration of interleukin 6 is associated with increased risk of coronary heart disease. Blockade of the interleukin-6 receptor (IL6R) with a monoclonal antibody (tocilizumab) licensed for treatment of rheumatoid arthritis reduces systemic and articular inflammation. However, whether IL6R blockade also reduces risk of coronary heart disease is unknown.
To evaluate the impact of treatment with disease-modifying antirheumatic drugs (DMARDs), including IL-6 receptor inhibitor tocilizumab (TCZ), on anaemia markers in patients with rheumatoid arthritis.
Enhanced B cell activity, particularly memory B cells have gained interest in evaluating response during therapies with biologics. CD27-IgD- double negative (DN) B cells lacking the conventional memory marker CD27 are reported to be part of the memory compartment, however only scarce data is available for rheumatoid arthritis (RA). We therefore focused on DN B cells in RA, studied their isotypes and modulation during interleukin-6 receptor (IL-6R) inhibition by tocilizumab (TCZ).
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.
Interstitial lung disease (ILD) is a common extra-articular condition in rheumatoid arthritis (RA), but few studies have systematically investigated its incidence and risk factors in patients receiving anti-tumor necrosis factor-alpha (anti-TNFα) agents or alternate mechanisms of action (MOAs) (e.g., T-cell, B-cell, and interleukin-6 inhibitors).
For clinical trials of therapeutic monoclonal antibodies (mAbs) to be successful, their efficacy needs to be adequately evaluated in preclinical experiments. However, in many cases it is difficult to evaluate the candidate mAbs using animal disease models because of lower cross-reactivity to the orthologous target molecules. In this study we have established a novel humanized Castleman’s disease mouse model, in which the endogenous interleukin-6 receptor gene is successfully replaced by human IL6R, and human IL6 is overexpressed. We have also demonstrated the therapeutic effects of an antibody that neutralizes human IL6R, tocilizumab, on the symptoms in this mouse model. Plasma levels of human soluble IL6R and human IL6 were elevated after 4-week treatment of tocilizumab in this mouse model similarly to the result previously reported in patients treated with tocilizumab. Our mouse model provides us with a novel means of evaluating the in vivo efficacy of human IL6R-specific therapeutic agents.
OBJECTIVES: BUILDER-1 and BUILDER-2 aimed to assess the efficacy and safety of tocilizumab (TCZ) in patients with ankylosing spondylitis (AS). METHODS: BUILDER-1 was a two part, phase II-III parallel-group trial in patients with AS naive to antitumour necrosis factor (aTNF) treatment. Patients in part 1 received TCZ 8 mg/kg or placebo for 12 weeks. In part 2 (beginning after part 1 enrolment ended), newly enrolled patients received TCZ 4 or 8 mg/kg or placebo for 24 weeks. The same treatment arms were used in BUILDER-2, a phase III study in aTNF-inadequate responders. The primary endpoint for both studies was the proportion of patients achieving 20% improvement in the Assessments in Axial SpondyloArthritis international Society (ASAS). Secondary and exploratory endpoints included ASAS40 response rates, Bath Ankylosing Spondylitis Disease Activity Index improvement, changes in joint counts, enthesitis score and C reactive protein (CRP). RESULTS: 102 patients were randomised in BUILDER-1 part 1; 99 (48 TCZ, 51 placebo) completed 12 weeks. Week 12 ASAS20 response rates were 37.3% and 27.5% in the TCZ and placebo arms, respectively (p=0.2823). Secondary and exploratory endpoints did not differ between treatment arms. CRP levels declined with TCZ treatment, suggesting adequate IL-6 receptor blockade. As a result, BUILDER-1 part 2 and BUILDER-2 were terminated. TCZ safety results were consistent with previous observations in rheumatoid arthritis, except for a cluster of anaphylactic and hypersensitivity events at Bulgarian study sites. No apparent explanation for this clustering could be found. CONCLUSIONS: BUILDER-1 failed to demonstrate TCZ efficacy in treating aTNF-naive patients with AS. CLINICAL TRIAL REGISTRATION NUMBERS:: NCT01209702 and NCT01209689 (www.clinicaltrials.gov).
To report on the 5-year efficacy and safety results of the AMBITION (Actemra versus Methotrexate double-Blind Investigative Trial In mONotherapy) monotherapy study (ClinicalTrials.gov: NCT00109408, NCT00720798).
Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates immune and inflammatory responses and its overproduction is a hallmark of inflammatory diseases. Inhibition of IL-6 signaling with the anti-IL-6 receptor antibody tocilizumab has provided some clinical benefit to patients; however, direct cytokine inhibition may be a more effective option. We used the SELEX process to discover SOMAmers (Slow Off-rate Modified Aptamers) with hydrophobic base modifications that inhibit IL-6 signaling in vitro. Two classes of IL-6 SOMAmers were isolated from modified DNA libraries containing 40 random positions and either 5-(N-benzylcarboxamide)-2'-deoxyuridine (Bn-dU) or 5-[N-(1-naphthylmethyl)carboxamide]-2'-deoxyuridine (Nap-dU) replacing dT. These modifications facilitate the high affinity binding interaction with IL-6 and provide resistance against degradation by serum endonucleases. Post-SELEX optimization of one Bn-dU and one Nap-dU SOMAmer led to improvements in IL-6 binding (10-fold) and inhibition activity (greater than 20-fold), resulting in lead SOMAmers with sub-nanomolar affinity (Kd = 0.2 nM) and potency (IC50 = 0.2 nM). Although similar in inhibition properties, the two SOMAmers have unique sequences and different ortholog specificities. Furthermore, these SOMAmers were stable in human serum in vitro for more than 48 hours. Both SOMAmers prevented IL-6 signaling by blocking the interaction of IL-6 with its receptor, and inhibited the proliferation of tumor cells in vitro as effectively as tocilizumab. This new class of IL-6 inhibitor may be an effective therapeutic alternative for patients suffering from inflammatory diseases.
BACKGROUND: Since approval of tocilizumab (TCZ) for treatment of rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA), interleukin 6 (IL-6) pathway inhibition was evaluated in trials of TCZ and other agents targeting the IL-6 receptor and ligand in various RA populations and other inflammatory diseases. This consensus document informs on interference with the IL-6 pathway based on evidence and expert opinion. METHODS: Preparation of this document involved international experts in RA treatment and RA patients. A systematic literature search was performed that focused on TCZ and other IL6-pathway inhibitors in RA and other diseases. Subsequently, incorporating available published evidence and expert opinion, the steering committee and a broader expert committee (both including RA patients) formulated the current consensus statement. RESULTS: The consensus statement covers use of TCZ as combination- or monotherapy in various RA populations and includes clinical, functional and structural aspects. The statement also addresses the second approved indication in Europe JIA and non-approved indications. Also early phase trials involving additional agents that target the IL-6 receptor or IL-6 were evaluated. Safety concerns, including haematological, hepatic and metabolic issues as well as infections, are addressed likewise. CONCLUSIONS: The consensus statement identifies points to consider when using TCZ, regarding indications, contraindications, screening, dose, comedication, response evaluation and safety. The document is aimed at supporting clinicians and informing patients, administrators and payers on opportunities and limitations of IL-6 pathway inhibition.