Irreversible covalent Bruton's tyrosine kinase inhibitor, TAS5315 versus placebo in rheumatoid arthritis patients with inadequate response to methotrexate: a randomised, double-blind, phase IIa trial

OBJECTIVE

To examine the efficacy and safety of TAS5315, an irreversible covalent Bruton's tyrosine kinase inhibitor, in Japanese patients with rheumatoid arthritis (RA) refractory to methotrexate.

METHODS

In part A of this phase IIa double-blind study, patients were randomised to TAS5315 4 or 2 mg or placebo once daily for 12 weeks; in part B, all patients received TAS5315 for another 24 weeks. The proportion of patients meeting American College of Rheumatology criteria for 20% improvement (ACR20) at week 12 was assessed (primary endpoint).

RESULTS

Ninety-one patients were randomised in part A, and 84 entered part B. At week 12, 78.9% of patients achieved ACR20 in the TAS5315 combined group vs 60.0% with placebo (p=0.053), 33.3% vs 13.3% achieved ACR50 (p=0.072) and 7.0% vs 0.0% achieved ACR70 (p=0.294), respectively. More patients receiving TAS5315 than placebo had low disease activity or remission at week 12. Clinical and biomarker improvements were maintained during part B. Adverse event (AE) incidence in TAS5315 was similar to placebo in part A; common AEs with TAS5315 were nasopharyngitis (10.3%), pruritus (6.9%) and cystitis (5.2%). Over 36 weeks, nine patients experienced bleeding events of whom four and two patients recovered with drug continuation and interruption, respectively. Three patients recovered after TAS5315 discontinuation.

CONCLUSIONS

The primary endpoint was not achieved. TAS5315 appears to have some bleeding risks, but nevertheless demonstrated numerical differences, compared with placebo, in the improvement rates of all measures of RA disease activity. Future analysis of the risk-benefit of TAS5315 should be considered.

TRIAL REGISTRATION NUMBERS

NCT03605251, JapicCTI-184020, jRCT2080223962.

Monoclonal Antibody Monitoring: Clinically Relevant Aspects, A Systematic Critical Review

Monoclonal antibody (mAb) therapy does not usually lead to a clinical response in all patients and resistance may increase over time after repeated mAb administration. This lack or loss of response to the treatment may originate from different and little-known epigenetic, biomolecular, or pathophysiological mechanisms, although an inadequate serum concentration is perhaps the most likely cause, even if not widely recognized and investigated yet. Patient factors that influence the pharmacokinetics (PK) of a mAb should be taken into account. Multiple analyses of patient-derived PK data have identified various factors influencing the clearance of mAbs. These factors include the presence of antidrug antibodies, low serum albumin, high serum levels of C-reactive protein, high body weight, and gender differences among others. The same clearance processes involved in systemic clearance after intravenous administration are also involved in local first-pass catabolism after subcutaneous administration of mAbs. Therapeutic drug monitoring has been proposed as a way to understand and respond to the variability in clinical response and remission. For both classes of mAbs with anti-inflammatory and antitumor effects, dose-guided optimization based on the measurement of serum concentrations in individual patients could be the next step for a personalized and targeted mAb therapy.

Adalimumab Biosimilars in the Treatment of Rheumatoid Arthritis: A Systematic Review of the Evidence for Biosimilarity

Although treatment with biologic disease-modifying antirheumatic drugs (bDMARDs) has significantly improved clinical outcomes in patients with rheumatoid arthritis (RA), many patients do not have access to these treatments. As cost-effective alternatives to their reference products (RPs), biosimilars provide an opportunity to increase access to bDMARDs. The European Medicines Agency and the US Food and Drug Administration have detailed pathways for the approval of biosimilars based on establishing the similarity of the biosimilar to the RP in terms of structure and function, pharmacokinetics (PK), efficacy, safety, and immunogenicity. A number of biosimilars of adalimumab, infliximab, etanercept, and rituximab RPs have been approved in the United States and/or European Union. This article is focused on the seven adalimumab biosimilars. A review of the data for the biosimilars FKB327, ABP 501, BI 695501, GP2017, MSB11022, PF-06410293, and SB5 confirm that these products are highly similar to the adalimumab RP with regard to structure, physicochemical and biological properties, PK, safety, immunogenicity, and efficacy in the treatment of RA and other chronic immune-mediated, inflammatory conditions. Data from several switching studies showed no changes in efficacy, safety, trough serum drug concentration, or immunogenicity between the biosimilars and their RP.Trial registration: ClinicalTrials.gov identifiers: NCT02260791, NCT02405780, NCT01970475, NCT02137226, NCT02045979, NCT02744755, NCT02144714, NCT02167139, NCT03014947, NCT02114931, NCT02640612, NCT02167139, NCT03052322, NCT02480153. EudraCT numbers: 2012-005140-23, 2012-000785-37, 2013-003722-84, 2015-000579-28, 2014-002879-29, 2014-000662-21, 2013-004654-13, 2015-002634-41, 2014-005229-11, 2016-002852-26, 2014-000352-29.

A Synthetic Cell-Penetrating Heparin-Binding Peptide Derived from BMP4 with Anti-Inflammatory and Chondrogenic Functions for the Treatment of Arthritis

We report dual therapeutic effects of a synthetic heparin-binding peptide (HBP) corresponding to residues 15–24 of the heparin binding site in BMP4 in a collagen-induced rheumatic arthritis model (CIA) for the first time. The cell penetrating capacity of HBP led to improved cartilage recovery and anti-inflammatory effects via down-regulation of the iNOS-IFNγ-IL6 signaling pathway in inflamed RAW264.7 cells. Both arthritis and paw swelling scores were significantly improved following HBP injection into CIA model mice. Anti-rheumatic effects were accelerated upon combined treatment with Enbrel^® and HBP. Serum IFNγ and IL6 concentrations were markedly reduced following intraperitoneal HBP injection in CIA mice. The anti-rheumatic effects of HBP in mice were similar to those of Enbrel^®. Furthermore, the combination of Enbrel^® and HBP induced similar anti-rheumatic and anti-inflammatory effects as Enbrel^®. We further investigated the effect of HBP on damaged chondrocytes in CIA mice. Regenerative capacity of HBP was confirmed based on increased expression of chondrocyte biomarker genes, including aggrecan, collagen type II and TNFα, in adult human knee chondrocytes. These findings collectively support the utility of our cell-permeable bifunctional HBP with anti-inflammatory and chondrogenic properties as a potential source of therapeutic agents for degenerative inflammatory diseases.

The Novel Synthetic Peptide AESIS-1 Exerts a Preventive Effect on Collagen-Induced Arthritis Mouse Model via STAT3 Suppression

Rheumatoid arthritis (RA) is a chronic autoimmune disease that is associated with systemic inflammation and results in the destruction of joints and cartilage. The pathogenesis of RA involves a complex inflammatory process resulting from the action of various proinflammatory cytokines and, therefore, many novel therapeutic agents to block cytokines or cytokine-mediated signaling have been developed. Here, we tested the preventive effects of a small peptide, AESIS-1, in a mouse model of collagen-induced arthritis (CIA) with the aim of identifying a novel safe and effective biological for treating RA. This novel peptide significantly suppressed the induction and development of CIA, resulting in the suppression of synovial inflammation and cartilage degradation in vivo. Moreover, AESIS-1 regulated JAK/STAT3-mediated gene expression in vitro. In particular, the gene with the most significant change in expression was suppressor of cytokine signaling 3 (Socs3), which was enhanced 8-fold. Expression of the STAT3-specific inhibitor, Socs3, was obviously enhanced dose-dependently by AESIS-1 at both the mRNA and protein levels, resulting in a significant reduction of STAT3 phosphorylation in splenocytes from severe CIA mice. This indicated that AESIS-1 regulated STAT3 activity by upregulation of SOCS3 expression. Furthermore, IL-17 expression and the frequency of Th17 cells were considerably decreased by AESIS-1 in vivo and in vitro. Collectively, our data suggest that the novel synthetic peptide AESIS-1 could be an effective therapeutic for treating RA via the downregulation of STAT3 signaling.

Sustained secretion of anti-tumor necrosis factor α monoclonal antibody from ex vivo genetically engineered dermal tissue demonstrates therapeutic activity in mouse model of rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a symmetric inflammatory polyarthritis associated with high concentrations of pro-inflammatory, cytokines including tumor necrosis factor (TNF)-α. Adalimumab is a monoclonal antibody (mAb) that binds TNF-α, and is widely used to treat RA. Despite its proven clinical efficacy, adalimumab and other therapeutic mAbs have disadvantages, including the requirement for repeated bolus injections and the appearance of treatment limiting anti-drug antibodies. To address these issues, we have developed an innovative ex vivo gene therapy approach, termed transduced autologous restorative gene therapy (TARGT), to produce and secrete adalimumab for the treatment of RA.

METHODS

Helper-dependent (HD) adenovirus vector containing adalimumab light and heavy chain coding sequences was used to transduce microdermal tissues and cells of human and mouse origin ex vivo, rendering sustained secretion of active adalimumab. The genetically engineered tissues were subsequently implanted in a mouse model of RA.

RESULTS

Transduced human microdermal tissues implanted in SCID mice demonstrated 49 days of secretion of active adalimumab in the blood, at levels of tens of microgram per milliliter. In addition, transduced autologous dermal cells were implanted in the RA mouse model and demonstrated statistically significant amelioration in RA symptoms compared to naïve cell implantation and were similar to recombinant adalimumab bolus injections.

CONCLUSIONS

The results of the present study report microdermal tissues engineered to secrete active adalimumab as a proof of concept for sustained secretion of antibody from the novel ex vivo gene therapy TARGT platform. This technology may now be applied to a range of antibodies for the therapy of other diseases.

Evaluation of the Effects of Animal Growth and Previous Exposure on the Pharmacokinetics of Rituximab in Rats

With a long half-life, pharmacokinetic (PK) evaluation of monoclonal antibodies in rodents lasts multiple weeks during which the animals may grow significantly. We evaluated the impact of weight, age, and previous drug exposure on the PK of rituximab. Serum concentrations of rituximab were measured after intravenous and subcutaneous dosing in Sprague Dawley rats aged between 7 and 21 weeks and weighing between 200 and 600 g. The growth of rats during the study was incorporated into the model through the increase of the volumes of compartments in relation to the rats total body weight. The final model successfully captured all the data; and no difference was observed in the rituximab PK profiles between exposure naïve and redosed or young and older rats. Incorporating the rodent growth over the time course of the study into the PK model was shown to be important for providing a more physiological description of the disposition of rituximab, especially when young and rapidly growing animals are used. Redosing the same rats with monoclonal antibodies might be a viable strategy for reducing the use of laboratory animals in accordance with the 3R principles.

Fixed dosing of intravenous tocilizumab in rheumatoid arthritis. Results from a population pharmacokinetic analysis

AIMS

Intravenous tocilizumab is currently dosed on body weight, although a weak correlation between body weight and clearance has been described. The aim of the study was to assess the current dosing strategy and provide a scientific rational for dosing using a modelling and simulation approach.

METHODS

Serum concentrations and covariates were obtained from intravenous tocilizumab treated subjects at a dose of 4, 6 or 8 mg every 28 days. A population pharmacokinetic analysis was performed using nonlinear mixed effects modelling. The final model was used to simulate tocilizumab exposure to assess a dosing strategy based on body weight or fixed dosing, using as target a cumulative area under the curve at 24 weeks of treatment above 100 × 10³  μg h ml^-1 .

RESULTS

A one-compartment disposition model with parallel linear and nonlinear elimination best described the concentration-time data. The typical population mean values for clearance, apparent volume of distribution, maximum elimination rate and Michaelis-Menten constant were 0.0104 l h^-1 , 4.83 l, 0.239 mg h^-1 and 4.22 μg ml^-1 , respectively. Interindividual variability was included for clearance (17.0%) and volume of distribution (30.8%). Significant covariates for clearance were patient body weight and C-reactive protein serum levels. An estimated exponent for body weight of 0.360 confirms the weak relationship with tocilizumab clearance. Simulations demonstrate that patients with lower weights are at risk of underdosing if the weight-based dosing approach is used. However, fixed-dosing provides a more consistent drug exposure regardless of weight category.

CONCLUSIONS

Our study provides evidence to support fixed dosing of intravenous tocilizumab in rheumatoid arthritis patients since it reduces variability in tocilizumab exposure among weight categories compared to the current weight-based dosing approach.

The importance of handling high-value biologicals: Physico-chemical instability and immunogenicity of monoclonal antibodies

The present review specifies the various chemical and physical factors that can influence drug stability and immunogenicity, and the treatment outcomes of antibody biologicals. Although monoclonal antibodies (mAbs) are known to be more resistant to environmental changes compared with other proteins, the molecules themselves can be subjected to chemical and physical processes that promote their degradation and transformation into their specific amino-acid moieties. With increasing use of medicinal products that contain mAbs, and their self-administration by the patients, the issue of the correct manipulation of these drugs is of increasing importance. This review summarises the correct handling of mAb biologicals from the point of view of the pharmacist, clinical biochemist and patient, as is supported by relevant cases from the literature and our own data and experience. In particular, if there is a break in the cold chain, both healthcare professionals and patients need to be aware of the potential pharmacokinetics and pharmacodynamics alterations to these biologicals. Furthermore, any alterations in the protein structure can induce harmful immune reactions, including anaphylaxis and cytokine storms, or result in the production of neutralising or blocking Abs. Overall, considering also that treatment costs usually remain high, drug stability can have a tremendous effect on the clinical, humanistic and economic outcomes of such treatments.

Suppression and resolution of autoimmune arthritis by rhesus θ-defensin-1, an immunomodulatory macrocyclic peptide

θ-defensins constitute a family of macrocyclic peptides expressed exclusively in Old World monkeys. The peptides are pleiotropic effectors of innate immunity, possessing broad spectrum antimicrobial activities and immunoregulatory properties. Here we report that rhesus θ-defensin 1 (RTD-1) is highly effective in arresting and reversing joint disease in a rodent model of rheumatoid arthritis (RA). Parenteral RTD-1 treatment of DA/OlaHsd rats with established pristane-induced arthritis (PIA) rapidly suppressed joint disease progression, restored limb mobility, and preserved normal joint architecture. RTD-1 significantly reduced joint IL-1β levels compared with controls. RTD-1 dose-dependently inhibited fibroblast-like synoviocyte (FLS) invasiveness and FLS IL-6 production. Consistent with the inhibition of FLS invasiveness, RTD-1 was a potent inhibitor of arthritogenic proteases including ADAMs 17 and 10 which activate TNFα, and inhibited matrix metalloproteases, and cathepsin K. RTD-1 was non-toxic, non-immunogenic, and effective when administered as infrequently as once every five days. Thus θ-defensins, which are absent in humans, have potential as retroevolutionary biologics for the treatment of RA.

Not all TNF inhibitors in rheumatoid arthritis are created equal: important clinical differences

INTRODUCTION

Anti-TNF therapy has dramatically changed how we manage rheumatoid arthritis. There are many similarities among the five approved agents but also some important differences. Rheumatologists have 5 different options to choose from when they are ready to commence anti-TNF therapy. Although all block the TNF cytokine, there are important critical differences among them that affect their safety profile and clinical utility in certain scenarios. Unfortunately, there are no head to head trials to compare the different anti-TNF agents and none appear to be in the horizon. Areas covered: This article reviews the various clinical situations where it may be important to use a particular anti-TNF agent. The authors also give their expert opinion and future perspectives on the area. Expert opinion: Although there are many similarities among the five different TNFi that are clinically available, there are important clinical niches, where the limited data that are available, that clearly support the preferential use of a particular agent or class of agents. Assays or tests that allow us to find the 'sweet spot' of TNF inhibition at the level of each patient are long overdue.

Current state of biosimilars in Mexico: The position of the Mexican College of Rheumatology, 2016

The present document is a position statement of the Mexican College of Rheumatology on the use of biosimilars in rheumatic diseases. This position considers that biosimilars should be considered as interchangeable, that automatic substitution without previous notice in stable patients during follow-up is not ethical, that the approval of a biosimilar should only be given after exhaustive review of preclinical and clinical data marked by Mexican regulations, that it should be clearly stated in the nomenclature of biologic drugs which is the innovator and which is the biosimilar, that it is not correct to choose a biosimilar as treatment based only on economic reasons or extrapolate indications based only on the approval of the innovator and in the absence of safety and efficacy data for the biosimilar.

The impact of immunogenicity of TNFα inhibitors in autoimmune inflammatory disease. A systematic review and meta-analysis

BACKGROUND

Monoclonal antibodies drugs directed against TNFα, TNFα inhibitors, are immunogenic, and consequent anti-drug antibodies (ADA) formation may decrease the functional drug concentration, resulting in a loss of response. We evaluated the impact of ADA on TNFα therapeutic response.

METHODS

We considered studies enrolling adult patients affected by autoimmune inflammatory disease in therapy with TNFα inhibitors. We collected data about study and population characteristics, treatment dosage, determination of ADA and adverse events (AE). We combined data in meta-analysis, calculating risk ratios (RR) for each study. p-Values<0.05 were considered as statistically significant. Methodological quality was evaluated. Analyses were performed with the STATA 11 and RevMan 5.3 softwares.

RESULTS

We included 34 studies enrolling 4273 patients. Of these, 794 (18.6%) developed ADA. Our analysis showed a significant reduction of response (RR 0.43, 95%CI 0.3-0.63) in patients with ADA respect to patients without, especially in patients treated with Infliximab (RR 0.37) or Adalimumab (RR 0.40). Furthermore, the administration of TNFα inhibitors produced a reaction at the infusion site in 17%, infection in 30% and serious AE in 5% of patients.

CONCLUSION

Detectable ADA significantly reduced TNFα inhibitors response. Drug administration can also cause injection site reaction and infections. Early detection of serum ADA levels may improve patients' management. Currently, there are many indications about the use of immunogenicity tests to guide the therapy, but information regarding how to implement it in clinical practice is needed.

Etanercept, adalimumab, and ustekinumab in psoriasis: analysis of 209 treatment series in Austria

BACKGROUND AND OBJECTIVES

Widely used in the treatment of psoriasis, biologics have been tested in numerous clinical trials. However, drug efficacies and adverse events (AEs) may differ in 'real-world' patients as they do not undergo as rigorous selection and monitoring. Our objective was to examine drug survival, efficacy, and AEs (quality, time of onset) in 'real-world' psoriasis patients treated with etanercept, adalimumab, and ustekinumab.

PATIENTS AND METHODS

Retrospective data analysis (Jan 1, 2004 to Jun 30, 2015) of patients treated at a psoriasis clinic in an Austrian hospital. All patients who had received at least one dose of etanercept, adalimumab, or ustekinumab were included in the analysis. We analyzed: demographics, drug survival, Psoriasis Area and Severity Index (PASI), as well as quality and time of onset of AEs.

RESULTS

In 209 treatment series, the estimated median drug survival varied among the various treatments: 21 months (SE: 6.9) for etanercept, 61 months (SE: 9.4) for adalimumab, and 65 months (SE 1.4) for ustekinumab. Male gender and pretreatment with a biologic were positive predictors of longer drug survival in adalimumab. We found no significant difference in drug efficacy as determined by PASI.

CONCLUSIONS

Most AEs occur during the first year of treatment. Adalimumab and ustekinumab are marked by longer drug survival compared to etanercept.

Is there potential for therapeutic drug monitoring of biologic agents in rheumatoid arthritis?

The use of biologics has significantly changed the management of rheumatoid arthritis over the last decade, becoming the cornerstone treatment for many patients. The current therapeutic arsenal consists of just under 10 biologic agents, with four different mechanisms of action. Several studies have demonstrated a large interindividual pharmacokinetic variability, which translates to unpredictability in clinical response among individuals. The present review focuses on the pharmacokinetics and pharmacodynamics of biologic agents approved for rheumatoid arthritis. The literature relating to their concentration-effect relationship and the use of pharmacokinetic-pharmacodynamic modelling to optimize drug regimens is analysed. Due to the scarcity and complexity of these studies, the current dosing strategy is based on clinical indexes/aspects. In general, dose individualization for biologics should be implemented increasingly in clinical practice as there is a direct benefit for treated rheumatoid arthritis patients. Moreover, there is an indirect benefit in terms of cost-effectiveness.

Low immunogenicity of tocilizumab in patients with rheumatoid arthritis

OBJECTIVE

Subcutaneous (SC) and intravenous formulations of tocilizumab (TCZ) are available for the treatment of patients with rheumatoid arthritis (RA), based on the efficacy and safety observed in clinical trials. Anti-TCZ antibody development and its impact on safety and efficacy were evaluated in adult patients with RA treated with intravenous TCZ (TCZ-IV) or TCZ-SC as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

METHODS

Data from 5 TCZ-SC and 8 TCZ-IV phase III clinical trials and 1 TCZ-IV clinical pharmacology safety study (>50 000 samples) were pooled to assess the immunogenicity profile of TCZ-SC and TCZ-IV (8974 total patients). The analysis included antidrug antibody (ADA) measurement following TCZ-SC or TCZ-IV treatment as monotherapy or in combination with csDMARDs, after dosing interruptions or in TCZ-washout samples, and the correlation of ADAs with clinical response, adverse events or pharmacokinetics (PK).

RESULTS

The proportion of patients who developed ADAs following TCZ-SC or TCZ-IV treatment was 1.5% and 1.2%, respectively. ADA development was also comparable between patients who received TCZ monotherapy and those who received concomitant csDMARDs (0.7-2.0%). ADA development did not correlate with PK or safety events, including anaphylaxis, hypersensitivity or injection-site reactions, and no patients who developed ADAs had loss of efficacy.

CONCLUSIONS

The immunogenicity risk of TCZ-SC and TCZ-IV treatment was low, either as monotherapy or in combination with csDMARDs. Anti-TCZ antibodies developed among the small proportion of patients had no evident impact on PK, efficacy or safety.

Long-term exposure to Myozyme results in a decrease of anti-drug antibodies in late-onset Pompe disease patients

Immunogenicity of recombinant human acid-alpha glucosidase (rhGAA) in enzyme replacement therapy (ERT) is a safety and efficacy concern in the management of late-onset Pompe disease (LOPD). However, long-term effects of ERT on humoral and cellular responses to rhGAA are still poorly understood. To better understand the impact of immunogenicity of rhGAA on the efficacy of ERT, clinical data and blood samples from LOPD patients undergoing ERT for >4 years (n = 28) or untreated (n = 10) were collected and analyzed. In treated LOPD patients, anti-rhGAA antibodies peaked within the first 1000 days of ERT, while long-term exposure to rhGAA resulted in clearance of antibodies with residual production of non-neutralizing IgG. Analysis of  T cell responses to rhGAA showed detectable T cell reactivity only after in vitro restimulation. Upregulation of several cytokines and chemokines was detectable in both treated and untreated LOPD subjects, while IL2 secretion was detectable only in subjects who received ERT. These results indicate that long-term ERT in LOPD patients results in a decrease in antibody titers and residual production of non-inhibitory IgGs. Immune responses to GAA following long-term ERT do not seem to affect efficacy of ERT and are consistent with an immunomodulatory effect possibly mediated by regulatory T cells.

Long-Term Safety and Efficacy of Subcutaneously Administered Tocilizumab for Adult Rheumatoid Arthritis: A Multicenter Phase 3b Long-term Extension Study

Introduction

To assess the long-term safety and efficacy of subcutaneous tocilizumab (TCZ-SC) in US patients with rheumatoid arthritis (RA) who rolled over from the two global phase 3 studies, SUMMACTA (NCT01194414) and BREVACTA (NCT1232569), into this open-label, single-arm, phase 3b study.

Methods

Patients continued to receive TCZ-SC 162 mg weekly or every other week or switched from intravenous TCZ to TCZ-SC 162 mg qw for up to 84 weeks. The primary endpoint was the proportion of patients with serious adverse events (SAEs). Secondary endpoints included clinical efficacy, laboratory abnormalities, and immunogenicity.

Results

Of the 217 patients treated, 76.5% were female, and the mean age was 58.4 years. A total of 23 patients (10.6%) had ≥1 SAE. The most common SAEs were infections (3.7%). Alanine aminotransferase elevations (38.2%) were not associated with hepatic injury. Grade 3/4 neutropenia (3%) was transient and not associated with serious infections. Immunogenicity was low (<1%) and not associated with SAEs. No anaphylaxis or deaths occurred. Thirteen patients (6.0%) withdrew due to safety reasons. Mean Clinical Disease Activity Index and Disease Activity Score in 28 joints remained stable throughout the trial.

Conclusions

The long-term safety of TCZ-SC during the long-term extension period was consistent with the safety profiles from SUMMACTA and BREVACTA, with no new safety signals. Efficacy improvements observed from baseline remained stable over time. These results demonstrated the durability of the safety and efficacy responses, and low immunogenicity, with long-term exposure to TCZ-SC in patients with RA.

Funding: F. Hoffmann-La Roche, Ltd.

Trial registration number: ClinicalTrials.gov identifier, NCT01662063.

Electronic supplementary material

The online version of this article (doi:10.1007/s40744-016-0043-1) contains supplementary material, which is available to authorized users.

Preexisting Antibodies to an F(ab')2 Antibody Therapeutic and Novel Method for Immunogenicity Assessment

Anti-therapeutic antibodies (ATAs) may impact drug exposure and activity and induce immune complex mediated toxicity; therefore the accurate measurement of ATA is important for the analysis of drug safety and efficacy. Preexisting ATAs to the hinge region of anti-Delta like ligand 4 (anti-DLL4) F(ab′)₂, a potential antitumor therapeutic, were detected in cynomolgus monkey serum, which presented a challenge in developing assays for detecting treatment induced ATA. A total ATA assay was developed using a bridging ELISA that detected both anti-CDR and anti-framework ATA including anti-hinge reactivity. A competition assay that could detect 500 ng/mL of anti-CDR ATA in the presence of preexisting ATA was also developed to determine ATA specific to the anti-DLL4 F(ab′)₂ CDR using anti-DLL4 F(ab′)₂ and a control F(ab′)₂. We used these assay methods in a cynomolgus monkey in vivo study to successfully evaluate total and anti-CDR ATA. The preexisting anti-hinge reactivity was also observed to a lesser extent in human serum, and a similar approach could be applied for specific immunogenicity assessment in clinical trials.

Antinociceptive Effects of Prim-O-Glucosylcimifugin in Inflammatory Nociception via Reducing Spinal COX-2

We measured anti-nociceptive activity of prim-o-glucosylcimifugin (POG), a molecule from Saposhnikovia divaricate (Turcz) Schischk. Anti-nociceptive or anti-inflammatory effects of POG on a formalin-induced tonic nociceptive response and a complete Freund’s adjuvant (CFA) inoculation-induced rat arthritis pain model were studied. Single subcutaneous injections of POG produced potent anti-nociception in both models that was comparable to indomethacin analgesia. Anti-nociceptive activity of POG was dose-dependent, maximally reducing pain 56.6% with an ED₅₀ of 1.6 mg. Rats given POG over time did not develop tolerance. POG also time-dependently reduced serum TNFα, IL-1β and IL-6 in arthritic rats and both POG and indomethacin reduced spinal prostaglandin E2 (PGE₂). Like indomethacin which inhibits cyclooxygenase-2 (COX-2) activity, POG dose-dependently decreased spinal COX-2 content in arthritic rats. Additionally, POG, and its metabolite cimifugin, downregulated COX-2 expression in vitro. Thus, POG produced potent anti-nociception by downregulating spinal COX-2 expression.

Evaluating and Reporting the Immunogenicity Impacts for Biological Products--a Clinical Pharmacology Perspective

Immunogenicity assessment is important for biological products due to potential impacts of immunogenicity on safety and efficacy. We reviewed the prescribing information and the FDA's clinical pharmacology review of 121 approved biological products for evaluating and reporting of immunogenicity data. Of the 121 products, 89% (n = 108) reported the incidence of immunogenicity and 49% (n = 59) reported immunogenicity impact on efficacy. However, only 26% (n = 31) reported whether the immunogenicity affected pharmacokinetics. A subset of 16 products reported effects of anti-drug antibodies (ADA) on both systemic clearance and efficacy; 8 of 16 products had increased systemic clearance coinciding with reduced efficacy, and 6 of 16 products had no changes in either clearance or efficacy. Factors contributing to infrequent reporting of the ADA effect on exposure and methods for determining the effect of ADA on exposure are summarized. Measuring ADA and drug concentrations concurrently over time enables the evaluation of ADA impact on pharmacokinetics. Within-subject comparison of concentration data (before vs. after ADA formation) is a useful alternative to between-subject (ADA+ vs. ADA-) comparison when sample size is limited or when the majority of subjects developed ADA. The biological complexity of immune responses presents challenges to quantifying the ADA impact on pharmacokinetics using model-based methods. Our findings support that pharmacokinetic exposure is more sensitive than efficacy endpoints for evaluating ADA effects. A decrease in drug concentration due to formation of ADA during treatment can serve as an early indicator for potential reduced efficacy occurring at a later time.

Advances in use of immunomodulatory agents--a rheumatology perspective

With the advent of biologic agents such as TNF inhibitors, the treatment paradigm for autoimmune systemic inflammatory diseases has progressed tremendously. Despite some distinct treatments, similarities exist in several aspects of the treatment of autoimmune inflammatory diseases such as rheumatoid arthritis (RA), IBD and psoriasis. With a so-called treat-to-target strategy aiming at remission, the intensive and early application of disease-modifying antirheumatic drugs within a 'window of opportunity', and in combination with TNF inhibitors, has become the overarching principle of RA therapy. In this Perspective, the concept of treatment approaches using immunomodulatory agents and the latest advances of therapies in autoimmune systemic inflammatory diseases, especially RA, are overviewed from a rheumatology perspective to provide insights into possible approaches to the treatment of inflammatory gastrointestinal disease.