A Stable CHO K1 Cell Line for Producing Recombinant Monoclonal Antibody Against TNF-α.

Monoclonal antibodies (mAbs) are one of the most significant molecules in protein therapeutics. They are employed in the field of immunology, oncology and organ transplant. They have been also been employed for alleviating several bacterial and viral infections. Moreover, they have revolutionized the area of targeted therapy and improved the quality of treatments, as compared to other cytotoxic drugs and therapies. mAbs bind to specific molecules on the antigen and exhibit specificity towards that molecule, i.e. epitope. Thus, mAbs have immense opportunity to be explored for personalized therapy. The introduction of targeted mAb-based therapeutics has promoted many important scientific achievements in rheumatology. This has warranted additional investigations for developing newer mAb producing clones, to supplement the limited industrial production of certain mAb therapeutics. In this investigation, an integrative approach comprising optimized expression, selection and expansion was adopted to develop a mammalian cell line expressing mAb against TNF-α.The resulting stable clone is anticipated to serve as an economic alternative to the industrial clones, especially for research purposes. The clone was constructed for development of biosimilar of the highly valued therapeutic antibody, Humira.

BAFF predicts immunogenicity in older patients with rheumatoid arthritis treated with TNF inhibitors.

Immunogenicity related to treatment with TNF inhibitors (TNFi) is one of the causes for the decreased attainment of clinical response in patients with rheumatoid arthritis (RA). The B-cell activating factor (BAFF) may be playing a role in the development of immunogenicity. The objective of this study was to analyse the association of baseline concentration of serum B-cell activating factor (BAFF) with immunogenicity after 6 months of TNFi treatment. A total of 127 patients with RA starting a TNFi (infliximab, adalimumab, certolizumab pegol or golimumab) were followed-up for 6 months. Serum samples were obtained at baseline and at 6 months and anti-drug antibody (ADA) and BAFF concentrations were measured. Logistic regression models were employed in order to analyse the association between BAFF concentrations and immunogenicity. Receiver operating characteristic analysis was performed to determine the BAFF concentrations with a greater likelihood of showing immunogenicity association. At 6 months, 31 patients (24%) developed ADA. A significant interaction between the age and baseline BAFF concentration was found for the development of ADA (Wald chi-square value = 5.30; p = 0.02); therefore, subsequent results were stratified according to mean age (≤ / > 55 years). Baseline serum BAFF concentration was independently associated with ADA development only in patients over 55 years (OR = 1.51; 95% CI 1.03-2.21). Baseline serum BAFF ≥ 1034 pg/mL predicted the presence of ADA at 6 months (AUC = 0.81; 95% confidence interval (CI) 0.69-0.93; p = 0.001; positive likelihood ratio = 3.7). In conclusion, our results suggest that the association of BAFF concentration and immunogenicity depends on the patient's age. Baseline serum BAFF concentration predicts the presence of ADA within 6 months of TNFi therapy in older patients with RA.

Disseminated coccidioidomycosis in a patient with juvenile idiopathic arthritis receiving infliximab.

BACKGROUND: Coccidioides immitis is a dimorphic fungus endemic to the arid climates of the Southwest United States, Mexico and parts of Central and South America. Human infection occurs through inhalation of spores with less than half of exposures progressing to a symptomatic state that primarily consists of pulmonary manifestations. Disseminated coccidioidomycosis is exceedingly rare, occurring in fewer than 1 % of symptomatic infections. Through hematogenous spread, the fungus can infect most organ systems and may be fatal without systemic antifungal treatment. Individuals with impaired cell-mediated immunity either from primary immunodeficiency disorders or secondary to immunosuppression with medications such as tumor necrosis factor alpha (TNF-α) inhibitors have increased risk of disseminated coccidioidomycosis and previous cases of coccidioidomycosis have been reported with biologic therapy. CASE PRESENTATION: We present a case of disseminated coccidioidomycosis in a 16-year-old female with polyarticular juvenile idiopathic arthritis (JIA) being treated with prednisone, methotrexate, and infliximab. The patient presented with symptoms of meningeal irritation, bilateral choroidal lesions, and necrotizing peripheral pneumonia. Her infection was thought to be a reactivation of coccidioidomycosis given her history of resolved pneumonia that occurred after traveling to Arizona, New Mexico, and El Paso one year prior to presentation. Following diagnosis, she improved with discontinuation of her immunosuppressive medications and two weeks of intravenous amphotericin B and fluconazole with plans for lifetime treatment with fluconazole while immunosuppressed. Due to worsening arthritis, she will begin tofacitinib and continue close monitoring of chest x-rays and coccidioides antibody. CONCLUSIONS: Patients undergoing immunosuppressive therapy for rheumatological conditions are at increased risk of disseminated coccidioidomycosis and should be evaluated with high suspicion when presenting with atypical symptoms and history of travel to endemic regions.

Use of conventional synthetic and biologic disease-modifying anti-rheumatic drugs in patients with rheumatic diseases contracting COVID-19: a single-center experience.

To examine whether patients with inflammatory arthritis (IA) treated with conventional synthetic (cs) disease-modifying anti-rheumatic drugs (DMARDs) and/or biologic (b) DMARDs, could be affected from SARS-CoV-2 infection and to explore the COVID-19 disease course and outcome in this population. This is a prospective observational study. During the period February-December 2020, 443 patients with IA who were followed-up in the outpatient arthritis clinic were investigated. All patients were receiving cs and/or bDMARDs. During follow-up, the clinical, laboratory findings, comorbidities and drug side effects were all recorded and the treatment was adjusted or changed according to clinical manifestations and patient's needs. There were 251 patients with rheumatoid arthritis (RA), 101 with psoriatic arthritis (PsA) and 91 with ankylosing spondylitis (AS). We identified 32 patients who contracted COVID-19 (17 RA, 8 PsA, 7 AS). All were in remission and all drugs were discontinued. They presented mild COVID-19 symptoms, expressed mainly with systemic manifestations and sore throat, while six presented olfactory dysfunction and gastrointestinal disturbances, and all of them had a favorable disease course. However, three patients were admitted to the hospital, two of them with respiratory symptoms and pneumonia and were treated appropriately with excellent clinical response and outcome. Patients with IA treated with cs and/or bDMARDs have almost the same disease course with the general population when contract COVID-19.

Presence of anti-nuclear antibodies is a risk factor for the appearance of anti-drug antibodies during infliximab or adalimumab therapy in patients with rheumatoid arthritis.

This study aimed to directly analyze the potential relationship of anti-nuclear antibodies (ANA) before and after the administration of TNF-α inhibitors (TNFi) with the appearance of anti-drug antibodies (ADrA) in patients with rheumatoid arthritis (RA). A total of 121 cases, viz., 38, 53, and 30 cases treated with infliximab (IFX), adalimumab (ADA), and etanercept (ETN), respectively, were enrolled. The ANA titers were measured using indirect immunefluorescence assay (IF-ANA) and multiplex flow immunoassay (ANA Screen) before and serially during the therapy. The anti-IFX antibodies (HACA) and anti-ADA antibodies (AAA) were measured with a radioimmunoassay. ADrA turned positive in 14 (36.8%) among 38 patients treated with IFX, and 16 (30.2%) among 53 treated with ADA. All of them were positive for IF-ANA before TNFi administration, while ADrA never appeared in any of the 15 patients negative for IF-ANA (< 40). IF-ANA of high titers (≥ 320 and ≥ 640) before IFX treatment showed a significant association with the appearance of HACA 52 weeks after IFX (P = 0.040 and 0.017, respectively), whereas AAA appearance was not related to IF-ANA titers before treatment. Moreover, IF-ANA of high titers before IFX treatment was significantly associated with inefficacy and discontinuation of the treatment. The positivity of anti-SS-A antibodies before therapy might be a risk factor for ADrA appearance in patients treated with IFX or ADA. The percentage of patients whose IF-ANA titers increased was significantly higher with IFX than with ADA or ETN treatments (P = 0.026 and 0.022, respectively). High ANA titers and positive ANA Screen after IFX therapy showed a significant association with HACA appearance and possibly led to treatment failure. Among the three TNFi, only IFX showed a close relationship with IF-ANA and ADrA appearance, suggesting the interaction of immunogenicity with autoimmunity as well as the advantage of ANA measurement before TNFi therapy.

Design and Evaluation of a Multiplexed Assay to Assess Human Immunogenicity Against Humira®.

The use of biologic-based therapeutics has revolutionized our ability to treat complex diseases such as cancer- and autoimmune-related disorders. Biologic-based therapeutics are known to generate anti-drug immune responses or immunogenicity in clinical patients which can lead to altered pharmacokinetics, decreased drug efficacy, and unwanted adverse clinical events. Assays designed to detect and assess anti-drug immune responses are used to help monitor patients and improve drug safety. Utilizing a tiered approach, screening assays are developed first to identify patients that are potentially positive for anti-drug-specific antibodies. Patients that screen positive are subjected to additional tiers of testing that include a confirmation assay to confirm the presence of expected anti-drug-specific antibodies, a titer assay to assess relative levels of anti-drug-specific antibodies, and, depending on the drug's mechanism of action or concerns of adverse clinical reactions, further characterization such as drug neutralization and anti-drug antibody isotyping. This tiered approach can prove to be detrimental to clinical samples from exposure to multiple cycles of testing, freeze thaws, and repeated handling by lab personnel. Multiplexing some of these assays together may streamline the characterization of anti-drug immune responses and help reduce the repeated usage of clinical samples. In this study, we combined a screening assay and anti-drug isotyping assays into one multiplexed assay using the Luminex® xMAP® Technology. The multiplexed assay was developed and validated to meet the FDA recommended guidelines for immunogenicity assessments. These results show that multiplexed assays perform comparably to industry standards. This study should encourage labs to explore the use of multiplexing immunogenicity assays to characterize anti-drug antibody responses quickly, with less repeat testing and reduced sample handling.

Cytokine storm in COVID-19: pathogenesis and overview of anti-inflammatory agents used in treatment.

COVID-19 infection has a heterogenous disease course; it may be asymptomatic or causes only mild symptoms in the majority of the cases, while immunologic complications such as macrophage activation syndrome also known as secondary hemophagocytic lymphohistiocytosis, resulting in cytokine storm syndrome and acute respiratory distress syndrome, may also occur in some patients. According to current literature, impairment of SARS-CoV-2 clearance due to genetic and viral features, lower levels of interferons, increased neutrophil extracellular traps, and increased pyroptosis and probable other unknown mechanisms create a background for severe disease course complicated by macrophage activation syndrome and cytokine storm. Various genetic mutations may also constitute a risk factor for severe disease course and occurrence of cytokine storm in COVID-19. Once, immunologic complications like cytokine storm occur, anti-viral treatment alone is not enough and should be combined with appropriate anti-inflammatory treatment. Anti-rheumatic drugs, which are tried for managing immunologic complications of COVID-19 infection, will also be discussed including chloroquine, hydroxychloroquine, JAK inhibitors, IL-6 inhibitors, IL-1 inhibitors, anti-TNF-α agents, corticosteroids, intravenous immunoglobulin (IVIG), and colchicine. Early recognition and appropriate treatment of immunologic complications will decrease the morbidity and mortality in COVID-19 infection, which requires the collaboration of infectious disease, lung, and intensive care unit specialists with other experts such as immunologists, rheumatologists, and hematologists.

The management of enthesitis in clinical practice.

PURPOSE OF REVIEW: Enthesitis is a hallmark feature of the spondyloarthropathies (SpA). This review provides an overview of recent insights on diagnosis and management of enthesitis. RECENT FINDINGS: Recent studies support the use of imaging for diagnosis because of its higher sensitivity and specificity compared with clinical examination. Several new MRI and ultrasound scoring systems have been developed for enthesitis, which may facilitate the use of imaging in research. Enthesitis has been evaluated as a primary study outcome mainly in psoriatic arthritis (PsA); however, the use of different indices and definitions of improvement limits comparison across studies. There is very limited information about the efficacy of synthetic disease modifying antirheumatic drugs (DMARDs) for the treatment of enthesitis. In contrast, targeted and biologic DMARDs have all shown efficacy in treating enthesitis compared with placebo. There have been only a few head-to-head trials that compared two different cytokine inhibitors for the treatment of enthesitis. Preliminary data suggest that targeting IL-17 or IL12/23 may be more efficacious for controlling enthesitis than TNF inhibition. SUMMARY: Emerging data suggest interleukin-17 and 12/23 inhibitors may be the first choice in PsA patients with enthesitis. Further head-to-head studies are needed before making definitive recommendations.

Therapeutic drug monitoring of adalimumab in RA: no predictive value of adalimumab serum levels and anti-adalimumab antibodies for prediction of response to the next bDMARD.

BACKGROUND: After adalimumab treatment failure, tumour necrosis factor inhibition (TNFi) and non-TNFi biological disease-modifying anti-rheumatic drugs (bDMARDs) are equally viable options on a group level as subsequent treatment in rheumatoid arthritis (RA) based on the current best evidence synthesis. However, preliminary data suggest that anti-adalimumab antibodies (anti-drug antibodies, ADA) and adalimumab serum levels (ADL) during treatment predict response to a TNFi as subsequent treatment. OBJECTIVE: To validate the association of presence of ADA and/or low ADL with response to a subsequent TNFi bDMARD or non-TNFi bDMARD. Sub-analyses were performed for primary and secondary non-responders. METHODS: A diagnostic test accuracy retrospective cohort study was done in consenting RA patients who discontinued adalimumab after >3 months of treatment due to inefficacy and started another bDMARD. Inclusion criteria included the availability of (random timed) serum samples between ≥8 weeks after start and ≤2 weeks after discontinuation of adalimumab, and clinical outcome measurements Disease Activity Score in 28 joints - C-reactive protein (DAS28-CRP) between 3 to 6 months after treatment switch. Test characteristics for EULAR (European League Against Rheumatism) good response (DAS28-CRP based) after treatment with the next (non-)TNFi bDMARD were assessed using area under the receiver operating characteristic and sensitivity/specificity. RESULTS: 137 patients were included. ADA presence was not predictive for response in switchers to a TNFi (sensitivity/specificity 18%/75%) or a non-TNFi (sensitivity/specificity 33%/70%). The same was true for ADL levels in patients that switched to a TNFi (sensitivity/specificity 50%/52%) and patients that switched to a non-TNFi (sensitivity/specificity 32%/69%). Predictive value of ADA and ADL were similar for both primary and secondary non-responders to adalimumab. CONCLUSIONS: In contrast to earlier research, we could not find predictive value for response to a second TNFi or non-TNFi for either ADA or random timed ADL.

What Is the Clinical Relevance of TNF Inhibitor Immunogenicity in the Management of Patients With Rheumatoid Arthritis?

Tumor necrosis factor-α inhibitors (TNFis) have revolutionized the management of rheumatoid arthritis (RA), however despite considerable progress, only a small proportion of patients maintain long-term clinical response. Selection of, and switching between, biologics is mainly empirical, experiential, and not evidence-based. Most biopharmaceutical proteins (BP) can induce an immune response against the foreign protein component. Immunogenicity and the development of anti-drug antibodies (ADAs) is considered one of the main reasons for loss of therapeutic efficacy (secondary failure). ADAs may neutralize and/or promote clearance of circulating BP with resultant low serum drug levels, loss of clinical response, poor drug survival and adverse events, such as infusion reactions. ADA identification is technically difficult and not standardized, making interpretation of immunogenicity data from published clinical studies challenging. Trough TNFi drug levels correlate with clinical outcomes, exhibiting a "concentration-response" relationship. Measurement of ADA and drug levels may improve patient care and improve cost-effectiveness of BP use. However, in the absence of clinically-validated, reliable assays and consensus guidelines, therapeutic drug monitoring (TDM) and immunogenicity testing have not been widely adopted in routine clinical practice in Rheumatology. Here we discuss the utility and relevance of TDM and immunogenicity testing of TNFis in RA (focusing on the most widely used TNFis globally, with the most available data, i.e., infliximab, adalimumab, and etanercept), the limitations of currently available assays and potential future immunopharmacological strategies to personalize disease management.

Immunogenicity of Infliximab Among Patients With Behçet Syndrome: A Controlled Study.

Background: Immunogenicity of tumor necrosis factor alpha inhibitors (TNFis) has been recognized as an important problem that may cause loss of efficacy and adverse events such as infusion reactions. TNFis are being increasingly used among patients with Behçet syndrome (BS) and scarce data exist on this topic. Objective: We aimed to investigate the prevalence of anti-infliximab (IFX) antibodies in patients with Behçet syndrome together with suitable controls. Methods: We collected serum samples from 66 consecutive Behçet syndrome patients (51 M, 15 F, mean age 37 ± 9 years) who were treated with IFX. Additionally, similarly treated 27 rheumatoid arthritis, 53 ankylosing spondylitis, 25 Crohn's disease patients, and 31 healthy subjects were included as controls. Samples were collected just before an infusion, stored at -80°C until analysis, and serum IFX trough levels and anti-IFX antibodies were measured by ELISA. We used a cut-off value of 1 µg/ml for serum IFX trough level, extrapolating from rheumatoid arthritis studies. Results: Anti-IFX antibodies were detected in four (6%) Behçet syndrome, five (18.5%) rheumatoid arthritis, three (12%) Crohn's disease, and one (2%) ankylosing spondylitis patient. The median serum IFX trough level was significantly lower in patients with anti-IFX antibodies compared to those without antibodies [2.32 (IQR: 0.6-3.6) vs. 3.35 (IQR: 1.63-5.6); p = 0.019]. The serum IFX trough level was lower than the cut-off value in 6/13 (46%) patients with anti-IFX antibodies and in 25/158 (16%) patients without anti-IFX antibodies (p = 0.015). Among the four Behçet syndrome patients with anti-IFX antibodies, two experienced relapses and two had infusion reactions. Conclusions: Immunogenicity does not seem to be a frequent problem in Behçet syndrome patients treated with IFX, but may be associated with relapses and infusion reactions, when present.

The effect of certolizumab drug concentration and anti-drug antibodies on TNF neutralisation.

OBJECTIVES: Tumour necrosis factor (TNF) inhibitors like certolizumab, elicit an immunogenic response leading to the formation of anti-drug antibodies (ADAs). We sought to mechanistically investigate the relationship between certolizumab concentrations, ADAs, and the effective TNF neutralising capacity in sera of rheumatoid arthritis (RA) patients. TNF neutralising capacity of certolizumab was compared to the neutralising capacity of adalimumab. METHODS: Serum samples were collected from 40 consecutive certolizumab-treated RA patients at baseline and 4, 16, 28 and 52 weeks after treatment initiation [Dutch Trial Register NTR (Nederlands Trial Register) Trial NL2824 no. 2965]. Certolizumab concentration and ADA titre were measured with a certolizumab bridging enzyme-linked immunosorbent assay (ELISA) and a drug-tolerant radioimmunoassay (RIA), respectively. TNF neutralisation by certolizumab and adalimumab, in presence or absence of ADAs, was analysed with the TNF-sensitive WEHI bioassay. RESULTS: Despite a high incidence of ADAs during one year of follow-up (65%; 26/40 patients), certolizumab levels of >10 µg/ml were measured in most patients. The capacity for TNF neutralisation highly correlated with certolizumab serum concentration, whereas no association with ADAs was observed. Similar results were obtained for adalimumab. The relative in vitro neutralising potency was higher for certolizumab compared to adalimumab. CONCLUSIONS: Anti-certolizumab antibodies were detected in a large proportion of patients, but in most cases where ADAs were detected, certolizumab was also present in high concentrations, directly correlating with in vitro neutralising capacity. These results indicate that measurement of certolizumab drug levels, rather than ADAs, have direct clinical significance.

Tuberculosis in biologic users for rheumatic diseases: results from the South African Biologics Registry (SABIO).

OBJECTIVES: To evaluate the rate of tuberculosis (TB) in biologic users for rheumatic diseases in South Africa, the effectiveness of our latent TB infection (LTBI) programme, risk factors and outcome. METHODS: TB cases were collected from the South African Biologics Registry (SABIO), rheumatologists and pharmaceutical companies. Demographics, LTBI screening and treatment, biological and disease modifying antirheumatic drug (DMARD) therapies, TB diagnosis and outcomes were recorded. RESULTS: 96 TB cases were collected from 1999 to June 2017: rheumatoid arthritis 55, ankylosing spondylitis 27, psoriatic arthritis 4, and juvenile inflammatory arthritis 10. The TB rate was 1240/100 000 person years for biologic users (n=96) versus the biologic naive cohort of 0/100 000 years with an incidence rate difference of 0.0124 (p<0.0001). 60/96 had pulmonary and 36/96 had extra-pulmonary TB. Reactivation TB occurred in 45/96 cases. TB occurred in all biologics licenced in South Africa, the majority in monoclonal inhibitors (1683/100 000 person years) compared with etanercept (861/100 000 person years) and non-tumour necrosis factor (TNF) inhibitors (681/100 000 person years). The incidence rate ratio for monoclonal inhibitors compared with etanercept was 1.96 (p=0.005) and 2.47 (p=0.002) compared with non-TNF inhibitors with no significant difference between non-TNF inhibitors and etanercept (p=0.336). From those (12.9%) who screened LTBI positive, 14 developed TB, while the majority (77) screened LTBI negative. Black race, male sex, younger age and residence in the Western Cape were statistical risk factors. Two drug resistant TB cases and six deaths occurred. CONCLUSION: Reactivation and new onset TB is a significant risk for all biologics users in SA. Screening for LTBI is an imperative preventative strategy.

Associations between certolizumab pegol serum levels, anti-drug antibodies and treatment response in patients with inflammatory joint diseases: data from the NOR-DMARD study.

OBJECTIVES: To identify a therapeutic target interval for certolizumab pegol drug levels and examine the influence of anti-drug antibodies in patients with inflammatory joint diseases. METHODS: Certolizumab pegol and anti-drug antibody levels were measured in serum samples collected after 3 months of certolizumab pegol treatment in 268 patients with inflammatory joint diseases (116 axial spondyloarthritis, 91 rheumatoid arthritis and 61 psoriatic arthritis) in the NOR-DMARD study. Treatment response was defined by Ankylosing Spondylitis Disease Activity Score Clinically important improvement in axial spondyloarthritis, European League Against Rheumatism good/moderate response in rheumatoid arthritis, and improvement in 28-joint Disease Activity Score of ≥ 0.6 in PsA. Serum drug levels and anti-drug antibodies were analysed using automated in-house assays. RESULTS: Certolizumab pegol serum levels varied considerably between individuals (median (IQR) 32.9 (17.3-43.9) mg/L). Certolizumab pegol level ≥ 20 mg/L was associated with treatment response for the total inflammatory joint disease population, with odds ratio (OR) 2.3 (95% CI 1.2-4.5, P = 0.01) and OR 1.9 (95% CI 1.0-3.5, P = 0.05) after 3 and 6 months of treatment, respectively. For individual diagnoses, this association was most consistent for axial spondyloarthritis, with OR 3.4 (95% CI 1.0-11.1, P < 0.05) and OR 3.3 (95% CI 1.0-10.8, P < 0.05), respectively. Certolizumab pegol level > 40 mg/L was not associated with any additional benefit for any of the diagnoses. Anti-drug antibodies were detected in 6.1% (19/310) of samples and were associated with low certolizumab pegol levels (P < 0.01). CONCLUSIONS: Serum certolizumab pegol levels 20-40 mg/L were associated with treatment response in inflammatory joint diseases. Our study is the first to show this association in axial spondyloarthritis and psoriatic arthritis patients. The results suggest a possible benefit of therapeutic drug monitoring in patients with inflammatory joint disease on certolizumab pegol treatment. TRIAL REGISTRATION: NCT01581294, April 2012.

Efficacy, immunogenicity and cost analysis of a systematic switch from originator infliximab to biosimilar CT-P13 of all patients with inflammatory arthritis from a single center.

Biosimilar drugs are intended to be as effective as the originator product but with a lower cost to healthcare systems. In our center we promoted a switch from originator infliximab (IFXor) to biosimilar infliximab (CT-P13). We analyzed efficacy, safety, immunogenicity and cost savings of switching. Eligible patients were adults with the diagnosis of rheumatoid arthritis (RA), spondyloarthritis (SpA) and psoriatic arthritis (PsA) on therapy with IFXor for at least 6 months and with stable disease activity. Efficacy was measured considering change from baseline in Disease Activity Score in 28 joints (DAS28) for RA and PsA and in Ankylosing Spondylitis Disease Activity Score (ASDAS) for SpA. Disease worsening was considered when an increase of 1.2 from baseline in DAS28 or an increase of 1.1 in ASDAS occurred. Serum IFX levels (sIFX) were dichotomized as therapeutic (between 3-6 µg/mL), low (< 3 µg/mL), and high (> 6 µg/mL). Anti-drug antibody (ADA) levels were dichotomized into detectable (> 10 ng/ml) or non-detectable (< 10 ng/ml). A cost analysis was done based on the purchasing prices of the 2 drugs at our center. During a period of 1 year switch to CT-P13 was performed in 60 patients for non-medical reasons. We had a total of 36 patients with SpA, 16 with RA and 8 with PsA. Disease activity was stable over the observation period and similar to the values observed with IFXor. Median follow-up time was 15 months during which 5 patients stopped CT-P13. Forty two switchers had blood samples collected before and after switch. A total of 27 patients had unaltered sIFX levels and ADA status during follow up. Three patients had detectable ADA at baseline, with low sIFX levels. After switch, ADAs became negative in 2 of those patients, and the other patient kept detectable ADA levels. ADAs became positive in 5 patients after switch. The switch to CT-P13 represented a 26.4 % reduction of costs in the use of IFX therapy in these patients. The switch in routine care of a group of RA, SpA and PsA patients from IFXor to CT-P13 did not affect efficacy, safety, immunogenicity and reduced costs in 26.4%. The observed changes in blood samples were not associated with higher disease activity and did not lead to stopping IFX therapy.

Anti-drug antibodies and low serum trough infliximab levels correlate with disease activity measures in spondyloarthritis patients on an as-needed infliximab treatment.

AIM: In India, many centers use infliximab at lower doses of 3-5 mg/kg without the loading dose for spondyloarthritis (SpA) patients. It is then continued on an as-required basis, rather than a fixed schedule. Our study was undertaken to see if the trough drug levels and anti-drug antibodies in patients with SpA treated with as-needed infliximab dosing correlated with the disease activity measures. METHODS: Thirty-five adult SpA patients in the age group 18-70 years were recruited. They had received three or more infusions of infliximab at 3-5 mg/kg over the past 6 to 12 months. Patient's serum tumor necrosis factor-α, trough infliximab levels and anti-drug antibodies were measured by enzyme-linked immunosorbent assay technique. The disease activity was quantified by Ankylosing Spondylitis Disease Activity Score - erythrocyte sedimentation rate/ C-reactive protein (ASDAS-ESR/CRP) scores. Correlation between quantitative variables was analyzed by the Spearman's correlation assay. The difference in mean trough infliximab and ASDAS between the drug antibody positive and negative patients was assessed using the Mann-Whitney U test. RESULTS: There was a significant negative correlation between the trough infliximab levels and the ASDAS-ESR (rs = -0.57, P < 0.01) and ASDAS-CRP scores (rs = -0.53, P < 0.01). Anti-drug antibodies were positive in 68.7% of the patients and in comparison to the antibody negative patients, had significantly higher ASDAS-ESR and ASDAS-CRP scores. CONCLUSIONS: Spondyloarthritis patients on low-dose, as-needed infliximab therapy, have both the trough infliximab and anti-drug antibodies correlate significantly with the measures of disease activity. We hypothesize that trough infliximab levels and anti-drug antibodies may be used to predict a suboptimal response due to secondary resistance in SpA patients.

Effects of the anti-RANKL antibody denosumab on joint structural damage in patients with rheumatoid arthritis treated with conventional synthetic disease-modifying antirheumatic drugs (DESIRABLE study): a randomised, double-blind, placebo-controlled phase 3 trial.

OBJECTIVE: To evaluate the efficacy of denosumab in suppressing joint destruction when added to conventional synthetic disease-modifying antirheumatic drug (csDMARD) therapy in patients with rheumatoid arthritis (RA). METHODS: This was a multi-centre, randomised, double-blind, parallel-group, placebo-controlled phase 3 study in Japan. Patients with RA aged ≥20 years receiving csDMARDs were randomly assigned (1:1:1) to denosumab 60 mg every 3 months (Q3M), denosumab 60 mg every 6 months (Q6M) or placebo. The change in the modified total Sharp score (mTSS) and effect on bone mineral density (BMD) at 12 months was evaluated. RESULTS: In total, 654 patients received the trial drugs. Denosumab groups showed significantly less progression of joint destruction. The mean changes in the mTSS at 12 months were 1.49 (95% CI 0.99 to 1.99) in the placebo group, 0.99 (95% CI 0.49 to 1.49) in the Q6M group (p=0.0235) and 0.72 (95% CI 0.41 to 1.03) in the Q3M group (p=0.0055). The mean changes in bone erosion score were 0.98 (95% CI 0.65 to 1.31) in the placebo group, 0.51 (95% CI 0.22 to 0.80) in the Q6M group (p=0.0104) and 0.22 (95% CI 0.09 to 0.34) in the Q3M group (p=0.0001). No significant between-group difference was observed in the joint space narrowing score. The per cent change in lumbar spine (L1-L4) BMD in the placebo, Q6M and Q3M groups were -1.03%, 3.99% (p<0.0001) and 4.88% (p<0.0001). No major differences were observed among safety profiles. CONCLUSIONS: Denosumab inhibits the progression of joint destruction, increases BMD and is well tolerated in patients with RA taking csDMARD.

Real-world treatment persistence of golimumab in the management of immune-mediated rheumatic diseases in Europe: a systematic literature review.

OBJECTIVES: To summarise real-world data from studies reporting golimumab persistence in European immune-mediated rheumatic disease (IMRD) populations and to report pooled estimates. DESIGN: Systematic literature review. DATA SOURCES: Relevant literature was identified through searching Medline and Embase via Ovid as well as the conference databases of European League Against Rheumatism and American College of Rheumatology-Association of Rheumatology Health Professionals. ELIGIBILITY CRITERIA: We screened records using predefined patients, interventions, comparators, outcomes and study design criteria. Eligible studies included reports of persistence among adult IMRD patients in Europe receiving treatment with subcutaneous golimumab. Clinical trials, randomised controlled trials, literature reviews, editorials, guidelines and studies with <20 patients receiving golimumab were excluded. DATA EXTRACTION AND SYNTHESIS: Following double screening by two independent reviewers, 27 studies out of 578 identified records were selected for inclusion and subsequent data extraction. Persistence was most commonly reported at 12and 24 months; hence, pooled persistence estimates were calculated for these two time points and reported according to indication. RESULTS: Persistence ranged between 58.1% (psoriatic arthritis (PsA) patients regardless of treatment line) and 75.7% (biological-naïve rheumatoid arthritis patients) at 12 months; at 24 months, the range was 43% (axial spondyloarthritis (AxSpA) patients regardless of treatment line) and 69.6% (biological-naïve PsA patients). On the basis of data from 12 studies, persistence with golimumab treatment was either significantly higher or not significantly different from other tumour necrosis factor inhibitors (TNFi). CONCLUSIONS: Golimumab persistence at 24 months approximates 50%, with a lower persistence among AxSpA (43%) patients. However, as the number of studies in these populations was low, they warrant further research. In 12 studies comparing various TNFi treatments, golimumab was shown to have significantly better or equal persistence to its comparators.