Double-blinded infliximab dose escalation in patients with rheumatoid arthritis

Comparison of Immunochemical Reactions of Infliximab Innovator and Biosimilars on an Infliximab Detection Kit Used for Therapeutic Drug Monitoring

Monitoring serum infliximab (INF) concentrations is crucial for designing appropriate doses for patients with rheumatoid arthritis. It is recommended to maintain the serum trough INF level at least 1.0 µg/mL. In Japan, an in vitro diagnostic kit using immunochromatography has been approved to determine whether the serum INF concentration is over 1.0 µg/mL or not, and to support the determination of the necessity of increasing the dose or switching to another drug. Biosimilars (BS) of INF may have immunochemical properties different from those of its innovator product, which may show different reactivities on the diagnostic kit. In this study, the responses of the innovator and five BS products on the kit were compared. Based on visually comparing the intensity of color development between the test and control samples, differences were found in the judgment results depending on the analyst. In particular, 1.0 µg/mL was not determined as positive in some cases, whereas 2.0 µg/mL was reliably determined as positive. Overall, no significant difference in reactivity was found between the innovator and five BS products. To further compare the differences in immunochemical properties, the reactivity of these products with three enzyme-linked immunosorbent assay (ELISA) kits was compared. The results confirmed that there were no significant differences among the innovator and BS products in reactivity with the examined kits. When using that diagnostic kit, the users need to be aware that the judgement around 1.0 µg/mL INF may differ depending on the test conditions, including the analyst.

CT-P13 SC for the treatment of rheumatoid arthritis

INTRODUCTION

Management of Rheumatoid Arthritis (RA) has improved following the implementation of early intensive treat to target recommendations and the availability of different biologicals. Most experience is with TNF blockers, but challenges remain in the efficacy/safety balance, immunogenicity, and long-term drug survival as well as availability and affordability despite the introduction of biosimilars.

AREA COVERED

We provide an overview of the development of CT-P13 SC based on infliximab biosimilar CT-P13 IV. The one-year pivotal phase I/III trial in RA showed CT-P13 120 mg SC fixed dose to have favorable pharmacokinetics compared to CT-P13 IV classical weight adapted dosing, similar to lower anti-drug antibodies, similar safety and non-inferiority for efficacy at 6 months.

EXPERT OPINION

CT-P13 SC is an additional option in RA treatment and by extension for other inflammatory diseases as Inflammatory Bowel Disease. This new way of administration has the potential to improve long-term drug survival of infliximab, improve patient outcomes, and patient comfort.

Precision Medicine: Towards Individualized Dosing in Pediatric Rheumatology

Despite an increase in the number of available therapeutics, many children with rheumatic disease continue to experience active inflammatory disease and treatment failure. One reason for treatment failure is the lack of dosing paradigms to account for the wide between-patient variability in drug pharmacokinetics because of developmental changes or genetic polymorphisms that effect drug absorption, distribution, metabolism, and elimination. This review highlights several strategies to optimize dosing for biologic and nonbiologic disease-modifying antirheumatic drugs, including therapeutic drug monitoring, pharmacogenomics, and the use of pharmacokinetic/pharmacodynamic modeling.

Budget Impact Analysis of the Introduction of Subcutaneous Infliximab (CT-P13 SC) for the Treatment of Rheumatoid Arthritis in the United Kingdom

BACKGROUND

CT-P13 subcutaneous (SC)-the first and only SC version of infliximab-is approved by the European Medicines Agency for the treatment of rheumatoid arthritis (RA). This new mode of infliximab administration will allow patients to self-inject at home, significantly reducing the number of outpatient visits and costs of intravenous (IV) administration. This paper describes the economic impact of introducing CT-P13 SC to the market from the UK societal perspective.

OBJECTIVE

The budget impact analysis was conducted to assess the financial impact of the adoption of CT-P13 SC over a 5-year period.

METHODS

A prevalence-based budget impact model was developed incorporating epidemiological data, administration cost data, and market share data. The analysis compared a "world with" CT-P13 SC scenario to a "world without" CT-P13 SC. A sensitivity analysis included dose escalation up to 4.1 mg/kg to reflect the real-world care delivery setting.

RESULTS

Compared to the "world without" scenario, the introduction of CT-P13 SC resulted in cost savings of ₤69.3 million in the UK over a 5-year period. In the scenario analysis, the saving increased to ₤173.5 million over 5 years.

CONCLUSION

Use of CT-P13 SC may lead to substantial cost savings for the UK society.

Comparative efficacy of subcutaneous (CT-P13) and intravenous infliximab in adult patients with rheumatoid arthritis: a network meta-regression of individual patient data from two randomised trials

BACKGROUND

A subcutaneous (SC) formulation of infliximab biosimilar CT-P13 is approved in Europe for the treatment of adult patients with rheumatoid arthritis (RA). It may offer improved efficacy versus intravenous (IV) infliximab formulations.

METHODS

A network meta-regression was conducted using individual patient data from two randomised trials in patients with RA, which compared CT-P13 SC with CT-P13 IV, and CT-P13 IV with reference infliximab IV. In this analysis, CT-P13 SC was compared with CT-P13 IV, reference infliximab IV and pooled data for both reference infliximab IV and CT-P13 IV. Outcomes included changes from baseline in 28-joint Disease Activity Score based on C-reactive protein (DAS28-CRP), Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI), and rates of remission, low disease activity or clinically meaningful improvement in functional disability per Health Assessment Questionnaire-Disability Index (HAQ-DI).

RESULTS

The two studies enrolled 949 patients with RA; pooled data for 840 and 751 patients were evaluable at weeks 30 and 54, respectively. For the CT-P13 SC versus pooled IV treatment arm comparison, differences in changes from baseline in DAS28-CRP (- 0.578; 95% confidence interval [CI] - 0.831, - 0.325; p < 0.0001), CDAI (- 3.502; 95% CI - 5.715, - 1.289; p = 0.002) and SDAI (- 4.031; 95% CI - 6.385, - 1.677; p = 0.0008) scores at 30 weeks were statistically significant in favour of CT-P13 SC. From weeks 30 to 54, the magnitude of the differences increased and remained statistically significant in favour of CT-P13 SC. Similar results were observed for the comparison of CT-P13 SC with CT-P13 IV and with reference infliximab IV. Statistically significant differences at week 30 favoured CT-P13 SC over the pooled IV treatment arms for the proportions of patients achieving EULAR-CRP good response, American College of Rheumatology (ACR) 50 and ACR70 responses, DAS28-CRP-defined remission, low disease activity (DAS28-CRP, CDAI and SDAI criteria) and clinically meaningful HAQ-DI improvement.

CONCLUSIONS

CT-P13 SC was associated with greater improvements in DAS28-CRP, CDAI and SDAI scores and higher rates of clinical response, low disease activity and clinically meaningful improvement in functional disability, compared with CT-P13 IV and reference infliximab IV.

TRIAL REGISTRATION

EudraCT, 2016-002125-11 , registered 1 July 2016; EudraCT 2010-018646-31 , registered 23 June 2010.

The Effect of Dose Escalation on the Cost-Effectiveness of Etanercept and Adalimumab with Methotrexate Among Patients with Moderate to Severe Rheumatoid Arthritis

BACKGROUND

Patients with moderate to severe rheumatoid arthritis (RA) occasionally increase their doses of tumor necrosis factor (TNF) inhibitors, especially the monoclonal antibody origin drugs such as adalimumab and infliximab, after inadequate response to the initial dose. Previous studies have evaluated the cost-effectiveness of various sequences of treatment for RA in the United States but have not considered the effect of dose escalation.

OBJECTIVE

To assess the cost-effectiveness of etanercept and adalimumab by incorporating the effect of dose escalation in moderate to severe RA patients.

METHODS

We adapted the open-source Innovation and Value Initiative - Rheumatoid Arthritis model, version 1.0 to separately simulate the magnitude and time to dose escalation among RA patients taking adalimumab plus methotrexate or etanercept plus methotrexate from a societal perspective and lifetime horizon. An important assumption in the model was that dose escalation would increase treatment costs through its effect on the number of doses but would have no effect on effectiveness. We estimated the dose escalation parameters using the IBM MarketScan Commercial and Medicare Supplemental Databases. We fit competing parametric survival models to model time to dose escalation and used model diagnostics to compare the fit of the competing models. We measured the magnitude of dose escalation as the percentage increase in the number of doses conditional on dose escalation. Finally, we used the parameterized model to simulate treatment sequences beginning with a TNF inhibitor (adalimumab, etanercept) followed by nonbiologic treatment.

RESULTS

In baseline models without dose escalation, the incremental cost per quality-adjusted life-year of the etanercept treatment sequence relative to the adalimumab treatment sequence was $85,593. Incorporating dose escalation increased treatment costs for each sequence, but costs increased more with adalimumab, lowering the incremental cost-effectiveness ratio to $9,001. At willingness-to-pay levels of $100,000, the etanercept sequence was more cost-effective compared with the adalimumab sequence, with probability 0.55 and 0.85 in models with and without dose escalation, respectively.

CONCLUSIONS

Dose escalation has important effects on cost-effectiveness and should be considered when comparing biologic medications for the treatment of RA.

DISCLOSURES

Funding for this study was contributed by Amgen. When this work was conducted, Incerti and Jansen were employees of Precision Health Economics, which received financial support from Amgen. Maksabedian Hernandez, Collier, Gharaibeh, and Stolshek were employees and stockholders of Amgen, and Tkacz and Moore-Schiltz were employees of IBM Watson Health, which received financial support from Amgen. Some of the results of this work were previously presented as a poster at the 2019 AMCP Managed Care & Specialty Pharmacy Annual Meeting, March 25-28, 2019, in San Diego, CA.

Insensitivity versus poor response to tumour necrosis factor inhibitors in rheumatoid arthritis: a retrospective cohort study

Background

With advancement in the treatment options of rheumatoid arthritis (RA), optimising the outcomes of difficult-to-treat patients has become increasingly important in clinical practice. In particular, insensitivity to first-line biologic disease-modifying anti-rheumatic drugs (bDMARD) is becoming a significant problem because it may decrease the treatment adherence of patients. This study aimed to compare RA patients with an insensitivity and those with a poor response to initial treatment with tumour necrosis factor inhibitors (TNFis), which are the most frequently used bDMARDs.

Methods

This is a retrospective cohort study using clinical data from the FIRST registry. bDMARD-naïve RA patients treated with tumour necrosis factor inhibitors (TNFis) from August 2003 to May 2019 were included and categorised into three groups: TNFi insensitivity, poor response to TNFis and controls. TNFi insensitivity was defined as follows: (1) discontinuation of TNFi treatment within 22 weeks due to lack of any response, or (2) an increase in the disease activity score in 28 joints–C-reactive protein (DAS28-CRP) of > 0.6 at week 22 compared with week 0. Among the remaining patients, those with a DAS28-CRP > 2.6 at week 22 were categorised in the poor response group.

Results

Of the included patients, 94 were classified in the insensitivity, 604 in the poor response and 915 in the control. A higher DAS28-CRP before treatment was a risk factor for a poor response but not for insensitivity. In contrast, dose escalation of infliximab decreased the risk of a poor response but not that of insensitivity.

Conclusions

In future research, poor and insensitivity to bDMARDs should be assessed separately to fully elucidate the aetiology of, and risk factors for, bDMARD refractoriness.

Effect of Golimumab Dose Escalation in Japanese Patients With Rheumatoid Arthritis: Post-Hoc Analysis of Post-Marketing Surveillance Data

Introduction

While dose escalation of golimumab has been used for patients with rheumatoid arthritis who demonstrate an inadequate response to the standard dose, its effectiveness has not been fully evaluated. The aim of this study was to assess the clinical outcome observed by dose escalation of golimumab for patients with rheumatoid arthritis in the daily clinical setting.

Methods

A post hoc analysis was performed of data from the 24-week post-marketing surveillance conducted in Japan (n = 5154). A total of 301 patients with moderate or high disease activity at baseline who underwent dose escalation of golimumab were assessed for effectiveness at 24 weeks based on several variables, such as DAS28-CRP, SDAI, and CDAI, as well as for medication persistence through 24 weeks. In addition, the study population was stratified by the time to dose escalation, and effectiveness was likewise evaluated. Logistic regression analysis was performed to identify factors associated with a moderate/good EULAR response to golimumab at 24 weeks.

Results

Patients with golimumab dose escalation showed significant improvement of the clinical signs and symptoms of rheumatoid arthritis at 24 weeks, as indicated by reduction of the DAS28-CRP (∆0.89), SDAI (∆8.64), and CDAI (∆8.28) scores. This result was relatively consistent across the subgroups stratified by the timing of dose escalation. According to Kaplan-Meier analysis, 78.1% of the patients continued to receive golimumab at 24 weeks, and this was also similar among the subgroups stratified by the time to dose escalation. Multivariate analysis identified male sex and previous biologic therapy as factors that were significantly associated with the clinical response at 24 weeks.

Conclusion

In real-world clinical practice, improvement of disease activity was observed after uptitration of golimumab from 50 to 100 mg regardless of the timing. Male patients and biologic-naive patients were more likely to respond to dose escalation of golimumab.

Trial Registration

UMIN-CTR, Identifier: UMIN000015895.

Electronic Supplementary Material

The online version of this article (10.1007/s40744-020-00198-4) contains supplementary material, which is available to authorized users.

Will savings from biosimilars offset increased costs related to dose escalation? A comparison of infliximab and golimumab for rheumatoid arthritis

Introduction

Biosimilar infliximab has the potential for appreciable cost savings compared to its reference biologic, but dose escalation is common and increases costs. We compared frequency of dose escalation and associated Medicare-approved amount so as to determine the break-even point at which infliximab dose escalation would offset the cost savings of using a biosimilar, referent to alternatively using golimumab.

Methods

We studied Medicare enrollees with rheumatoid arthritis (RA) initiating infliximab or golimumab. Frequency of dose escalation was summarized descriptively over 18 months, as were Medicare-approved amounts for reimbursement. Analyses were repeated conditioning on high adherence (i.e., non-discontinuation, > 10-week gap). Multivariable-adjusted logistic regression and mixed models evaluated factors associated with infliximab dose escalation.

Results

A total of 5174 infliximab and 2843 golimumab initiators were observed. Dose escalation was rare for golimumab (5%) but common for infliximab (49%), and was even more common (72%) for infliximab among patients who persisted on treatment. Regardless of dose escalation, the adjusted least square mean dollar amounts were appreciably higher for golimumab ($28,146) than for infliximab ($21,216) and greater among persistent patients (cost difference $9269, favoring infliximab). Only when patients escalated infliximab to ≥ 8 mg/kg every 6 weeks was golimumab IV at break-even or less expensive. After controlling for multiple factors, physician ownership of the infusion center was associated with greater likelihood of infliximab dose escalation (odds ratio = 1.25, 95% CI 1.09–1.44).

Conclusion

Despite frequent dose escalation with infliximab that often increase its dose by threefold or more, the savings from the current price of its biosimilar substantially offsets the costs of an alternative infused TNFi biologic for which no biosimilar is available.

Effectiveness of long-term infliximab use and impact of treatment adherence on disease control in refractory, non-infectious pediatric uveitis

BACKGROUND

Refractory non-infectious uveitis is a serious condition that leads to ocular complications and vision loss and requires effective systemic treatment to control disease. The effectiveness of long-term infliximab [IFX] in refractory non-infectious childhood uveitis and the impact of treatment adherence on disease control were evaluated.

METHODS

Retrospective, single-center study between December 2002 and April 2016 of 27 children with refractory non-infectious uveitis [17 with juvenile idiopathic arthritis, JIA] treated with long-term IFX [9+ months]. Disease activity was assessed prior to and while on IFX using the Standardization of Uveitis Nomenclature [SUN]. Number of visits per year with active uveitis was analyzed by repeated measures logistic regression analysis from 2 years prior to IFX initiation or from onset of uveitis until most recent visit on IFX. Incomplete treatment adherence was assessed for each visit and defined as any deviance in corticosteroid use, prescribed infusion frequency, and/or follow-up examination frequency.

RESULTS

Primary outcomes were sustained uveitic and systemic disease control prior to and during IFX treatment and the impact of incomplete adherence on uveitic disease control while on IFX. Secondary outcomes included corticosteroid and glaucoma medication requirement, ocular complications and need for surgical intervention. Mean age at IFX initiation was 10.4 ± 4.5 years; initial mean dose was 6.6 ± 2.2 mg/kg [and given at weeks 0, 2, 4 and q4 weeks thereafter for 93%]. Median duration on IFX was 35 [range 9-128] months. Prior to IFX, 14/27 patients had failed adalimumab ± methotrexate [MTX]; 21/27 failed MTX. IFX led to uveitis control in 89% and arthritis control in 76% (13/17). The odds ratio of having controlled disease after IFX was 4.1 (2.6, 6.4) compared to pre-treatment visits. Topical corticosteroids and glaucoma medications were statistically decreased (p = 0.007 right eye [OD], 0.003 left eye [OS] and p = 0.001 OD, p = 0.028 OS respectively). Incomplete adherence to treatment showed 10.3 times greater odds (7.1, 15.0) of having disease activity than full adherence.

CONCLUSIONS

This study adds significantly to the IFX literature by documenting outstanding uveitis control with long-term IFX treatment in non-infectious pediatric uveitis patients. Higher dosage and shorter interval were utilized without adverse effects. Importantly, this is the first study, to our knowledge, to document the significant impact of treatment adherence on uveitis control.

Infliximab for Refractory Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is frequently difficult to treat. Infliximab (IFX) is useful for extracardiac sarcoidosis, but its use in CS has been limited due to concerns about cardiotoxicity and an FDA blackbox warning about use in heart failure. We reviewed 36 consecutive patients treated with infliximab for CS refractory to standard therapies. IFX was initiated for patients with refractory dysrhythmias, moderate to severe cardiomyopathy, and evidence of persistent F-18 fluorodeoxyglucose uptake on positron emission tomography scan, despite standard therapies. We compared the prednisone dose, ejection fraction (EF), and dysrhythmias before and after IFX therapy. The prednisone-equivalent steroid dose decreased from a median of 20 mg at initiation of infliximab to 7.5 at 6 months and 5 mg at 12 months postinitiation of infliximab (p <0.001). In the 25 patients with serial EF measurements, no statistically significant difference was detected in EF (41% at baseline, 42% at 6 months). Of the 16 patients with serial dysrhythmia data, there was a trend toward reduction of percent of patients with ventricular tachycardia (VT), from 32% at baseline, to 22% at 6 months and 19% at 12 months (p = 0.07). Adverse events were common, occurring in 6 of 36 patients, with 3 of 36 patients stopping infliximab for a prolonged period. In responder analysis, 24 patients improved in at least 1 of 3 outcome categories. In conclusion, infliximab may be useful for refractory cardiac sarcoidosis.

Remicade® (infliximab): 20 years of contributions to science and medicine

On August 24, 1998, Remicade^® (infliximab), the first tumor necrosis factor-α (TNF) inhibitor, received its initial marketing approval from the US Food and Drug Administration for the treatment of Crohn’s disease. Subsequently, Remicade was approved in another five adult and two pediatric indications both in the USA and across the globe. In the 20 years since this first approval, Remicade has made several important contributions to the advancement of science and medicine: 1) clinical trials with Remicade established the proof of concept that targeted therapy can be effective in immune-mediated inflammatory diseases; 2) as the first monoclonal antibody approved for use in a chronic condition, Remicade helped in identifying methods of administering large, foreign proteins repeatedly while limiting the body’s immune response to them; 3) the need to establish Remicade’s safety profile required developing new methods and setting new standards for postmarketing safety studies, specifically in the real-world setting, in terms of approach, size, and duration of follow-up; 4) the study of Remicade has improved our understanding of TNF’s role in the immune system, as well as our understanding of the pathophysiology of a range of diseases characterized by chronic inflammation; and 5) Remicade and other TNF inhibitors have transformed treatment practices in these chronic inflammatory diseases: remission has become a realistic goal of therapy and long-term disability resulting from structural damage can be prevented. This paper reviews how, over the course of its development and 20 years of use in clinical practice, Remicade was able to make these contributions.

Association of female sex and positive rheumatoid factor with low serum infliximab and anti-drug antibodies, related to treatment failure in early rheumatoid arthritis: results from the SWEFOT trial population

Objective: Infliximab-treated patients with rheumatoid arthritis (RA) may respond insufficiently due to low serum infliximab (sIFX) levels, caused by anti-drug antibodies (ADAs). However, monitoring of sIFX and ADAs is not routinely implemented, and levels for optimal outcome have not been validated. We searched for predictors for sIFX < 0.2 μg/mL and ADA development in a randomized setting. Methods: In the SWEFOT trial, of 128 patients randomized to methotrexate + IFX therapy, 101 had serum samples at 3, 9, and 21 months that were analysed for sIFX [enzyme-linked immunosorbent assay (ELISA)] and ADAs [ELISA, and precipitation and acid dissociation (PandA) when sIFX > 0.2 μg/mL]. The primary and secondary outcome measures were low disease activity [LDA = 28-joint Disease Activity Score (DAS28) ≤ 3.2] and remission (DAS28 < 2.6). Baseline characteristics were assessed as potential predictors of sIFX < 0.2 μg/mL or ADA positivity, using logistic regression. Results: Categorization of sIFX levels into < 0.2, 0.2-2.9, 3.0-7.0, and > 7.0 μg/mL showed a dose-response association with LDA (30%, 64%, 67%, and 79%, respectively, p = 0.008) and remission (10%, 45%, 39%, and 66%, p = 0.004) at trial cessation (21 months). Female patients had sIFX < 0.2 μg/mL more often than males (35% vs 7%, p = 0.006), with a similar trend for rheumatoid factor (RF)-positive vs RF-negative patients (34% vs 16%, p = 0.059). ADA positivity showed similar patterns, also after adjustment for potential confounders (female sex: p = 0.050; RF positivity: p = 0.067). PandA captured four highly ADA-reactive patients with sIFX > 0.2 μg/mL, of whom three were ADA positive at other time-points, all with high DAS28 at follow-up. Conclusion: In early RA patients receiving IFX as a second-line agent, sIFX < 0.2 μg/mL and ADA development were associated with treatment failure and were more common in females, with a similar trend for RF positivity. Our findings support the use of therapeutic drug monitoring, and PandA in ADA-negative non-responders. Trial registration: SWEFOT NCT00764725 ( https://clinicaltrials.gov/ct2/show/NCT00764725 ).

Outcomes of infliximab dose escalation in patients with rheumatoid arthritis

INTRODUCTION

Dose escalation of infliximab in both primary and secondary nonresponders is widely reported; however, the usefulness of dose escalation has been disputed. The objective of this analysis is to evaluate trends in clinical efficacy following multiple infliximab dose escalations in patients with rheumatoid arthritis (RA).

METHODS

Patients enrolled in a US RA registry were included if they initiated infliximab at 3 mg/kg every 8 weeks, received ≥ 1 infliximab dose escalation within 12 months of initiation, and had ≥ 1 visit following dose escalation. Trends in mean Clinical Disease Activity Index (CDAI) and Health Assessment Questionnaire (HAQ) scores from visits following dose escalations were evaluated.

RESULTS

In patients who received 2 or 3 dose escalations, the initial (1 or 2) dose escalations resulted in reduced mean CDAI scores, but subsequent escalations did not further reduce disease activity. In patients who received ≥ 4 dose escalations, mean CDAI scores did not further reduce disease activity over time. Mean HAQ scores were stable over time in patients who received 2 or 3 dose escalations. In patients who received ≥ 4 dose escalations, mean HAQ scores decreased following 1 dose escalation but progressively increased following subsequent dose escalations.

CONCLUSION

Initial dose escalations (from 3 mg/kg to the equivalent of approximately 5 to 7 mg/kg) may be useful in controlling disease activity; however, there may be diminishing clinical benefit of further escalations, which can also increase the potential risk for infection and increase incremental drug costs.

KEY POINTS

• Initial infliximab dose escalations (1 to 2) may be useful in lowering disease activity in patients with rheumatoid arthritis. • There does not appear to be a clinical benefit in infliximab dose escalations above the equivalent of 5 to 7 mg/kg.

Physicochemical characterization and phase I study of CMAB008, an infliximab biosimilar produced by a different expression system

Background

Infliximab (Remicade), a chimeric monoclonal antibody against human TNFα, will inevitably face competition from biosimilar products, because of its effectiveness in autoimmune diseases and rapidly increasing market demand. According to guidelines for biosimilar development, the “biosimilar-expression system” may differ from that of the innovator, but more appropriate studies should be carried out to demonstrate the comparability between biosimilar and innovator. CMAB008 is an infliximab biosimilar candidate developed by the State Key Laboratory of Antibody Medicine and Targeted Therapy of China. Infliximab was expressed in SP2/0 cells, while CMAB008 was produced in a CHO-expression system.

Methods

In this study, infliximab and CMAB008 were compared on physicochemical and biological characterizations, including protein content, activity, physiochemical integrity, impurities, additives, and immunogenicity.

Results

The results showed that they were highly similar and comparable, except some differences in glycosylation. As glycosylation profiles can influence immunogenicity and occurrence of allergy or other adverse reactions of antibody therapeutics, primary tolerability and pharmacokinetics of CMAB008 were evaluated. In the phase I clinical trial, plasma concentration of CMAB008 and antidrug antibodies were also measured using ELISA and bridging ELISA, respectively. CMAB008 exhibited favorable clinical tolerability, no adverse events in the 3 mg/kg single-dose group (recommended therapeutic dosage), and no serious adverse events in the multiple-dose group. Also, no injection-site reactions were observed in the experiment.

Conclusion

In summary, CMAB008 might have the potential to be an effective drug compared with infliximab.

Beneficio económico de los ensayos clínicos controlados patrocinados: El gasto evitable en medicamentos para el tratamiento de la artritis reumatoidea

OBJECTIVES

To estimate the following: (1) the avoidable cost of biologic (bDMARDs) and conventional synthetic Rheumatoid Arthritis (RA) modifying antirheumatic drugs (csDMARDs) during controlled clinical trials (CCTs), their extension period, and for bDMARDs in post study drug programs; and (2) to evaluate the impact on health insurances.

METHODS

We analyzed 13 CCTs (233 patients) that evaluated bDMARDs. Avoidable cost was what the health insurance should have paid if the patient had not received the medication from the CCT sponsor and was estimated with a micro-costing approach (bottom-up method). Results were expressed as mean ± standard deviation (SD) or percentages. Approved by the Ethics Committee.

RESULTS

Mean age was 50.62 SD 11.8 years, 84% were women, 72% (n = 166) had health insurance. The mean annual cost of bDMARDs was US$ 30 567.40 while the cost for csDMARDs was US$ 104.90 during the CCTs. The mean annual cost in extension periods and post study drug programs for bDMARDs was US$ 36 016.20 and for csDMARs during the extension period was US$ 81.70. The avoidable cost for public health insurances exceeded one million dollars per year.

CONCLUSION

This work describes for the first time in Argentina the significant economic benefit that may represent for RA patients' health insurances the participation in CCTs with bDMARDs. It shows that during the execution of the CCT, its extension periods, or post study access programs, while medication provision is guaranteed, the economic burden imposed by the treatment of the RA is relieved.

Infliximab dose adjustment can improve the clinical and radiographic outcomes of rheumatoid arthritis patients: REVIVE study results

Purpose

We evaluated the clinical responses and radiographic outcomes of 90 patients with rheumatoid arthritis (RA) undergoing continuous or dose-adjusted infliximab treatment over 104 weeks.

Patients and methods

Patients received 3 mg/kg infliximab continuously (the contin group; n=50), or the dose escalation and de-escalation of infliximab (3, 6, and 10 mg/kg) from week 14 (the adjusted group; n=40) based on the patient’s Disease Activity Score in 28 joints (DAS28). The retention rate, clinical response, and radiographic assessment were determined at week 104.

Results

The contin and adjusted groups’ retention rates at week 104 were 56.8 and 66.7%, and the groups’ low disease activity in the DAS28 was 39.1 and 66.7%, respectively. Remission based on the DAS28 and the American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) Boolean-based criteria was significantly increased in the adjusted group. In the radiographic assessment, there was also a significant reduction in the mean changes in total Sharp score. The cumulative rates of any adverse effects showed no significant difference between the groups.

Conclusion

In an assessment of adequate DAS28 results, the RA patients who did not respond to the initial dose of infliximab showed improved clinical responses and radiographic assessment after a dose adjustment of infliximab, without an increased risk of serious adverse events.

Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Comparing biosimilar SB2 with reference infliximab after 54 weeks of a double-blind trial: clinical, structural and safety results

Objectives

SB2 is a biosimilar to the reference infliximab (INF). Similar efficacy, safety and immunogenicity between SB2 and INF up to 30 weeks were previously reported. This report investigates such clinical similarity up to 54 weeks, including structural joint damage.

Methods

In this phase III, double-blind, parallel-group, multicentre study, patients with moderate to severe RA despite MTX were randomized (1:1) to receive 3 mg/kg of either SB2 or INF at 0, 2, 6 and every 8 weeks thereafter. Dose escalation by 1.5 mg/kg up to a maximum dose of 7.5 mg/kg was allowed after week 30. Efficacy, safety and immunogenicity were measured at each visit up to week 54. Radiographic damage evaluated by modified total Sharp score was measured at baseline and week 54.

Results

A total of 584 patients were randomized to receive SB2 (n = 291) or INF (n = 293). The rate of radiographic progression was comparable between SB2 and INF (mean modified total Sharp score difference: SB2, 0.38; INF, 0.37) at 1 year. ACR responses, 28-joint DAS, Clinical Disease Activity Index and Simplified Disease Activity Index were comparable between SB2 and INF up to week 54. The incidence of treatment-emergent adverse events and anti-drug antibodies were comparable between treatment groups. Such comparable trends of efficacy, safety and immunogenicity were consistent from baseline up to 54 weeks. The pattern of dose increment was also comparable between SB2 and INF.

Conclusion

SB2 maintained similar efficacy, safety and immunogenicity with INF up to 54 weeks in patients with moderate to severe RA. Radiographic progression was comparable at 1 year.

Trial registration

ClinicalTrials.gov (http://clinicaltrials.gov; NCT01936181) and EudraCT (https://www.clinicaltrialsregister.eu; 2012-005733-37)

Efficacy and safety of infliximab: A comparison with other biological disease-modifying anti-rheumatic drugs

OBJECTIVES

The intensification of infliximab (IFX) treatment, involving escalation of the dose and shortening of interval, was approved in Japan in July 2009. We consider IFX intensification therapy to be preferable for patients with treatment-resistant active rheumatoid arthritis (RA). We retrospectively compared the efficacy of IFX with that of other bDMARDs in methotrexate (MTX)-resistant patients.

METHODS

Patients who satisfied the following criteria were enrolled: (i) those who started bDMARDs between February 2011 and December 2016, and (ii) those who required bDMARDs after 180 d of MTX treatment. We compared 33 patients who had been treated with IFX (IFX group) and 146 who had received other bDMARDs treatment (non-IFX group).

RESULTS

IFX was administered at a dose of 6.98 mg/kg/8-week equivalent at 52 weeks. Clinical disease activity index clinical remission (CDAI-CR) was achieved in 49 of the 179 patients at 52 weeks and 13 of these 49 patients received IFX. Logistic regression analysis showed that treatment with IFX was an important variable for the achievement of CDAI-CR at 52 weeks (odds ratio 2.69, 95% confidence interval 1.13-6.42). The severity and frequency of adverse events did not differ.

CONCLUSION

Intensification of IFX was effective and well tolerated for MTX resistant patients.

High titers of both rheumatoid factor and anti-CCP antibodies at baseline in patients with rheumatoid arthritis are associated with increased circulating baseline TNF level, low drug levels, and reduced clinical responses: a post hoc analysis of the RISING study

Background

Although both rheumatoid factor (RF) and anticyclic citrullinated peptide antibodies (anti-CCP) are useful for diagnosing rheumatoid arthritis (RA), the impact of these autoantibodies on the efficacy of tumor necrosis factor (TNF) inhibitors has been controversial. The aim of this post hoc analysis of a randomized double-blind study (the RISING study) was to investigate the influences of RF and anti-CCP on the clinical response to infliximab in patients with RA.

Methods

Methotrexate-refractory patients with RA received 3 mg/kg of infliximab from weeks 0 to 6 and then 3, 6, or 10 mg/kg every 8 weeks from weeks 14 to 46. In this post hoc analysis, patients were stratified into three classes on the basis of baseline RF/anti-CCP titers: “low/low-C” (RF < 55 IU/ml, anti-CCP < 42 U/ml), “high/high-C” (RF ≥ 160 IU/ml, anti-CCP ≥ 100 U/ml), and “middle-C” (neither low/low-C nor high/high-C). Baseline plasma TNF level, serum infliximab level, and disease activity were compared between the three classes.

Results

Baseline RF and anti-CCP titers showed significant correlations with baseline TNF and infliximab levels in weeks 2–14. Comparison of the three classes showed that baseline TNF level was lowest in the low/low-C group and highest in the high/high-C group (median 0.73 versus 1.15 pg/ml), that infliximab levels at week 14 were highest in the low/low-C group and lowest in the high/high-C group (median 1.0 versus 0.1 μg/ml), and that Disease Activity Score in 28 joints based on C-reactive protein at week 14 was lowest in the low/low-C group and highest in the high/high-C group (median 3.17 versus 3.82). A similar correlation was observed at week 54 in the 3 mg/kg dosing group, but not in the 6 or 10 mg/kg group. Significant decreases in both RF and anti-CCP were observed during infliximab treatment.

Conclusions

RF/anti-CCP titers correlated with TNF level. This might explain the association of RF/anti-CCP with infliximab level and clinical response in patients with RA. Baseline RF/anti-CCP titers may serve as indices that aid infliximab treatment.

Trial registration

ClinicalTrials.gov, NCT00691028. Retrospectively registered on 3 June 2008.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1401-2) contains supplementary material, which is available to authorized users.

Efficacy and safety of dose escalation of infliximab therapy in Japanese patients with psoriasis: Results of the SPREAD study

Although infliximab is approved for psoriasis, its efficacy is reduced over time in some patients. The aim of this phase III trial is to evaluate efficacy and safety of infliximab dose escalation in Japanese psoriasis patients with loss of efficacy to standard‐dose therapy. Patients with plaque psoriasis, psoriatic arthritis, pustular psoriasis or psoriatic erythroderma who showed loss of efficacy to standard‐dose therapy received infliximab dose escalation (10 mg/kg every 8 weeks) from weeks 0 to 32. Loss of efficacy was defined as not maintaining 50% reduction in the Psoriasis Area and Severity Index (PASI 50) after achieving PASI 75. Efficacy and safety were evaluated up to week 40. Fifty‐one patients received dose escalation and 43 completed the study. PASI 75 and median improvement rate of PASI score at week 40 were 44% and 70.0%, respectively, showing efficacy in skin symptoms. Efficacies in quality of life, nail psoriasis and joint pain were also obtained. Median serum infliximab level increased from less than 0.1 to 1.1 μg/mL from weeks 0 to 40, showing positive correlation between efficacy and serum infliximab level at week 40. Favorable efficacy was observed in patients with detectable serum infliximab levels (≥0.1 μg/mL) at baseline. Incidences of adverse events, serious adverse events, serious infections and serious infusion reactions were 92%, 10%, 4% and 0%, respectively. No marked difference was observed in both efficacy and safety among psoriasis types. No new safety concerns were observed. Infliximab dose escalation was effective and well‐tolerated in psoriasis patients with loss of efficacy to standard‐dose therapy, suggesting that dose escalation may be a useful therapeutic option for these patients.

The underlying inflammatory chronic disease influences infliximab pharmacokinetics

Infliximab is an anti-tumor necrosis factor monoclonal antibody approved in chronic inflammatory diseases such as rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), Crohn's disease (CD) and ulcerative colitis (UC). Infliximab pharmacokinetics is variable between patients, but influence of the underlying disease was never assessed. This study aimed at assessing this influence using a cohort of patients monitored in a single center and with the same assay. Infliximab trough concentrations were determined on samples collected between weeks 0 and 22 after treatment initiation in 218 patients treated for RA, PsA, AS, CD or UC. Infliximab pharmacokinetics was analyzed by a one-compartment population model with first-order elimination rate constant. In AS patients, volume of distribution (V) and elimination clearance (CL) were 5.4 L and 0.24 L/day, respectively. In CD and UC patients, V was 49% and 52% higher than in AS, respectively, and CL was 47% and 60% higher than in AS, respectively. In RA patients, CL was 49% higher than in AS patients. Simulations showed that without methotrexate, a 3 mg/kg dosing regimen would lead only 16% of RA patients to reach the target concentration (2.5 mg/L) at week 22, whereas target concentrations would be reached in approximately half of RA patients cotreated with methotrexate, as well as half of CD (3.5 mg/L) and UC (3.7 mg/L) patients. The suboptimality of approved dosing regimens supports the development of dosing optimization based on concentration measurements.

Clinical Pharmacokinetics and Pharmacodynamics of Monoclonal Antibodies Approved to Treat Rheumatoid Arthritis

Monoclonal antibodies (mAbs) are increasingly used to treat rheumatoid arthritis (RA). At present, anti-tumor necrosis factor-α drugs (infliximab, adalimumab, certolizumab pegol, and golimumab), rituximab, and tocilizumab are approved for RA treatment. This review focuses on the pharmacokinetics and pharmacodynamics of mAbs approved in RA. Being large proteins, mAbs exhibit complex pharmacokinetic and pharmacodynamic properties. In particular, owing to the interactions of mAbs with their antigenic targets, the pharmacokinetics of mAbs depends on target turnover and exhibits non-specific (linear) and target-mediated (often nonlinear) clearances. Their volume of distribution is low (3-4 L) and their elimination half-life usually ranges from 2 to 3 weeks. The inter-individual pharmacokinetic variability of mAbs is usually large and is partly explained by differences in antigenic burden or by anti-drug antibodies, which accelerate mAb elimination. The inter-individual variability of clinical response is large and influenced by the pharmacokinetics. The analysis of mAbs concentration-effect relationship relies more and more often on pharmacokinetic-pharmacodynamic modeling; these models being suitable for dosing optimization. Even if adverse effects of mAbs used in RA are well known, the relationship between mAb concentration and adverse effects is poorly documented, especially for anti-tumor necrosis factor-α mAbs. Overall, RA patients treated with mAbs should benefit from individualized dosing strategies. Because of the complexity of their pharmacokinetics and mechanisms of action, the current dosing strategy of mAbs is not based on sound knowledge. New studies are needed to assess individual dosing regimen, adjusted notably to disease activity.

Infliximab therapy for intestinal, neurological, and vascular involvement in Behcet disease: Efficacy, safety, and pharmacokinetics in a multicenter, prospective, open-label, single-arm phase 3 study

Behçet disease (BD) is a multisystem disease associated with a poor prognosis in cases of gastrointestinal, neurological, or vascular involvement. We conducted a multicenter, prospective, open-label, single-arm phase 3 study to determine the efficacy, safety, and pharmacokinetics of infliximab (IFX) in BD patients with these serious complications who had displayed poor response or intolerance to conventional therapy.IFX at 5 mg/kg was administered to 18 patients (11 intestinal BD, 3 neurological BD [NBD], and 4 vascular BD [VBD]) at weeks 0, 2, and 6 and every 8 weeks thereafter until week 46. In patients who showed inadequate responses to IFX after week 30, the dose was increased to 10 mg/kg. We then calculated the percentage of complete responders according to the predefined criteria depending on the symptoms and results of examinations (ileocolonoscopy, brain magnetic resonance imaging, computed tomography angiography, positron emission tomography, cerebrospinal fluid, or serum inflammatory markers), exploring the percentage of complete responders at week 30 (primary endpoint).The percentage of complete responders was 61% (11/18) at both weeks 14 and 30 and remained the same until week 54. Intestinal BD patients showed improvement in clinical symptoms along with decrease in C-reactive protein (CRP) levels after week 2. Consistently, scarring or healing of the principal ulcers was found in more than 80% of these patients after week 14. NBD patients showed improvement in clinical symptoms, imaging findings, and cerebrospinal fluid examinations. VBD patients showed improvement in clinical symptoms after week 2 with reductions in CRP levels and erythrocyte sedimentation rate. Imaging findings showed reversal of inflammatory changes in 3 of the 4 VBD patients. Irrespective of the type of BD, all patients achieved improvement in quality of life, leading to the dose reduction or withdrawal of steroids. IFX dose was increased to 10 mg/kg in 3 intestinal BD patients, resulting in the improvement of clinical symptoms, CRP levels, and visual analogue scale score. Safety and pharmacokinetics profiles were comparable to those in patients with rheumatoid arthritis or Crohn disease. These findings support IFX as a new therapeutic option for patients with intestinal BD, NBD, or VBD.

Therapeutic drug monitoring of monoclonal antibodies in inflammatory and malignant disease: Translating TNF-α experience to oncology

Lack of response to monoclonal antibodies (mAbs) has been associated with inadequate mAb serum concentrations. Therapeutic drug monitoring (TDM) of mAbs has the potential to guide to more effective dosing in individual patients. This review discusses the mechanisms responsible for interpatient variability of mAb pharmacokinetics, summarizes exposure-response data of mAbs used in inflammatory and malignant disease, presents current evidence of mAb-TDM in inflammatory disease, and provides hurdles and required future steps for further implementing mAb-TDM.

Effect of Infliximab Dose Increase in Rheumatoid Arthritis at Different Trough Concentrations: A Cohort Study in Clinical Practice Conditions

Background

Evidence supporting treatment intensification in rheumatoid arthritis (RA) is limited and controversial. We explored outcomes of infliximab dose increases and accounted for pre-existing trough levels in patients with active RA.

Methods

This study was a retrospective study of 42 RA patients who received increased infliximab following an insufficient response (DAS28 >3.2). Serum concentrations of infliximab and antibodies to infliximab (ATI) and DAS28 and EULAR clinical response parameters were recorded for 1 year. Analyses were performed in three patient groups that were defined by infliximab serum concentration prior to treatment enhancement: no detectable, low (<1.1 μg/mL) or high (≥1.1 μg/mL) drug levels.

Results

No circulating infliximab was detected in 20 patients (47.6%), but 13 (31%) and 9 (21.4%) patients exhibited low and high levels, respectively. ATI was only detected in patients with no detectable drug levels because the drug interferes with ELISA. DAS28 disease activity globally showed a modest improvement after dose escalation, but this improvement did not persist after 6 and 12 months. Infliximab serum levels increased significantly in the high group (p = 0.016), but no increase was achieved in the low and no detectable groups. The three study groups exhibited similar disease activity over time, and no improvement was observed in the non-responder EULAR rates.

Conclusion

These results suggest that the efficacy of an infliximab dose increase is limited, and the response is independent of the infliximab trough serum concentration that is achieved prior to escalation.

Prediction of clinical response after 1 year of infliximab therapy in rheumatoid arthritis based on disease activity at 3 months: posthoc analysis of the RISING study

OBJECTIVE

To investigate the probability of clinical remission (REM) or low disease activity (LDA) after 1 year of infliximab (IFX) therapy based on disease activity at 3 months in patients with rheumatoid arthritis (RA).

METHODS

Methotrexate-refractory patients with RA received 3 mg/kg of IFX at weeks 0, 2, and 6, followed by 3 mg/kg, 6 mg/kg, or 10 mg/kg every 8 weeks from Week 14 (W14) to Week 46. Correlation of disease activity at W14 with disease activity at W54 and probability of REM/LDA at W54 were analyzed in each dosing group.

RESULTS

Disease activities at W14 were significantly correlated with both disease activity at W54 and probability of REM/LDA at W54 in patients continuing 3 mg/kg as well as in those receiving 6 mg/kg or 10 mg/kg therapy from W14. Results showed that, if approximate REM or LDA had not been achieved by W14, > 50% of patients continuing 3 mg/kg therapy would not be able to achieve REM or LDA at W54. However, even in patients with high or moderate disease activity at W14, dose escalation to 6 mg/kg or 10 mg/kg enabled many to achieve REM/LDA.

CONCLUSION

Disease activity at W14 in standard-dose IFX therapy enabled the prediction of longterm clinical response at continued standard dose, as well as subsequent escalated-dose regimens. Disease activity at W14 was hypothesized to be an important index for IFX treatment strategy.

Economic evaluation of anti-TNF agents for patients with rheumatoid arthritis in Greece

Objectives

We aimed to estimate the total mean annual treatment cost of different therapy options for patients with moderate-to-severe rheumatoid arthritis (RA) in Greece.

Methods

A cost-minimization approach was adopted. An economic model was developed to estimate the direct costs of the three widely used treatments within a 1-year time horizon, from a health care payer perspective, either for new or for existing patients. Data on resource use, dose escalation, and frequency of therapy were based on a nationwide field survey of rheumatologists. Other analyses were also undertaken based on evidence from the literature. Total cost comprised the cost of drugs, administration, and hospital day care visits. Unit cost data were obtained from the price bulletin and the government gazettes issued by the Ministry of Health. Due to the short time horizon of the study, the cost was not discounted.

Results

The mean annual total cost per new (or per existing) responder patient on etanercept was estimated at €9,845 (€9,840), and the total cost on etanercept/methotrexate (MTX) was estimated at €9,857 (€9,852). Therapy with etanercept had lower annual cost relative to adalimumab and infliximab. On an annual basis, it was estimated that the difference between etanercept monotherapy and adalimumab monotherapy was €544 (€1,323). Similarly, the difference between etanercept/MTX and infliximab/MTX was €1,871 (€1,490) and €543 (€1,323), respectively, relative to adalimumab/MTX. Results remained constant under other scenario analyses undertaken.

Conclusion

In the real-life practice setting in Greece, where dose intensity and frequency differences occur, etanercept alone or in combination with MTX, if prescribed as per label, represents the option with lower annual cost per patient when compared with adalimumab or infliximab in patients with RA. These results hold true as long as the assumptions and data used in the analysis remain stable and may alter if any of the underlying parameters, such as drug price, change.

Dose modification of anti-TNF in rheumatoid arthritis and estimated economical impact: a review of observational studies

Anti-TNF drugs indicated for the treatment of moderate-to-severe active rheumatoid arthritis (RA) presents similar efficacy, safety and potential toxicity profiles, with more than 10 years' treatment experience. Several pharmacoeconomic evaluations had demonstrated their favorable cost-effectiveness profile in RA patients, based on pivotal clinical studies data from different countries and perspectives. However, in clinical practice, individual profiles of patients and drugs leads to dose modifications that may be associated with substantial cost deviations. Here, we further discuss the effect of dose titration of these biological drugs in clinical practice over their RA cost-effectiveness profiles.

The comparative safety of tumor necrosis factor inhibitors in rheumatoid arthritis: a meta-analysis update of 44 trials

OBJECTIVE

The study objective was to evaluate and update the safety data from randomized controlled trials of tumor necrosis factor inhibitors in patients treated for rheumatoid arthritis.

METHODS

A systematic literature search was conducted from 1990 to May 2013. All studies included were randomized, double-blind, controlled trials of patients with rheumatoid arthritis that evaluated adalimumab, certolizumab pegol, etanercept, golimumab, or infliximab treatment. The serious adverse events and discontinuation rates were abstracted, and risk estimates were calculated by Peto odds ratios (ORs).

RESULTS

Forty-four randomized controlled trials involving 11,700 subjects receiving tumor necrosis factor inhibitors and 5901 subjects receiving placebo or traditional disease-modifying antirheumatic drugs were included. Tumor necrosis factor inhibitor treatment as a group was associated with a higher risk of serious infection (OR, 1.42; 95% confidence interval [CI], 1.13-1.78) and treatment discontinuation due to adverse events (OR, 1.23; 95% CI, 1.06-1.43) compared with placebo and traditional disease-modifying antirheumatic drug treatments. Specifically, patients taking adalimumab, certolizumab pegol, and infliximab had an increased risk of serious infection (OR, 1.69, 1.98, and 1.63, respectively) and showed an increased risk of discontinuation due to adverse events (OR, 1.38, 1.67, and 2.04, respectively). In contrast, patients taking etanercept had a decreased risk of discontinuation due to adverse events (OR, 0.72; 95% CI, 0.55-0.93). Although ORs for malignancy varied across the different tumor necrosis factor inhibitors, none reached statistical significance.

CONCLUSIONS

These meta-analysis updates of the comparative safety of tumor necrosis factor inhibitors suggest a higher risk of serious infection associated with adalimumab, certolizumab pegol, and infliximab, which seems to contribute to higher rates of discontinuation. In contrast, etanercept use showed a lower rate of discontinuation. These data may help guide clinical comparative decision making in the management of rheumatoid arthritis.

Therapeutic drug monitoring in rheumatic diseases: utile or futile?

Rapid and effective suppression of inflammation is a primary goal in the treatment of rheumatic diseases. However, the therapeutic effect of most medications may be slow to manifest, in the order of weeks or months in the case of DMARDs. Monitoring of drug concentrations allows the possibility of appropriate dose adjustment or changes in medication to achieve more rapid or better outcomes. We review the evidence for drug concentration monitoring. Despite the theoretical utility for monitoring of MTX polyglutamate concentrations in red blood cells in patients with RA, studies have not shown a clear association between concentrations and either efficacy or toxicity and routine measurement is not yet recommended. Small studies associating disease control with concentrations of anti-TNF therapies and anti-drug antibodies suggest that routine monitoring may be useful in the future. However, the data are not yet sufficient for this recommendation. With the use of allopurinol in gout, there is a putative therapeutic range for the active metabolite oxypurinol; however, adjusting the allopurinol dose to achieve a target urate concentration is likely to be most effective, and measuring oxypurinol may be best suited to assessing drug adherence. Although measuring thiopurine metabolite concentrations with AZA therapy has been shown to be useful in IBD, studies in rheumatic diseases have so far failed to confirm a useful association between concentrations and disease control or drug toxicity. Whole blood concentrations of HCQ have been associated with disease control in SLE and future studies may be able to determine a therapeutic range.

Theory-based analysis of the anti-inflammatory effect of TNF inhibitors on rheumatoid arthritis

TNF inhibitors are used as therapeutic agents for rheumatoid arthritis (RA). Each has a different dosage regimen and it is thought that the differences among them have implications on efficacy. However, those differences have not been analyzed in a theoretical manner. In the present study, we tried to explain theoretically the differences. We theoretically analyzed the anti-inflammatory effect of infliximab (IFX), etanercept (ETN), and adalimumab (ADA) for RA by using a pharmacokinetic and pharmacodynamic model. Then, we simulated values for sequential changes of tender joint count (TJC) after repeated administrations of TNF inhibitors by using the model. The sequential changes of TJC obtained with our model were in good agreement with observed TJC ratio data, which was considered to show the validity of our analytical method. The following results were obtained: the onset of clinical response was fastest with IFX, the fluctuation of IFX was greater than that of the others, and the clinical response with ADA was as stable as that with ETN. The present model was useful to analyze theoretically the anti-rheumatic effect of TNF inhibitors. Our results showed that different dosage regimens have implications on the onset and fluctuation of clinical response.

Long-term durability and dose escalation patterns in infliximab therapy for psoriasis

BACKGROUND

Infliximab often requires dose escalation to maintain response. Studies regarding long-term durability and dose escalation patterns for psoriasis are few.

OBJECTIVE

We sought to evaluate dose escalation patterns in psoriatic patients to identify factors of lack of optimal response to infliximab.

METHODS

A retrospective cohort study included 93 patients (216.3 patient-years) treated with infliximab for psoriasis. Kaplan-Meier analysis assessed drug durability.

RESULTS

A median infliximab dose of 5.42 mg/kg/mo (range: 2.71-10.83) for a mean of 28 months was administered. Two thirds of patients received a dose escalation. Concurrent methotrexate extended duration of therapy (by a mean ± SD of 19.5 ± 8.1 months, P = .034), including time until first dose escalation (by a mean ± SD of 12.0 ± 6.1 months, P = .037), and failure (by a mean ± SD of 20.7 ± 6.7 months, P = .034). Patients who increased the infusion frequency before increasing the dose remained on infliximab 8.4 months longer than those who first increased the dose (P = .045). Four patients experienced adverse events; 2 required discontinuation.

LIMITATIONS

Psoriasis Area and Severity Index, infliximab levels, and antibody titers were not measured.

CONCLUSIONS

Dose escalation optimizes durability of infliximab. The probability of maintaining response is enhanced by concomitant methotrexate and increasing the infusion frequency before increasing the dose.

Minimum effective dosages of anti-TNF in rheumatoid arthritis: a cross-sectional study

AIMS

To evaluate the modified dosages of anti-TNF in controlling disease activity in rheumatoid arthritis (RA) measured by DAS28-ESR.

PATIENTS AND METHODS

Cross-sectional study: RA patients treated with etanercept (ETN), adalimumab (ADA) or infliximab (IFX), at standard or modified doses.

MAIN VARIABLES

dosage, concomitant disease modifying drugs (DMARDs), DAS28-ESR.

RESULTS

195 RA patients included (79% women, mean age 58.1 years): ETN=81, ADA=56, IFX=58. Mean disease duration and time to first biological treatment was higher in IFX group (P=.01). Patients distribution by dosage: standard: ETN (72.8%), ADA (69.6%), IFX (27.6%); escalated: IFX (69%), ADA (5.4%), ETN (0%); reduced: ETN (27.1%), ADA (25%), IFX (3.4%). Concomitant DMARDs use was lower in ETN (58.2%) than ADA (66.07%) and IFX (79.31%). Higher proportion of responders (DAS28 ≤3.2) in ADA (65.3%) and ETN (61.7%) than IFX (48.3%).

CONCLUSIONS

RA clinical control can be preserved with modified anti-TNF dosages. Controlled prospective studies should be performed to define when therapy can be tailored and for which patients.

Golimumab in patients with active rheumatoid arthritis despite methotrexate therapy: results through 2 years of the GO-FORWARD study extension

OBJECTIVE

To assess the longterm efficacy and safety of golimumab in patients with active rheumatoid arthritis (RA) despite methotrexate (MTX) therapy.

METHODS

We randomized 444 RA patients with inadequate response to MTX (3:3:2:2) to placebo + MTX (Group 1), golimumab 100 mg + placebo (Group 2), golimumab 50 mg + MTX (Group 3), or golimumab 100 mg + MTX (Group 4). Subcutaneous golimumab/placebo was injected every 4 weeks. Patients could escape early (Group 1 added golimumab 50 mg, Group 2 added MTX, Group 3 increased golimumab to 100 mg, Group 4 continued 100 mg) based on Week 16 swollen and tender joint counts. From Week 24, Group 1 patients received golimumab 50 mg + MTX. After the Week 52 database lock, patients in the longterm extension received golimumab 50-100 mg ± MTX. Coprimary endpoints [Week 14 American College of Rheumatology (ACR)20, Week 24 Health Assessment Questionnaire Disability Index (HAQ-DI)] and Week 52 findings have been published; 2-year findings (observed data by randomized group, no imputation) are presented.

RESULTS

Of 444 randomized patients, 392 continued from Week 52 (Group 1: n = 116, Group 2: n = 116, Group 3: n = 84, Group 4: n = 76). Clinical improvement was maintained through Week 104; ~75% and 72% of patients randomized to golimumab 50 mg + MTX and 100 mg + MTX achieved ACR20 response, respectively. The majority [88% (105/120)] of golimumab + MTX-treated patients with Week 24 HAQ-DI improvement ≥ 0.25 maintained improved physical function through Week 104. Group 1 patients with delayed golimumab treatment exhibited more Week 104 radiographic progression (mean change score = 1.15) than golimumab + MTX-randomized patients (0.52). Incidences of serious infections were 2.24, 4.77, 5.78/100 patient-years of followup for golimumab 50 mg + MTX, 100 mg + placebo, and 100 mg + MTX, respectively.

CONCLUSION

Clinical improvement was maintained and no new safety signals were identified with 2 years of golimumab + MTX. Golimumab efficacy and safety, including serious infections, will continue to be monitored through 5 years (Clinical Trial No. NCT00264550).

Safety of Infliximab Treatment in Patients with Rheumatoid Arthritis in a Real-world Clinical Setting: Description and Evaluation of Infusion Reactions

Objective.

To describe acute and delayed infusion reactions in a large cohort of patients with inflammatory arthritis, treated with infliximab (IFX).

Methods.

We conducted a retrospective chart review of patients treated with IFX at the Mary Pack Arthritis Centre between 2000 and 2008. The primary outcome was the occurrence of acute infusion reactions during infusions or 1–2 hours after each infusion, and secondary outcome was the occurrence of delayed infusion reactions 1–14 days after an infusion. Descriptive analyses were conducted to summarize study outcomes and identify trends over followup.

Results.

Since 2000, 376 patients were referred to the Mary Pack IFX clinic and 200 received 4399 IFX infusions over a mean 140 ± 132 weeks of followup. Of these, 135 were patients with RA who received 2977 IFX infusions over mean followup of 138 ± 132 weeks. In total 258 episodes of acute reactions were observed for an overall acute reaction rate of 5.8%. Acute infusion reactions were mostly mild (42.6%) and moderate (43.8%) and commonly affected sites were head and neck (31.5%) and cutaneous (21.1%). A total of 37 delayed infusion reaction episodes were observed (0.9% rate); reactions were also mostly mild (16.2%) and moderate (64.9%).

Conclusion.

These clinical data from 200 patients treated with IFX demonstrate that acute and delayed infusion reactions occur infrequently and are mostly mild to moderate in presentation.

Durability of infliximab dose intensification in Crohn's disease

BACKGROUND

Dose intensification is a common approach to treat Crohn's disease (CD) patients who lose response to infliximab maintenance therapy. Few studies have reported upon its long-term efficacy or predictors of response.

AIM

The goal of this study is to investigate durability and predictors of response to dose intensification-including method of dose intensification, combination immunomodulator therapy, and premedication with intravenous hydrocortisone.

METHODS

We performed a retrospective study of dose-intensified CD patients at our institution. Dose intensification was defined as an increase in dose from 5 to 10 mg/kg, an increase in frequency of infusions from every 8 weeks to every 6 weeks or less, or both an increase in dose and frequency.

RESULTS

Thirty CD patients (mean age, 39.9 years) met study criteria and underwent dose intensification. Ten (33.3%) patients remained on dose intensification at the end of our study or returned to their former infliximab dose or schedule (median follow-up, 41 months). Fourteen patients (46.7%) eventually lost response to dose intensification, but dose intensification extended infliximab therapy by a median duration of 9 months. Six patients (20%) didn't respond to dose intensification. Neither method of dose intensification, combination immunomodulator therapy, nor premedication with intravenous hydrocortisone predicted initial or durable response to dose intensification. However, analysis of predictors was limited by the small sample size of our study.

CONCLUSIONS

The majority of CD patients respond to dose intensification, and a substantial portion will experience durable response such that infliximab therapy is successfully extended by one or more years.

Systematic review of tocilizumab for rheumatoid arthritis: a new biologic agent targeting the interleukin-6 receptor

BACKGROUND

Tocilizumab (TCZ), a humanized anti-interleukin-6 receptor monoclonal antibody, represents a new treatment strategy for patients with rheumatoid arthritis (RA) and is currently approved in the United States for RA patients who have failed to improve with at least one anti-tumor necrosis factor therapy.

OBJECTIVE

The goal of this study was to summarize the efficacy and safety profile of TCZ.

METHODS

A systematic literature review was conducted to identify English-language articles within PubMed and the Cochrane Library from January 1989 to August 2011 reporting results from Phase III TCZ double-blind, randomized controlled trials (RCTs), noncontrolled clinical trials, and open-label extensions with a duration ≥6 months. Study outcomes had to include at least one of the following: American College of Rheumatology (ACR) 20, 50, or 70 response rates; tender/swollen joint count; Health Assessment Questionnaire-Disability Index; radiographic outcomes and drug persistence. Phase II RCTs were included only if they contained relevant information not available in Phase III RCTs. Relevant studies were selected to evaluate TCZ's pharmacokinetics and pharmacodynamics.

RESULTS

Ten published clinical trials (7 Phase III, 3 Phase II) for TCZ were retrieved (7833 articles initially identified) from PubMed and 31 from the Cochrane library. Compared with methotrexate (MTX) monotherapy, TCZ 8 mg/kg IV monotherapy had higher rates of ACR20 (P < 0.001), ACR50 (P = 0.002), and ACR70 (P < 0.001) scores at week 24. TCZ 8 mg/kg IV plus oral MTX had a higher ACR20 response rate than oral MTX plus placebo in patients with RA who failed to respond to MTX or anti-tumor necrosis factor therapy (P < 0.001). Patients receiving TCZ 8 mg/kg had less radiographic progression on the Genant-modified Sharp score (85% had no progression) than the control group (67% had no progression) (P < 0.001). The rate of serious infections was 4.7 events/100 patient-years of exposure in the TCZ groups. A greater frequency of neutropenia, thrombocytopenia, hyperlipidemia, and transaminitis was observed with TCZ compared with placebo.

CONCLUSION

The short-term efficacy and safety profile of TCZ is promising. Additional long-term safety data are needed to better characterize the risk-benefit profile of this agent.