Maintenance of infliximab treatment in ankylosing spondylitis: results of a one-year randomized controlled trial comparing systematic versus on-demand treatment

The role of DMARDs in reducing the immunogenicity of TNF inhibitors in chronic inflammatory diseases

The management of RA, SpA, psoriasis and inflammatory bowel disease has significantly improved over the last decade with the addition of tumour necrosis factor inhibitors (anti-TNFs) to the therapeutic armamentarium. Immunogenicity in response to monoclonal antibody therapies (anti-drug antibodies) may give rise to low serum drug levels, loss of therapeutic response, poor drug survival and/or adverse events such as infusion reactions. To combat these, the use of concomitant MTX may attenuate the frequency of anti-drug antibodies in RA, SpA and Crohn's disease. Although a similar effect to methotrexate has been observed with AZA usage in the management of Crohn's disease, there is insufficient evidence to suggest that other DMARDs impact immunogenicity. In this article we review the evidence to date on the effect of immunomodulatory therapy when co-administered with anti-TNFs. We also discuss whether such a strategy should be employed in SpA and psoriasis, and if optimization of the MTX dose could improve biologic drug survival and thereby benefit disease management.

New era of biologic therapeutics in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use.

AREAS COVERED

This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease.

EXPERT OPINION

Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.

Methotrexate for ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown cause, characterized by sacroiliitis and spondylitis. Methotrexate (MTX), a widely used disease-modifying antirheumatic drug (DMARD), is effective for rheumatoid arthritis (RA), and so might work for AS. This is an update of a Cochrane review first published in 2004, and previously updated in 2006.

OBJECTIVES

To evaluate the benefits and harms of MTX for treating AS.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library Issue 6, 2012), MEDLINE (2005 to June 25, 2012), EMBASE (2005 to June 25, 2012), Ovid MEDLINE Scopus, World Health Organization International Clinical Trials Registry Platform and the reference sections of retrieved articles. Trials published in any language were acceptable.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-randomized controlled trials (qRCTs) examining the benefits and harms of MTX versus placebo, other medication, or no medication for treatment of AS.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We resolved any disagreements through discussions with a third review author. In the absence of significant heterogeneity, we combined results for continuous data using mean difference or standardized mean difference values. We calculated the risk ratio for dichotomous data.

MAIN RESULTS

We identified three RCTs (no additional new studies), which included 116 participants. Of these three trials, one was a 12-month trial that compared naproxen plus MTX with naproxen alone. Also, there were two 24-week trials that compared different doses of MTX with placebo. We included the outcomes of response, physical function, pain, spinal mobility, peripheral joints/entheses pain, swelling and tenderness, changes in spine radiographs, and patient and physician global assessment. We judged only one trial to be at low risk of bias. Across these three trials, we did not identify any statistically significant differences favoring MTX treatment over no MTX treatment apart from one exception. The response rate in one trial showed a statistically significant absolute benefit of 36% and a number to treat for benefit (NNT) of three in the MTX group compared to the placebo group (RR 3.18, 95% CI 1.03 to 9.79). This response rate was based on a composite index that included assessments of morning stiffness, physical well-being, Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), health assessment questionnaire for spondyloarthropathies (HAQ-S), and physician and patient global assessment. We did not identify any outcome that showed a statistically significant difference between the MTX treated and no MTX treatment groups when endpoint results were compared. Furthermore, no serious side effects were reported in any of the included trials.

AUTHORS' CONCLUSIONS

There is not enough evidence to support any benefit of MTX in the treatment of AS. High-quality RCTs of larger sample sizes are needed to clarify the effect(s) of MTX on AS.

Biologic therapies for spondyloarthritis: what is new?

The course of axial spondyloarthritis (axSpA), including ankylosing spondylitis (AS), is strongly influenced by the degree of disease activity over time, which is mainly based on inflammation, and by the impairment of function, which is based on structural damage-mainly, new bone formation-and inflammation. In AS, nonsteroidal anti-inflammatory agents are currently recommended as the first choice of medical therapy, and there is also a clear role for regular exercise and physiotherapy in order to preserve and prevent loss of spinal mobility. For patients who have insufficiently responded to conventional medications, there are now four biologics approved for the treatment of patients with active AS in many countries, all directed against TNFα: infliximab, etanercept, adalimumab, and golimumab; studies with certolizumab are currently ongoing. Several studies with patients classified as nonradiographic axSpA have also shown a good response to TNF blockers; in patients with early disease and high CRP levels, the response rates were even better. Long-term studies with TNF blockers have shown declining retention rates over time but sustained clinical efficacy in the patients who remained on treatment. States of drug-free remission are rarely reached and only for relatively short periods of time. More studies including magnetic resonance imaging (MRI) are needed to further examine the lack of effect of anti-TNF treatment on radiographic progression in the axial skeleton. Whether the effect of an early intervention with biologics will prevent the development of bone growth in patients with nonradiographic axial SpA remains to be seen. Biologics other than TNF blockers are currently not recommended for the treatment of patients with axSpA, because of insufficient evidence of clinically relevant efficacy. The anti-IL-17a antibody secukinumab may be efficacious, on the basis of a proof-of-concept trial. Finally, first data on biosimilars of TNF blockers have recently been presented.

Update on biologic therapies in ankylosing spondylitis: a literature review

AIM

The present paper aims to review the recent advances in diagnosis and management of ankylosing spondylitis (AS).

METHOD

Medline and abstracts submitted to the recent European League Against Rheumatism (EULAR) congress were searched to obtain quality-controlled information on the management of AS.

RESULTS

The use of magnetic resonance imaging (MRI) allows the diagnosis of AS to be made in the pre-radiographic stage. The Assessment in Spondylarthritis International Society recommendations for the management of AS have been modified so that patients with non-radiographic spondyloarthritis (SpA) can now be considered for biological therapy. The 'older' anti-tumour necrosis factor (TNF) continued to be effective in longer-term studies. Studies with longer duration of follow-up have shown that some patients with pre-radiographic SpA entered into prolonged drug-free remission. It is likely that in the foreseeable future, more AS patients will be treated with biological therapies at an earlier stage of the disease. New biologic therapies, golimumab and secukinumab, are looking promising in improving the signs and symptoms of AS, at least in the short-term.

CONCLUSION

Longer-term studies of AS patients treated with infliximab, etanercept and adalimumab continued to show a good clinical response. There is a need for more long-term studies to examine the longitudinal efficacy of golimumab and secukinumab in AS.

Developments in therapies for spondyloarthritis

First-line therapy for spondyloarthritis (SpA) has not yet altered in the wake of new classification criteria; NSAIDs and physical therapy are recommended. Anti-TNF agents can be used when NSAIDs fail, but their efficacy has potentially been limited in previous trials by inclusion criteria requiring the presence of established, active disease. Now, not only patients with axial SpA (axSpA) with radiographic signs of sacroiliitis (that is, with ankylosing spondylitis), but also patients in whom structural damage is not-yet-visible radiographically (non-radiographic axSpA) can be included in trials of therapy for axSpA. TNF blockers, it seems already, are at least similarly effective in patients with non-radiographic axSpA as in those with established AS. Short symptom duration and a positive C-reactive protein test at baseline are currently the best predictors for a good response to TNF-blocking agents. Biologic agents besides anti-TNF therapies have so far failed in the treatment of axSpA. New bone formation seems currently to be best prevented by NSAIDs, not by TNF blockers. Whether earlier effective treatment of bony inflammation with anti-TNF therapy will be able to prevent ossification at a later stage has yet to be determined. New classification criteria for peripheral SpA will also allow treatment trials to be conducted more systematically than has previously been possible in this subgroup of patients.

Influence of methotrexate on infliximab pharmacokinetics and pharmacodynamics in ankylosing spondylitis

AIMS

Infliximab, an anti-tumour necrosis factor α monoclonal antibody, has profoundly modified the treatment of several inflammatory diseases. The objective was to assess the influence of methotrexate on the variability of infliximab pharmacokinetics and concentration-effect relationship in axial ankylosing spondylitis (AAS) patients.

METHODS

Twenty-six patients with AAS were included in a prospective study. They were treated by infliximab 5 mg kg⁻¹ infusions at weeks 0, 2, 6, 12 and 18. Infliximab concentrations were measured before, and 2 and 4 h after each infusion, and at each intermediate visit (weeks 1, 3, 4, 5, 8, 10 and 14). Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was measured at each visit. Infliximab pharmacokinetics was described using a two-compartment model with first-order distribution and elimination constants. A population approach was used. Infliximab pharmacodynamics was described using the area under the BASDAI curve.

RESULTS

A total of 507 blood samples and 329 BASDAI measurements were collected. The following pharmacokinetic parameters were obtained (interindividual coefficient of variation): volumes of distribution for the central compartment = 2.4 l (9.6%) and peripheral compartment = 1.8 l (26%), systemic clearance = 0.23 l day⁻¹ (22%) and intercompartment clearance = 2.3 l day⁻¹. Methotrexate influenced neither pharmacokinetic nor BASDAI variability.

CONCLUSIONS

Using the present dosage, the clinical efficacy of infliximab is only weakly influenced by its serum concentrations. The results do not support the combination of methotrexate with infliximab in ankylosing spondylitis.

[How to optimize the antiTNF alpha therapy in spondylitis?]

TNFalpha inhibitors have been a major advance in the treatment of spondyloarthropathies, having demonstrated their safety and efficacy, with higher response and survival rates than those observed in patients with rheumatoid arthritis. The fact that disease modifying anti-arthritic drugs (DMARD) have shown utility in the treatment of this disease, especially in the axial forms, gives them greater importance, since it is known that up to 30%of patients do not respond to treatment with non-steroidal anti-inflammatory drugs. However, we must take into account that these drugs are expensive and not without side effects, so it is necessary to optimize their use. We intend to review the use of antiTNF alpha in spondyloarthropathies and review the available evidence on strategies that can help with their rational use.

Current therapeutics for spondyloarthritis

INTRODUCTION

Ankylosing spondylitis (AS) belongs to a clinically related group of disorders named spondyloarthritis (SpA) that mainly affect the axial skeleton and present with specific extra-articular manifestations. The therapeutic management of AS and other SpA has considerably progressed over the past 10 years.

AREAS COVERED

This paper provides a review of the available treatments for AS including traditional treatments (NSAIDs, sulfasalazine and methotrexate, local corticosteroids) and biological therapies (TNF-α antagonists), as well as nonpharmacological procedures (education and physical therapy) and specific recommendations for this therapeutic management.

EXPERT OPINION

NSAIDs remain the first-line treatment in patients with AS, especially with axial disease. There is an increasing amount of evidence showing the short-term and long-term efficacy of TNF-α antagonists in AS, with the control of pain, extra-articular manifestations and spinal inflammation as evidenced by MRI. By contrast, there is no proof for the control of radiographic progression at the spine with these agents. An early diagnosis is now possible using the new classification criteria for SpA. However, it remains to be established if an early intervention might control the progression of the disease. Since about 20 - 25% of patients are considered as nonmajor responders to TNF-α blockers, there is an unmet need for developing new biological therapies. Targeting the IL-17 pathway may be an interesting option. International recommendations for the management of AS by the Assessment of Spondyloarthritis (ASAS) group were recently updated and discussed the respective place of each current therapeutic option in AS.

Adalimumab successful in sarcoidosis patients with refractory chronic non-infectious uveitis

INTRODUCTION

Adalimumab, a humanized monoclonal antibody targeted against TNF-α, has proved to be successful in the treatment of uveitis. Another anti-TNF-α agent, i.e., infliximab, has been reported of benefit in the treatment of refractory sarcoidosis. The aim of this prospective case series was to evaluate the effect of adalimumab on intraocular inflammatory signs and other relevant clinical manifestations (lung function, serological inflammatory parameters, and fatigue) of sarcoidosis.

METHODS

Sarcoidosis patients with refractory posterior uveitis (n = 26, 17 females, 41 eyes in total) were systematically followed for 12 months after initiation of adalimumab 40 mg sc once a week. Inclusion criteria were non-responsiveness to prednisone and methotrexate (MTX) or intolerance to these drugs. Adjunctive therapy with prednisone and MTX was tapered during treatment with adalimumab. Localization and improvement, stabilization or deterioration of intraocular inflammatory signs was scored. Pulmonary function- and laboratory testing were performed and Fatigue Assessment Scale was completed. Results at baseline, 6 months, and 12 months were compared.

RESULTS

Choroidal involvement resolved in 10/15 patients, five had partial improvement; vasculitis resolved in 1/1 patient; papillitis resolved in 7/8 patients, one had partial response; macular edema resolved in 5/8 patients, three had partial response; vitreous cleared completely in 5/5 patients. Overall outcome regarding intraocular inflammatory signs showed improvement in 22 patients (85%) and stabilization in four patients (15%). At 12 months, no recurrences were reported in those successfully treated. Laboratory parameters of inflammatory activity (C-reactive protein; serum angiotensin-converting enzyme and soluble interleukin-2 Receptor) improved (p < 0.01). Moreover, fatigue improved in 14/21 (67%) of the patients suffering from fatigue and the diffusion capacity for carbon monoxide (DLCO) improved in 7/8 (88%) of patients with a decreased DLCO (p < 0.01). The dosage of both prednisone and MTX could be tapered down significantly (p < 0.01 and p < 0.05, respectively).

CONCLUSIONS

Adalimumab appeared successful in sarcoidosis patients with refractory chronic non-infectious uveitis showing improvement in intraocular inflammatory signs as well as in other relevant clinical indicators of disease activity. Future randomized studies are needed to determine the optimal dosage, dose interval and duration of therapy in refractory multisystemic sarcoidosis.

TNF alpha antagonist therapy and safety monitoring

OBJECTIVES

To develop and/or update fact sheets about TNFα antagonists treatments, in order to assist physicians in the management of patients with inflammatory joint disease.

METHODS

1. selection by a committee of rheumatology experts of the main topics of interest for which fact sheets were desirable; 2. identification and review of publications relevant to each topic; 3. development and/or update of fact sheets based on three levels of evidence: evidence-based medicine, official recommendations, and expert opinion. The experts were rheumatologists and invited specialists in other fields, and they had extensive experience with the management of chronic inflammatory diseases, such as rheumatoid. They were members of the CRI (Club Rhumatismes et Inflammation), a section of the Société Francaise de Rhumatologie. Each fact sheet was revised by several experts and the overall process was coordinated by three experts.

RESULTS

Several topics of major interest were selected: contraindications of TNFα antagonists treatments, the management of adverse effects and concomitant diseases that may develop during these therapies, and the management of everyday situations such as pregnancy, surgery, and immunizations. After a review of the literature and discussions among experts, a consensus was developed about the content of the fact sheets presented here. These fact sheets focus on several points: 1. in RA and SpA, initiation and monitoring of TNFα antagonists treatments, management of patients with specific past histories, and specific clinical situations such as pregnancy; 2. diseases other than RA, such as juvenile idiopathic arthritis; 3. models of letters for informing the rheumatologist and general practitioner; 4. and patient information.

CONCLUSION

These TNFα antagonists treatments fact sheets built on evidence-based medicine and expert opinion will serve as a practical tool for assisting physicians who manage patients on these therapies. They will be available continuously at www.cri-net.com and updated at appropriate intervals.

Antibodies toward infliximab are associated with low infliximab concentration at treatment initiation and poor infliximab maintenance in rheumatic diseases

INTRODUCTION

A proportion of patients receiving infliximab have antibodies toward infliximab (ATI), which are associated with increased risk of infusion reaction and reduced response to treatment. We studied the association of infliximab concentration at treatment initiation and development of ATI as well as the association of the presence of ATI and maintenance of infliximab.

METHODS

All patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA) receiving infliximab beginning in December 2005 were retrospectively followed until January 2009 or until infliximab discontinuation. Trough serum infliximab and ATI concentrations were measured at each visit. The patients were separated into two groups: ATI(pos) if ATI were detected at least once during the follow-up period and ATI(neg) otherwise. Repeated measures analysis of variance was used to study the association of infliximab concentration at treatment initiation and the development of ATI. Maintenance of infliximab in the two groups was studied by using Kaplan-Meier curves.

RESULTS

We included 108 patients: 17 with RA and 91 with SpA. ATI were detected in 21 patients (19%). The median time to ATI detection after initiation of infliximab was 3.7 months (1.7 to 26.0 months). For both RA and SpA patients, trough infliximab concentration during the initiation period was significantly lower for ATI(pos) than ATI(neg) patients. RA patients showed maintenance of infliximab at a median of 19.5 months (5.0 to 31.0 months) and 12.0 months (2.0 to 24.0 months) for ATI(neg) and ATI(pos) groups, respectively (P = 0.08). SpA patients showed infliximab maintenance at a median of 16.0 months (3.0 to 34.0 months) and 9.5 months (3.0 to 39.0 months) for ATI(neg) and ATI(pos) groups, respectively (P = 0.20). Among SpA patients, those who were being treated concomitantly with methotrexate had a lower risk of developing ATI than patients not taking methotrexate (0 of 14 patients (0%) vs. 25 of 77 patients (32%); P = 0.03).

CONCLUSIONS

High concentrations of infliximab during treatment initiation reduce the development of ATI, and the absence of ATI may be associated with prolonged maintenance of infliximab. Thus, trough serum infliximab concentration should be monitored early in patients with rheumatic diseases.

Infliximab in ankylosing spondylitis: alone or in combination with methotrexate? A pharmacokinetic comparative study

INTRODUCTION

Methotrexate (MTX) has been shown to modify infliximab pharmacokinetics in rheumatoid arthritis. However, its combination with infliximab in the treatment of ankylosing spondylitis (AS) is not recommended. The objective of this study was to examine the influence of MTX on infliximab exposure in patients with AS.

METHODS

Patients with AS patients who had predominantly axial symptoms were randomised to receive infliximab alone (infusions of 5 mg/kg at weeks 0, 2, 6, 12 and 18) or infliximab combined with MTX (10 mg/week). Infliximab concentrations were measured before and 2 hours after each infusion and at 1, 3, 4, 5, 8, 10, 14 and 18 weeks. We estimated individual cumulative area under the concentration versus time curves (AUC) for infliximab concentration between baseline and week 18 (AUC(0-18)). Clinical and laboratory evaluations were performed at each visit. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score was the primary end point for clinical response.

RESULTS

Twenty-six patients were included (infliximab group: n = 12, infliximab + MTX group: n = 14), and 507 serum samples were available for measurement of infliximab concentration. The two groups did not differ with regard to AUC(0-18) or evolution of BASDAI scores and biomarkers of inflammation.

CONCLUSIONS

The combination of MTX and infliximab does not increase the exposure to infliximab over infliximab alone in patients with AS.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00507403.

Spondyloarthritides: evolving therapies

TNF blockade therapy has substantially advanced the treatment of peripheral spondyloarthritides but revolutionised the treatment of severe ankylosing spondylitis. The capacity of biologic treatment to improve dramatically symptoms and quality of life in patients with spinal disease is undoubted, although important questions remain. Notable amongst these are concerns about skeletal disease modification and the true balance between costs and effectiveness. Guidelines for the biologic treatment of ankylosing spondylitis and psoriatic arthritis have been introduced in North America and Europe with considerable consensus. However, the absence of clear criteria for the diagnosis of early disease leaves the issue of biologic treatment of ankylosing spondylitis at the pre-radiographic stage unresolved. Newer biologic agents are entering the field, although superiority over TNF blockers will be difficult to demonstrate.

[Anti-TNFα therapy in ankylosing spondylitis: symptom control and structural damage modification]

Anti-TNFα agents represent an outstanding advance in the symptomatic control of patients with ankylosing spondylitis presenting an inadequate response to non-steroidal anti-inflammatory drugs. Anti-TNFα antagonists have demonstrated efficacy and safety in the long-term but continuous therapy is needed for an adequate control of symptoms. After the failure to a first anti-TNFα agent, the use of a second TNFα antagonist seems to be effective and safe. Despite the fast and continuous suppression of bone inflammation, demonstrated by magnetic resonance imaging, the beneficial effect of treatment with TNFα antagonists on the radiological evolution has not been demonstrated to date in ankylosing spondylitis. It seems that insights into new therapeutic molecular targets implicated in the process of ossification are needed.

A Double-blind, Placebo-controlled Trial of Low Dose Infliximab in Ankylosing Spondylitis

Objective.

The tumor necrosis factor-α (TNF-α) inhibitor infliximab (IFX) has been proven effective for the treatment of ankylosing spondylitis (AS). The primary objective of this double-blind, placebo-controlled study was to assess the safety and efficacy of low-dose (3 mg/kg q8w) IFX therapy in AS.

Methods.

In the 12-week double-blind phase of the study, patients (N = 76) were randomized to infusions of placebo or IFX (3 mg/kg) at Weeks 0, 2, and 6. The primary endpoint was 20% improvement in ASsessments in Ankylosing Spondylitis criteria (ASAS20) at 12 weeks. In the open-label extension phase, all patients received scheduled IFX infusions (q 8 weeks) up to 46 weeks. Patients who did not meet target response criteria (i.e., BASDAI score did not improve by at least 50% and was > 3) at Weeks 22 or 38 had a dose increase to IFX 5 mg/kg.

Results.

At 12 weeks, 53.8% of IFX-treated patients achieved ASAS20, compared with 30.6% of placebo-treated patients (p = 0.042). IFX-treated patients showed significant improvement in measures of disease activity, spinal mobility, and quality of life over the course of the study. During the extension phase, 68% of patients in the IFX group did not meet the clinical target and had an increase in the dose of IFX to 5 mg/kg by 38 weeks. In general, IFX was safe and well tolerated. Ten patients withdrew from the study for various reasons, with only 2 (2.6%) attributed to adverse events.

Conclusion.

IFX 3 mg/kg was effective in reducing the signs and symptoms of active AS, and was generally safe and well tolerated. Dose escalation to 5 mg/kg every 8 weeks was warranted in most patients to achieve the target clinical response of the study.

[Management of the patient with ankylosing spondylitis (AS) in partial remission with biologic therapy: is it possible to suspend treatment?]

The management of patients with AS and a good clinical response to biologic therapy is controversial. The results of the different published papers suggest that the suspension of treatment is not a good therapeutic option in these patients. There is currently no validated definition for clinical remission in patients with AS. A hypothetical definition should include the absence of signs and symptoms of disease in any localization, associated to the lack of progression of the disease and all of this during a period of time long enough to establish its persistence with time. In our experience, those patients presenting an apparent clinical remission, based on the previously established definition, could be considered for temporary treatment suspension, especially if we take into account that the reintroduction of treatment is safe and effective.

Clinical review: Anti-TNFalpha therapies in uveitis: perspective on 5 years of clinical experience

Despite a lack of robust evidence, anti-TNF therapies are in wide use for the treatment of noninfectious ocular inflammatory diseases. There is a clear rationale, based on mechanistic and preclinical efficacy data, for their use in posterior segment intraocular inflammation. However, their increasing use for other indications has been largely extrapolated from the benefit observed in autoinflammatory and autoimmune systemic diseases. Given their cost and the potential for significant adverse events, this review highlights the evidence for their continued use, possibilities for switching anti-TNF agents, and ways of reducing the risk of therapy.

Ankylosing spondylitis patients commencing biologic therapy have high baseline levels of comorbidity: a report from the Australian rheumatology association database

Aims. To compare the baseline characteristics of a population-based cohort of patients with ankylosing spondylitis (AS) commencing biological therapy to the reported characteristics of bDMARD randomised controlled trials (RCTs) participants. Methods. Descriptive analysis of AS participants in the Australian Rheumatology Association Database (ARAD) who were commencing bDMARD therapy. Results. Up to December 2008, 389 patients with AS were enrolled in ARAD. 354 (91.0%) had taken bDMARDs at some time, and 198 (55.9%) completed their entry questionnaire prior to or within 6 months of commencing bDMARDs. 131 (66.1%) had at least one comorbid condition, and 24 (6.8%) had a previous malignancy (15 nonmelanoma skin, 4 melanoma, 2 prostate, 1 breast, cervix, and bowel). Compared with RCT participants, ARAD participants were older, had longer disease duration and higher baseline disease activity. Conclusions. AS patients commencing bDMARDs in routine care are significantly different to RCT participants and have significant baseline comorbidities.

Circulating concentration of infliximab and response to treatment in ankylosing spondylitis: results from a randomized control study

OBJECTIVE

A minority of patients with ankylosing spondylitis (AS) fail to respond to infliximab treatment. This study compared the circulating infliximab concentration and the presence of clinical symptoms in patients continuously treated with infliximab or after treatment interruption.

METHODS

Patients with active AS were randomly assigned at week 0 to receive infliximab either at weeks 4, 6, 10, and then every 6 weeks (continuous treatment), or at weeks 4, 6, and 10 and then upon symptom recurrence (on-demand treatment). The circulating concentration of infliximab was determined early during treatment and at weeks 46 and 52 for the continuous treatment group or upon relapse for the on-demand group. Response in the continuous treatment group was defined at week 58 using the ASsessment in AS International Working Group Criteria for 20% improvement.

RESULTS

Among the 93 patients in the continuous treatment group, treatment failure was not associated with a low circulating concentration of infliximab, either during early treatment or at 1 year. Eleven (39.2%) of the 28 nonresponders had an infliximab concentration of >10 microg/ml at week 52, whereas 9 (13.8%) of the 65 responders had an infliximab concentration of <1 microg/ml. In the on-demand group, the infliximab concentration at relapse closely correlated with the time to relapse. However, 24 (36.9%) of 65 patients had a resurgence of clinical symptoms at an infliximab concentration of >10 microg/ml, whereas 25 patients (38.4%) had a relapse at an infliximab concentration of <0.5 microg/ml.

CONCLUSION

Responsiveness to infliximab treatment is highly heterogeneous among individuals with AS, and this parameter overcomes the circulating infliximab concentration to explain treatment success or failure.

Developments in the scientific and clinical understanding of the spondyloarthritides

Major advances have been achieved over the last 10 years both in the clinical and scientific understanding of the spondyloarthritides (SpA), which can be separated in predominantly axial and predominantly peripheral SpA. The clinical progress includes the development of classification criteria, strategies for early diagnosis, definition of outcome criteria for clinical studies, and the conduction of a series of clinical studies with a focus on tumor necrosis factor (TNF) blockers. The proven high efficacy of TNF blocker treatment has meant a breakthrough for SpA patients, who until recently had only quite limited treatment options. More and more data have accumulated over recent years in regard to long-term efficacy and safety, prediction of response, and the relevance of extrarheumatic manifestations such as uveitis, psoriasis, and inflammatory bowel disease for treatment decisions with TNF blockers. A better understanding of the interaction of the immune system and inflammation with bone degradation/new bone formation is crucial for the development of optimal treatment strategies to prevent structural damage. Recent results from genetic studies could show that, besides HLA-B27, the interleukin-23 receptor and the ARTS1 enzyme are associated with ankylosing spondylitis. Only when the exact pathogenesis is clarified will a curative treatment be possible.

The treatment of psoriatic arthritis and inflammatory spondylitis

NSAIDs still remain the initial therapeutic modality for psoriatic arthritis and inflammatory spondylitis. Disease-modifying antirheumatic drugs have only been proven to be useful in peripheral arthritis, without efficacy in axial inflammatory spondylitis. In recent years, the introduction of tumor necrosis alpha inhibitors into clinical practice has produced a substantial impact in both peripheral and axial disease, with improvement in pain, function, and quality of life. Factors such as cost-effectiveness and safety will need to be better characterized over time.