Treatment of psoriatic arthritis with traditional DMARD’s and novel therapies: approaches and recommendations

Exposure-response analyses demonstrate no evidence of interleukin 17A contribution to efficacy of ABT-122 in rheumatoid or psoriatic arthritis

Objectives

ABT-122 is a dual-variable-domain immunoglobulin that neutralizes both TNF-α and IL-17A. The objective of this work was to characterize exposure-response relationships for ABT-122 relative to adalimumab (TNF-α inhibitor) using ABT-122 phase 2 trials in patients with RA or PsA.

Methods

Patients received subcutaneous doses of ABT-122 ranging from 60 mg every other week (EOW) to 240 mg every week, adalimumab 40 mg EOW, or placebo (PsA patients only) for 12 weeks. Relationships between ABT-122 or adalimumab serum concentrations and time course of ACR20, ACR50 and ACR70 and PASI50, PASI75 and PASI90 responses were characterized using a non-linear mixed-effects Markov modelling approach.

Results

A total of 221 RA patients and 240 PsA patients were included in the analyses. At comparable molar exposures, there was no differentiation of efficacy between ABT-122 and adalimumab and there were no consistent differences between ABT-122 and adalimumab in the potency estimates for different efficacy endpoints based on the Markov models. Plateau of ABT-122 efficacy was achieved at exposures associated with the 120 mg EOW dose in patients with RA, which were comparable to molar exposures of adalimumab 40 mg EOW, and at the lowest dose of 120 mg every week in patients with PsA.

Conclusion

The exposure-response relationships for ABT-122 were not distinguishably different from those of adalimumab in patients with RA or PsA. Overall, there was no clear evidence that inhibition of the IL-17 pathway provided incremental benefit in the presence of TNF-α inhibition.

Trial registration

ClinicalTrials.gov, NCT02433340, NCT02349451.

Cytopenia induced by low-dose methotrexate: An analysis of 433 cases from the French pharmacovigilance database

INTRODUCTION

Up to 5% of individuals exposed to low-dose methotrexate (MTX) (i.e., ≤30 mg/week) may develop cytopenia. However, MTX-induced cytopenia have been poorly described.

MATERIAL AND METHODS

All cases of cytopenia (i.e., anaemia, leukopenia, thrombocytopenia, bi- or pancytopenia) in patients receiving low-dose MTX reported to the French pharmacovigilance database during 2006-2016 were analysed. Three groups were defined: cytopenia due to MTX medication errors (e.g., daily rather than weekly administration), cytopenia in people receiving several medications including MTX, cytopenia in people receiving only MTX.

RESULTS

433 cases were analysed. Eighty-four cases (19.4%) were due to medication errors, 180 (41.6%) occurred in individuals exposed both to MTX and other drugs, and 169 (39.0%) occurred in individuals only exposed to MTX. By comparison to other patients, those with cytopenia due to medication errors were older (74 ± 13 vs 69 ± 15 years, p = 0.002), received more frequently MTX orally (92.9% vs 65.3%, p<0.001) and had more frequently pancytopenia (71.4% vs 54.4%, p = 0.005). By comparison to individuals exposed to multiple drugs (n = 180), those exposed only to MTX (n = 169) were older (71 ± 15 vs 67 ± 14, p = 0.02), and had more often pancytopenia (62.7% vs 46.7%, p = 0.001). Among those only exposed to MTX, most cases (n = 140, 82.8%) were considered as toxic rather than idiosyncratic reactions and a trigger (e.g. diarrhoea) was found in 59.3% of those cases. Overall 30 (6.9%) deaths occurred, including 8 in the "medication error" group and 8 in the "MTX only" group.

CONCLUSION

These data may be useful for defining optimal biological monitoring of patients prescribed low-dose MTX.

Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison

Ankylosing spondylitis (AS) was first identified in the late 17th century. 250 years later, inflammatory spine disease was recognized to be one of the patterns of psoriatic arthritis (PsA). Isolated spondylitis is rare among patients with PsA, occurring in less than 5% of patients; however, many patients with PsA have axial disease that is concurrent with peripheral arthritis. At the other end of the spondyloarthritis spectrum, psoriasis is observed in 10% of patients with AS. Although axial involvement in PsA can be indistinguishable from axial disease in AS, it can also differ in several respects, raising the question of whether axial PsA and AS (with or without psoriasis) are different clinical presentations of the same disease, or whether they are separate diseases that have overlapping features. In this Review, the clinical presentation, metrology, radiographic characteristics, genetic factors, treatment options and axial prognosis of the two diseases are addressed. The aim of this Review is to capture all available comparisons made to date, to highlight the similarities and differences between AS and axial PsA and to propose a research agenda.

Economic Burden of Switching to Different Biologic Therapies Among Tumor Necrosis Factor Inhibitor-Experienced Patients with Psoriatic Arthritis

Introduction

Patients with psoriatic arthritis (PsA) who receive an initial tumor necrosis factor inhibitor (TNFi) may switch to another TNFi or a non-TNFi biologic therapy. This study compared the healthcare resource use (HRU), expenditures, and time to discontinuation among TNFi-experienced patients with PsA who switched to different biologic therapies in the United States (US).

Methods

Adults with PsA who discontinued an initial TNFi (adalimumab, etanercept, infliximab, golimumab, or certolizumab pegol) and switched to another TNFi or a non-TNFi (ustekinumab or secukinumab) were identified in the Symphony Health Solutions database [Quarter (Q)1 2010–Q2 2017]. Eligible patients had claims data activity for ≥ 12 months before (baseline) and after (study period) the switching date. All-cause HRU, costs (2017 US dollars), and time to discontinuation during the study period were compared between patients switching to another TNFi vs. a non-TNFi (index drug). Multivariable regression models adjusted for baseline covariates (index year, age, sex, initial TNFi, comorbidities, baseline HRU, and PsA-related treatment history).

Results

Of 2107 patients switching to another TNFi and 253 switching to a non-TNFi, adalimumab and etanercept were the most common initial TNFi in both cohorts. During the study period, patients switching to another TNFi had significantly fewer dermatologists visits (0.43; p < 0.01) but more rheumatologist visits (1.56, p < 0.01) than patients switching to a non-TNFi. Patients switching to another TNFi vs. a non-TNFi incurred significantly lower total average healthcare expenditures (adjusted difference: $17,625; p < 0.01), driven by lower prescription drug (adjusted difference: $17,172; p < 0.01) and hospitalization expenditures (adjusted difference: $5772; p = 0.04). Patients who switched to another TNFi vs. a non-TNFi continued on their index therapy significantly longer (median time to discontinuation: 8.31 vs. 5.68 months; log-rank p < 0.01).

Conclusions

Patients with PsA who switched to another TNFi had lower total healthcare expenditures and longer persistence compared with patients who switched to a non-TNFi biologic.

Funding

AbbVie.