Abstract Background Immunogenicity to tumour necrosis factor inhibitors is a significant clinical problem leading to treatment failure and adverse events. The study aimed to assess human leukocyte antigen (HLA) associations with anti‐drug antibody (ADAb) formation to infliximab. Methods Immune‐mediated inflammatory disease patients on infliximab therapy ( n = 612) were included. Neutralising ADAb were assessed with a drug‐sensitive assay. Next generation sequencing‐based HLA typing was performed. Results Overall, 147 (24%) patients developed ADAb. Conditional analyses indicated HLA‐DQB1 ( p = 1.4 × 10 −6 ) as a primary risk locus. Highest risk of ADAb was seen when carrying at least one of the HLA‐DQ2 haplotypes; DQB1*02:01–DQA1*05:01 or DQB1*02:02–DQA1*02:01 (OR 3.18, 95% CI 2.15–4.69 and p = 5.9 × 10 −9 ). Results were consistent across diseases and when adjusting for concomitant immunomodulator. Computational predictions indicated that these HLA‐DQ2 haplotypes bind to peptide motifs from infliximab light chain. Conclusion A genome‐wide significant association between two HLA‐DQ2 haplotypes and the risk of ADAb formation to infliximab was identified, suggesting that HLA‐DQ2 testing may facilitate personalised treatment decisions.
Abstract Background Infliximab (INX) and other tumour necrosis factor inhibitors (TNFi) have revolutionised the treatment of several immune mediated inflammatory diseases. Still, many patients do not respond sufficiently to therapy or lose efficacy over time. The large interindividual variation in serum drug concentrations on standard doses and the development of anti-drug antibodies are thought to be major reasons for treatment failures. Therapeutic drug monitoring (TDM), an individualised treatment strategy based on systematic assessments of serum drug concentrations, has been proposed as a clinical tool to optimise efficacy of INX treatment. TDM seems reasonable both from a clinical and an economical point of view, but the effectiveness of this treatment strategy has not yet been demonstrated in randomised clinical trials. The NORwegian DRUg Monitoring study (NOR-DRUM) aims to assess the effectiveness of TDM, both with regard to the achievement of remission in patients starting INX treatment (part A) as well as to maintain disease control in patients on INX treatment (part B). Methods The NOR-DRUM study is a randomised, open, controlled, parallel-group, comparative, multi-centre, national, superiority, phase IV study with two separate parts, NOR-DRUM A and NOR-DRUM B. Patients with rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, ulcerative colitis, Crohn’s disease and psoriasis are included. In both study parts participants are randomised 1:1 to either TDM of infliximab (intervention group) or to standard treatment with infliximab without knowledge of drug levels or ADAb status (control group). NOR-DRUM A will include 400 patients starting INX therapy. The primary outcome is remission at 30 weeks. In NOR-DRUM B, 450 patients on maintenance treatment with INX will be included. The primary endpoint is occurrence of disease worsening during the 52-week study period. Discussion As the first trial to assess the effectiveness, safety and cost-effectiveness of TDM in patients receiving TNFi for a range of immune mediated inflammatory diseases, we hope that the NOR-DRUM study will contribute to the advancement of evidence based personalised treatment with biological medicines. Trial registration Clinicaltrials.gov, NCT03074656 . Registered on 090317.
Measurement of serum drug levels can help clinicians tailor treatment with TNF-inhibitors. An association between certolizumab pegol (CP) serum levels and treatment response in rheumatoid arthritis (RA) patients (pts) has previously been demonstrated in a prospective observational study (1). These results need to be confirmed in other studies, with particular focus on finding an optimal therapeutic serum level for CP.
Objectives:
To examine the association between serum CP drug levels and treatment response in RA pts and to identify a therapeutic target level.
Methods:
Patients with a clinical diagnosis of RA starting standard treatment with CP included in the NOR-DMARD registry with biobank sample at 3 months follow-up, were included in the present analyses. Serum drug levels (non-trough) were analysed with an in-house immunofluorometric assay automated on the AutoDELFIA immunoassay platform. We studied association between serum CP level and &x25B3;DAS28 and EULAR good/moderate response at 3 months by multivariable linear and logistic regression analyses, respectively, adjusting for age, sex and prior bDMARD (Y/N).
Results:
In 91 included patients, median serum drug level at 3 months follow up was 34.7 mg/L (17.6–44.6). Response data were available in 81/91 patients. Serum CP level ≥20 mg/L was associated with greater improvement in DAS28 at 3 months (β=0.89 (95% CI 0.03–1.74), P=0.04. 44.4 % of pts with CP level <20 mg/L achieved EULAR response after 3 months treatment, while 73.5 % of pts with CP level 20–40 mg/L and 55.2 % with ≥40 mg/L were responders. However, the difference in EULAR response between pts with CP level ≥20 vs. <20 mg/L did not reach statistical significance (OR 1.5 (95% CI 0.5–5.1), P=0.48).
Conclusions:
Certolizumab serum levels ≥20 mg/L were associated with DAS28 improvement, but not significantly with EULAR response after 3 months treatment in RA pts. We suggest 20 mg/L as a lower target limit for non-trough CP samples in RA-patients. No additional benefit of having a certolizumab level over 40 mg/L was observed.
Reference
[1]Jani M, et al. AnnRheum Dis2017;76(1):208–13.
Disclosure of Interest:
J. E. Gehin Consultant for: Roche, S. Syversen Consultant for: Roche, D. Warren: None declared, G. Goll Consultant for: Abbvie, Biogen, Boehringer Ingelheim, Orion Pharma, Eli Lilly, Novartis, Pfizer, MSD, Roche, UCB, J. Sexton: None declared, E. Strand Consultant for: Pfizer, T. Kvien Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Epirus, Hospira, Merck-Serono, MSD, Mundipharma, Novartis, Oktal, Orion Pharma, Hospira/Pfizer, Roche, Sandoz, UCB, N. Bolstad Consultant for: Pfizer, Orion Pharma, Napp pharmaceuticals, Takeda, Roche, E. Lie: None declared
Measurement of serum drug levels can help clinicians tailor treatment with TNF-inhibitors. An association between certolizumab pegol (CP) serum levels and response has previously been found in patients (pts) with rheumatoid arthritis.1 Data for pts with axial spondyloarthritis (axSpA) are lacking.
Objectives
To examine the association between serum CP levels and treatment response in pts with axSpA and to identify a therapeutic target level.
Methods
Patients with a clinical diagnosis of axSpA starting standard treatment with CP included in the NOR-DMARD study with biobank sample at 3 months follow-up, were included in the present analyses. Serum drug levels (non-trough) were analysed with an in-house immunofluorometric assay automated on the AutoDELFIA immunoassay platform. Associations between CP level and improvement in ASDAS-CRP and response (defined as ASDAS clinically important improvement (CII)) were assessed by multivariable linear and logistic regression (adjusting for age, sex and prior bDMARD (Y/N)), respectively.
Results
Median serum drug level at 3 month follow up was 35.0 mg/L (IQR 21.3–45.3) in 116 pts. Response data were available in 110/116 patients. Serum CP level ≥20 mg/L was associated with improvement in ASDAS at 3 months (β=0.55, (95% CI 0.12–1.98), p=0.01). Serum CP level ≥20 mg/L was associated with ASDAS CII at 3 months (OR 3.4 (95% CI 1.0–11.1, p=0.045)). Only 18.2% of pts with CP level <20 mg/L achieved ASDAS CII at 3 months, while 53.2% of pts with CP level 20–40 mg/L and 36.6% with ≥40 mg/L were responders.
Conclusions
Serum CP level was associated with clinical response after 3 months of treatment in pts with axSpA. We suggest 20 mg/L as a lower target level for non-trough samples. No additional benefit of having a certolizumab level over 40 mg/L was observed. These results suggest that a therapeutic level of 20–40 mg/L can be implemented in clinical practice for non-trough serum samples in pts with axSpA.
Reference
[1] Jani M, et al. Ann Rheum Dis2017;76(1):208–13.
Disclosure of Interest
J. E. Gehin Consultant for: Roche, S. Syversen Consultant for: Roche, D. Warren: None declared, G. Goll Consultant for: Abbvie, Biogen, Boehringer Ingelheim, Orion Pharma, Eli Lilly, Novartis, Pfizer, MSD, Roche, UCB, J. Sexton: None declared, E. Strand Consultant for: Pfizer, T. Kvien Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Epirus, Hospira, Merck-Serono, MSD, Mundipharma, Novartis, Oktal, Orion Pharma, Hospira/Pfizer, Roche, Sandoz, UCB, N. Bolstad Consultant for: Pfizer, Orion Pharma, Napp pharmaceuticals, Takeda, Roche, E. Lie: None declared
The aim of the study was to assess RF cross-reactivity to animal antibodies used in immunoassays, and to test if selected commercial immunoassays are vulnerable to interference from RF, causing false test results. Our study included samples from patients with RF-positive rheumatoid arthritis (RA) and controls (patients with RF-negative RA and psoriatic arthritis), included in an early arthritis-cohort. Reactivity to mouse IgG1, mouse IgG2a, rabbit IgG, bovine IgG, sheep/goat IgG and human IgG was analysed using in-house interference assays. RF-positive sera with strong reactivity to mouse IgG1 were analysed in three commercial immunoassays. To reveal interference, results before and after addition of blocking aggregated murine IgG1 were compared. Samples from 124 RF-positive RA patients and 66 controls were tested. We found considerably stronger reactivity toward animal antibodies, particularly mouse IgG1 (73% vs. 12%) and rabbit IgG (81% vs. 6%), in sera from RF-positive RA-patients compared to controls (p < 0.001). After selecting samples for testing in commercial assays, interference was revealed in 6/30 sera in the Architect β-hCG assay, 7/10 sera in the 27-plex cytokine assays, and in 2/33 samples in the Elecsys Soluble Transferrin Receptor assay. Our study revealed considerable RF reactivity to animal antibodies used in immunoassays and RF was associated with falsely elevated results in immunoassays used in clinical care and research. Clinicians, laboratorians, researchers and assay manufacturers must be alert to the risk of falsely elevated test results in RF-positive RA patients.
According to national guidelines issued in 2015, a non-medical switch from originator infliximab (IFX) to biosimilar IFX was conducted in all Danish patients with inflammatory rheumatic diseases treated in routine care.
Objectives
To investigate effects of the switch on serum (s) IFX and anti-drug antibodies (ADA) in patients with rheumatoid arthritis (RA), axial spondyloarthrits (SpA) and psoriatic arthritis (PsA).
Methods
We included originator infliximab treated patients, who switched to and were treated with biosimiilar infliximab for >2 months with 2 available trough level serum samples (baseline immediately before switching/follow-up 2–4 months after switching time of 2nd–4th infusion). Patients stopping treatment earlier were not included. Trough sIFX <3mg/l was considered low and ≤1mg/l very low. If sIFX <5mg/l, ADA was measured. ADA ≤30AU/l was considered low and ADA >30AU/l median-high. sIFX and ADA were analyzed using automated in-house assays at OUS-Radiumhospitalet. Characteristics and outcomes were registered in the DANBIO registry. Remission was defined by disease activity indices (DAS28 <2.6 (RA, PsA) and ASDAS <1.3 (SpA)). Comparisons were by Mann Whitney U test (unpaired) and Wilcoxon signed rank test (paired). Outcomes are shown as medians (interquartile ranges).
Results
96 pts (192 samples) from 4 departments (49 RA, 27 SpA, 10 PsA, 10 other) were included (age 52 (43–62) years, 47% women). Previous IFX treatment duration was 7.5 (5.1–10.3) years. Follow-up was after 81 (71–90) days. 58 patients (60%) received concomitant methotrexate (15 (10–20) mg/wk). Baseline IFX dose was 3.1 (3.0–4.8) mg/kg every 7 (6–9) weeks. At baseline, 60% of pts had low sIFX and 29% very low and at follow-up it was 57% and 29%, respectively. At baseline, 14 pts (15%) had medium-high ADA, at follow up 16%. Median sIFX was lower at baseline vs. follow-up (1.8 (0.8–5.8) vs 2.4 (0.8–6.2) mg/l, p=0.006) whereas ADA were similar (p=0.7). Six of 58 pts with low baseline sIFX had high sIFX at follow-up, and 3 of 38 pts with high baseline sIFX had low sIFX at follow-up. Similar numbers for low vs. medium–high ADA at baseline and follow-up were 2/81 and 3/15. For the rest, sIFX and ADA remained stable between baseline and follow-up in 87/96 (91%) and 91/96 (95%), respectively (Figure). MTX use was not associated with sIFX or ADA (both p>0.05). Patients with low sIFX received lower IFX doses than pts with sIFX ≥3mg/l (255 (200–320) mg vs. 300 (250–400) mg, p=0.02) and with longer intervals (8 (6–10) weeks vs. 6 (6–6)weeks, p<0.01). Remission rates at baseline (56%/11%/75%) or follow-up (52%/21%/100%) for RA/SpA/PsA were not associated with sIFX (all p>0.05).
Conclusions
In this highly selected group of patients treated with originator infliximab for >5 years, non-medical switch to biosimilar IFX had no negative impact on sIFX or ADA 2–4 months following switch. At baseline, 60% of patients had low sIFX but few patients had ADA, perhaps indicating low immunogenicity in these patients.
The objectives of this review were to collect and summarise evidence on therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases and to inform the EULAR Task Force for the formulation of evidence-based points to consider. A systematic literature review (SLR) was performed, covering technical aspects and (clinical) utility of TDM, to answer 13 research questions. MEDLINE, Embase and Cochrane were searched until July 2020. American College of Rheumatology and EULAR abstracts were also considered for inclusion. Data were extracted in evidence tables and risk of bias assessment was performed. For the search on technical aspects, 678 records were identified, of which 22 papers were selected. For the clinical utility search, 3846 records were identified, of which 108 papers were included. Patient-related factors associated with biopharmaceutical blood concentrations included body weight, methotrexate comedication and disease activity. The identification of a target range was hampered by study variability, mainly disease activity measures and study type. Evidence was inconsistent for multiple clinical situations in which TDM is currently applied. However, for some particular scenarios, including prediction of future treatment response, non-response to treatment, tapering and hypersensitivity reactions, robust evidence was found. There is currently no evidence for routine use of proactive TDM, in part because published cost-effectiveness analyses do not incorporate the current landscape of biopharmaceutical costs and usage. This SLR yields evidence in favour of TDM of biopharmaceuticals in some clinical scenarios, but evidence is insufficient to support implementation of routine use of TDM.
To identify a therapeutic target interval for certolizumab pegol drug levels and examine the influence of anti-drug antibodies in patients with inflammatory joint diseases.Certolizumab pegol and anti-drug antibody levels were measured in serum samples collected after 3 months of certolizumab pegol treatment in 268 patients with inflammatory joint diseases (116 axial spondyloarthritis, 91 rheumatoid arthritis and 61 psoriatic arthritis) in the NOR-DMARD study. Treatment response was defined by Ankylosing Spondylitis Disease Activity Score Clinically important improvement in axial spondyloarthritis, European League Against Rheumatism good/moderate response in rheumatoid arthritis, and improvement in 28-joint Disease Activity Score of ≥ 0.6 in PsA. Serum drug levels and anti-drug antibodies were analysed using automated in-house assays.Certolizumab pegol serum levels varied considerably between individuals (median (IQR) 32.9 (17.3-43.9) mg/L). Certolizumab pegol level ≥ 20 mg/L was associated with treatment response for the total inflammatory joint disease population, with odds ratio (OR) 2.3 (95% CI 1.2-4.5, P = 0.01) and OR 1.9 (95% CI 1.0-3.5, P = 0.05) after 3 and 6 months of treatment, respectively. For individual diagnoses, this association was most consistent for axial spondyloarthritis, with OR 3.4 (95% CI 1.0-11.1, P < 0.05) and OR 3.3 (95% CI 1.0-10.8, P < 0.05), respectively. Certolizumab pegol level > 40 mg/L was not associated with any additional benefit for any of the diagnoses. Anti-drug antibodies were detected in 6.1% (19/310) of samples and were associated with low certolizumab pegol levels (P < 0.01).Serum certolizumab pegol levels 20-40 mg/L were associated with treatment response in inflammatory joint diseases. Our study is the first to show this association in axial spondyloarthritis and psoriatic arthritis patients. The results suggest a possible benefit of therapeutic drug monitoring in patients with inflammatory joint disease on certolizumab pegol treatment.NCT01581294, April 2012.