G. Bonilla

Influence of immunogenicity on the efficacy of long-term treatment with infliximab in rheumatoid arthritis

OBJECTIVE To analyse the clinical relevance of the production of anti-infliximab antibodies (anti-infliximab Abs) in patients with RA undergoing infliximab treatment over a prolonged period of time. METHODS Clinical characteristics, serum trough infliximab and antibody levels were evaluated in 85 RA patients treated with infliximab for a median of 4.42 (interval 0.4-10.2) years. DAS in 28 joints (DAS-28), EULAR response criteria and survival of treatment were assessed at 3 time points (6 months, 12 months and >4 years). RESULTS Antibodies against infliximab were detected in 28 (32.9%) patients and were present in all EULAR non-responder patients. Antibody levels were higher in EULAR non-responders throughout the study period (P = 0.05 at 6 months, P = 0.02 at 1 year, P = 0.003 at >4 years) compared with EULAR (good and moderate) responders. Nine (10.5%) patients, all of them with high-serum anti-infliximab Ab levels, developed infusion-related reactions. Patients with anti-infliximab Abs more often required increased infliximab doses (51.7%) (P = 0.032) and median survival time on treatment was shorter (4.15 vs 8.89 years) (P = 0.0006). MTX co-therapy was not associated with lower proportion of anti-infliximab Ab-positive patients, but those receiving both infliximab and MTX had lower levels of anti-infliximab Abs (P = 0.073) and longer survival (P = 0.015) on treatment. CONCLUSION The formation of anti-infliximab Abs during treatment with infliximab is associated with a loss of clinical response, the appearance of infusion reactions and discontinuation of treatment.

Comprehensive Description of Clinical Characteristics of a Large Systemic Lupus Erythematosus Cohort from the Spanish Rheumatology Society Lupus Registry (RELESSER) With Emphasis on Complete Versus Incomplete Lupus Differences

AbstractSystemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement and pronounced racial and ethnic heterogeneity. The aims of the present work were (1) to describe the cumulative clinical characteristics of those patients included in the Spanish Rheumatology Society SLE Registry (RELESSER), focusing on the differences between patients who fulfilled the 1997 ACR-SLE criteria versus those with less than 4 criteria (hereafter designated as incomplete SLE (iSLE)) and (2) to compare SLE patient characteristics with those documented in other multicentric SLE registries.RELESSER is a multicenter hospital-based registry, with a collection of data from a large, representative sample of adult patients with SLE (1997 ACR criteria) seen at Spanish rheumatology departments. The registry includes demographic data, comprehensive descriptions of clinical manifestations, as well as information about disease activity and severity, cumulative damage, comorbidities, treatments and mortality, using variables with highly standardized definitions.A total of 4.024 SLE patients (91% with ≥4 ACR criteria) were included. Ninety percent were women with a mean age at diagnosis of 35.4 years and a median duration of disease of 11.0 years. As expected, most SLE manifestations were more frequent in SLE patients than in iSLE ones and every one of the ACR criteria was also associated with SLE condition; this was particularly true of malar rash, oral ulcers and renal disorder. The analysis—adjusted by gender, age at diagnosis, and disease duration—revealed that higher disease activity, damage and SLE severity index are associated with SLE [OR: 1.14; 95% CI: 1.08–1.20 (P < 0.001); 1.29; 95% CI: 1.15–1.44 (P < 0.001); and 2.10; 95% CI: 1.83–2.42 (P < 0.001), respectively]. These results support the hypothesis that iSLE behaves as a relative stable and mild disease. SLE patients from the RELESSER register do not appear to differ substantially from other Caucasian populations and although activity [median SELENA-SLEDA: 2 (IQ: 0–4)], damage [median SLICC/ACR/DI: 1 (IQ: 0–2)], and severity [median KATZ index: 2 (IQ: 1–3)] scores were low, 1 of every 4 deaths was due to SLE activity.RELESSER represents the largest European SLE registry established to date, providing comprehensive, reliable and updated information on SLE in the southern European population.

Comparing Tapering Strategy to Standard Dosing Regimen of Tumor Necrosis Factor Inhibitors in Patients with Spondyloarthritis in Low Disease Activity

Objective. To compare clinical outcomes, incidence of flares, and administered drug reduction between patients with spondyloarthritis (SpA) under TNF inhibitor (TNFi) tapering strategy with patients receiving a standard regimen. Methods. In this retrospective study, 74 patients with SpA from Spain on tapering strategy (tapering group; TG) were compared with 43 patients from the Netherlands receiving a standard regimen (control group; CG). The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was measured at visit 0 (prior to starting the TNFi), visit 1 (prior to starting tapering strategy in TG and at least 6 months with BASDAI < 4 after starting the TNFi in the TG and CG), visit 2 (6 mos after visit 1), visit 3 (1 year after visit 1), and visit 4 (the last visit available after visit 1). Results. An overall reduction of the administered drug was seen at visit 4 in the TG [dose reduction of 22% for infliximab (IFX) and an interval elongation of 28.7% for IFX, 45.2% for adalimumab, and 51.5% for etanercept] without significant differences in the BASDAI between the groups at visit 4 (2.15 ± 1.55 in TG vs 2.11 ± 1.31 in CG, p = 0.883). The number of patients with flares was similar in both groups [22/74 (30%) in the TG vs 8/43 (19%) in the CG, p = 0.184]. Conclusion. The tapering strategy in SpA results in an important reduction of the drug administered, and the disease control remains similar to that of the patients with SpA receiving the standard regimen.

Incidence, associated factors and clinical impact of severe infections in a large, multicentric cohort of patients with systemic lupus erythematosus

OBJECTIVES To estimate the incidence of severe infection and investigate the associated factors and clinical impact in a large systemic lupus erythematosus (SLE) retrospective cohort. METHODS All patients in the Spanish Rheumatology Society Lupus Registry (RELESSER) who meet ≥4 ACR-97 SLE criteria were retrospectively investigated for severe infections. Patients with and without infections were compared in terms of SLE severity, damage, comorbidities, and demographic characteristics. A multivariable Cox regression model was built to calculate hazard ratios (HRs) for the first infection. RESULTS A total of 3658 SLE patients were included: 90% female, median age 32.9 years (DQ 9.7), and mean follow-up (months) 120.2 (±87.6). A total of 705 (19.3%) patients suffered ≥1 severe infection. Total severe infections recorded in these patients numbered 1227. The incidence rate was 29.2 (95% CI: 27.6-30.9) infections per 1000 patient years. Time from first infection to second infection was significantly shorter than time from diagnosis to first infection (p < 0.000). Although respiratory infections were the most common (35.5%), bloodstream infections were the most frequent cause of mortality by infection (42.0%). In the Cox regression analysis, the following were all associated with infection: age at diagnosis (HR = 1.016, 95% CI: 1.009-1.023), Latin-American (Amerindian-Mestizo) ethnicity (HR = 2.151, 95% CI: 1.539-3.005), corticosteroids (≥10mg/day) (HR = 1.271, 95% CI: 1.034-1.561), immunosuppressors (HR = 1.348, 95% CI: 1.079-1.684), hospitalization by SLE (HR = 2.567, 95% CI: 1.905-3.459), Katz severity index (HR = 1.160, 95% CI: 1.105-1.217), SLICC/ACR damage index (HR = 1.069, 95% CI: 1.031-1.108), and smoking (HR = 1.332, 95% CI: 1.121-1.583). Duration of antimalarial use (months) proved protective (HR = 0.998, 95% CI: 0.997-0.999). CONCLUSIONS Severe infection constitutes a predictor of poor prognosis in SLE patients, is more common in Latin-Americans and is associated with age, previous infection, and smoking. Antimalarials exerted a protective effect.

AB0573 The immunogenicity of biological therapies correlates with clinical efficacy in psoriatic arthritis (psa) in long-term treatment with infliximab and adalimumab.

Background In psoriatic arthritis (PsA) with peripheral involvement classical DMARDs refractory, the anti-TNF therapy has proven to be effective. In recent years, there are some publications that demostrate the correlation between clinical activity and the anti-drug antibodies (ADA) development in rheumatic diseases such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). To date, there is no studies that reveals theses findings in PsA patients treated with infliximab (Ifx) and adalimumab (Ada). Objectives To evaluate in PsA patients treated with Ifx and Ada wether the development of ADA correlate with clinical activity and biological treatment discontinuation. Methods We studied 37 patients with PsA treated with Ifx and Ada from La Paz University Hospital. Clinical activity was assessed using the Disease Activity Score 28 (DAS28), clinical improvement by the delta-DAS28 and treatment response by EULAR criteria at baseline, at 6 months, at 1 year and at > 2nd years of treatment. Ifx and Ada were administred at standard therapeutic schedule. Serum drug and ADA levels were measured by ELISA. Statistical analysis was performed using SPSS 11.0. Results Of the total of patients, 24/37 (64.9%) were treated with Ifx and 13/37 (35.1%) with Ada, being female 23 (62.1%). The mean age was 55.1 ± 12.3 years and the mean disease duration was 14.4 ± 9.9 years. The average time on biological therapy was 4.4 ± 3.2 years. Most patients received concomitantly classical DMARDs [29/37 (78.3%) with DMARDs vs 8/37 (21.7%) in monotherapy]. At baseline, clinical activity (DAS28) was higher in patients who subsequently not developed ADA (5.1 ± 0.9 without ADA vs 13.4 ± 0.6 with ADA, p = 0.021). Clinical activity (DAS28) tended to be higher in patients with ADA at all studied time points (5.4 ± 1.2 with ADA vs 2.8 ± 1.3 without ADA at 6 months, p = 0.007; 4.0 ± 1.2 with ADA vs 3.0 ± 1.3 without ADA at 1 year, p = 0.144; 2.9 ± 1.3 with ADA vs 2.4 ± 0.4 without ADA a> 2nd year, p = 0.169). Clinical improvement (delta-DAS28) was lower in patients with ADA throughout the study (-1.0 ± 1.6 with ADA vs 2.0 ± 1.4 without ADA at 6 months, p = 0.006, 0.3 ± 1.8 with ADA vs 2.1 ± 1.5 without ADA at 1 year, p = 0.052; 0.9 ± 1.5 with ADA vs 2.7 ± 0.8 without ADA a> 2nd year, p = 0.007). Patients without ADA were classified as responders more frequently based on criteria EULAR [2/5 (40%) with ADA vs. 27/30 (90%) without ADA, p = 0.006]. The median time to drug discontinuation was lower in patients with ADA (4.83 ± 1.6 years with ADA vs 7.93 ± 1.4 years without ADA, p = 0.061). The dose increase was more frequent in patients with ADA [3/6 (50%) with ADA vs 4/31 (12.9%) without ADA, p = 0.053], and in contrast, in patients without ADA was more often performed dose decrease of anti-TNF therapy [0/6 (0%) with ADA vs 15/31 (48.3%) without ADA, p = 0.053]. Conclusions The development of ADA correlates with poorer clinical response and more frequent treatment discontinuation in PsA patients in long-term treatment with Ifx and Ada. Disclosure of Interest None Declared

Abatacept in patients with rheumatoid arthritis and interstitial lung disease: A national multicenter study of 63 patients

OBJECTIVE Interstitial lung disease (ILD) is one of the most serious complications of rheumatoid arthritis (RA). In the present study, we aimed to assess the efficacy of abatacept (ABA) in patients with ILD associated to RA. METHODS National multicenter, non-controlled, open-label registry study of RA patients with ILD treated with ABA. RESULTS 63 patients (36 women) with RA-associated ILD undergoing ABA therapy were studied. The mean ± standard deviation age at the time of the study was 63.2 ± 9.8 years. The median duration of RA and ILD from diagnosis were 6.8 and 1 year, respectively. RA was seropositive in 55 patients (87.3%). In 15 (23.8%) of 63 patients the development of ILD was closely related to the administration of synthetic or biologic disease modifying anti-rheumatic drugs. After a follow-up of 9.4 ± 3.2 months, two-thirds of patients remained stable whereas one-quarter experienced improvement in the Modified Medical Research Council scale. At that time forced vital capacity remained stable in almost two-thirds of patents and improved in one out of five patients assessed. Also, diffusing capacity of the lung for carbon monoxide remained stable in almost two-thirds and showed improvement in a quarter of the patients assessed. At 12 months, 50% of the 22 patients in whom chest HRCT scan was performed due persistence of respiratory symptoms showed stabilization, 8 (36.4%) improvement and 3 worsening of the HRCT scan pattern. Eleven of 63 patients had to discontinue ABA, mainly due to adverse events. CONCLUSION ABA appears to be an effective in RA-associated ILD.

Dose-Tapering Of TNF Inhibitors in Daily Rheumatology Practice Enables the Maintenance of Clinical Efficacy While Improving Cost-Effectiveness

Background The fact that biologics consume a growing portion of health care budget has resulted in an increased attention towards therapy optimization. One of the potential ways to optimize treatment is the down-titration of the administered drug dose. Objective To assess whether the clinical activity remains stable after dose tapering of TNF inhibitors in patients with low disease activity and to evaluate the potential benefit of this strategy on the treatment costs. Method A cohort of 77 patients with low disease activity treated with TNF inhibitors (TNFi) was monitored. The patients were studied over two time periods: in the 1st period with the drug standard dose, and in the 2nd period with a reduced dose. Clinical efficacy was monitored by DAS28 in rheumatoid arthritis (RA) and by BASDAI in spondyloarthritis (SpA). Serum drug and anti-drug antibody levels were measured by ELISA. The amount of drug dispensed per patient in both periods was compared. Results In the 2nd period, although patients received a lower amount of TNF inhibitor, no differences in clinical activity were observed (DAS28 in RA patients: 2.37 ± 0.50 in the 2nd P vs 2.28 ± 0.47 in the 1st P, p=0.20; BASDAI in SpA patients: 1.90 ± 0.93 in the 2nd P vs 1.88 ± 0.95 in the 1st P, p=0.910) and circulating serum trough drug levels were lower (Infliximab: 3.2 ± 2.5 μg/ml in the 1st P vs 1.8 ± 1.5 μg/ml in the 2nd P, p<0.0001; Adalimumab: 5.5 ± 2.8 μg/ml in the 1st P vs 3.1 ± 2.1 μg/ml in the 2nd P, p<0.0001; Etanercept: 1.8 ± 1.1 μg/ml in the 1st P vs 1.3 ± 0.8 μg/ml in the 2nd P p<0.05). The amount of administered drug per patient was reduced in an average of 20% per year. Conclusion Dose tapering can be successfully performed in patients with low disease activity, resulting in remarkable savings in the amount of drug used and in the associated costs.

SAT0331 Effect of Methotrexate on the Immnunogenicity of TNF Inhibitors in Spondyloartrhitis Patients

Background The spondyloarthritis (SpA) patients treated under TNF inhibitors (TNFi) with detectable antidrug antibodies (ADA) often develop loss of efficacy. Concomitant therapy with methotrexate (MTX) appears to reduce the the immunogenicity of biological drugs. Objectives To analyze if the use of combined therapy with MTX and TNFi can reduce the incidence of ADA and whether its effect is MTX dose dependent in SpA patients. Methods In this retrospective observational study, 162 SpA patients (including ankylosing spondylitis, Psoriatic SpA, SpA associated with inflammatory bowel disease and undifferentiated SpA) were included. The patients are treated with infliximab (Ifx) or adalimumab (Ada). The presence of ADA were measured at baseline and before each administration by ELISA to complete a follow up of 3 years. The patients were divided in two groups [MTX-15 (dose <15 mg/week) and MTX+15 (≥15 mg/week)] to study the influence of baseline MTX dose on immunogenicity. The statistical analysis was performed using SPSS 11.0. Results Eighty nine out of 162 (54,9%) patients were male. Eighty five out of 162 (52,5%) patients received Ifx and 77 out of 162 (47,5%) Ada. The mean duration of treatment was 13.38±9.19 years to Ifx and 12.71±10.46 years for Ada. Forty five patients received MTX weekly at baseline [25/85 (29.4%)in Ifx and 20/77 (26%)in Ada]. The mean dose of MTX was 15,9±4.76 mg/week. Twenty nine out of 162 (17,9%) patients developed ADA, and ADA presence was significantly higher in SpA patients on Ifx therapy [21/85 (24.7%) in Ifx vs 8/77 (10.4%) in Ada, p=0.018)]. The presence of ADA was less frequent in SpA patients taking MTX [3/162 (1.8%) with MTX vs 26/162 (16%) without MTX, p=0.021]. No statistically differences were observed in the influence of baseline MTX dose on the ADA appearance (in Ifx: 2/18 (11,1%) in MTX+15 vs 1/9 (11,1%)in MTX-15, p=1,0; in Ada: 1/17 (5,9%) in MTX+15 vs 0/4 (0,0%)in MTX-15, p=1,0). Conclusions In this cohort of SpA patients treated with Ifx and Ada, the use of MTX has a preventive effect on the ADA development. However, the baseline MTX dose is not a determinant factor to get this effect. Further prospective studies are needed to confirm these data. Disclosure of Interest A. Villalba Yllan: None declared, C. Plasencia Grant/research support: Pfizer, D. Pascual-Salcedo Grant/research support: Pfizer, Speakers bureau: Pfizer, D. Peiteado: None declared, L. Nuño: None declared, G. Bonilla: None declared, R. del Moral: None declared, A. Balsa Grant/research support: Pfizer, Speakers bureau: Pfizer, Roche, Abbvie, E. Martin Mola Speakers bureau: Pfizer, Roche, Abbvie, Amgen DOI 10.1136/annrheumdis-2014-eular.5819

FRI0168 Effect of Methotrexate in The Presence of Drug and The Appearance of Antibodies against TNF Inhibitors in Patients with Rheumatoid Arthritis

Background Several factors influence pharmacokinetics of TNFinhibitors (TNFi). One relevant factor is the formation of anti drug- antibodies (ADA) associated with low drug levels and a worse clinical response. Recent publications in rheumatoid arthritis (RA) 1,2 have demonstrated a beneficial effect of concomitant use of anti-TNF drugs and methotrexate (MTX), with a dose-dependent effect. Objectives To analyze the MTX influence on the presence of drug and appearance of ADA in a cohort of RA patients treated with Infliximab (Ifx), Adalimumab (Ada) or Etanercept (Etn) with a long follow-up (3 years). Methods This is a retrospective study that analyzed patients with RA treated with Ifx (112 patients), Ada (71 patients) and Etn (110 patients), in a prospective observational biological cohort from the University Hospital La Paz, Madrid, Spain. Patients were grouped according to the use of MTX: no MTX, low dose (≤12.5 mg/week), intermediate dose (12.5–20 mg/week) and high dose (≥20 mg/week). Levels of drug and ADA were measured by capture and bridging ELISA respectively at baseline, 0.5, 1, 2 and 3 years. All samples were obtained just before drug administration. Statistical analysis was performed using GraphPad Prism 5.0 software. Results Out of 293 RA patients with a TNFi treatment; 184 (71 with Ifx, 40 with Ada and 73 with Etn) were included. In this cohort, 111 (61%) were on MTX and 72 (39%) were on monotherapy. Most patients with high dose of MTX had levels of drug over 3 years of treatment (93% with MTX ≥20 mg/week vs 77% without MTX; p=0.01) being significant since 0.5 years (≥60% with MTX 20 mg/week vs 39% without MTX; p=0.02) To analyze the ADA development, patients treated with Ifx and Ada were grouped and we observed a trend to a higher percentage of ADA in the group which did not receive MTX (n=37) compared to those who received high-dose MTX (n=27) although not statistically significant (32% vs 19%, p=0.21). Analysing by separate drugs MTX significantly reduced the immunogenicity of Ada, (53% in patients with MTX vs 15% in monotherapy; p=0.02). When we study the lack of circulating drug (Ifx, Ada and Etn) as an indicator of immunogenicity, patients who did not receive MTX (n=56) had higher absence of drug than patients with high-dose MTX (n=61) (34% vs 10%, respectively; p<0.01). This effect was significant since 0.5 years of treatment (16% MTX ≥20 mg/week vs 3% without MTX; p=0.017) Conclusions In our cohort of RA patients the concomitant use of MTX has a positive effect in the persistence of TNFi levels together with a decrease of immunogenicity. Furthermore, the MTX has a dose-dependent effect being greater at high dose of MTX. References Krickaert C et al.ARD 2012; 71:11. Vogelzang E H et al.ARD 2015; 74:2 Acknowledgement This work is partially funded by a non restricted grant from Pfizer Disclosure of Interest None declared

Complex Situations in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease involving large and small joints resulting in pain, joint destruction, and disability. The disease course of RA is unpredictable with some patients having only mild symptoms while others may experience persistent and acute synovitis leading to severe joint destruction. However, being a systemic disease, it can affect other tissues and organs, causing a wide range of symptoms and complications that although usually not life threatening are the cause of significant morbidity. Knowledge of articular or extra-articular complications may aid in promoting a high index of suspicion and contribute significantly to an early diagnosis and avoid many potentially dangerous conditions.