A pinboard by
Karen Hambardzumyan

PhD student, Karolinska Institutet


We investigated relationship between biological drug concentration, anti-drug antibody and response

Rheumatoid arthritis (RA) is a chronic autoimmune disorder causing inflammation and pain in the joints. It can lead to disability if not treated properly. The use of biological drugs, targeting specific key molecules in the immune system, improved dramatically health care in the rheumatology. However, still a substantial proportion of patients does not respond to these drugs. These biological drugs have very complex structure, which gives them immunogenic properties - patient's immune system recognises the drug molecule as foreign body and produces antibodies against the drug. The produced anti-drug antibodies (ADA) bind and neutralise the drug leading to a loss in drug effectiveness. This is why in some patients, the biological drugs become ineffective in controlling the disease activity. Considering high cost of biological medications, identification of predictors of ADA development and non-response to these drugs would improve effectiveness of both cost and treatment in clinical care of patients with RA.


Formation of antibodies against infliximab and adalimumab strongly correlates with functional drug levels and clinical responses in rheumatoid arthritis.

Abstract: Tumour necrosis factor alpha (TNFalpha) neutralising antibody constructs are increasingly being used to treat rheumatoid arthritis (RA).To determine potential differences in clinical responses, soluble drug levels and antibody formation between patients with RA receiving infliximab and adalimumab.69 patients with RA fulfilling the 1987 American College of Rheumatology criteria and about to start treatment with infliximab or adalimumab, were enrolled consecutively. All patients had active disease (28-joint count Disease Activity Score >3.2). Infliximab was given intravenously at 3 mg/kg at baseline and after 2, 6 and 14 weeks. Adalimumab was administered as 40 mg biweekly subcutaneously. Concomitant drug treatment was monitored and continued at constant dosage during the study. All serum samples were tested for infliximab/adalimumab levels and anti-infliximab/anti-adalimumab antibodies.35 patients received infliximab, 34 received adalimumab. At 6 months, 15 (43%), 6 (17%) and 14 (40%) of the infliximab-treated patients fulfilled the EULAR criteria for good, moderate and non-responders, respectively, whereas the corresponding figures for adalimumab-treated patients were 16 (47%), 8 (24%) and 10 (29%). Clinical responses correlated with the levels of S-infliximab/adalimumab and the formation of anti-infliximab/anti-adalimumab antibodies.The clinical response to two anti-TNFalpha biological agents closely follows the trough drug levels and the presence of antibodies directed against the drugs. Further studies that focus on the underlying pathways leading to antibody formation are warranted to predict immunogenicity of these expensive biological agents and treatment outcomes.

Pub.: 21 Nov '08, Pinned: 29 Jan '18

Double-blinded infliximab dose escalation in patients with rheumatoid arthritis.

Abstract: To determine the efficacy, safety and pharmacokinetics of infliximab dose escalation in patients with rheumatoid arthritis (RA) who had an inadequate response to 3 mg/kg infliximab treatment or whose disease flared after initially responding.Patients with active RA, despite receiving methotrexate, received infliximab 3 mg/kg at weeks 0, 2, 6 and 14 in one of the three arms of the START trial. Beginning at week 22, patients had their infliximab dose increased in a double-blind fashion in increments of 1.5 mg/kg if the total tender and swollen joint count did not improve by at least 20% from baseline (lack of response) or the improvement at week 22 or later worsened by 50% or more (criterion for flare).Of the 329 evaluable patients, 100 (30.4%) patients required dose escalation at or after week 22 because of flare or lack of response. The majority of patients (>80%) who received up to three dose escalations showed >/=20% improvement in the total tender and swollen joint count after their last dose escalation. Patients who required dose escalations generally had lower preinfusion serum infliximab concentrations than those who did not require them. The incidences of adverse events and serious adverse events for the patients who received dose escalation(s) were similar to those of patients who did not receive dose escalation.Fewer than one-third of patients required a dose escalation. The majority of patients showed improvement after receiving increased doses of infliximab, without an increased risk of adverse events.

Pub.: 30 Mar '07, Pinned: 29 Jan '18

Immunogenicity of Biologics in Chronic Inflammatory Diseases: A Systematic Review.

Abstract: A systematic review was conducted to explore the immunogenicity of biologic agents across inflammatory diseases and its potential impact on efficacy/safety.Literature searches were conducted through November 2016 to identify controlled and observational studies of biologics/biosimilars administered for treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), non-radiographic axial spondyloarthritis (nr-axSpA), psoriasis (Ps), Crohn's disease, and ulcerative colitis.Of >21,000 screened publications, 443 were included. Anti-drug antibody (ADAb) rates varied widely among biologics across diseases (and are not directly comparable because of immunoassay heterogeneity); the highest overall rates were reported with infliximab (0-83%), adalimumab (0-54%), and infliximab biosimilar CT-P13 (21-52%), and the lowest with secukinumab (0-1%), ustekinumab (1-11%), etanercept (0-13%), and golimumab (0-19%). Most ADAbs were neutralizing, except those to abatacept and etanercept. ADAb+ versus ADAb- patients had lower rates of clinical response to adalimumab (RA, PsA, JIA, AS, Ps), golimumab (RA), infliximab (RA, PsA, AS, Ps), rituximab (RA), ustekinumab (Ps), and CT-P13 (RA, AS). Higher rates of infusion-related reactions were reported in infliximab- and CT-P13-treated ADAb+ patients. Background immunosuppressives/anti-proliferatives reduced biologic immunogenicity across diseases.Based on reviewed reports, biologic/biosimilar immunogenicity differs among agents, with the highest rates observed with infliximab and adalimumab. As ADAb formation in biologic-/biosimilar-treated patients may increase the risk of lost response, the immunogenicity of these agents is an important (albeit not the only) consideration in the treatment decision-making process.

Pub.: 15 Jun '17, Pinned: 29 Jan '18