Immunology and Biotherapies

SummaryBackground

One-third of patients with Crohn's disease (CD) or ulcerative colitis (UC) receiving anti-TNFs do not respond to treatment, and a relevant proportion experience loss of response or intolerance.

Aim

To investigate the efficacy and safety of a second anti-TNF agent after primary/secondary failure or intolerance to a first drug.

Methods

Inclusion criteria: studies evaluating the efficacy of infliximab (IFX), adalimumab (ADA) and certolizumab-pegol (CZP) as the second anti-TNF in CD or UC. Search strategy: Bibliographical searches (PubMed/Embase). Data synthesis: percentage of response/remission; the meta-analysis was performed using the inverse variance method.

Results

We included 46 studies (37 CD, 8 UC, 1 pouchitis). The CD studies comprised 32 switching IFXADA, 4 IFXCZP and 1 ADAIFX. Overall, the second anti-TNF after the failure of IFX in CD induced remission in 43% and response in 63% of patients. The remission rate was higher when the reason to withdraw the first anti-TNF was intolerance (61%) than after secondary (45%) or primary failure (30%); response rates were, respectively, 72%, 62% and 53%. All UC studies switched IFXADA, six of them reporting remission rates ranging from 0% to 50%. Adverse events rate ranged from 0% to 81% in CD, most of them mild (serious adverse event 0–21%, discontinuation rate <20%).

Conclusions

The efficacy of a second anti-TNF in CD patients largely depends on the cause for switching. The remission rate is higher when the reason to withdraw the first anti-TNF is intolerance (61%), compared with secondary (45%) or primary failure (30%). Further studies of switch ADAIFX are needed to evaluate this strategy. PROSPERO-registry-number: CRD42014012943.

Via Krishan Maggon

Antidrug antibodies against TNF-blocking agents: correlations between disease activity, hypersensitivity reactions, and different classes of immunoglobulins Maurizio Benucci,1 Francesca Li Gobbi,1 Francesca Meacci,2 Mariangela Manfredi,2 Maria Infantino,2 Maurizio Severino,3 Sergio Testi,3 Piercarlo Sarzi-Puttini,4 Cristian Ricci,5 Fabiola Atzeni4 1Rheumatology Unit, 2Immunology and Allergology Laboratory Unit, 3Allergy and Clinical Immunology Unit, Nuovo Ospedale S Giovanni di Dio, Florence, Italy; 4Rheumatology Unit, L Sacco University Hospital, Milan, Italy; 5Department of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany Abstract: Although anti-TNF drugs have changed the clinical course of rheumatoid arthritis (RA), survival rates and resistance-to-therapy data confirm that about 30% of RA patients fail to respond. The aim of this study was to evaluate the correlations between the development of antidrug antibodies, specific IgG4 antibodies against TNF inhibitors, and resistance to therapy in RA patients. This retrospective study involved 129 patients with established RA naïve to biological agents (98 females and 32 males, mean age 56.7±12.3 years, disease duration 6.3±1.2 years, baseline Disease Activity Score [DAS]-28 3.2–5.6) who received treatment with anti-TNF agents after the failure of conventional disease-modifying antirheumatic drugs (32 received infliximab [IFX], 58 etanercept [ETN], and 39 adalimumab [ADA]). After 6 months of treatment, the patients were classified as being in remission (DAS28 <2.6), having low disease activity (LDA; DAS28 2.6–3.2), or not responding (NR: DAS28 >3.2). The patients were also tested for serum antidrug antibodies and IgG4 antibodies against TNF inhibitors. After 24 weeks of treatment, 38% of the ETN-treated patients and 28% of those treated with ADA had injection-site reactions; the rate of systemic reactions in the IFX group was 25%. The differences among the three groups were not statistically significant (P=0.382; ETN versus ADA P=0.319). The percentages of patients with adverse events stratified by drug response were: LDA 8% and NR 18% in the ADA group; in remission 3%, LDA 22%, and NR 10% in the ETN group; and LDA 6% and NR 16% in the IFX group (P=0.051). The percentages of patients with antidrug antibodies were: ADA 33.3%, ETN 11.5%, and IFX 10.3% (P=0.025; ADA versus ETN P=0.015). The percentages of patients with IgG4 antibodies were: ADA 6%, ETN 13%, and IFX 26% (P=0.017; ADA versus ETN P=0.437). Associations between antidrug antibodies, specific IgG4 antibodies, and adverse reactions were not significant for any of the three drugs. IgG4 levels were higher in the ADA group than in the other two groups, and higher in the patients with worse DAS28 (NR) and in those experiencing adverse events. These data suggest a possible association between IgG4 levels and worse DAS28 (r2=5.8%, P=0.011). The presence of specific IgG4 antibodies against TNF blockers in patients with RA might affect the drugs’ activity. Patients with injection-site reactions and IgG4 against ETN may show a decreased response.Keywords: antidrug antibodies, TNF-blocking agents, IgG4 antibodies

Via Krishan Maggon

Abstract

While for a century therapeutics has been dominated by small molecules, i.e. organic chemicals of ~400Da absorbable via the gut, this is no longer the case. There are now a plethora of important medicines which are proteins and injectable, which have dramatically improved the therapy of many inflammatory diseases and of cancer. Most of these are monoclonal antibodies, some are receptor Ig Fc fusion proteins, others are cytokines or enzymes. The key to this new aspect of therapeutics has been the filling of unmet needs, and the consequent commercial success, which promoted further research and development. The first ‘biologic’ for a common disease, rheumatoid arthritis (RA), was a monoclonal antibody, infliximab, to human tumour necrosis factor (TNF). This was based on our work, which is described in this review, summarizing how TNF was defined as a good target in RA, how it was developed is described here, as well as future indications for anti-TNF and related agents. Biologics are now the fastest growing sector of therapeutics.

Via Krishan Maggon

Targeting pro-inflammatory cytokines such as tumour necrosis factor-α (TNF-α) has been an effective therapeutic approach in patients with a variety of autoimmune diseases, including psoriasis, psoriatic arthritis, rheumatoid arthritis, Crohn's disease, ulcerative colitis, and ankylosing spondylitis. New targets along the interleukin-17 (IL-17)–TH17 (T helper cell 17) pathway, 

Via Krishan Maggon