Pharmacogenetic analysis of canonical versus noncanonical pathway of NF-kB in Crohn's disease patients under anti-tumor necrosis factor-α treatment.

OBJECTIVES: This study explores the potential of gene polymorphisms in the canonical and noncanonical NF-kB signaling pathway as a prediction biomarker of anti-tumor necrosis factor (TNF)α response in Crohn's patients. MATERIALS AND METHODS: A total of 109 Greek patients with Crohn's disease (CD) were recruited, and the genotype of TLR2 rs3804099, LTA rs909253, TLR4 rs5030728, and MAP3K14/NIK rs7222094 single nucleotide polymorphisms was investigated for association with response to anti-TNFα therapy. Patient's response to therapy was based on the Crohn's Disease Activity Index, depicting the maximum response within 24 months after initiation of treatment. RESULTS: Seventy-three patients (66.7%) were classified as responders while 36 as nonresponders (33.3%). Comparing allelic frequencies between responders and nonresponders, the presence of TLR2 rs3804099 T allele was associated with nonresponse (P = 0.003), even after stratification by anti-TNFα drugs (infliximab: P = 0.032, adalimumab: P = 0.026). No other association was identified for the rest of the polymorphisms under study. Haplotype analysis further enhanced the association of rs3804099 T allele with loss of response, even though the results were NS (P = 0.073). CONCLUSION: Our results suggest that polymorphisms in the canonical NF-kB pathway genes could potentially act as a predictive biomarker of anti-TNFα response in CD.

Network-based response module comprised of gene expression biomarkers predicts response to infliximab at treatment initiation in ulcerative colitis.

This cross-cohort study aimed to (1) determine a network-based molecular signature that predicts the likelihood of inadequate response to the tumor necrosis factor-ɑ inhibitor (TNFi) therapy, infliximab, in ulcerative colitis (UC) patients, and (2) address biomarker irreproducibility across different cohort studies. Whole-transcriptome microarray data were derived from biopsies of affected colon tissue from 2 cohorts of infliximab-treated UC patients (training N = 24 and validation N = 22). Response was defined as endoscopic and histologic healing at 4-6 weeks and 8 weeks, respectively. From the training cohort, genes with RNA expression that significantly correlated with clinical response outcomes were mapped onto the Human Interactome network map of protein-protein interactions to identify a largest connected component (LCC) of proteins indicative of infliximab response status in UC. Expression levels of transcripts within the LCC were fed into a probabilistic neural network model to generate a classifier that predicts inadequate response to infliximab. A classifier predictive of inadequate response to infliximab was generated and tested in a cross-cohort, blinded fashion; the AUC was 0.83 and inadequate response was predicted with a 100% positive predictive value and 64% sensitivity. Genes separately identified from the 2 cohorts that correlated with response to infliximab appeared distinct but mapped onto the same network region of the Human Interactome, reflecting a common underlying biology of response among UC patients. Cross-cohort validation of a classifier predictive of infliximab response status in UC patients indicates that a molecular signature of non-response to TNFi therapies is present in patients' baseline gene expression data. The goal is to develop a diagnostic test that predicts which patients will have an inadequate response to targeted therapies and define new targets and pathways for therapeutic development.

[Development and Optimization of Therapeutic Analogues of Anti-TNFα Antibody Infliximab].

Previously, we have reported the crystal structures of Fab fragment of Infliximab in complex with TNFα. The structurally identified epitope on TNFα revealed the mechanism of TNFα inhibition by partially overlapping with the TNFα-receptor interface and the possibility to optimize the binding affinity. In this study, we launched a screen of a phage display library to isolate novel anti-TNFα antibodies based on the infliximab epitope. To develop novel anti-TNFα antibodies, structural analysis, the phage display antibody isolation, step by step antibody optimization, CDR residues random mutagenesis, and binding affinity characterization were performed. One of the novel antibodies generated on the backbone of infliximab, Inf3D6, has the superior binding affinity to TNFα, thus, demonstrating the potential for structure guided optimization for improvement of existing antibody-based therapeutics.

Stable expression of infliximab in CRISPR/Cas9-mediated BAK1-deficient CHO cells.

OBJECTIVES: To establish stable infliximab-expressing Chinese hamster ovary (CHO) cells with high tolerance to serum-free culture. RESULTS: Bcl-2 antagonist/killer 1 (BAK1), which is a key mediator of the apoptosis pathway, was disrupted, and infliximab, which is a broadly used monoclonal antibody for the treatment of rheumatoid arthritis and other autoimmune diseases, was incorporated into the BAK1 locus of the CHO chromosome using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas genome-editing technique. The activating effects of serum starvation on BAK1 and cytochrome C (CytC) were suppressed in the genome-edited cells, and the ability of the cells to resist the serum starvation-induced loss of mitochondrial membrane potential and apoptosis was increased, as indicated by the results of polymerase chain reaction (PCR), flow cytometry, enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) analysis. In addition, during subsequent passages, infliximab could be stably produced in the genome-edited CHO cells, and the recombinant antibody could effectively antagonize the cytotoxic effect of tumor necrosis factor α (TNFα). CONCLUSIONS: A CHO cell line capable of stably expressing infliximab and adapting to serum-free culture was constructed. This work lays the foundation for the development of infliximab biosimilars.

Molecular mechanisms of action of anti-TNF-α agents - Comparison among therapeutic TNF-α antagonists.

Tumor necrosis factor (TNF)-α is a potent pro-inflammatory and pathological cytokines in inflammatory diseases such as rheumatoid arthritis and inflammatory bowel diseases. Anti-TNF-α therapy has been established as an efficacious therapeutic strategy in these diseases. In clinical settings, three monoclonal anti-TNF-α full IgG1 antibodies infliximab, adalimumab, and golimumab, PEGylated Fab' fragment of anti-TNF-α antibody certolizumab pegol, extracellular domain of TNF receptor 2/IgG1-Fc fusion protein etanercept, are almost equally effective for rheumatoid arthritis. Although monoclonal full IgG1 antibodies are able to induce clinical and endoscopic remission in inflammatory bowel diseases, certolizumab pegol without Fc portion has been shown to be less effective for inflammatory bowel diseases compared to full IgG1 antibodies. In addition, there are no evidences that etanercept leads clinical remission in inflammatory bowel diseases. Besides the common effect of anti-TNF-α agents on neutralization of soluble TNF-α, each anti-TNF-α agent has its own distinctive pharmacological properties which cause the difference in clinical efficacies. Here we focus on the distinctions of action of anti-TNF-α agents especially in following points; (1) blocking ability against ligands, transmembrane TNF-α and lymphotoxin, (2) effects toward transmembrane TNF-α-expressing cells, (3) effects toward Fcγ receptor-expressing cells, (4) degradation and distribution in inflamed tissue. Accumulating evidence will give us the idea how to modify anti-TNF-α agents to enhance the clinical efficacy in inflammatory diseases.

Rheumatoid arthritis response to treatment across IgG1 allotype - anti-TNF incompatibility: a case-only study.

INTRODUCTION: We have hypothesized that incompatibility between the G1m genotype of the patient and the G1m1 and G1m17 allotypes carried by infliximab (INX) and adalimumab (ADM) could decrease the efficacy of these anti-tumor necrosis factor (anti-TNF) antibodies in the treatment of rheumatoid arthritis (RA). METHODS: The G1m genotypes were analyzed in three collections of patients with RA totaling 1037 subjects. The first, used for discovery, comprised 215 Spanish patients. The second and third were successively used for replication. They included 429 British and Greek patients and 393 Spanish and British patients, respectively. Two outcomes were considered: change in the Disease Activity Score in 28 joint (ΔDAS28) and the European League Against Rheumatism (EULAR) response criteria. RESULTS: An association between less response to INX and incompatibility of the G1m1,17 allotype was found in the discovery collection at 6 months of treatment (P = 0.03). This association was confirmed in the replications (P = 0.02 and 0.08, respectively) leading to a global association (P = 0.001) that involved a mean difference in ΔDAS28 of 0.4 units between compatible and incompatible patients (2.3 ± 1.5 in compatible patients vs. 1.9 ± 1.5 in incompatible patients) and an increase in responders and decrease in non-responders according to the EULAR criteria (P = 0.03). A similar association was suggested for patients treated with ADM in the discovery collection, but it was not supported by replication. CONCLUSIONS: Our results suggest that G1m1,17 allotypes are associated with response to INX and could aid improved therapeutic targeting in RA.