Clinically relevant dosing and pharmacokinetics of DNA-encoded antibody therapeutics in a sheep model.

DNA-encoded delivery and expression of antibody therapeutics presents an innovative alternative to conventional protein production and administration, including for cancer treatment. To support clinical translation, we evaluated this approach in 18 40-45 kg sheep, using a clinical-matched intramuscular electroporation (IM EP) and hyaluronidase-plasmid DNA (pDNA) coformulation setup. Two cohorts of eight sheep received either 1 or 4 mg pDNA encoding an ovine anti-cancer embryonic antigen (CEA) monoclonal antibody (mAb; OVAC).

Real-world Endoscopic and Histological Outcomes Are Correlated with Ustekinumab Exposure in Patients with Ulcerative Colitis.

Background: Histo-endoscopic outcomes are being proposed as new treatment targets in ulcerative colitis [UC]. Little is known about the pharmacokinetic-pharmacodynnamic [PK-PD] relationship of ustekinumab [UST] in UC patients or whether serum UST concentrations reflect tissue drug exposure. We aimed to study UST serum concentrations and their relation to tissue exposure and drug effectiveness in a real-world setting.

Endoscopic remission can be predicted by golimumab concentrations in patients with ulcerative colitis treated with the changed label.

Background: In 2018, the European Medicines Agency (EMA) replaced a fixed 50 mg every 4-week maintenance regimen of golimumab for ulcerative colitis (UC) patients weighing <80 kg with new, flexible dosing that allows reactive dose optimization to 100 mg if clinically needed. We analyzed the endoscopic remission rates and pharmacokinetics of this new dosing regimen in real-life settings.

Methods: We prospectively recruited 30 consecutive (17 with body weight <80 kg) patients with UC who received golimumab with the new EMA label.

Anti-infliximab antibodies: How to compare old and new data?

Background: Anti-drug-antibodies (ADA) against infliximab are frequently measured in patients receiving infliximab treatment with loss of response and undetectable infliximab concentrations. Different ADA bridging assays (1st generation, 2nd generation and ready-to-use kit) have been developed successively and were applied over the last 10 years, making comparison between ADA concentrations very challenging. A cutoff of 8 μg/ml was established to discriminate low from high ADA concentrations using the 1st generation ADA bridging assay.

Evaluating Efficacy, Safety, and Pharmacokinetics After Switching From Infliximab Originator to Biosimilar CT-P13: Experience From a Large Tertiary Referral Center.

Background: The use of infliximab biosimilar CT-P13 has increased in patients with inflammatory bowel disease. Nevertheless, doubts about switching from infliximab originator to biosimilar still exist among patients and health care professionals.

Methods: Our tertiary referral center underwent a mandatory switch from infliximab originator to CT-P13 in 2017.

Early vedolizumab trough levels predict combined endoscopic and clinical remission in inflammatory bowel disease.

Background: The relationship between vedolizumab trough levels and combined endoscopic and clinical remission is unknown.

Objective: To compare vedolizumab trough levels in patients with and without combined remission within the first year of treatment.

Methods: We prospectively collected vedolizumab trough levels in 51 consecutive patients (28 Crohn's disease (CD) and 23 ulcerative colitis (UC)) before all infusions up to week 22, and at weeks 38 and 54, with concentrations measured after study completion.

Subcutaneous Absorption Contributes to Observed Interindividual Variability in Adalimumab Serum Concentrations in Crohn's Disease: A Prospective Multicentre Study.

Background And Aim: Therapeutic drug monitoring is used to optimise adalimumab therapy in patients with Crohn's disease [CD]. However, the interindividual variability in drug absorption and the quantitative effect on drug clearance of anti-adalimumab antibodies [AAA], measured with a drug-resistant assay, are unclear. We aimed to characterise adalimumab population pharmacokinetics [PopPK] and identify determinants of interindividual variability in patients with CD.

Ustekinumab Exposure-outcome Analysis in Crohn's Disease Only in Part Explains Limited Endoscopic Remission Rates.

Background And Aims: Ustekinumab, an anti-IL12/23p40 monoclonal antibody, has been approved for Crohn's disease [CD]. Real-life data in CD patients receiving ustekinumab intravenously [IV] during induction, followed by subcutaneous [SC] maintenance, are lacking. We assessed efficacy of ustekinumab and studied exposure-response correlations.

Evidence to Support Monitoring of Vedolizumab Trough Concentrations in Patients With Inflammatory Bowel Diseases.

Background & Aims: Trough concentrations of vedolizumab were found to correlate with clinical response in phase 3 studies of patients with ulcerative colitis (UC) or Crohn's disease (CD). Nevertheless, there are no solid data to support monitoring of vedolizumab trough concentrations in treated patients. We investigated the correlation between vedolizumab exposure and response in a real-world population and aimed to identify patient factors that affect exposure and response.

Antibodies Toward Vedolizumab Appear from the First Infusion Onward and Disappear Over Time.

Background: Vedolizumab (VDZ) has been approved for the treatment of patients with moderate-to-severe Crohn's disease and ulcerative colitis. The GEMINI trials reported a low prevalence of anti-VDZ antibodies (AVA). However, the AVA assays used in GEMINI were drug sensitive, resulting in a possible underestimation of the rate of AVA formation.

Prediction and Reduction of the Aggregation of Monoclonal Antibodies.

Protein aggregation remains a major area of focus in the production of monoclonal antibodies. Improving the intrinsic properties of antibodies can improve manufacturability, attrition rates, safety, formulation, titers, immunogenicity, and solubility. Here, we explore the potential of predicting and reducing the aggregation propensity of monoclonal antibodies, based on the identification of aggregation-prone regions and their contribution to the thermodynamic stability of the protein.

Bioassay Development for Ultrasensitive Detection of Influenza A Nucleoprotein Using Digital ELISA.

Flu is caused by the influenza virus that, due to mutations, keeps our body vulnerable for infections, making early diagnosis essential. Although immuno-based diagnostic tests are available, they have low sensitivity and reproducibility. In this paper, the prospect of detecting influenza A virus using digital ELISA has been studied.

Generation and characterization of a unique panel of anti-adalimumab specific antibodies and their application in therapeutic drug monitoring assays.

A number of assays are currently available to support therapeutic drug monitoring of adalimumab. A complete characterization of the assays and comparison of different assays has not been performed. The aim of this study, therefore, is to generate and characterize of a panel of monoclonal antibodies towards adalimumab (MA-ADM); to use this panel to develop novel assays to determine adalimumab concentrations; to assess the impact of tumor necrosis factor (TNF) and (non-)neutralizing antibodies on adalimumab detection and to compare the performance of assays.

An Optimized Anti-infliximab Bridging Enzyme-linked Immunosorbent Assay for Harmonization of Anti-infliximab Antibody Titers in Patients with Inflammatory Bowel Diseases.

Background: The formation of anti-infliximab antibodies (ATI) is associated with loss of response and adverse events in patients with inflammatory bowel diseases, leading to the introduction of ATI monitoring for guiding treatment adjustments. However, a lack of standardization among current available assays exists, hampering comparison of results from different studies. This study aimed to improve the harmonization of clinically validated ATI enzyme-linked immunosorbent assays (ELISAs) by introducing a monoclonal anti-infliximab antibody (MA-IFX).

Trough concentrations of infliximab guide dosing for patients with inflammatory bowel disease.

Background & Aims: Infliximab, a tumor necrosis factor antagonist, is effective for treating patients with Crohn's disease (CD) and ulcerative colitis (UC). We aimed to determine whether dosing based on therapeutic drug monitoring increases rate of remission and whether continued concentration-based dosing is superior to clinically based dosing of infliximab for maintaining remission in patients with CD and UC.

Methods: We performed a 1-year randomized controlled trial at a tertiary referral center, including 263 adults (178 with CD and 85 with UC) with stable responses to maintenance infliximab therapy.

Withdrawal of immunomodulators after co-treatment does not reduce trough level of infliximab in patients with Crohn's disease.

Background & Aims: The addition of immunomodulators increases the efficacy of maintenance therapy with infliximab for up to 1 year in patients with Crohn's disease who have not been previously treated with immunomodulators. However, there are questions about the effect of withdrawing immunomodulator therapy from these patients. We studied the effects of treatment with infliximab and immunomodulators (co-treatment) and then immunomodulator withdrawal on long-term outcomes of patients, as well as trough levels of infliximab and formation of anti-infliximab antibodies (ATI).

Development of a universal anti-adalimumab antibody standard for interlaboratory harmonization.

Background: Therapeutic drug monitoring of adalimumab (ADM) has been introduced recently. When no detectable ADM serum concentrations can be found, the formation of antidrug antibodies (ADA) should be investigated. A variety of assays to measure the occurrence of ADA have been developed.

Maximal PAI-1 inhibition in vivo requires neutralizing antibodies that recognize and inhibit glycosylated PAI-1.

Plasminogen activator inhibitor-1 (PAI-1) regulates the activity of t-PA and u-PA and is an important inhibitor of the plasminogen activator system. Elevated PAI-1 levels have been implicated in the pathogenesis of several diseases. Prior to the evaluation of PAI-1 inhibitors in humans, there is a strong need to study the effect of PAI-1 inhibition in mouse models.

Subtle structural differences between human and mouse PAI-1 reveal the basis for biochemical differences.

Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor (serpin) that plays an important role in cardiovascular disorders and tumor development. The potential role of PAI-1 as a drug target has been evaluated in various animal models (e.g.

Biochemical importance of glycosylation in thrombin activatable fibrinolysis inhibitor.

Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa) exerts an antifibrinolytic effect by removing C-terminal lysines from partially degraded fibrin. These lysines are essential for a rapid conversion of plasminogen to plasmin by tissue type plasminogen activator. TAFI is heavily glycosylated at Asn22, Asn51, Asn63, and Asn86.

Site-directed targeting of plasminogen activator inhibitor-1 as an example for a novel approach in rational drug design.

As plasminogen activator inhibitor-1 (PAI-1), the physiological inhibitor of tissue-type plasminogen activator, is considered to be an important risk factor in several (patho)physiological conditions, many research activities focus on attempts to inhibit this serpin. The approach illustrated in the current study focuses on elucidating important interaction sites allowing the inhibition of PAI-1. Since monoclonal antibodies are in most cases not ideal for therapeutic use, the question of whether smaller molecules exert comparable effects is a hot issue.

Elucidation of the epitope of a latency-inducing antibody: identification of a new molecular target for PAI-1 inhibition.

The monoclonal antibody MA-33B8, directed against the serpin plasminogen activator inhibitor-1 (PAI-1), has unique functional properties as it induces acceleration of the active-to-latent transition (Verhamme I et al. J Biol Chem 274: 17511-7, 1999), resulting in PAI-1 activity neutralization. In this study, we have identified Lys(88), Asp(89), Lys(176) and His(229) as the major residues of the conformational epitope.