Low immunogenicity of tocilizumab in patients with rheumatoid arthritis.

OBJECTIVE: Subcutaneous (SC) and intravenous formulations of tocilizumab (TCZ) are available for the treatment of patients with rheumatoid arthritis (RA), based on the efficacy and safety observed in clinical trials. Anti-TCZ antibody development and its impact on safety and efficacy were evaluated in adult patients with RA treated with intravenous TCZ (TCZ-IV) or TCZ-SC as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). METHODS: Data from 5 TCZ-SC and 8 TCZ-IV phase III clinical trials and 1 TCZ-IV clinical pharmacology safety study (>50 000 samples) were pooled to assess the immunogenicity profile of TCZ-SC and TCZ-IV (8974 total patients). The analysis included antidrug antibody (ADA) measurement following TCZ-SC or TCZ-IV treatment as monotherapy or in combination with csDMARDs, after dosing interruptions or in TCZ-washout samples, and the correlation of ADAs with clinical response, adverse events or pharmacokinetics (PK). RESULTS: The proportion of patients who developed ADAs following TCZ-SC or TCZ-IV treatment was 1.5% and 1.2%, respectively. ADA development was also comparable between patients who received TCZ monotherapy and those who received concomitant csDMARDs (0.7-2.0%). ADA development did not correlate with PK or safety events, including anaphylaxis, hypersensitivity or injection-site reactions, and no patients who developed ADAs had loss of efficacy. CONCLUSIONS: The immunogenicity risk of TCZ-SC and TCZ-IV treatment was low, either as monotherapy or in combination with csDMARDs. Anti-TCZ antibodies developed among the small proportion of patients had no evident impact on PK, efficacy or safety.

2017 White Paper on recent issues in bioanalysis: a global perspective on immunogenicity guidelines & biomarker assay performance (Part 3 - LBA: immunogenicity, biomarkers and PK assays).

The 2017 11th Workshop on Recent Issues in Bioanalysis took place in Los Angeles/Universal City, California, on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule analysis involving LC-MS, hybrid ligand-binding assay (LBA)/LC-MS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations for large-molecule bioanalysis, biomarkers and immunogenicity using LBA. Part 1 (LC-MS for small molecules, peptides and small molecule biomarkers) and Part 2 (hybrid LBA/LC-MS for biotherapeutics and regulatory agencies' inputs) are published in volume 9 of Bioanalysis, issues 22 and 23 (2017), respectively.

Validation of a ligand-binding assay for active protein drug quantification following the 'free analyte QC concept'.

AIM: Active drug assays are becoming increasingly important in protein drug development. We describe the validation of a ligand-binding assay for active protein drug quantification and address practical challenges as well as regulatory implications. RESULTS: A bioanalytical method for active protein drug quantification was successfully validated. Validation data prove that this method can be routinely used applying the commonly accepted acceptance criteria for ligand-binding assays. CONCLUSION: Active drug assays are a powerful tool to elucidate the pharmacokinetic/pharmacodynamic relationship as they take into consideration the influence of various matrix components, such as soluble ligand and anti-drug antibodies. However, not all aspects of the validation concept described in the guidelines for pharmacokinetic assays can be applied to active drug assays and thus regulatory guidelines should be adapted in consequence.

2016 White Paper on recent issues in bioanalysis: focus on biomarker assay validation (BAV): (Part 3 - LBA, biomarkers and immunogenicity).

The 2016 10th Workshop on Recent Issues in Bioanalysis (10th WRIB) took place in Orlando, Florida with participation of close to 700 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations, and regulatory agencies worldwide. WRIB was once again a weeklong event - A Full Immersion Week of Bioanalysis for PK, Biomarkers and Immunogenicity. As usual, it is specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecules involving LCMS, hybrid LBA/LCMS, and LBA approaches, with the focus on PK, biomarkers and immunogenicity. This 2016 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. This White Paper is published in 3 parts due to length. This part (Part 3) discusses the recommendations for large molecule bioanalysis using LBA, biomarkers and immunogenicity. Parts 1 (small molecule bioanalysis using LCMS) and Part 2 (Hybrid LBA/LCMS and regulatory inputs from major global health authorities) have been published in the Bioanalysis journal, issues 22 and 23, respectively.

2015 White Paper on recent issues in bioanalysis: focus on new technologies and biomarkers (Part 3--LBA, biomarkers and immunogenicity).

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5 day, week-long event - A Full Immersion Bioanalytical Week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS and LBA approaches, including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 3 discusses the recommendations for large molecule bioanalysis using LBA, biomarkers and immunogenicity. Part 1 (small molecule bioanalysis using LCMS) and Part 2 (hybrid LBA/LCMS and regulatory inputs from major global health authorities) have been published in volume 7, issues 22 and 23 of Bioanalysis, respectively.

Subset analysis of patients experiencing clinical events of a potentially immunogenic nature in the pivotal clinical trials of tocilizumab for rheumatoid arthritis: Evaluation of an antidrug antibody ELISA using clinical adverse event-driven immunogenicity testing.

BACKGROUND: Tocilizumab (TCZ) is a recombinant humanized monoclonal antibody directed against the interleukin-6 receptor. In Europe, TCZ is approved for use in combination with methotrexate in the treatment of adult patients with moderate to severe rheumatoid arthritis (RA) who have failed to respond to or were unable to tolerate previous therapy with one or more disease-modifying antirheumatic drugs or tumor necrosis factor (TNF) antagonists; in the United States, it is approved for the treatment of adult patients with moderate to severe active RA who have failed to respond to one or more TNF antagonists. As part of the Phase III clinical development program, the immunogenicity of TCZ was evaluated using a bridging ELISA; however, this assay is considered limited in detecting low-affinity or immunoglobulin G4 subisotype antidrug antibodies (ADAs). OBJECTIVE: This study assessed the validity of the ELISA for detecting anti-TCZ ADAs by using complementary bioanalytic assays to test samples from a subgroup of patients with clinical adverse events (AEs) of a potentially immunogenic nature, who were considered highly likely to have ADAs. The goal was to determine whether use of these additional assays led to detection of ADAs not found on the ELISA, thus minimizing the risk of false-negative results. METHODS: The Phase III program for TCZ consisted of 5 core studies in which adult patients with RA received either TCZ 4 or 8 mg/kg IV or control every 4 weeks, with or without concomitant antirheumatic therapy. Blood samples obtained at baseline and at regular intervals thereafter were tested using the ELISA for ADA screening and confirmation. Regardless of the results on ADA screening, samples from patients who developed clinical AEs of a potentially immunogenic nature (ie, falling within predefined system organ classes, occurring during or within 24 hours of TCZ infusion, considered related to TCZ therapy, or leading to study withdrawal) were subjected to additional testing with a surface plasmon resonance (SPR) assay for isotyping and epitope localization and a standard ImmunoCAP immunoglobulin E (IgE) assay made specific for TCZ. RESULTS: The 5 core studies and their open-label, longterm extension studies enrolled a total of 4199 adult patients with RA (82.1% female; 74.0% white; mean age, 52.0 years [range, 18-89 years]; mean weight, 73.4 kg [range, 35-150 kg]); 2928 patients received TCZ and 1271 received control. Of the 2816 samples from TCZ-treated patients tested, 64 (2.3%) had samples that tested positive at least once on the ELISA screening and confirmation assay, 48 (75.0%) of them at baseline. A clinical AE of a potentially immunogenic nature occurred during TCZ treatment in 21 patients, 8 of whom had an anaphylactic reaction. Eleven of the samples from these 21 patients had tested negative for AD As on the screening ELISA. Only 1 of these 11 patients tested positive for ADAs on both additional assays; all others tested negative. The results of the ELISA, SPR, and IgE assays were consistent for 16 of 18 tested patients (88.9%) who provided data on at least 2 of the 3 assays. CONCLUSIONS: Based on the findings of this analysis in a relevant patient population, the bridging-type screening and confirmation ELISA was a valid method of detecting anti-TCZ ADAs. Immunogenicity testing of samples from patients with clinical AEs of a potentially immunogenic nature using assays complementary to the ELISA added valuable information about the incidence and character of ADAs.

Antitumor activity of erlotinib (OSI-774, Tarceva) alone or in combination in human non-small cell lung cancer tumor xenograft models.

Our objective was the preclinical assessment of the pharmacokinetics, monotherapy and combined antitumor activity of the epidermal growth factor receptor (HER1/EGFR) tyrosine kinase inhibitor erlotinib in athymic nude mice bearing non-small cell lung cancer (NSCLC) xenograft models. Immunohistochemistry determined the HER1/EGFR status of the NSCLC tumor models. Pharmacokinetic studies assessed plasma drug concentrations of erlotinib in tumor- and non-tumor-bearing athymic nude mice. These were followed by maximum tolerated dose (MTD) studies for erlotinib and each chemotherapy. Erlotinib was then assessed alone and in combination with these chemotherapies in the NSCLC xenograft models. Complete necropsies were performed on most of the animals in each study to further assess antitumor or toxic effects. Erlotinib monotherapy dose-dependently inhibited tumor growth in the H460a tumor model, correlating with circulating levels of drug. There was antitumor activity at the MTD with each agent tested in both the H460a and A549 tumor models (erlotinib 100 mg/kg: 71 and 93% tumor growth inhibition; gemcitabine 120 mg/kg: 93 and 75% tumor growth inhibition; cisplatin 6 mg/kg: 81 and 88% tumor growth inhibition). When each compound was given at a fraction of the MTD, tumor growth inhibition was suboptimal. Combinations of gemcitabine or cisplatin with erlotinib were assessed at 25% of the MTD to determine efficacy. In both NSCLC models, doses of gemcitabine (30 mg/kg) or cisplatin (1.5 mg/kg) with erlotinib (25 mg/kg) at 25% of the MTD were well tolerated. For the slow growing A549 tumor, there was significant tumor growth inhibition in the gemcitabine/erlotinib and cisplatin/erlotinib combinations (above 100 and 98%, respectively), with partial regressions. For the faster growing H460a tumor, there was significant but less remarkable tumor growth inhibition in these same combinations (86 and 53% respectively). These results show that in NSCLC xenograft tumors with similar levels of EGFR expression, the antitumor activity of erlotinib is robust both as monotherapy and in combination with chemotherapies.