Saloumeh Kadkhodayan Fischer

Lebrikizumab in moderate-to-severe asthma: pooled data from two randomised placebo-controlled studies

Introduction In a subset of patients with asthma, standard-of-care treatment does not achieve disease control, highlighting the need for novel therapeutic approaches. Lebrikizumab is a humanised, monoclonal antibody that binds to and blocks interleukin-13 activity. Methods LUTE and VERSE were replicate, randomised, double-blind, placebo-controlled studies, evaluating multiple doses of lebrikizumab in patients with uncontrolled asthma despite the use of medium-to-high-dose inhaled corticosteroid and a second controller. Patients received lebrikizumab 37.5, 125, 250 mg or placebo subcutaneously every four weeks. The primary endpoint was the rate of asthma exacerbations during the placebo-controlled period. Analyses were performed on prespecified subgroups based on baseline serum periostin levels. Following the discovery of a host-cell impurity in the study drug material, protocols were amended to convert from phase III to phase IIb. Subsequently, dosing of study medication was discontinued early as a precautionary measure. The data collected for analysis were from a placebo-controlled period of variable duration and pooled across both studies. Results The median duration of treatment was approximately 24 weeks. Treatment with lebrikizumab reduced the rate of asthma exacerbations, which was more pronounced in the periostin-high patients (all doses: 60% reduction) than in the periostin-low patients (all doses: 5% reduction); no dose–response was evident. Lung function also improved following lebrikizumab treatment, with greatest increase in FEV1 in periostin-high patients (all doses: 9.1% placebo-adjusted improvement) compared with periostin-low patients (all doses: 2.6% placebo-adjusted improvement). Lebrikizumab was well tolerated and no clinically important safety signals were observed. Conclusions These data are consistent with, and extend, previously published results demonstrating the efficacy of lebrikizumab in improving rate of asthma exacerbations and lung function in patients with moderate-to-severe asthma who remain uncontrolled despite current standard-of-care treatment. Trial registration numbers The LUTE study was registered under NCT01545440 and the VERSE study under NCT01545453 at http://www.clinicaltrials.gov

Efficacy and safety of lebrikizumab in patients with uncontrolled asthma (LAVOLTA I and LAVOLTA II): replicate, phase 3, randomised, double-blind, placebo-controlled trials

BACKGROUND In phase 2 trials, lebrikizumab, an anti-interleukin-13 monoclonal antibody, reduced exacerbation rates and improved FEV1 in patients with uncontrolled asthma, particularly in those with high concentrations of type 2 biomarkers (eg, periostin or blood eosinophils). We undertook replicate phase 3 studies to assess the efficacy and safety of lebrikizumab in patients with uncontrolled asthma despite inhaled corticosteroids and at least one second controller medication. METHODS Adult patients with uncontrolled asthma, pre-bronchodilator FEV1 40-80% predicted, and stable background therapy were randomly assigned (1:1:1) with an interactive voice-web-based response system to receive lebrikizumab 37·5 mg or 125 mg, or placebo subcutaneously, once every 4 weeks. Randomisation was stratified by screening serum periostin concentration, history of asthma exacerbations within the last 12 months, baseline asthma medications, and country. The primary efficacy endpoint was the rate of asthma exacerbations over 52 weeks in biomarker-high patients (periostin ≥50 ng/mL or blood eosinophils ≥300 cells per μL), analysed with a Poisson regression model corrected for overdispersion with Pearson χ2 that included terms for treatment group, number of asthma exacerbations within the 12 months before study entry, baseline asthma medications, geographic region, screening periostin concentration, and blood eosinophil counts as covariates. Both trials are registered at ClinicalTrials.gov, LAVOLTA I, number NCT01867125, and LAVOLTA II, number NCT01868061. FINDINGS 1081 patients were treated in LAVOLTA I and 1067 patients in LAVOLTA II. Over 52 weeks, lebrikizumab reduced exacerbation rates in biomarker-high patients in the 37·5 mg dose group (rate ratio [RR] 0·49 [95% CI 0·34-0·69], p<0·0001) and in the 125 mg dose group (RR 0·70 [0·51-0·95], p=0·0232) versus placebo in LAVOLTA I. Exacerbation rates were also reduced in biomarker-high patients in both dose groups versus placebo in LAVOLTA II (37·5 mg: RR 0·74 [95% CI 0·54-1·01], p=0·0609; 125 mg: RR 0·74 [0·54-1·02], p=0·0626). Pooling both studies, the proportion of patients who experienced treatment-emergent adverse events (79% [1125 of 1432 patients] for both lebrikizumab doses vs 80% [576 of 716 patients] for placebo), serious adverse events (8% [115 patients] for both lebrikizumab doses vs 9% [65 patients] for placebo), and adverse events leading to study drug discontinuation (3% [49 patients] for both lebrikizumab doses vs 4% [31 patients] for placebo) were similar between lebrikizumab and placebo. The following serious adverse events were reported in the placebo-controlled period: one event of aplastic anaemia and five serious adverse events related to raised concentrations of eosinophils in patients treated with lebrikizumab and one event of eosinophilic pneumonia in the placebo group. INTERPRETATION Lebrikizumab did not consistently show significant reduction in asthma exacerbations in biomarker-high patients. However, it blocked interleukin-13 as evidenced by the effect on interleukin-13-related pharmacodynamic biomarkers, and clinically relevant changes could not be ruled out. FUNDING F Hoffmann-La Roche.

Synovial phenotypes in rheumatoid arthritis correlate with response to biologic therapeutics.

IntroductionRheumatoid arthritis (RA) is a complex and clinically heterogeneous autoimmune disease. Currently, the relationship between pathogenic molecular drivers of disease in RA and therapeutic response is poorly understood.MethodsWe analyzed synovial tissue samples from two RA cohorts of 49 and 20 patients using a combination of global gene expression, histologic and cellular analyses, and analysis of gene expression data from two further publicly available RA cohorts. To identify candidate serum biomarkers that correspond to differential synovial biology and clinical response to targeted therapies, we performed pre-treatment biomarker analysis compared with therapeutic outcome at week 24 in serum samples from 198 patients from the ADACTA (ADalimumab ACTemrA) phase 4 trial of tocilizumab (anti-IL-6R) monotherapy versus adalimumab (anti-TNFα) monotherapy.ResultsWe documented evidence for four major phenotypes of RA synovium – lymphoid, myeloid, low inflammatory, and fibroid - each with distinct underlying gene expression signatures. We observed that baseline synovial myeloid, but not lymphoid, gene signature expression was higher in patients with good compared with poor European league against rheumatism (EULAR) clinical response to anti-TNFα therapy at week 16 (P =0.011). We observed that high baseline serum soluble intercellular adhesion molecule 1 (sICAM1), associated with the myeloid phenotype, and high serum C-X-C motif chemokine 13 (CXCL13), associated with the lymphoid phenotype, had differential relationships with clinical response to anti-TNFα compared with anti-IL6R treatment. sICAM1-high/CXCL13-low patients showed the highest week 24 American College of Rheumatology (ACR) 50 response rate to anti-TNFα treatment as compared with sICAM1-low/CXCL13-high patients (42% versus 13%, respectively, P =0.05) while anti-IL-6R patients showed the opposite relationship with these biomarker subgroups (ACR50 20% versus 69%, P =0.004).ConclusionsThese data demonstrate that underlying molecular and cellular heterogeneity in RA impacts clinical outcome to therapies targeting different biological pathways, with patients with the myeloid phenotype exhibiting the most robust response to anti-TNFα. These data suggest a path to identify and validate serum biomarkers that predict response to targeted therapies in rheumatoid arthritis and possibly other autoimmune diseases.Trial registrationClinicalTrials.gov NCT01119859

Emerging Technologies to Increase Ligand Binding Assay Sensitivity

Ligand binding assays (LBAs) have been the method of choice for protein analyte measurements for more than four decades. Over the years, LBA methods have improved in sensitivity and achieved larger dynamic ranges by using alternative detection systems and new technologies. As a consequence, the landscape and application of immunoassay platforms has changed dramatically. The introduction of bead-based methods, coupled with single molecule detection standardization and the ability to amplify assay signals, has improved the sensitivity of many immunoassays, in some cases by several logs of magnitude. Three promising immunoassay platforms are described in this article: Single Molecule Counting (SMC™) from Singulex Inc, Single Molecule Arrays (Simoa™) from Quanterix Corporation, and Immuno-PCR (Imperacer®) from Chimera Biotec GmbH. These platforms have the potential to significantly improve immunoassay sensitivity and thereby address the bioanalytical needs and challenges faced during biopharmaceutical drug development.

The assay design used for measurement of therapeutic antibody concentrations can affect pharmacokinetic parameters: Case studies

To interpret pharmacokinetic (PK) data of biotherapeutics, it is critical to understand which drug species is being measured by the PK assay. For therapeutic antibodies, it is generally accepted that “free” circulating antibodies are the pharmacologically active form needed to determine the PK/ pharmacodynamic (PD) relationship, safety margin calculations, and dose projections from animals to humans and the eventual characterization of the exposure in the clinic. However, “total” drug may be important in evaluating the dynamic interaction between the drug and the target, as well as the total drug exposure. In the absence of or with low amounts of soluble ligand /shed receptor, total and free drug species are often equivalent and their detection is less sensitive to assay formats or reagent choices. In contrast, in the presence of a significant amount of ligand, assay design and characterization of assay reagents are critical to understanding the PK profiles. Here, we present case studies where different assay formats affected measured PK profiles and data interpretation. The results from reagent characterizations provide a potential explanation for the observed discrepancies and highlight the importance of reagent characterization in understanding which drug species are being measured to accurately interpret PK parameters.

Increased rheumatoid factor interference observed during immunogenicity assessment of an Fc-engineered therapeutic antibody

Protein therapeutics may elicit an anti-therapeutic antibody (ATA) response in patients. This response depends on a number of factors including patient population, disease state, route of delivery or characteristics specific to the product. Therapeutics for immunological indications often target relatively young and healthy patients with hyperactive immune systems who have periodic flares and remissions. The hyperactive immune system of these patients can add several levels of bioanalytical complexity due to the presence of cross reactive molecules such as autoantibodies. In addition, the long-term chronic dosing regimen often necessary in this patient population can increase their risks of immunogenicity against the therapeutic and lead to safety concerns. Therefore, development of a sensitive and drug-tolerant ATA method is important. Bridging ATA assays are usually very sensitive and drug-tolerant methods for immunogenicity assessment; however these methods are particularly vulnerable to any factor that is able to bridge the conjugated therapeutics used as reagents and can generate false positive signal. Although there are many potential interfering factors in serum, rheumatoid factors (RFs), autoantibodies associated with rheumatoid arthritis (RA), are of particular concern in this type of assay. MTRX1011A is a non-depleting anti-CD4 monoclonal antibody therapeutic that was clinically tested in RA patients. This paper will discuss the bioanalytical challenges encountered during development of a clinical ATA assay for MTRX1011A. These challenges highlight interference due to patient disease state, in this case presence of RF in RA patients, as well as specific molecule-related interference caused by an engineered mutation in the Fc region of MTRX1011A designed to enhance its binding to the neonatal Fc receptor (FcRn). We will discuss the characterization work used to identify the cross-reactive epitope and our strategy to overcome this interference during development of an effective ATA assay to support clinical evaluation of MTRX1011A.

Clinical immunogenicity specificity assessments: A platform evaluation

Immunogenicity assessment is an integral part of the evaluation of the safety and efficacy for protein therapeutics during drug development, and is required by the regulatory authorities. A tiered strategy is typically utilized to assess immunogenicity and is often comprised of a screening method, a confirmation/specificity step and a characterization step. To ensure methods with appropriate sensitivity are utilized, the threshold for screening assays is set to minimize false negatives resulting in a certain rate of false positivity. The confirmatory step is critical for determining assay specificity and eliminating false positives identified in the screening assay. Using a widely implemented technology and bridging assay format commonly used for immunogenicity assessments, unacceptably poor specificity was observed for the confirmatory/specificity step for a subset of monoclonal antibodies in our group. Therefore, we believe that this challenge will be relevant to others in the field. In this paper, we will describe our challenges with one of these antibodies, monoclonal antibody therapeutic X (rhuMAb X). This paper presents extensive evaluation of two technology platforms and various conditions to evaluate and provide solutions to improving the assay specificity in the immunogenicity assessment of antibody therapeutics.

Specific Immune Response to Phospholipase B-Like 2 Protein, a Host Cell Impurity in Lebrikizumab Clinical Material

Host cell proteins are manufacturing process-related impurities that may co-purify with the product despite extensive efforts to optimize the purification process. The risks associated with these impurities can vary and may be patient and/or therapeutic dependent. Therefore, it is critical to monitor and control the levels of these impurities in products and their potential impact on safety and efficacy. Lebrikizumab is a humanized immunoglobulin G4 monoclonal antibody (mAb) that binds specifically to soluble interleukin 13. This mAb is currently in phase III clinical development for the treatment of asthma. Following initial phase III studies, the material used in lebrikizumab clinical trials was found to have a process-related impurity identified as Chinese hamster ovary phospholipase B-like 2 (PLBL2) which co-purified with lebrikizumab. The immunogenic potential of PLBL2 and its potential impact on the immunogenicity of lebrikizumab in clinical studies were therefore evaluated. Data from the clinical studies demonstrated that ∼90% of subjects developed a specific and measurable immune response to PLBL2. Given the high incidence of antibodies to PLBL2 as well as the comparable safety profile observed between placebo- and drug-treated subjects, no correlation between safety events and anti-PLBL2 antibodies could be made. Additionally, no impact on the incidence of anti-lebrikizumab antibodies was observed, suggesting the lack of an adjuvant effect from PLBL2. Interim analysis from ongoing phase III studies using material with substantially reduced levels of PLBL2 with patients having had longer exposure shows significantly less and dose-dependent frequency of immune responses to PLBL2.

Critical role of bioanalytical strategies in investigation of clinical PK observations, a Phase I case study

RG7652 is a human immunoglobulin 1 (IgG1) monoclonal antibody (mAb) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and is designed for the treatment of hypercholesterolemia. A target-binding enzyme-linked immunosorbent assay (ELISA) was developed to measure RG7652 levels in human serum in a Phase I study. Although target-binding assay formats are generally used to quantify free therapeutic, the actual therapeutic species being measured are affected by assay conditions, such as sample dilution and incubation time, and levels of soluble target in the samples. Therefore, in the presence of high concentrations of circulating target, the choice of reagents and assay conditions can have a significant effect on the observed pharmacokinetic (PK) profiles. Phase I RG7652 PK analysis using the ELISA data resulted in a nonlinear dose normalized exposure. An investigation was conducted to characterize the ELISA to determine whether the assay format and reagents may have contributed to the PK observation. In addition, to confirm the ELISA results, a second orthogonal method, liquid chromatography tandem mass spectrometry (LC-MS/MS) using a signature peptide as surrogate, was developed and implemented. A subset of PK samples, randomly selected from half of the subjects in the 6 single ascending dose (SAD) cohorts in the Phase I clinical study, was analyzed with the LC-MS/MS assay, and the data were found to be comparable to the ELISA data. This paper illustrates the importance of reagent characterization, as well as the benefits of using an orthogonal approach to eliminate bioanalytical contributions when encountering unexpected observations.

Evaluation of two commercial omalizumab/free IgE immunoassays: implications of use during therapy

Abstract Background: The anti-IgE monoclonal antibody, omalizumab, is approved in the US as add-on therapy for patients ≥12 years of age with moderate-to-severe persistent allergic asthma. Omalizumab is administered according to the US Food and Drug Administration approved dosing table included in the prescribing information. The dosing table was developed using Genentech’s free IgE assay and is designed to achieve free serum IgE levels of <50 ng/mL, known to be associated with clinical benefit. Lack of clinical benefit in a subset of patients on omalizumab has prompted demand for commercial free IgE assays to guide omalizumab dosing. To date, two commercial free IgE assays marketed by ViraCor-IBT (no longer offered) and BioTeZ have been available to physicians. Objective: This study compares the results generated from the two commercial free IgE assays with the free IgE levels generated by the Genentech assay. Methods: Two serum sample sets were prepared using 20 samples from patients with a wide range of IgE and omalizumab from an omalizumab clinical trial and 36 samples from omalizumab-naïve patients. Different amounts of omalizumab were added to the 36 omalizumab naïve samples based on measured total IgE levels to ensure that a good range of IgE and omalizumab was represented in the study samples. Samples were randomized for blinded analysis of free IgE levels using the Genentech, ViraCor-IBT and BioTeZ free serum IgE assays. Analysis of samples in the ViraCor-IBT assay were conducted by ViraCor-IBT and the analysis of samples using the Genentech and BioTeZ assay methods were conducted by a third party contract research organization. Results: The ViraCor-IBT and BioTeZ free IgE assays demonstrated significantly higher free IgE levels than the Genentech free IgE assay. Twenty-nine of 56 samples tested <50 ng/mL in the Genentech assay; of these, 12/29 (41%) and 20/29 (69%) tested >50 ng/mL in the BioTeZ and ViraCor-IBT assays, respectively. In the BioTeZ free IgE evaluations, 11/20 samples that were re-tested had inter-assay differences ranging from 40–190%. Conclusions: Free ligand (such as IgE) measurements are challenging and dependent on the method and reagents used. The Viracor-IBT and BioTeZ methods tend to over-estimate free serum IgE levels compared with the Genentech free IgE assay. Using these assays to monitor therapy and adjust omalizumab doses post treatment is considered off-label use and could lead to a potential risk for unnecessary treatment and/or risk to patient safety.