A model for harmonizing flow cytometry in clinical trials.

Complexities in sample handling, instrument setup and data analysis are barriers to the effective use of flow cytometry to monitor immunological parameters in clinical trials. The novel use of a central laboratory may help mitigate these issues.

Efficacy and safety of tabalumab, an anti-B-cell-activating factor monoclonal antibody, in patients with rheumatoid arthritis who had an inadequate response to methotrexate therapy: results from a phase III multicentre, randomised, double-blind study.

OBJECTIVES: Randomised, double-blind, placebo-controlled study to evaluate efficacy and safety of tabalumab in patients with rheumatoid arthritis (RA) with inadequate responses to methotrexate (MTX-IR). METHODS: 1041 patients with moderate-severe RA despite ongoing MTX enrolled in a 52-week study evaluating subcutaneous tabalumab 120 mg every four weeks (120/Q4W) or 90 mg every two weeks (90/Q2W) versus placebo. Primary endpoints were American College of Rheumatology 20% (ACR20) response rate and Health Assessment Questionnaire-Disability Index change from baseline at 24 weeks and modified Total Sharp Score (mTSS) change at 52 weeks. RESULTS: There were no significant differences in ACR20 responses at week 24 or mTSS change from baseline at week 52 among treatment groups. Declines were seen in CD20+ B cells and immunoglobulin levels in tabalumab groups, but not placebo: B cells (-15.0%, -18.8%, 5.3%, in the 120/Q4W, 90/Q2W, and placebo groups, respectively); IgM (-16.3%, -19.4%, -0.1%), IgA (-11.4%, -4.7%, 1.2%) and IgG (-8.6%, -7.8%, 0.1%). Discontinuations due to adverse events were similar between groups. Numerically more serious infections were reported in tabalumab groups (1.7%, 0.6%, 0.3%); numerically more injection-site reactions were reported in the 90/Q2W group (2.3%, 4.3%, 2.3%). CONCLUSIONS: Neither clinical efficacy nor significant safety signals were observed with tabalumab despite evidence of biological activity. This study was terminated early due to insufficient efficacy. TRIAL REGISTRATION NUMBER: NCT01198002.

Efficacy and Safety of Tabalumab, an Anti-B-Cell-Activating Factor Monoclonal Antibody, in a Heterogeneous Rheumatoid Arthritis Population: Results From a Randomized, Placebo-Controlled, Phase 3 Trial (FLEX-O).

OBJECTIVES: The efficacy and safety of 2 different dosing regimens of tabalumab, a monoclonal antibody that neutralizes membrane-bound and soluble B-cell-activating factor (BAFF), were evaluated in patients with rheumatoid arthritis. METHODS: In this phase 3, multicenter, randomized study, 1004 patients (intention-to-treat population) received subcutaneous 120 mg tabalumab every 4 weeks (120/Q4W), 90 mg tabalumab every 2 weeks (90/Q2W), or placebo over 24 weeks. At baseline, a loading dose double the planned dose (ie, 240 mg, 180 mg, or placebo) was administered. Efficacy analyses were based on a prespecified subset of patients with 5 or more of 68 tender and 5 or more of 66 swollen joints at baseline (efficacy population, n = 849). The primary efficacy end point was ACR20 (20% improvement in American College of Rheumatology criteria) response at week 24. RESULTS: At week 24, there were no differences in ACR20 response rates (120/Q4W = 34.4%, 90/Q2W = 33.5%, placebo = 31.5%) or any other measures of efficacy across the treatment groups. Discontinuations due to adverse events (AE) were 3.4%, 2.7%, and 4.0%; incidence of treatment-emergent AEs were 64.1%, 58.2%, and 58.8%, with 23.2%, 25.9%, and 22.0% treatment-emergent infections; and incidence rates of serious AEs were 3.7%, 2.2%, and 2.8% with 1.1%, 0.3%, and 0.7% serious infections in the 120/Q4W, 90/Q2W, and placebo groups, respectively. Three deaths were reported (120/Q4W, n = 2; 90/Q2W, n = 1). Each tabalumab group had significant decreases versus placebo in CD3-CD20 B cells (P ≤ 0.05) and in serum immunoglobulins (P ≤ 0.001). CONCLUSIONS: Although tabalumab administration resulted in biologic activity, as demonstrated by changes in B cells and immunoglobulins, targeting BAFF-dependent pathways alone is not sufficient to significantly reduce rheumatoid arthritis disease activity.

Drug hypersensitivity reactions: review of the state of the science for prediction and diagnosis.

Drug hypersensitivity reactions (DHRs) are a type of adverse drug reaction that can occur with different classes of drugs and affect multiple organ systems and patient populations. DHRs can be classified as allergic or non-allergic based on the cellular mechanisms involved. Whereas nonallergic reactions rely mainly on the innate immune system, allergic reactions involve the generation of an adaptive immune response. Consequently, drug allergies are DHRs for which an immunological mechanism, with antibody and/or T cell, is demonstrated. Despite decades of research, methods to predict the potential for a new chemical entity to cause DHRs or to correctly attribute DHRs to a specific mechanism and a specific molecule are not well-established. This review will focus on allergic reactions induced by systemically administered low-molecular weight drugs with an emphasis on drug- and patient-specific factors that could influence the development of DHRs. Strategies for predicting and diagnosing DHRs, including potential tools based on the current state of the science, will also be discussed.

Treatment and biologic maintenance-dosing patterns among pediatric patients with ulcerative colitis or Crohn's disease.

OBJECTIVES: To assess treatment patterns and initial and maintenance dosing of biologics over 3 years in pediatric patients with ulcerative colitis (UC) or Crohn's disease (CD), utilizing data from the ImproveCareNow registry. METHODS: Pediatric patients diagnosed with UC or CD and aged 2-17 years were included in the study. Descriptive statistics were employed to summarize baseline demographics. The proportion of patients on medication for UC or CD were analyzed at the baseline visit, 1-year, and 3-year time points (Cohort 1). Biologic maintenance dosage was calculated only for patients who had data for dose and weight at all-time points (Cohort 2). RESULTS: In Cohort 1 (UC = 1784; CD = 4720), baseline treatment in UC included corticosteroid, 5-ASA, and 6-MP/AZA; at 1-year and 3-year time points, treatment with 5-ASA and corticosteroid decreased, whereas 6-MP/AZA and anti-TNFs increased. In CD, baseline treatment included corticosteroid, anti-TNF, 6-MP/AZA, and methotrexate; use of corticosteroids decreased, whereas the use of methotrexate and anti-TNFs increased over 3 years. In Cohort 2 (UC = 350; CD = 1537), at first maintenance dose, UC patients on infliximab received a mean dose of 10.5 mg/kg/8 wk, adalimumab (weight < 40 kg and ≥40 kg) 1.3 mg/kg/2 wk and 0.8 mg/kg/2 wk, and vedolizumab 6.9 mg/kg/8 wks. At the first maintenance dose, CD patients on infliximab received a mean dose of 8.1 mg/kg/8 wk, adalimumab (weight < 40 kg) 1.1 mg/kg/2 wk, adalimumab (weight ≥ 40 kg) 0.8 mg/kg/2 wk, and vedolizumab 10.5 mg/kg/8 wks. CONCLUSION: The use of corticosteroids was common at the initial visit in patients. Anti-TNFs remain the most used class of biologics, however, reported doses in our study were substantially higher than the standard dosing guidelines.

The Role of Master Protocols in Pediatric Drug Development.

Master protocols are innovative clinical trial designs that enable new approaches to analytics and operations, creating value for patients and drug developers. To date, the use of master protocols in pediatric drug development has been limited, focused primarily on pediatric oncology with limited experience in rare and ultra-rare pediatric diseases. This article explores the application of master protocols to pediatric programs required by FDA and EMA based on adult developmental programs. These required programs involve multiple assets developed in limited pediatric populations for registrational purposes. However, these required programs include the possibility for extrapolation of efficacy and safety from the adult population. The use of master protocols is a potential solution to the challenge of conducting clinical trials in small pediatric populations provided that such use would improve enrollment or reduce the required sample size. Toward that end, Janssen and Lilly have been working on a collaborative cross-company pediatric platform trial in pediatric Crohn's disease using an innovative Bayesian analysis. We describe how two competing companies can work together to design and execute the proposed platform, focusing on selected aspects-the usefulness of a single infrastructure, the regulatory submission process, the choice of control group, and the use of pediatric extrapolation. Master protocols offer the potential for great benefit in pediatrics by streamlining clinical development, with the goal of reducing the delay in pediatric marketing approvals when compared to adults so that children have timelier access to safe and effective medications.

Clinical Outcome Assessments in Pediatric Patients With Ulcerative Colitis and Crohn's Disease Receiving Biologics: A Retrospective Cohort Study.

Background: To assess disease activity, steroid-free remission, and other clinical outcome assessments among pediatric patients with ulcerative colitis (UC) and Crohn's disease (CD) in the ImproveCareNow (ICN) registry. Methods: Patients aged 2-17 years diagnosed with UC or CD between June 1, 2013 and December 31, 2019 were enrolled if they initiated a biologic after enrollment in the ICN registry and completed at least 12 months follow-up after first maintenance dose. Baseline (at biologic initiation) demographics were summarized using descriptive statistics. Pediatric UC Activity Index (PUCAI), partial Mayo score, and Physician Global Assessment (PGA) were assessed for UC; and the Short Pediatric Crohn's Disease Activity Index (sPCDAI) and PGA were assessed for CD at first maintenance dose, 1- and 3-year time points. Kappa coefficients were used to assess the level of agreement between the outcome measures. Results: A total of 1887 patients (UC = 350; CD = 1537) were included. Baseline demographics were similar across groups. For UC patients, mean PUCAI scores decreased and the proportion of patients in steroid-free remission, quiescent state based on PGA, and remission based on partial Mayo score increased from first maintenance dose to 1 and 3 years. For CD patients, mean sPCDAI score of CD patients decreased and the proportion of patients in steroid-free remission by sPCDAI and in quiescent state based on PGA increased from first maintenance dose to 1 and 3 years. Kappa coefficients showed only modest correlation between disease activity assessments. Conclusions: Disease activity scores improved over time, with more pediatric patients with UC and CD achieving steroid-free remission at 1 and 3 years after first biologic maintenance dose.

Acute lymphoid and gastrointestinal toxicity induced by selective p38alpha map kinase and map kinase-activated protein kinase-2 (MK2) inhibitors in the dog.

Exposure to moderately selective p38alpha mitogen-activated protein kinase (MAPK) inhibitors in the Beagle dog results in an acute toxicity consisting of mild clinical signs (decreased activity, diarrhea, and fever), lymphoid necrosis and depletion in the gut-associated lymphoid tissue (GALT), mesenteric lymph nodes and spleen, and linear colonic and cecal mucosal hemorrhages. Lymphocyte apoptosis and necrosis in the GALT is the earliest and most prominent histopathologic change observed, followed temporally by neutrophilic infiltration and acute inflammation of the lymph nodes and spleen and multifocal mucosal epithelial necrosis and linear hemorrhages in the colon and cecum. These effects are not observed in the mouse, rat, or cynomolgus monkey. To further characterize the acute toxicity in the dog, a series of in vivo, in vitro, and immunohistochemical studies were conducted to determine the relationship between the lymphoid and gastrointestinal (GI) toxicity and p38 MAPK inhibition. Results of these studies demonstrate a direct correlation between p38alpha MAPK inhibition and the acute lymphoid and gastrointestinal toxicity in the dog. Similar effects were observed following exposure to inhibitors of MAPK-activated protein kinase-2 (MK2), further implicating the role of p38alpha MAPK signaling pathway inhibition in these effects. Based on these findings, the authors conclude that p38alpha MAPK inhibition results in acute lymphoid and GI toxicity in the dog and is unique among the species evaluated in these studies.

Evaluation of pneumococcal and tetanus vaccine responses in patients with rheumatoid arthritis receiving baricitinib: results from a long-term extension trial substudy.

BACKGROUND: Clinical guidelines recommend pneumococcal and tetanus vaccinations in patients with rheumatoid arthritis (RA). Baricitinib is an oral, selective Janus kinase (JAK) 1/JAK 2 inhibitor and is approved for the treatment of moderately to severely active RA in adults in over 50 countries including European countries, the USA, and Japan. This substudy evaluated pneumococcal conjugate and tetanus toxoid vaccine (TTV) responses in patients with RA receiving baricitinib. These vaccines elucidate predominantly T cell-dependent humoral antibody response. METHODS: Eligible RA patients receiving baricitinib 2 mg or 4 mg with or without concomitant methotrexate (MTX) were enrolled in a phase 3 long-term extension trial (RA-BEYOND; ClinicalTrials.gov, NCT01885078) in USA/Puerto Rico. Patients were vaccinated with 13-serotype pneumococcal conjugate vaccine (PCV-13) and TTV. Primary endpoints were the proportion of patients achieving a satisfactory humoral response for PCV-13 (≥ 2-fold increase in anti-pneumococcal antibody concentrations in ≥ 6 serotypes) and TTV (≥ 4-fold increase in anti-tetanus concentrations) at 5 weeks post-vaccination. Secondary endpoints included humoral responses at 12 weeks and functional responses of serotypes 4, 6B, 14, and 23F (twofold and fourfold increases in opsonic indexes at 5 and 12 weeks). RESULTS: Of 106 patients with a mean duration of RA of approximately 12 years, 80% were female, 30% were taking corticosteroids, and 89% (N = 94) were taking baricitinib plus MTX; most patients (97% PCV-13/96% TTV) completed the evaluations. Overall, 68% (95% CI 58.4, 76.2) of patients achieved a satisfactory response to PCV-13, 43% (34.0, 52.8) achieved a ≥ 4-fold increase in anti-tetanus concentrations, and 74% (64.2, 81.1) achieved a ≥ 2-fold increase. PCV-13 response was similar for patients taking corticosteroids (71%; 53.4, 83.9) vs those not (67%; 55.2, 76.5). The percentage of sera with a ≥ 2-fold increase in post-vaccination opsonic indexes at week 5 ranged from 47% (serotype 14) to 76% (serotype 6B). Through 12 weeks post-vaccination, seven patients (6.6%) reported injection-site events. There were no deaths during the substudy, and three patients experienced a serious adverse event. CONCLUSIONS: Approximately two thirds of patients on long-term baricitinib achieved satisfactory humoral and functional responses to PCV-13 vaccination, while TTV responses were less robust. PCV-13 response was not diminished in those taking concomitant corticosteroids. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01885078 . Registered on 24 June 2013.

A qualitative study exploring the health-related quality of life and symptomatic experiences of adults and adolescents with ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) often first presents during adolescence and early adulthood. Primary symptoms of UC are well known, yet similarities and differences of disease experience in adults and adolescents are not well characterized. METHODS: To understand the health-related quality of life (HRQoL) and symptomatic experience of UC, in-depth interviews were conducted in the US with 21 adults (20-70 years) and 14 adolescents (12-17 years). Eligibility and medical history were confirmed by clinician report. A previously conducted literature review and resultant conceptual model informed the discussion guide to explore symptoms and HRQoL. Age appropriate creative tasks ("animal" task and collage) were employed to facilitate discussion. Transcripts and collages were subjected to thematic analysis using ATLAS.ti software. RESULTS: Clinician-reported UC severity included 24% mild, 38% moderate, 38% severe among adults; and 64% mild, 29% moderate, 7% severe among adolescents. Among adults, 52% were female, 67% were white. Among adolescents, 50% were female, 71% were white. During analysis it was noted that all participants reported stomach/abdominal pain. Other key symptoms identified were frequent bowel movements, diarrhea, blood in stools, sudden need for bowel movement, stomach cramping, bloating, and feeling gassy/passing gas (≥75% of participants). Key impacts identified were embarrassment, dietary limitations, having to plan around UC, worry/fear, anger, low mood/depression, and relationship with others, (≥75% of participants). In creative tasks, animals were chosen to represent their UC and content included in the collages reflected the most commonly discussed themes from the interviews. Only adults discussed feeling dehydrated, while only adolescents discussed the impact of UC on school life. CONCLUSIONS: Open-ended interviews highlighted the HRQoL and symptomatic experiences of UC from the patient's perspective, which were similar between adult and adolescent UC patients.

Gene Expression and Pharmacodynamic Changes in 1,760 Systemic Lupus Erythematosus Patients From Two Phase III Trials of BAFF Blockade With Tabalumab.

OBJECTIVE: To characterize baseline gene expression and pharmacodynamically induced changes in whole blood gene expression in 1,760 systemic lupus erythematosus (SLE) patients from 2 phase III, 52-week, randomized, placebo-controlled, double-blind studies in which patients were treated with the BAFF-blocking IgG4 monoclonal antibody tabalumab. METHODS: Patient samples were obtained from SLE patients from the ILLUMINATE-1 and ILLUMINATE-2 studies, and control samples were obtained from healthy donors. Blood was collected in Tempus tubes at baseline, week 16, and week 52. RNA was analyzed using Affymetrix Human Transcriptome Array 2.0 and NanoString. RESULTS: At baseline, expression of the interferon (IFN) response gene was elevated in patients compared with controls, with 75% of patients being positive for this IFN response gene signature. There was, however, substantial heterogeneity of IFN response gene expression and complex relationships among gene networks. The IFN response gene signature was a predictor of time to disease flare, independent of anti-double-stranded DNA (anti-dsDNA) antibody and C3 and C4 levels, and overall disease activity. Pharmacodynamically induced changes in gene expression following tabalumab treatment were extensive, occurring predominantly in B cell-related and immunoglobulin genes, and were consistent with other pharmacodynamic changes including anti-dsDNA antibody, C3, and immunoglobulin levels. CONCLUSION: SLE patients demonstrated increased expression of an IFN response gene signature (75% of patients had an elevated IFN response gene signature) at baseline in ILLUMINATE-1 and ILLUMINATE-2. Substantial heterogeneity of gene expression was detected among individual patients and in gene networks. The IFN response gene signature was an independent risk factor for future disease flares. Pharmacodynamic changes in gene expression were consistent with the mechanism of BAFF blockade by tabalumab.

Fully human anti-BAFF inhibitory monoclonal antibody tabalumab does not adversely affect T-dependent antibody responses in cynomolgus monkey (Macaca fasicularis): A summary of three pre-clinical immunotoxicology evaluations.

The potential immunotoxicity of tabalumab was assessed as a component of standard pre-clinical toxicology studies in cynomolgus monkeys. To evaluate potential tabalumab-associated immunosuppression after antigen challenge, cynomolgus monkeys were administered placebo control or tabalumab in three immunotoxicological safety studies. Study 1, a 4-week pilot study, evaluated biweekly intravenous (IV) control, and 0.3, 1.0, 5.0, and 15.0 mg/kg tabalumab doses. Study 2 evaluated IV control, and 0.1, 1.0, and 30.0 mg/kg tabalumab doses biweekly for 6 weeks. Study 3 evaluated IV control and 0.1, 1.0, 30.0 mg/kg, and subcutaneous (SC) 30.0 mg/kg tabalumab biweekly for 6 months, with recovery (16 weeks) to monitor standard immunotoxicity endpoints. T-cell dependent primary and secondary antibody responses to tetanus toxoid antigen challenge (4-week and 6-week studies) or keyhole limpet hemocyanin (KLH; 6-week and 6-month studies) were evaluated as a measure of immunocompetence, together with quantitation of T- and B-cell subsets. In addition, anti-tabalumab antibody formation (6-week and 6-month studies) was assessed. The results indicated that, despite expected decreases in circulating B-cell populations, no changes in follicle histopathology or organ weights, except decreases in spleen weight (after 6-months of 30 mg/kg IV/SC treatment only), were attributed to tabalumab. Non-adverse microscopic decreases in size or number of germinal centers in spleen, mesenteric, and mandibular lymph nodes occurred, but without an effect on antibody responses to KLH or tetanus. At 16-weeks recovery, microscopic compound-related changes observed after 6 months of treatment were completely reversed (0.1 mg/kg group) and partially reversed (1.0 and 30.0 mg/kg groups), while peripheral blood B cells remained 66-72% reduced from baseline. Despite reduced germinal centres in lymphoid organs, and reductions in circulating B cells, T-cell-dependent humoral immunity was maintained following tabalumab administration in three safety studies in cynomolgus monkeys.

Efficacy and safety of tabalumab, an anti-BAFF monoclonal antibody, in patients with moderate-to-severe rheumatoid arthritis and inadequate response to TNF inhibitors: results of a randomised, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: Tabalumab is a human monoclonal antibody that neutralises B-cell activating factor. OBJECTIVES: To evaluate tabalumab efficacy and safety in patients with rheumatoid arthritis (RA). METHODS: This phase 3, randomised, double-blind, placebo-controlled study evaluated 456 patients with active RA after 24-week treatment with subcutaneous tabalumab (120 mg every 4 weeks (120/Q4W) or 90 mg every 2 weeks (90/Q2W)) versus placebo, with loading doses (240 or 180 mg) at week 0. Patients were allowed background disease-modifying antirheumatic drugs and previously discontinued ≥1 tumour necrosis factor α inhibitors for lack of efficacy/intolerance. Primary end point was American College of Rheumatology 20% (ACR20) response at 24 weeks. This study was terminated early due to futility. RESULTS: Most patients had moderate-to-high baseline disease activity. There was no significant difference in week 24 ACR20 responses between 120/Q4W, 90/Q2W, and placebo (17.6%, 24.3%, 20%) per non-responder imputation analysis. Mean percent changes in CD20+ B-cell count (-10.8%, -9.6%, +10.9%) demonstrated expected pharmacodynamic effects. Treatment-emergent adverse events (AEs) were similar (59.5%, 51.7%, 52.6%), as were AE discontinuations (2.6%, 2.7%, 2.6%), serious AEs (4.6%, 4.1%, 3.9%), serious infectious events (1.3%, 0, 0) and events of interest: infections (23.5%, 25.9%, 24%), injection site reactions (13.1%, 25.8%, 11%) and allergy/hypersensitivity (3.9%, 4.1%, 3.9%) reports. Incidence of treatment-emergent antidrug antibodies was similar to placebo (3.9%, 4.8%, 3.9%). No deaths or new/unexpected safety findings were reported. CONCLUSIONS: Tabalumab did not demonstrate clinical efficacy in patients with RA in this phase 3 study, despite evidence of biological activity. There were no notable differences in safety parameters between tabalumab treatment groups and placebo. TRIAL REGISTRATION NUMBER: NCT01202773.

Acute thrombocytopenia in patients treated with the oral glycoprotein IIb/IIIa inhibitors xemilofiban and orbofiban: evidence for an immune etiology.

Thrombocytopenic episodes occurring in 18,845 patients treated with the GPIIb/IIIa inhibitors xemilofiban and orbofiban ("fibans") were analyzed by a blinded review panel and 73 patients were classified as having "possible fiban-induced thrombocytopenia". When the treatment codes were broken, a significant association between drug exposure and assignment to this group was found (p <0.001). Twenty-eight (82%) of 34 archived serum samples from these patients contained fiban-dependent antibodies specific for GPIIb/IIIa, but no such antibodies were found in 61 drug treated patients not classified as having "possible fiban-induced thrombocytopenia" (p <0.001). We conclude that fiban-dependent antibodies were the major cause of acute, severe thrombocytopenia in patients judged on the basis of clinical findings to have thrombocytopenia "possibly-induced" by xemilofiban and orbofiban. Measurement of drug-dependent antibodies may be helpful in determining the basis for acute thrombocytopenia in fiban-treated patients and possibly for identification of patients at risk to develop thrombocytopenia.

A 52-week, open-label study evaluating the safety and efficacy of tabalumab, an anti-B-cell-activating factor monoclonal antibody, for rheumatoid arthritis.

INTRODUCTION: The objective of this study was to evaluate the long-term safety and efficacy of tabalumab, a monoclonal antibody that neutralizes membrane-bound and soluble B-cell-activating factor, in rheumatoid arthritis (RA) patients. METHODS: Patients with RA who completed one of two 24-week randomized controlled trials (RCTs) participated in this 52-week, flexible-dose, open-label extension study. Patients in RCT1 received intravenous placebo, 30-mg tabalumab or 80-mg tabalumab every 3 weeks, and patients in RCT2 received subcutaneous placebo or 1-, 3-, 10-, 30-, 60- or 120-mg tabalumab every 4 weeks (Q4W). Regardless of prior treatment, all patients in this study received subcutaneous 60-mg tabalumab Q4W for the first 3 months, then a one-time increase to 120-mg tabalumab Q4W (60-mg/120-mg group) and a one-time decrease to 60-mg tabalumab Q4W per patient was allowed (60-mg/120-mg/60-mg group). RESULTS: There were 182 patients enrolled: 60 mg (n = 60), 60/120 mg (n = 121) and 60/120/60 mg (n = 1). Pretabalumab baseline disease activity was generally higher in the 60-mg/120-mg group. There was a higher frequency of serious adverse events and treatment-emergent adverse events, as well as infections and injection-site reactions, in the 60-mg/120-mg group. One death unrelated to the study drug occurred (60-mg/120-mg group). In both groups, total B-cell counts decreased by approximately 40% from the baseline level in the RCT originating study. Both groups demonstrated efficacy through 52 weeks of treatment relative to baseline pretabalumab disease activity based on American College of Rheumatology criteria improvement ≥20%, ≥50% and ≥70%; European League against Rheumatism Responder Index in 28 joints; Disease Activity Score in 28 joints-C-reactive protein; and Health Assessment Questionnaire-Disability Index. CONCLUSIONS: With long-term, open-label tabalumab treatment, no unexpected safety signals were observed, and B-cell reductions were consistent with previous findings. Despite differences in RCT originating studies, both groups demonstrated an efficacy response through the 52-week extension. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00837811 (registered 3 February 2009).

Survey: immune function and immunotoxicity assessment in dogs.

While immunotoxicology evaluations are often conducted in either rodents or non-human primates, findings in standard toxicology studies may trigger additional investigations in dogs. A survey sponsored by the HESI Immunotoxicology Technical Committee, and described herein, was conducted to gather information regarding the extent and nature of immunology and immunotoxicity assessments available in the dog, and the need thereof. The survey was issued via e-mail to scientists affiliated with 39 organizations in industry and academia, including contract research organizations, academic research organizations, pharmaceutical companies, and veterinary practices. Fifteen institutions responded, including 10 biotechnology or pharmaceutical industry organizations, 4 contract research organizations, and 1 academic institution. Responses indicated that indeed, immunological assessments in dogs are necessary for research and/or toxicology purposes. The survey demonstrated that multiple types of assays are used in the dog model, including assessment of T-cell-dependent antibody responses, immunoglobulins, complement CH(50), cytokines and cytokine mRNAs, lymphocyte proliferation in response to T-cell mitogens, neutrophil activation, phagocytosis, and immunophenotyping of several cell types. The survey also revealed that certain assays/endpoints are not available in the dog (complement components, NK immunophenotyping, T-cell activation and memory immunophenotyping) or require further optimization (ex vivo cytolysis assays such as CTL and NK function, B-cell proliferation in response to LPS). In addition, the survey indicated that a greater understanding of the specificity of the available immunophenotyping reagents is needed.

Developmental immunotoxicity (DIT) testing of pharmaceuticals: current practices, state of the science, knowledge gaps, and recommendations.

The development and regulatory approval of immunomodulatory pharmaceuticals to treat many human diseases has increased significantly over the last two decades. As discussed by FDA and ICH guidelines, all human pharmaceuticals in development should be evaluated for potential adverse effects on the immune system. Developmental immunotoxicology (DIT) focuses on the concern that early-life (during pre-/post-natal development) exposure to agents which target the immune system may result in enhanced susceptibility to immune-related disease (e.g., infection, autoimmunity, and cancer, particularly leukemia) compared to adults, unique effects not observed in adults, or more persistent effects in comparison to those following adult exposure. This article provides a substantive review of the literature and presents detailed considerations for DIT testing strategies with a specific focus on pharmaceuticals and biopharmaceuticals. In this regard, differences between small molecule and large molecule therapeutics will be considered, along with recommendations for best practices in the assessment of DIT during drug development. In addition, gaps in the DIT knowledge base and current testing strategies are identified. Finally, a summary of an ILSI-HESI-ITC sponsored Workshop conducted in 2010, entitled 'Developmental Immunotoxicity Testing of Pharmaceuticals' will be presented. This Workshop consisted of participants from the pharmaceutical, biotechnology, academic, and regulatory sectors, where many of the issues relating to DIT outlined in this review were discussed, key points of consensus reached, and current gaps in the science identified.

Screening New Drugs for Immunotoxic Potential: II. Assessment of the Effects of Selective and Nonselective COX-2 Inhibitors on Complement Activation, Superoxide Anion Production and Leukocyte Chemotaxis and Migration Through Endothelial Cells.

Results from earlier experiments in our laboratories revealed that both selective and nonselective inhibitors of cyclooxygenase-2 possess little potential for decreasing in vitro phagocytosis by rat macrophages or canine neutrophils and no potential for decreasing in vivo phagocytosis by the intact murine immune system. We now report the results of studies to assess in vitro and ex vivo effects of the drugs on 1) canine complement activation, 2) generation of superoxide anion and hydrogen peroxide (oxidative burst) by canine neutrophils, and 3) leukocytic chemotaxis and transmigration through endothelial cell monolayers. In vitro concentrations of naproxen sodium, SC-236, SC-245, and SC-791 ranging from 0.1 to 10 muM were tested for their abilities to inhibit canine complement-mediated hemolysis of opsonized sheep erythrocytes and to block phorbol myristate acetate-induced oxidative burst in canine neutrophils. Both models responded to known inhibitory agents, leupeptin in the complement activation test and staurosporine in the superoxide anion assay. In contrast, tested nonsteroidal anti-inflammatory drugs produced only trivial changes in complement activation and superoxide anion production. Experiments on plasma and neutrophils isolated from dogs administered an experimental selective COX-2 inhibitor during a 28-day toxicology study revealed no evidence of drug-associated changes in complement activation or formation of superoxide anion. SC-791 reduced chemotaxis of canine leukocytes toward zymosan-activated dog plasma, but not toward leukotriene B(4). None of the other drugs tested significantly affected leukocytic chemotaxis. Ibuprofen, SC-245 and SC-791 but not SC-236, reduced transmigration of canine leukocytes through endothelial cell monolayers. Based on the results of these experiments and our earlier studies we have concluded that, although high (suprapharmacologic) concentrations of the drugs may induce in vitro evidence of apparent immunomodulation of the innate immune system, the findings are unlikely to represent a significant human health risk.