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1.  Comparison of tocilizumab as monotherapy or with add-on disease-modifying antirheumatic drugs in patients with rheumatoid arthritis and inadequate responses to previous treatments: an open-label study close to clinical practice 
Clinical Rheumatology  2015;34(3):563-571.
This was an exploratory analysis comparing the safety and efficacy of tocilizumab monotherapy with those of tocilizumab in combination with disease-modifying anti-rheumatic drugs (DMARDs). Data were from a single-arm, nonrandomized, open-label, 24-week study in patients with rheumatoid arthritis in which patients with inadequate responses to DMARDs or tumor necrosis factor-α inhibitors received tocilizumab 8 mg/kg intravenously every 4 weeks plus methotrexate/other DMARD(s) combination therapy. If they were intolerant of methotrexate/other DMARD, patients received tocilizumab monotherapy. Effectiveness endpoints included American College of Rheumatology (ACR) responses (ACR20/50/70/90) and disease activity score using 28 joints (DAS28). Of 1,681 patients, 239 received tocilizumab monotherapy, and 1,442 received combination therapy. Methotrexate was the most common DMARD (79 %) used in combination therapy. The frequency of adverse events (AEs), serious AEs, and AEs leading to withdrawal were similar between tocilizumab monotherapy (82.4, 7.9, and 5.4 %, respectively) and combination therapy (76.6, 7.8, and 5.1 %, respectively). No differences in ACR20/50/70/90 responses were observed between treatment groups (66.9 %/43.5 %/23.8 %/10.0 % vs 66.9 %/47.2 %/26.8 %/8.5 %, respectively; p > 0.12 for all individual comparisons, including ACR50 propensity score analyses). The decrease in DAS28 was also similar between treatment groups (mean ± standard deviation: −3.41 ± 1.49 for tocilizumab monotherapy vs −3.43 ± 1.43 for combination therapy; p > 0.33 all analyses, including propensity score analyses). Tocilizumab had a comparable safety profile, and was similarly effective, when used as monotherapy or in combination with DMARDs in a broad population of patients with rheumatoid arthritis.
Electronic supplementary material
The online version of this article (doi:10.1007/s10067-014-2857-y) contains supplementary material, which is available to authorized users.
PMCID: PMC4348534  PMID: 25604316
Disease activity; DMARDs (biologic); DMARDs (synthetic); Monotherapy; Open-label; Rheumatoid arthritis; Tocilizumab; Tumor necrosis factor-α inhibitor
2.  Rituximab in patients with rheumatoid arthritis in routine practice (GERINIS): six-year results from a prospective, multicentre, non-interventional study in 2,484 patients 
The aim of this study was to evaluate the safety and efficacy of rituximab (RTX) in a large cohort of patients with rheumatoid arthritis in routine care, and to monitor changes in daily practice since the introduction of RTX therapy.
This was a multicentre, prospective, non-interventional study conducted under routine practice conditions in Germany. Efficacy was evaluated using Disease Activity Score in 28 joints (DAS28) and Health Assessment Questionnaire-Disability Index (HAQ-DI). Safety was assessed by recording adverse drug reactions (ADRs). Physician and patient global efficacy and tolerability assessments were also evaluated.
Overall, 2,484 patients (76.7% female, mean age 56.4 years, mean disease duration 11.7 years) received RTX treatment (22.7% monotherapy). The total observation period was approximately six-years (median follow-up 14.7 months). RTX treatment led to improvements in DAS28 and HAQ-DI that were sustained over multiple courses. DAS28 improvements positively correlated with higher rheumatoid factor levels up to 50 IU/ml. Response and tolerability were rated good/very good by the majority of physicians and patients. Mean treatment intervals were 10.5 and 6.8 months for the first and last 400 enrolled patients, respectively. Infections were the most frequently reported ADRs (9.1%; 11.39/100 patient-years); approximately 1% of patients per course discontinued therapy due to ADRs.
Prolonged RTX treatment in routine care is associated with good efficacy and tolerability, as measured by conventional parameters and by physicians’ and patients’ global assessments. Rheumatoid factor status served as a distinct and quantitative biomarker of RTX responsiveness. With growing experience, physicians repeated treatments earlier in patients with less severe disease activity.
PMCID: PMC4060207  PMID: 24670196
3.  Integrated pharmacokinetics and pharmacodynamics of epoprostenol in healthy subjects 
The aim of the study was to report the first thorough characterization of the pharmacokinetics (PK) and pharmacodynamics (PD) of epoprostenol in an integrated manner.
Twenty healthy male subjects received two formulations of i.v. epoprostenol, in a crossover design, in sequential infusions of 2, 4, 6 and 8 ng kg−1 min−1 for 2 h each. A sensitive assay was developed which allowed accurate PK characterization of epoprostenol via analysis of the concentration–time profiles of its two primary metabolites, 6-keto-prostacyclin F1α and 6,15-diketo-13,14-dihydro-prostacyclin F1α. PD parameters included cardiac output (CO), cardiac index (CIn) and heart rate (HR).
The pharmacokinetics of epoprostenol deviated slightly from dose-proportionality, probably due to a food effect. After infusion of the two formulations of epoprostenol, the t1/2 values expressed as geometric mean (95% confidence interval) were 0.25 h (0.14, 0.46) and 0.22 h (0.13, 0.38) for 6-keto-prostacyclin F1α, and 0.32 h (0.22, 0.45) and 0.34 h (0.26, 0.46) for 6,15-diketo-13,14-dihydro-prostacyclin F1α. A single compartment infusion model with first order elimination adequately described the PK of 6-keto-prostacyclin F1α. This model also characterized the food effect. Stepwise infusions with epoprostenol resulted in a progressive increase in CO, CIn and HR.
Of the two metabolites analyzed, the appearance of 6-keto-prostacyclin F1α in plasma was more closely associated with the haemodynamic effects of i.v. epoprostenol. PK and PD profiles showed that CIn relates proportionally and linearly to the plasma concentrations of 6-keto-prostacyclin F1α. These results suggest that 6-keto-prostacyclin F1α is a suitable surrogate marker of plasma concentrations of epoprostenol.
PMCID: PMC3522811  PMID: 22515646
epoprostenol; haemodynamics; pharmacokinetics; prostacyclin
4.  SCHEMA Designed Variants of Human Arginase I & II Reveal Sequence Elements Important to Stability and Catalysis 
ACS synthetic biology  2012;1(6):221-228.
Arginases catalyze the divalent cation-dependent hydrolysis of L-arginine to urea and L-ornithine. There is significant interest in using arginase as a therapeutic anti-neogenic agent against L-arginine auxotrophic tumors and in enzyme replacement therapy for treating hyperargininemia. Both therapeutic applications require enzymes with sufficient stability under physiological conditions. To explore sequence elements that contribute to arginase stability we used SCHEMA-guided recombination to design a library of chimeric enzymes composed of sequence fragments from the two human isozymes Arginase I and II. We then developed a novel active learning algorithm that selects sequences from this library that are both highly informative and functional. Using high-throughput gene synthesis and our two-step active learning algorithm, we were able to rapidly create a small but highly informative set of seven enzymatically active chimeras that had an average variant distance of 40 mutations from the closest parent arginase. Within this set of sequences, linear regression was used to identify the sequence elements that contribute to the long-term stability of human arginase under physiological conditions. This approach revealed a striking correlation between the isoelectric point and the long-term stability of the enzyme to deactivation under physiological conditions.
PMCID: PMC3378063  PMID: 22737599
Enzyme engineering; arginase; homologous recombination; SCHEMA library design; active learning; protein stability
5.  Impact of patient and disease characteristics on therapeutic success during adalimumab treatment of patients with rheumatoid arthritis: data from a German noninterventional observational study 
Rheumatology International  2011;32(9):2759-2767.
The objective of this study was to use data from a noninterventional study to evaluate the effectiveness of adalimumab in rheumatoid arthritis (RA) patients during routine clinical practice and to explore the potential impact of patient and disease characteristics in response to adalimumab therapy. A total of 2,625 RA patients with specified data at baseline (prior to initiating adalimumab treatment) and 12 months entered this study between April 2003 and March 2009. We evaluated response to adalimumab therapy and conducted stepwise regression and subgroup analyses of factors influencing therapeutic response. During the 1-year adalimumab treatment period, disease activity decreased from a baseline mean disease activity score-28 joints (DAS28) of 5.9–3.9, while functional capacity improved from 59.0 to 68.4 Funktionsfragebogen Hannover (FFbH) percentage points. In multivariate regression models, high baseline DAS28 was the strongest positive predictor for decrease in disease activity, and high baseline functional capacity was associated with reduced gains in functional capacity. Male gender was a positive predictor of therapeutic response for both disease activity and functional capacity, while older age and multiple previous biologics were associated with a reduced therapeutic response. Subset analyses provided further support for the impact of baseline DAS28, FFbH, and prior biologic therapy on therapeutic response during treatment. We conclude that treatment with adalimumab leads to decreased disease activity and improved function during routine clinical practice. Patients with high disease activity and low functional capacity are particularly benefitted by adalimumab therapy.
PMCID: PMC3429775  PMID: 21822659
Adalimumab; Arthritis, rheumatoid; Treatment outcome; Regression analysis; Antirheumatic agents
6.  Drug Development for Pediatric Populations: Regulatory Aspects 
Pharmaceutics  2010;2(4):364-388.
Pediatric aspects are nowadays integrated early in the development process of a new drug. The stronger enforcement to obtain pediatric information by the regulatory agencies in recent years resulted in an increased number of trials in children. Specific guidelines and requirements from, in particular, the European Medicines Agency (EMA) and the Food and Drug Administration (FDA) form the regulatory framework. This review summarizes the regulatory requirements and strategies for pediatric drug development from an industry perspective. It covers pediatric study planning and conduct, considerations for first dose in children, appropriate sampling strategies, and different methods for data generation and analysis to generate knowledge about the pharmacokinetics (PK) and pharmacodynamics (PD) of a drug in children. The role of Modeling and Simulation (M&S) in pediatrics is highlighted—including the regulatory basis—and examples of the use of M&S are illustrated to support pediatric drug development.
PMCID: PMC3967144
pediatrics; children; pediatric drug development; pediatric legislation; health authorities; regulatory guidelines; PIP; clinical studies; Modeling and Simulation; PK/PD modeling
7.  Failure of catecholamines to shift T-cell cytokine responses toward a Th2 profile in patients with rheumatoid arthritis 
To further understand the role of neuro-immunological interactions in the pathogenesis of rheumatoid arthritis (RA), we studied the influence of sympathetic neurotransmitters on cytokine production of T cells in patients with RA. T cells were isolated from peripheral blood of RA patients or healthy donors (HDs), and stimulated via CD3 and CD28. Co-incubation was carried out with epinephrine or norepinephrine in concentrations ranging from 10-5 M to 10-11 M. Interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-4, and IL-10 were determined in the culture supernatant with enzyme-linked immunosorbent assay. In addition, IFN-γ and IL-10 were evaluated with intracellular cytokine staining. Furthermore, basal and agonist-induced cAMP levels and catecholamine-induced apoptosis of T cells were measured. Catecholamines inhibited the synthesis of IFN-γ, TNF-α, and IL-10 at a concentration of 10-5 M. In addition, IFN-γ release was suppressed by 10-7 M epinephrine. Lower catecholamine concentrations exerted no significant effect. A reduced IL-4 production upon co-incubation with 10-5 M epinephrine was observed in RA patients only. The inhibitory effect of catecholamines on IFN-γ production was lower in RA patients as compared with HDs. In RA patients, a catecholamine-induced shift toward a Th2 (type 2) polarised cytokine profile was abrogated. Evaluation of intracellular cytokines revealed that CD8-positive T cells were accountable for the impaired catecholaminergic control of IFN-γ production. The highly significant negative correlation between age and catecholamine effects in HDs was not found in RA patients. Basal and stimulated cAMP levels in T-cell subsets and catecholamine-induced apoptosis did not differ between RA patients and HDs. RA patients demonstrate an impaired inhibitory effect of catecholamines on IFN-γ production together with a failure to induce a shift of T-cell cytokine responses toward a Th2-like profile. Such an unfavorable situation is a perpetuating factor for inflammation.
PMCID: PMC1779439  PMID: 16889669
8.  A standard curve based method for relative real time PCR data processing 
BMC Bioinformatics  2005;6:62.
Currently real time PCR is the most precise method by which to measure gene expression. The method generates a large amount of raw numerical data and processing may notably influence final results. The data processing is based either on standard curves or on PCR efficiency assessment. At the moment, the PCR efficiency approach is preferred in relative PCR whilst the standard curve is often used for absolute PCR. However, there are no barriers to employ standard curves for relative PCR. This article provides an implementation of the standard curve method and discusses its advantages and limitations in relative real time PCR.
We designed a procedure for data processing in relative real time PCR. The procedure completely avoids PCR efficiency assessment, minimizes operator involvement and provides a statistical assessment of intra-assay variation.
The procedure includes the following steps. (I) Noise is filtered from raw fluorescence readings by smoothing, baseline subtraction and amplitude normalization. (II) The optimal threshold is selected automatically from regression parameters of the standard curve. (III) Crossing points (CPs) are derived directly from coordinates of points where the threshold line crosses fluorescence plots obtained after the noise filtering. (IV) The means and their variances are calculated for CPs in PCR replicas. (V) The final results are derived from the CPs' means. The CPs' variances are traced to results by the law of error propagation.
A detailed description and analysis of this data processing is provided. The limitations associated with the use of parametric statistical methods and amplitude normalization are specifically analyzed and found fit to the routine laboratory practice. Different options are discussed for aggregation of data obtained from multiple reference genes.
A standard curve based procedure for PCR data processing has been compiled and validated. It illustrates that standard curve design remains a reliable and simple alternative to the PCR-efficiency based calculations in relative real time PCR.
PMCID: PMC1274258  PMID: 15780134
10.  Rapid Typing of Borrelia burgdorferi Sensu Lato Species in Specimens from Patients with Different Manifestations of Lyme Borreliosis 
Journal of Clinical Microbiology  2001;39(3):1130-1133.
To further investigate the pathogenic potential of different Borrelia burgdorferi genospecies, specimens from 27 patients with different manifestations of Lyme borreliosis were analyzed by PCR and reverse line blotting (RLB). In samples from Lyme arthritis patients, B. burgdorferi sensu stricto was predominantly identified, while in patients with neuroborreliosis or acrodermatitis, Borrelia garinii and Borrelia afzelii, respectively, were exclusively detected. The results demonstrate that PCR-RLB is a valuable tool for epidemiological and pathogenetic studies of Lyme borreliosis.
PMCID: PMC87886  PMID: 11230440
11.  Tocilizumab in patients with active rheumatoid arthritis and inadequate responses to DMARDs and/or TNF inhibitors: a large, open-label study close to clinical practice 
Annals of the Rheumatic Diseases  2012;71(12):1950-1954.
To evaluate the safety and efficacy of tocilizumab in clinical practice in patients with rheumatoid arthritis (RA) with inadequate responses (IR) to disease-modifying antirheumatic drugs (DMARDs) or both DMARDs and tumour necrosis factor α inhibitors (TNFis).
Patients—categorised as TNFi-naive, TNFi-previous (washout) or TNFi-recent (no washout) —received open-label tocilizumab (8 mg/kg) every 4 weeks ± DMARDs for 24 weeks. Adverse events (AEs) and treatment discontinuations were monitored. Efficacy end points included American College of Rheumatology (ACR) responses, 28-joint disease activity score (DAS28) and European League Against Rheumatism responses.
Overall, 1681 (976 TNF-naive, 298 TNFi-previous and 407 TNFi-recent) patients were treated; 5.1% discontinued treatment because of AEs. The AE rate was numerically higher in TNFi-recent (652.6/100 patient-years (PY)) and TNFi-previous (653.6/100PY) than in TNFi-naive (551.1/100PY) patients. Serious AE rates were 18.0/100PY, 28.0/100PY and 18.6/100PY; serious infection rates were 6.0/100PY, 6.8/100PY and 4.2/100PY, respectively. At week 4, 36.5% of patients achieved ACR20 response and 14.9% DAS28 remission (<2.6); at week 24, 66.9%, 46.6%, 26.4% and 56.8% achieved ACR20/ACR50/ACR70 responses and DAS28 remission, respectively. Overall, 61.6% (TNFi-naive), 48.5% (TNFi-previous) and 50.4% (TNFi-recent) patients achieved DAS28 remission.
In patients with RA who were DMARD-IR/TNFi-IR, tocilizumab ± DMARDs provided rapid and sustained efficacy without unexpected safety concerns.
PMCID: PMC3595980  PMID: 22615456

Results 1-11 (11)