Maria Karlsson

A novel reflux inhibitor lesogaberan (AZD3355) as add-on treatment in patients with GORD with persistent reflux symptoms despite proton pump inhibitor therapy: a randomised placebo-controlled trial

Objective To evaluate the efficacy and tolerability of add-on treatment with lesogaberan (AZD3355), a novel reflux inhibitor, in patients with persistent gastro-oesophageal reflux disease (GORD) symptoms despite proton pump inhibitor (PPI) therapy. Methods A double-blind, placebo-controlled, randomised, parallel-group, multicentre phase IIA study was carried out in outpatient clinics. The study group comprised 244 adult patients with persistent GORD symptoms (heartburn and/or regurgitation) of at least mild intensity and for 3 days of 7 days before enrolment, despite ≥6 weeks of continuous PPI therapy. Patients received either lesogaberan (65 mg twice daily) or placebo in addition to PPI therapy for a period of 4 weeks. Symptom intensity, based on the Reflux Disease Questionnaire, was recorded twice daily. Treatment response (defined as at most one 24 h period with heartburn or regurgitation of not more than mild intensity during the last 7 days of treatment). Time to response, proportion of symptom-free days and measures of tolerability were also analysed. Results A total of 232 (114 lesogaberan- and 118 placebo-treated patients) of the 244 randomised patients were analysed for efficacy. Treatment with lesogaberan, compared with placebo, resulted in a significantly larger proportion of responders to treatment (16% vs 8% of patients; p=0.026) and cumulative proportion of responders over time (log-rank p=0.0195). Lesogaberan was well tolerated: adverse events of mostly mild to moderate intensity were reported in 45% of patients on lesogaberan and in 37% on placebo. Conclusions Lesogaberan add-on therapy to PPIs significantly improved heartburn and regurgitation symptoms; however, the proportion of responders was small. Clinical trial number NCT00394472.

Efficacy and safety of lesogaberan in gastro-oesophageal reflux disease: a randomised controlled trial

Objective Lesogaberan (AZD3355) is a novel γ-aminobutyric acid B-type receptor agonist designed to treat gastro-oesophageal reflux disease (GERD) by inhibiting transient lower oesophageal sphincter relaxations. A randomised, double-blind, placebo-controlled, multi-centre phase IIb study was performed to assess the efficacy and safety of lesogaberan as an add-on to proton pump inhibitor (PPI) therapy in patients with GERD who are partially responsive to PPI therapy (ClinicalTrials.gov reference: NCT01005251). Design In total, 661 patients were randomised to receive 4 weeks of placebo or 60, 120, 180 or 240 mg of lesogaberan twice daily, in addition to ongoing PPI therapy. Symptoms were measured using the Reflux Symptom Questionnaire electronic Diary. Response to treatment was defined as having an average of ≥3 additional days per week of not more than mild GERD symptoms during treatment compared with baseline. Results In the primary analysis, 20.9%, 25.6%, 23.5% and 26.2% of patients responded to the 60, 120, 180 and 240 mg twice daily lesogaberan doses, respectively, and 17.9% responded to placebo. The response to the 240 mg twice daily dose was statistically significantly greater than the response to placebo using a one-sided test at the predefined significance level of p<0.1. However, the absolute increases in the proportions of patients who responded to lesogaberan compared with placebo were low. Lesogaberan was generally well tolerated, although six patients receiving lesogaberan developed reversible elevated alanine transaminase levels. Conclusions In patients with GERD symptoms partially responsive to PPI therapy, lesogaberan was only marginally superior to placebo in achieving an improvement in symptoms.

A synthetic mammalian electro-genetic transcription circuit

Electric signal processing has evolved to manage rapid information transfer in neuronal networks and muscular contraction in multicellular organisms and controls the most sophisticated man-built devices. Using a synthetic biology approach to assemble electronic parts with genetic control units engineered into mammalian cells, we designed an electric power-adjustable transcription control circuit able to integrate the intensity of a direct current over time, to translate the amplitude or frequency of an alternating current into an adjustable genetic readout or to modulate the beating frequency of primary heart cells. Successful miniaturization of the electro-genetic devices may pave the way for the design of novel hybrid electro-genetic implants assembled from electronic and genetic parts.

A Versatile Approach to Engineering Biomolecule‐Presenting Cellular Microenvironments

By combining a novel protein-capture hydrogel with state-of-the-art mammalian recombinant protein production, cellular microenvironments are fabricated that locally instruct in-vitro cell behavior through selective presentation of the expressed proteins.

Therapeutic synthetic gene networks

The field of synthetic biology is rapidly expanding and has over the past years evolved from the development of simple gene networks to complex treatment-oriented circuits. The reprogramming of cell fate with open-loop or closed-loop synthetic control circuits along with biologically implemented logical functions have fostered applications spanning over a wide range of disciplines, including artificial insemination, personalized medicine and the treatment of cancer and metabolic disorders. In this review we describe several applications of interactive gene networks, a synthetic biology-based approach for future gene therapy, as well as the utilization of synthetic gene circuits as blueprints for the design of stimuli-responsive biohybrid materials. The recent progress in synthetic biology, including the rewiring of biosensing devices with the bodys endogenous network as well as novel therapeutic approaches originating from interdisciplinary work, generates numerous opportunities for future biomedical applications.

De novo Design and Construction of an Inducible Gene Expression System in Mammalian Cells

Inducible expression systems represent the founding technology for the emergence of synthetic biology in mammalian cells. The core molecules in these systems are bacterial regulator proteins that bind to or dissociate from a cognate DNA operator sequence in response to an exogenous stimulus like a small-molecule inducer. In this chapter, we describe a generic protocol of how bacterial regulator proteins can be applied to the design, construction, and optimization of an inducible expression system in mammalian cells. By choosing regulator proteins with an appropriate small-molecule inducer, this protocol provides a straightforward approach for establishing biosensors, cell-to-cell communication systems, or tools to control gene expression in vivo.

Validation of the Reflux Symptom Questionnaire Electronic Diary in Partial Responders to Proton Pump Inhibitor Therapy

OBJECTIVES:We aimed to develop and validate the Reflux Symptom Questionnaire electronic Diary (RESQ-eD) for use in clinical trials in patients with a partial response to proton pump inhibitor (PPI) therapy, using methods that meet US Food & Drug Administration (FDA) regulatory standards.METHODS:Patient interviews were performed to elicit new items and evaluate existing items from the Reflux Disease Questionnaire. The instruments measurement properties were evaluated, based on data from two clinical trials of patients with gastroesophageal reflux disease (GERD) with a partial response to PPIs who received lesogaberan or placebo as an add-on to PPI therapy.RESULTS:The content validity phase resulted in 13 RESQ-eD items. Principal component analysis supported a four-domain structure. All domains had a high inter-item correlation (Cronbachs alpha lower 95% confidence limit: 0.87–0.95). Test-retest reliability was good to excellent (intraclass correlation coefficient: 0.65–0.85). Convergent and discriminant validity was confirmed by correlation assessments referencing the Gastrointestinal Symptom Rating Scale. The RESQ-eD demonstrated a good ability to capture change in mean intensity and proportion of symptom-free days. Confirmatory psychometric evaluation verified internal consistency reliability, test-retest reliability, and ability to capture change.CONCLUSIONS:The RESQ-eD demonstrated good content validity and psychometric properties in the clinical trial setting in patients with GERD who have a partial response to PPI therapy. To our knowledge, the RESQ-eD is the first electronic symptom diary for use in partial responders to PPI that has been developed in line with the FDA guidance on patient-reported outcomes.

Cost and burden of gastroesophageal reflux disease among patients with persistent symptoms despite proton pump inhibitor therapy: an observational study in France

BackgroundGastrointestinal reflux disease (GERD) is a common disorder that negatively impacts health-related quality of life (HRQL) and work productivity. Many patients have only a partial response to proton pump inhibitor (PPI) therapy and continue to experience GERD symptoms despite optimized treatment. This observational study aimed to provide information on symptoms, HRQL, resource usage, costs and treatment pathways associated with partial response to PPI therapy in French patients with GERD.MethodsPatients with partial response to PPI therapy, defined as persistent GERD symptoms ≥3 days/week despite optimized treatment with a PPI, were recruited for this 12-month observational study. GERD symptoms, HRQL, work productivity and resource use were assessed by patient surveys. Costs were calculated based on lost work productivity and resource use.ResultsThe patient population (n=262; mean age, 54 years; 40% men) carried a significant symptom burden, with 98% of patients having moderate-to-severe GERD symptoms and 65% of patients experiencing daily symptoms at baseline. HRQL and work productivity were significantly impaired, with a greater degree of impairment in patients with higher symptom burden. The mean total cost per patient over the 12-month follow-up period was €5237, of which €4674 (89%) was due to lost work productivity.ConclusionsPartial response to PPI therapy for GERD is associated with a high symptom burden, significant impairment of HRQL and work productivity, and substantial GERD-related costs.

Pharmacologically Controlled Protein Switch for ON-OFF Regulation of Growth Factor Activity

The precise manipulation of growth factor signaling is central to the progress of tissue engineering. Methods for direct time-resolved activation of signaling pathways through controlled receptor dimerization have been reported; however, these suffer from the risks associated with gene transfer. Here we present an alternative gene transfer-free approach in the form of a protein switch featuring pharmacologically controlled ON-OFF regulation of growth factor activity. The reversible operation of the switch enables stimulation of target processes within a defined period of time. The protein switch provides a means for both studying and manipulating signaling processes, and is thus believed to be a valuable tool for basic research as well as tissue engineering and biomedical applications.

Cell-Mediated Proteolytic Release of Growth Factors from Poly(Ethylene Glycol) Matrices.

Engineering in vitro tissue mimetics that resemble the corresponding living tissues requires the 3D arrangement of tissue progenitor cells and their differentiation by localized growth factor (GF) signaling cues. Recent technological advances open a large field of possibilities for the creation of complex GF arrangements. Additionally, cell-instructive biomaterials, which bind GFs by various mechanisms and release them with different kinetics depending on binding affinity, have become available. This paper describes the development of a matrix metalloproteinase (MMP)-degradable streptavidin-based linker module, which allows the release of immobilized GFs from synthetic biomimetic poly(ethylene glycol) hydrogels independently of the hydrogel degradation. The MMP-sensitive streptavidin linker is shown to efficiently bind biotinylated molecules, and as proof of concept, bone morphogenetic protein-2 (BMP-2) delivery via the MMP-degradable linker is used to induce osteogenic differentiation in C2C12 cells and mesenchymal stem cells. The results show a significantly increased net effect of proteolytically releasable BMP-2 in comparison to stably immobilized and soluble BMP-2. This study indicates that a GF delivery system directly responsive to cellular activity can have important implications for the synthesis of tissue mimetics and regenerative medicine, as it can influence the availability, the localization of effects, as well as efficacy of employed GFs.