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1.
Trials ; 25(1): 169, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38448965

ABSTRACT

BACKGROUND: Good vision highly depends on the transparency of the cornea, which is the "windscreen" of the eye. In fact, corneal blindness due to transparency loss is the second most common cause of blindness worldwide, and corneal transplantation is the main cure. Importantly, the cornea is normally avascular but can secondarily be invaded by pathological (blood and lymphatic) vessels due to severe inflammation, and the survival prognosis of a corneal graft mainly depends on the preoperative vascular condition of the recipient's cornea. Whereas transplants placed into avascular recipient beds enjoy long-term survival rates of > 90%, survival rates significantly decrease in pathologically pre-vascularized, so-called high-risk recipients, which account for around 10% of all performed transplants in Germany and > 75% in lower and middle-income countries worldwide. METHODS: This parallel-grouped, open-randomized, multicenter, prospective controlled exploratory investigator-initiated trial (IIT) intends to improve graft survival by preconditioning pathologically vascularized recipient corneas by (lymph)angioregressive treatment before high-risk corneal transplantation. For this purpose, corneal crosslinking (CXL) will be used, which has been shown to potently regress corneal blood and lymphatic vessels. Prior to transplantation, patients will be randomized into 2 groups: (1) CXL (intervention) or (2) no pretreatment (control). CXL will be repeated once if insufficient reduction of corneal neovascularization should be observed. All patients (both groups) will then undergo corneal transplantation. In the intervention group, remaining blood vessels will be additionally regressed using fine needle diathermy (on the day of transplantation). Afterwards, the incidence of graft rejection episodes will be evaluated for 24 months (primary endpoint). Overall graft survival, as well as regression of corneal vessels and/or recurrence, among other factors, will be analyzed (secondary endpoints). DISCUSSION: Based on preclinical and early pilot clinical evidence, we want to test the novel concept of temporary (lymph)angioregressive pretreatment of high-risk eyes by CXL to promote subsequent corneal graft survival. So far, there is no evidence-based approach to reliably improve graft survival in the high-risk corneal transplantation setting available in clinical routine. If successful, this approach will be the first to promote graft survival in high-risk transplants. It will significantly improve vision and quality of life in patients suffering from corneal blindness. TRIAL REGISTRATION: ClinicalTrials.gov NCT05870566. Registered on 22 May 2023.


Subject(s)
Corneal Transplantation , Graft Survival , Humans , Prospective Studies , Quality of Life , Ultraviolet Rays/adverse effects , Corneal Transplantation/adverse effects , Cornea/surgery , Blindness , Randomized Controlled Trials as Topic , Multicenter Studies as Topic
2.
BMC Cancer ; 20(1): 781, 2020 Aug 20.
Article in English | MEDLINE | ID: mdl-32819399

ABSTRACT

BACKGROUND: Adenocarcinoma of the gastroesophageal junction (GEJ) Siewert type II can be resected by transthoracic esophagectomy or transhiatal extended gastrectomy. Both allow for a complete tumor resection, yet there is an ongoing controversy about which surgical approach is superior with regards to quality of life, oncological outcomes and survival. While some studies suggest a better oncological outcome after transthoracic esophagectomy, others favor transhiatal extended gastrectomy for a better postoperative quality of life. To date, only retrospective studies are available, showing ambiguous results. METHODS: This study is a multinational, multicenter, randomized, clinical superiority trial. Patients (n = 262) with a GEJ type II tumor resectable by both transthoracic esophagectomy and transhiatal extended gastrectomy will be enrolled in the trial. Type II tumors are defined as tumors with their midpoint between ≤1 cm proximal and ≤ 2 cm distal of the top of gastric folds on preoperative endoscopy. Patients will be included in one of the participating European sites and are randomized to either transthoracic esophagectomy or transhiatal extended gastrectomy. The trial is powered to show superiority for esophagectomy with regards to the primary efficacy endpoint overall survival. Key secondary endpoints are complete resection (R0), number and localization of tumor infiltrated lymph nodes at dissection, post-operative complications, disease-free survival, quality of life and cost-effectiveness. Postoperative survival and quality of life will be followed-up for 24 months after discharge. Further survival follow-up will be conducted as quarterly phone calls up to 60 months. DISCUSSION: To date, as level 1 evidence is lacking, there is no consensus on which surgery is superior and both surgeries are used to treat GEJ type II carcinoma worldwide. The CARDIA trial is the first randomized trial to compare transthoracic esophagectomy versus transhiatal extended gastrectomy in patients with GEJ type II tumors. Several quality control measures were implemented in the protocol to ensure data reliability and increase the trial's significance. It is hypothesized that esophagectomy allows for a higher rate of radical resections and a more complete mediastinal lymph node dissection, resulting in a longer overall survival, while still providing an acceptable quality of life and cost-effectiveness. TRIAL REGISTRATION: The trial was registered on August 2nd 2019 at the German Clinical Trials Register under the trial-ID DRKS00016923 .


Subject(s)
Esophageal Neoplasms/surgery , Esophagectomy/methods , Esophagogastric Junction/pathology , Gastrectomy/methods , Postoperative Complications/epidemiology , Stomach Neoplasms/surgery , Adult , Cardia/pathology , Cardia/surgery , Cost-Benefit Analysis , Disease-Free Survival , Equivalence Trials as Topic , Esophageal Neoplasms/economics , Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Esophagectomy/adverse effects , Esophagogastric Junction/surgery , Esophagus/pathology , Esophagus/surgery , Europe/epidemiology , Female , Follow-Up Studies , Gastrectomy/adverse effects , Gastrectomy/economics , Humans , Lymph Node Excision , Male , Margins of Excision , Multicenter Studies as Topic , Postoperative Complications/economics , Postoperative Complications/etiology , Prospective Studies , Quality of Life , Randomized Controlled Trials as Topic , Stomach Neoplasms/economics , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology
3.
J Antimicrob Chemother ; 75(3): 618-627, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31828337

ABSTRACT

OBJECTIVES: To investigate pharmacokinetics (PK) and safety (primary objectives) and efficacy (secondary objective) of the investigational monobactam/ß-lactamase inhibitor combination aztreonam/avibactam in patients with complicated intra-abdominal infection (cIAI). METHODS: This Phase 2a open-label, multicentre study (NCT02655419; EudraCT 2015-002726-39) enrolled adults with cIAI into sequential cohorts for 5-14 days treatment. Cohort 1 patients received an aztreonam/avibactam loading dose of 500/137 mg (30 min infusion), followed by maintenance doses of 1500/410 mg (3 h infusions) q6h; Cohort 2 received 500/167 mg (30 min infusion), followed by 1500/500 mg (3 h infusions) q6h. Cohort 3 was an extension of exposure at the higher dose regimen. Doses were adjusted for creatinine clearance of 31-50 mL/min (Cohorts 2 + 3). All patients received IV metronidazole 500 mg q8h. PK, safety and efficacy were assessed. RESULTS: Thirty-four patients (Cohort 1, n = 16; Cohorts 2 + 3, n = 18) comprised the modified ITT (MITT) population. Mean exposures of aztreonam and avibactam in Cohorts 2 + 3 were consistent with those predicted to achieve joint PK/pharmacodynamic target attainment in >90% patients. Adverse events (AEs) were similar between cohorts. The most common AEs were hepatic enzyme increases [n = 9 (26.5%)] and diarrhoea [n = 5 (14.7%)]. Clinical cure rates at the test-of-cure visit overall were 20/34 (58.8%) (MITT) and 14/23 (60.9%) (microbiological-MITT population). CONCLUSIONS: Observed AEs were consistent with the known safety profile of aztreonam monotherapy, with no new safety concerns identified. These data support selection of the aztreonam/avibactam 500/167 mg (30 min infusion) loading dose and 1500/500 mg (3 h infusions) maintenance dose q6h regimen, in patients with creatinine clearance >50 mL/min, for the Phase 3 development programme.


Subject(s)
Aztreonam , Intraabdominal Infections , Adult , Anti-Bacterial Agents/adverse effects , Azabicyclo Compounds/adverse effects , Aztreonam/adverse effects , Ceftazidime , Drug Combinations , Humans , Intraabdominal Infections/drug therapy
4.
Clin Trials ; 14(6): 584-596, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28786330

ABSTRACT

Background According to Good Clinical Practice, clinical trials must protect rights and safety of patients and make sure that the trial results are valid and interpretable. Monitoring on-site has an important role in achieving these objectives; it controls trial conduct at trial sites and informs the sponsor on systematic problems. In the past, extensive on-site monitoring with a particular focus on formal source data verification often lost sight of systematic problems in study procedures that endanger Good Clinical Practice objectives. ADAMON is a prospective, stratified, cluster-randomised, controlled study comparing extensive on-site monitoring with risk-adapted monitoring according to a previously published approach. Methods In all, 213 sites from 11 academic trials were cluster-randomised between extensive on-site monitoring (104) and risk-adapted monitoring (109). Independent post-trial audits using structured manuals were performed to determine the frequency of major Good Clinical Practice findings at the patient level. The primary outcome measure is the proportion of audited patients with at least one major audit finding. Analysis relies on logistic regression incorporating trial and monitoring arm as fixed effects and site as random effect. The hypothesis was that risk-adapted monitoring is non-inferior to extensive on-site monitoring with a non-inferiority margin of 0.60 (logit scale). Results Average number of monitoring visits and time spent on-site was 2.1 and 2.7 times higher in extensive on-site monitoring than in risk-adapted monitoring, respectively. A total of 156 (extensive on-site monitoring: 76; risk-adapted monitoring: 80) sites were audited. In 996 of 1618 audited patients, a total of 2456 major audit findings were documented. Depending on the trial, findings were identified in 18%-99% of the audited patients, with no marked monitoring effect in any of the trials. The estimated monitoring effect is -0.04 on the logit scale with two-sided 95% confidence interval (-0.40; 0.33), demonstrating that risk-adapted monitoring is non-inferior to extensive on-site monitoring. At most, extensive on-site monitoring could reduce the frequency of major Good Clinical Practice findings by 8.2% compared with risk-adapted monitoring. Conclusion Compared with risk-adapted monitoring, the potential benefit of extensive on-site monitoring is small relative to overall finding rates, although risk-adapted monitoring requires less than 50% of extensive on-site monitoring resources. Clusters of findings within trials suggest that complicated, overly specific or not properly justified protocol requirements contributed to the overall frequency of findings. Risk-adapted monitoring in only a sample of patients appears sufficient to identify systematic problems in the conduct of clinical trials. Risk-adapted monitoring has a part to play in quality control. However, no monitoring strategy can remedy defects in quality of design. Monitoring should be embedded in a comprehensive quality management approach covering the entire trial lifecycle.


Subject(s)
Biomedical Research/standards , Clinical Protocols , Clinical Trials as Topic/standards , Risk Assessment/standards , Clinical Trials Data Monitoring Committees , Clinical Trials as Topic/statistics & numerical data , Cluster Analysis , Data Interpretation, Statistical , Humans , Logistic Models , Prospective Studies , Quality Control
5.
Clin Trials ; 6(6): 585-96, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19897532

ABSTRACT

BACKGROUND: The concept of risk assessment for clinical trials has been discussed before, but no comprehensive structured procedure leading to risk-adapted quality management has been published so far. Such a procedure is of particular interest for noncommercial trials in order to optimally use the sparse resources. PURPOSE: To provide a structured procedure for risk analysis in clinical trials. To propose strategies for on-site monitoring adapted to the risks identified. RESULTS: The risk analysis refers to the risk of noncompliance with the main objectives of Good Clinical Practice. It takes into account risks of the study intervention compared to the risks a patient would run if treated outside a protocol as well as further potential risks regarding patient safety, patient rights, or the credibility of results. The risk analysis is based on detailed questionnaires, which are used to draw up (a) an on-site monitoring strategy recommendation, (b) a list of trial-specific tasks to be covered by on-site monitoring, and (c) a specification of further quality management measures e.g., central monitoring measures. The resulting risk-adapted monitoring strategies focus on the trial's critical aspects, and differ in terms of the recommended extent of on-site activities. LIMITATIONS: The effectiveness of the proposed risk analysis and risk-adapted monitoring has not yet been confirmed. However, the ADAMON project (prospective cluster-randomised study of trial-specific adapted strategies for on-site monitoring in combination with additional quality management measures) has been started in Germany to investigate whether a trial-specific, risk-adapted, reduced on-site monitoring strategy is as effective as an intensive monitoring strategy with regard to the occurrence of serious or critical audit findings. Twelve clinical trials planning to recruit more than 3200 patients participate in this investigation. CONCLUSIONS: Our proposal will provide sponsor-investigators and other noncommercial sponsors with an instrument that may facilitate risk analysis and the implementation of targeted quality management measures.


Subject(s)
Clinical Protocols , Clinical Trials as Topic/methods , Quality Control , Research Design , Clinical Trials Data Monitoring Committees/organization & administration , Data Interpretation, Statistical , Decision Making , Humans , Reminder Systems , Risk Assessment , Safety Management/organization & administration
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