Diabetes management intervention studies: lessons learned from two studies.

INTRODUCTION: Several clinical studies investigated improvements of patient outcomes due to diabetes management interventions. However, chronic disease management is intricate with complex multifactorial behavior patterns. Such studies thus have to be well designed in order to allocate all observed effects to the defined intervention and to exclude effects of other confounders as well as possible. This article aims to provide challenges in interpreting diabetes management intervention studies and suggests approaches for optimizing study implementation and for avoiding pitfalls based on current experiences. MAIN BODY: Lessons from the STeP and ProValue studies demonstrated the difficulty in medical device studies that rely on behavioral changes in intervention group patients. To successfully engage patients, priority should be given to health care professionals being engaged, operational support in technical issues being available, and adherence being assessed in detail. Another difficulty is to avoid contamination of the control group with the intervention; therefore, strict allocation concealment should be maintained. However, randomization and blinding are not always possible. A limited effect size due to improvements regarding clinical endpoints in the control group is often caused by the Hawthorne effect. Improvements in the control group can also be caused with increased attention paid to the subjects. In order to reduce improvements in the control group, it is essential to identify the specific reasons and adjust study procedures accordingly. A pilot phase is indispensable for this. Another option is to include a third study arm to control for enhanced standard of care and study effects. Furthermore, retrospective data collection could be a feasible option. Adaptive study designs might reduce the necessity of a separate pilot study and combine the exploratory and confirmatory stages of an investigation in one single study. CONCLUSION: There are several aspects to consider in medical device studies when using interventions that rely on changes in behavior to achieve an effective implementation and significant study results. Improvements in the control group may reduce effect sizes and limit statistical significance; therefore, alternatives to the traditional randomized controlled trials may be considered.

[Studies on novel immune therapies: challenges from an ethical point of view]. / Studien zu neuen Immuntherapien: Herausforderungen aus Sicht der Ethik.

Novel immune therapies are more and more based on the molecular differentiation of disease patterns and related clinical studies are thus more often characterized by so-called adaptive study designs (umbrella or basket studies including platform studies), which are continuously adjusted based on novel results. This paper analyses new study designs beyond the often-postulated need for regulation in order to identify ethical problems based on typical structural features and to - whenever possible - suggest solutions. Additionally to the relationship between social and scientific values of a study as well as aspects of the scientific validity of new forms of evidence, the inclusion of study subjects under the condition of relative uncertainty, specific challenges in the process of ethical approval, as well as ethical and practical challenges in the process of informing patients and receiving informed consent will be addressed.

Clinical experience with desvenlafaxine in treatment of pain associated with diabetic peripheral neuropathy.

PURPOSE: To assess the safety and efficacy of the serotonin-norepinephrine reuptake inhibitor desvenlafaxine in adults with painful diabetic peripheral neuropathy (DPN). CLINICALTRIALSGOV IDENTIFIERS: NCT00283842, NCT01050218. PATIENTS AND METHODS: This was a 13-week, randomized, double-blind, placebo-controlled, fixed-dose study of desvenlafaxine in adults with painful DPN. The primary efficacy endpoint was change from baseline in numeric rating scale (NRS) score. Patients who completed the 13-week trial could continue in a 9-month open-label, flexible-dose extension study. RESULTS: A total of 412 patients were randomized to treatment with placebo or desvenlafaxine 50, 100, 200, or 400 mg/day. Of those, 240 patients continued in the extension study. After a planned interim analysis, conducted when the first 225 patients had completed 6 weeks of treatment in the short-term study, randomization to the 50 mg or 400 mg doses was stopped. At week 13, the mean change from baseline in NRS score was significantly greater compared with placebo in the desvenlafaxine 200 mg (difference [95% confidence interval {CI}]: 1.10 [0.50 to 1.70]; P<0.001) and 400 mg groups (0.91 [95% CI: 0.23 to 1.59]; P=0.027); differences from placebo were not statistically significant for the 50 mg (0.58 [95% CI: -0.08 to 1.25]) and 100 mg (0.59 [95% CI: -0.03 to 1.21]) groups. Nausea and dizziness were the most common treatment-emergent adverse events reported in the short-term study, and the most common adverse events leading to discontinuation in the short-term study and the extension. Adverse events rates were dose-dependent in the short-term studies. CONCLUSION: Desvenlafaxine was effective in relieving pain associated with DPN at doses of 200 and 400 mg/day, and improved activity impairment at all doses assessed. Desvenlafaxine was generally well-tolerated in the short-term and long-term studies.

Rethinking Phase II Clinical Trial Design in Heart Failure.

The incidence and economic burden of heart failure continue to rise worldwide, despite implementation of a number of effective heart failure therapies. Although there have been a number phase I-II studies of potential novel heart failure therapies over the past decade, none of these new compounds have been successful in phase III clinical trials. While there are likely a number of reasons for this failure, one of the problems that has become increasingly apparent is the inability of phase II trials to correctly identify novel therapies that will be successful in phase III clinical trials. In the following review, we will discuss the some of the problems inherent with current phase II heart failure clinical trials, as well as discuss possible ways to rethink phase II development of new therapies for heart failure.