Improved glycaemic control, as measured by reduction in glycated haemoglobin levels (HbA1c), should not be considered a useful end-point going forward, even though it was used (albeit unsuccessfully) in the Phase III teplizumab (anti-CD3) trial. Patients enrolled into intervention trials should be treated to prespecified HbA1c target levels using standard clinical care, and thus any differences between treatment and placebo groups GS 1101 raise concerns about

study design and conduct. In general, therefore, changes in immune correlates of the autoimmune process [5] have not been selected as study end-points, even though the disease process is

immune-mediated. Given that defining changes in disease progression by C-peptide measurement imposes long-term study follow-up, and new insights which suggest that β cell function does not necessarily equate with β cell mass [6], there is a strong argument to be made that the field should shift towards alternative, immune-based end-points that can deliver more rapidly and potentially in smaller-sized treatment groups, at least at a ‘proof-of-concept’ stage [5, 7]. As the unmet medical needs and potential benefits of successful immunotherapy are find more greatest in children, it is evident that the inclusion of children in clinical trials is highly desirable, provided that there is adequate risk assessment. Indeed, the inclusion of younger patients in the rituximab trial secured short-term efficacy

that would have remained unnoticed if subjects only beyond 18 years of age had been recruited [8]. Effects of otelixizumab in older patients became apparent only upon extended follow-up [9]. In addition to age, the timing Avelestat (AZD9668) of inclusion and window of opportunity for success in relation to disease progression remain poorly defined. Depending on the type of intervention, it may prove difficult to treat during the medical emergency of newly manifested disease, although early enrolment (typically 3 months after diagnosis) has become the common inclusion criterion for intervention trials. As β cells survive up to decades after diagnosis, together with insulitic lesions [10, 11], there is in reality no reason to exclude patients beyond 3–6 months after diagnosis who have measurable C-peptide, other than the slower slope in decline of stimulated β cell function and associated reduced statistical power to define treatment-induced changes. This, again, argues for alternative (surrogate) end-points of therapeutic efficacy [5].