The term ‘biologic cyclosporin’ has been coined in this context. The recently reported failure of anti-thymocyte globulin to preserve C-peptide in a Phase II setting is a further wake-up

call in this respect, emphasizing at the same time the complexity of human cellular autoimmune responsiveness and the bluntness of some of the tools at our disposal [22]. While biologics may prevent priming or spreading of the immune response, for most there is little evidence that they affect existing adaptive immunity. Indeed, abatacept [cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA4-Ig)] is effective at preventing CX 5461 priming alloreactivity, but appears to have little impact in reversing primed islet autoimmunity [14]. The reduced requirement for co-stimulation of autoreactive memory T cells [23] probably explains the limited clinical efficacy observed in the established disease process of chronic islet autoimmunity [14]. None the less, Selleck RAD001 dimming immune reactivity with abatacept proved successful in delaying the progressive loss of stimulated C-peptide capacity in some patients in this study. The fact that the effect waned, even during continued treatment, again hints at disease heterogeneity, for example in the degree to which

autoreactive T cell responses are co-stimulation-dependent. With the exception of a small study using tumour necrosis factor (TNF)-α blockade [24], which showed potential clinical efficacy (which cannot currently be explored further due to safety concerns; see Table 4), interference in the activity of effector cytokines has not yet delivered in type 1 diabetes, as underlined by two recent failed studies of IL-1 blockade [25] (Table 4). This is in striking contrast with rheumatoid

arthritis (e.g. benefits of blockade of TNF-α, IL-6 receptor, IL-1) and psoriasis (TNF-α, IL-23 and IL-17 pathways, IL-1). A central role for these cytokines in the immunopathogenesis may therefore be worthy of greater scrutiny and reconsideration, in spite of their clear role in some preclinical models of autoimmune diabetes and other autoimmune diseases. It remains plausible, of course, that cytokine inhibition SPTLC1 will be highly effective and synergistic in combinations with other immune intervention strategies, as preclinical models imply [26]. Viewed by many as the best chance to restore immunological self-tolerance in autoimmune diseases, antigen-specific immunotherapy (ASI) faces many challenges in its development and deployment, which is perhaps reflected in the more limited pipelines and activity in this arena (Tables 1 and 3; Fig. 1). Many of the relevant issues have been discussed elsewhere [27], but to put this modality into perspective several of the notable challenges are highlighted in Table 6. Perhaps in reflection of these, there has been limited new activity in this arena since 2007.