Morphea, like systemic sclerosis (SSc), presents with sclerotic hardening of the skin. However, unlike SSc, morphea has no systemic involvement. While this skin-limited, chronic sclerosis, has no impact on mortality, it can have significant morbidity, as lesions can affect joint mobility, and be disfiguring, especially when involving the face. While some patients respond well to use of steroids, whether topical or intralesional, antimalarials such as plaquenil, or traditional immuno-suppressants there is a significant proportion of patients who remain non-responsive to these treatments, or require high dosages of these, oral steroids, or experimental therapies to suppress the condition. For this group of patients there is a high clinical need to find alternate therapies. In addition, as the disease creates permanent scarring, and traditional immuno-suppressants take several months to take effect there is a need for medications that can act more quickly to halt the progression of scarring.
Although the pathways of inflammation are poorly understood, one cytokine of potential interest is IL (interleukin)-6. In the bleomycin mouse model of skin sclerosis targeting IL-6 by both passive and active immunization strategies prevented the development of bleomycin-induced dermal fibrosis. Dysregulation of IL-6 has also been seen in the serum of patients suffering from SSc. As a result, preliminary clinical trials have been undertaken in SSc. While results did not reach statistical significance the skin thickening was better in the treatment group than in placebo and the lack of signal is likely due to the late stage of patients skin involvement, and the slow progression of thickening in SSc. In contrast morphea often progresses rapidly and as such is much more likely to give a clear clinical signal.
Recently sarilumab, an anti-IL-6 monoclonal antibody, has been approved for use in severe rheumatoid arthritis (RA) after rapid and sustained results in clinical trials. Given its good safety profile, its impressive response in RA, and the immunohistochemical evidence that IL-6 may be important in creation of sclerosis in SSc, the investigators propose a pilot study to determine the safety and efficacy of sarilumab in morphea.
