Fiorentino, David Franklin

Abstract Dermatomyositis is driven by overactivation of type I and II interferons and other proinflammatory cytokines that signal via the JAK-STAT pathway. We conducted a 12-week, open-label study of brepocitinib, an oral TYK2/JAK1 inhibitor, in five adults with severe cutaneous dermatomyositis. Treatment was associated with rapid, clinically meaningful improvement in cutaneous disease activity. Single-cell and spatial transcriptomic profiling of lesional skin showed marked suppression of interferon-responsive pathways and inflammatory cell states by week 4. Together with findings from a Phase 3 randomized trial in DM patients with skin and muscle involvement (VALOR, NCT05437263 ), these data support TYK2/JAK1 inhibition as a promising therapeutic strategy for DM.

Objective To prepare a dermatologic addendum to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides ( CHCC 2012) to address vasculitides affecting the skin (D‐ CHCC ). The goal was to standardize the names and definitions for cutaneous vasculitis. Methods A nominal group technique with a facilitator was used to reach consensus on the D‐ CHCC nomenclature, using multiple face‐to‐face meetings, e‐mail discussions, and teleconferences. Results Standardized names, definitions, and descriptions were adopted for cutaneous components of systemic vasculitides (e.g., cutaneous IgA vasculitis as a component of systemic IgA vasculitis), skin‐limited variants of systemic vasculitides (e.g., skin‐limited IgA vasculitis, drug‐induced skin‐limited antineutrophil cytoplasmic antibody–associated vasculitis), and cutaneous single‐organ vasculitides that have no systemic counterparts (e.g., nodular vasculitis). Cutaneous vasculitides that were not included in the CHCC 2012 nomenclature were introduced. Conclusion Standardized names and definitions are a prerequisite for developing validated classification and diagnostic criteria for cutaneous vasculitis. Accurate identification of specifically defined variants of systemic and skin‐limited vasculitides requires knowledgeable integration of data from clinical, laboratory, and pathologic studies. This proposed nomenclature of vasculitides affecting the skin, the D‐ CHCC , provides a standard framework both for clinicians and for investigators.

ObjectiveTo develop response criteria for adult dermatomyositis (DM) and polymyositis (PM).MethodsExpert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures. Myositis experts rated greater improvement among multiple pairwise scenarios in conjoint analysis surveys, where different levels of improvement in 2 core set measures were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined the relative weights of core set measures and conjoint analysis definitions. The performance characteristics of the definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using data from a clinical trial. The nominal group technique was used to reach consensus.ResultsConsensus was reached for a conjoint analysis–based continuous model using absolute percent change in core set measures (physician, patient, and extramuscular global activity, muscle strength, Health Assessment Questionnaire, and muscle enzyme levels). A total improvement score (range 0–100), determined by summing scores for each core set measure, was based on improvement in and relative weight of each core set measure. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the total improvement score. The same criteria were chosen for juvenile DM, with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 92% and 98% for minimal, moderate, and major improvement, respectively. Definitions were validated in the clinical trial analysis for differentiating the physician rating of improvement (P < 0.001).ConclusionThe response criteria for adult DM/PM consisted of the conjoint analysis model based on absolute percent change in 6 core set measures, with thresholds for minimal, moderate, and major improvement.