Study protocol: A multi-centre, double blind, randomised, placebo-controlled, parallel group, phase II trial (RIDD) to determine the efficacy of intra-nodular injection of anti-TNF to control disease progression in early Dupuytren’s disease, with an embedded dose response study. [version 1; peer review: 1 approved, 1 approved with reservations]

Dupuytren’s disease is a common fibrotic condition of the hand affecting 4% of the population and causes the fingers to curl irreversibly into the palm. It has a strong familial tendency, there is no approved treatment for early stage disease, and patients with established digital contractures are most commonly treated by surgery. This is associated with prolonged recovery, and less invasive techniques have high recurrence rates.The myofibroblasts, the cells responsible for the excessive matrix deposition and contraction, are aggregated in nodules. Using excised diseased and control human tissue, we found that immune cells interspersed amongst the myofibroblasts secrete cytokines. Of these, only tumour necrosis factor (TNF) promoted the development of myofibroblasts. The clinically approved anti-TNF agents led to inhibition of the myofibroblast phenotype <ns4:italic>in vitro</ns4:italic>. This clinical trial is designed to assess the efficacy of the anti-TNF agent adalimumab on participants with early disease. The first part is a dose-ranging study where nodules of participants already scheduled for surgery will be injected with either placebo (saline) or varying doses of adalimumab. The excised tissue will then be analysed for markers of myofibroblast activity.The second part of the study will recruit participants with early stage disease. They will be randomised 1: 1 to receive either adalimumab or placebo at 3 month intervals over 1 year and will then be followed for a further 6 months. Outcome measures will include nodule hardness, size and disease progression. The trial will also determine the cost-effectiveness of adalimumb treatment for this group of participants.