Discoid cutaneous lupus is the most common cutaneous manifestation of lupus erythematosus, a chronic, immune mediated disease of unknown etiology. The immune processes underlying cutaneous lupus remain largely unexplored, but recent evidence suggests a role for dendritic cells (DCs), type 1 interferons (IFN) and Th1-type immune processes. Treatment of cutaneous lupus remains limited primarily to anti-malarials, with thalidomide an effective secondary agent. However, side effects associated with these treatments are potentially problematic with chronic use. Phosphodiesterases (PDE) are critical enzymes that degrade cAMP. In particular, PDE type 4 (PDE4) activity is found in inflammatory and immune cells, including DCs. The immune modulator CC-10004 is a PDE4 inhibitor with demonstrated low toxicity in phase I and II clinical studies with potential efficacy in cutaneous lupus. CC-10004 is a well-tolerated, selective PDE4 inhibitor with demonstrated inhibitory effects on Th1-type cytokines and other inflammatory mediators and is under development for the treatment of inflammatory and immune mediated conditions. Prior studies include pilot trials in psoriasis and exercise-induced asthma, with results suggesting clinical efficacy in the former study. This open label, pilot study of 16 weeks duration will explore the clinical and immune-modulating effects of CC-10004 in 10 cutaneous discoid lupus patients. Patients meeting study criteria will receive the drug for 12 weeks, followed by a 4-week washout period. Study visit time points will include weeks 0, 1, 2, 4, 6, 8, 10, 12 and 16, during which we will measure outcomes for clinical, immunological and safety parameters. To investigate early immunological changes occurring in response to treatment, we will also perform skin punch biopsies of lesional sites at week 0 and week 4 for immunohistochemical and molecular analysis.
