Drug Survival in the Treatment of Mucosal Lichen Planus: A Retrospective Multicenter Study

Background and Objectives: Mucosal lichen planus (LP) is a rare chronic inflammatory skin disease. Its treatment is difficult and comparative data on the sustainability of different drugs are lacking. We aimed to retrospectively assess patient and disease characteristics and analyze drug survival rates in the treatment of mucosal LP under real‐world conditions. Patients and Methods: Our retrospective study included patients with mucosal LP treated systemically in the dermatology departments of five German University Medical Centers between 01/2005 and 03/2022. Patient and disease characteristics and treatment responses were evaluated. Drug survival from systemic therapies was assessed by Kaplan–Meier analysis and multivariate regression. Results: Overall, 281 patients with a total of 407 treatment courses were identified. The overall median drug survival was 5.0 months (conventional drugs: 5.0 months vs. novel drugs [biologicals and Janus kinase inhibitors]: 17.0 months, p = 0.029). Among conventional drugs, median drug survival was numerically the highest for methotrexate (13.0 months), followed by mycophenolate mofetil (12.0 months); hydroxychloroquine (9.0 months); acitretin and cyclosporine (6.0 months each); azathioprine, dapsone, and other retinoids (5.0 months each); and finally glucocorticoids (2.0 months). Among novel drugs, median drug survival was numerically the highest in TNF‐α blockers and IL‐17 antagonists (median: 21.0 and 17.0 months, respectively), while median drug survival for Janus kinase inhibitors has not yet been reached. Altogether, the outcomes were documented in 68.6% of cases, with excellent (33.5%), partial (34.5%) or nonresponse (32.0%) in one‐third of cases each. The group of novel therapies comprising biologicals and Janus kinase inhibitors was significantly more effective than the group of conventional drugs (excellent response: 66.7%, 8/12 vs. 32.1%, 83/258; P = 0.013, χ 2 ‐test). Conclusions: In addition to glucocorticoids, cyclosporine, mycophenolate mofetil, and methotrexate (plus hydroxychloroquine), biologicals and Janus kinase inhibitors in particular seem to be therapeutic options for the treatment of mucosal LP, which is worth investigating further.