Baricitinib for Prurigo Nodularis: A Pilot Study on Efficacy and Safety

Background. Breaking the itch-scratch cycle and facilitating lesion healing are pivotal in managing prurigo nodularis (PN). This study seeks to assess the efficacy of baricitinib, an oral JAK1/2 inhibitor, for treating PN. Methods. In this prospective pilot study, 12 patients with moderate to severe PN were administered oral baricitinib at a dosage of 4 mg/day for 12 weeks. The primary objective was to assess the efficacy of baricitinib in PN patients using the numeric rating scale (NRS) for pruritus, NRS sleep score, a 5-point investigator’s global assessment (IGA) scale, dermatology life quality index (DLQI), and nodular lesion count at weeks 0, 1, 2, 4, 8 and 12. In addition, the NRS pruritus and sleep scores were assessed via phone on days 2 and 4 after baricitinib treatment. Results. Baricitinib treatment led to a statistically significant improvement in the mean NRS pruritus and sleep scores, evident as early as day 2 (57.7% change from baseline; P<0.001, and 34.7% change from baseline, P=0.029, respectively) and consistently declining thereafter. Evaluation of nodular lesions revealed a significant reduction starting from week 2 (mean difference of 37.08 from baseline; P<0.001). Analysis of other endpoints, including mean DLQI and IGA scores, also demonstrated substantial improvement at all time points (week 1, 2, 4, 8, and 12) compared to baseline. However, it is important to acknowledge the limitation of a small sample size. This constraint warrants consideration when interpreting the results and generalizing the findings. Conclusion. This preliminary study underscores baricitinib’s potential for PN treatment by providing a rapid clinical response. The larger and longer randomized controlled trials are essential to determine the effectiveness, longevity, and safety of baricitinib in managing PN. This trial is registered with TCTR20230227002.