Khalaf Kridin, Christoph M. Hammers, Ralf J. Ludwig, Dana Tzur Bitan, Arnon D. Cohen
DOI: 10.2340/00015555-3831

Drug survival reflects the real-life efficacy and safety of therapeutic agents. Evidence regarding the durability of adjuvant agents in the treatment of pemphigus is sparse. The aims of this study were to investigate the survival of adjuvant agents used to manage patients with pemphigus, and to identify predictors of treatment dropout. A retrospective population-based cohort study was designed to follow patients with pemphigus managed by adjuvant agents. The study population included 436 patients with pemphigus managed by 608 adjuvant agent courses. The highest median drug survival time was observed for rituximab (43.6 months, 95% confidence interval (95% CI) 5.3–81.9), followed by cyclophosphamide (30.5 months; 95% CI 10.5–50.5), azathioprine (22.9 months; 95% CI 15.6–30.2), and mycophenolate mofetil (20.2 months; 95% CI 10.0–30.4). Compared with azathioprine, cyclosporine (adjusted hazard ratio 2.98; 95% CI 1.57–5.62; p = 0.005) and dapsone (adjusted hazard ratio 1.83; 95% CI 1.07–3.15; p = 0.027) were associated with a significantly increased risk of drug discontinuation. To conclude, rituximab, azathioprine, and mycophenolate mofetil demonstrated better durability, whilst dapsone and cyclosporine were associated with low drug survival and high dropout.

This large-scale population-based cohort study found that rituximab had the highest median drug survival time compared with the remaining adjuvant agents used to treat patients with pemphigus. Dapsone and cyclosporine were associated with increased risk of adjuvant drug dropout. This study provides evidence in favour of the efficacy and safety of azathioprine, mycophenolate mofetil, and rituximab in pemphigus, and implies that the use of dapsone and cyclosporine in pemphigus should be abandoned.