Efficacy and safety of adjuvant immunoadsorption in pemphigus vulgaris and pemphigus foliaceus (IA-Pem Study): a multicentre randomized controlled trial

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are potentially life-threatening autoimmune blistering diseases. Treatment is based on long-term immunosuppression with high doses of glucocorticosteroids in combination with potentially corticosteroid-sparing agents and/or rituximab. Immunoadsorption (IA) has emerged as a fast-acting adjuvant treatment option. To assess the clinical efficacy of IA in addition to best medical treatment (BMT). We conducted a multicentre (26 centres from Germany and Austria) randomized controlled trial in 72 patients with newly diagnosed, relapsed or chronic active PV or PF (34 female patients and 38 male patients, aged 42-72 years) comparing BMT (prednisolone 1.0 mg kg-1 per day plus azathioprine or mycophenolate) with adjuvant IA (BMT + IA). Central 1 : 1 randomization was done at the coordinating centre for clinical trials (KKS Marburg). The primary endpoint was analysed using Kaplan-Meier and Cox regression methods. The study was ended prematurely owing to safety concerns after random allocation of 72 patients to BMT + IA (n = 34) or BMT (n = 38). The primary endpoint, time to complete remission on therapy, was not significantly different for the two groups [hazard ratio (HR) 1.35, 95% confidence interval (CI) 0.68-2.69; P = 0.39]. The cumulative dose of prednisolone was significantly lower in the BMT + IA group compared with BMT alone (difference -1214, 95% CI -2225 to -70; P = 0.03). In a post hoc analysis, patients with more extensive PV/PF showed a tendency towards a shorter time to remission in the BMT + IA group compared with the BMT group (HR 1.87, P = 0.17 in patients with baseline Pemphigus Disease Area Index ≥ 15). While more adverse events were observed in patients in the BMT group (29 vs. 25), severe adverse events were more frequent in patients in the BMT + IA group (17 events in 10 patients vs. 11 events in 8 patients). In this study, adjuvant IA did not demonstrate a shorter time to clinical remission, but a corticosteroid-sparing effect was observed. In patients with extensive PV/PF, post hoc analysis suggests that adjuvant IA may lead to earlier remission, but potential adverse events must be carefully weighed against the expected benefits.