Patients with autoimmune pancreatitis treated with steroids or immunomodulators were similarly prone to relapse, but rituximab effectively treated those intolerant or resistant to either therapy in a recent study.
Researchers evaluated 116 patients with type 1 autoimmune pancreatitis (AIP) treated with immunomodulators (IMs) or steroids alone following surgery or medical or supportive therapy. Patients who were resistant or unresponsive to either treatment received antiCD20 antibody rituximab, and their response was assessed via weekly liver function tests and radiographic evaluation.
Philip A. Hart
“This study was derived from over 10 years of clinical experience managing these challenging cases,” Philip A. Hart, MD, instructor of medicine, division of gastroenterology and hepatology at Mayo Clinic in Rochester, Minn., told Healio.com. “Since autoimmune pancreatitis is an uncommon disease, it has required years of accumulating data to be able to provide any coherent conclusions. Many clinicians have been faced with similar dilemmas, and encouraged us to publish our experience.”
Relapse occurred 76 times in 52 patients of 113 who received 1 month or more of follow-up. An additional course of steroids was administered to 24 of these patients after initial relapse, while 27 participants received both steroids and IM. Relapse-free survival was similar between these two groups, with nine of those receiving only steroids and eight of the IM-receiving patients experiencing relapse (P=.23).
Among 38 participants who received more than 2 months of IM therapy, 17 experienced treatment failure or intolerance. Other organs were found to be the primary factor associated with resistance; particularly retroperitoneal fibrosis, which was present in seven patients, all of whom were IM-resistant (P<.01 for both).
Twelve patients resistant to IM or steroid treatment received rituximab, and all participants experienced symptomatic improvement during the induction phase. Full remission without relapse occurred in 10 participants, with one experiencing incomplete remission and one experiencing a malignancy after partial remission that required treatment cessation. No disease recurrence was reported in this group across a median follow-up of 10.6 months. Three rituximab patients experienced adverse events related to treatment, with one developing a reaction to the initial infusion, one developing neutropenia 2.5 months after initial infusion and one diagnosed with probable bronchiolitis obliterans organizing pneumonia.
“We were unable to show that treating relapses with steroids plus immunomodulators was better at preventing relapses than using steroids alone,” Hart said. “On the other hand, essentially all patients treated with rituximab, even those resistant to immunomodulators … achieved complete remission of disease, [although] the durability of response is unknown. This is the first study detailing the management of patients with difficult-to-treat disease, and provides preliminary data for future studies regarding this increasingly common clinical scenario.”
Disclosure: Researcher Mark D. Topazian reported grant funding from Genentech expected later this year.