Immune enhancement to prevent infected pancreatic necrosis: A double-blind randomized controlled trial

BACKGROUND&AIMS Infected pancreatic necrosis (IPN) is a highly morbid complication of acute pancreatitis(AP). Since there is evidence of immunosuppression in the early phase of AP, immune enhancement using Thymosin alpha 1 (Tα1), which stimulates both innate and adaptive immunity, may be a therapeutic strategy to prevent IPN. Our aim was to assess the efficacy of early Tα1 treatment on the development of IPN. METHODS We conducted a multicenter, randomized, double-blind, placebo-controlled trial in patients with predicted severe acute necrotizing pancreatitis (ANP). ANP patients with an APACHE II score≥8 admitted within seven days of the advent of symptoms were considered eligible. Enrolled patients were assigned to receive a subcutaneous injection of Tα1 1.6 mg, every 12 hours for the first 7 days and 1.6 mg once a day for the subsequent 7 days or matching placebo (normal saline). The primary outcome was the development of IPN during the index admission. RESULTS From Mar 2017 through Dec 2020, 508 patients were randomized at 16 hospitals, of whom 254 were assigned to receive Tα1 and 254 placebo. During the index admission, 40/254 (15.7%) patients in the Tα1 group developed IPN compared with 46/254 patients (18.1%) in the placebo group (difference -2.4% [95%CI -7.4% to 5.0%]; p=0.47). The results were similar in four predefined subgroups. There was no difference in other major complications, including new-onset organ failure (10.6% vs. 15.0%; p=0.15), bleeding (6.3% vs. 3.5%; p=0.15), and gastrointestinal fistula (2.0% vs. 2.4%; p=0.75) during the index admission. CONCLUSIONS The immune-enhancing Tα1 treatment of patients with predicted severe ANP did not reduce the incidence of IPN during the index admission.