Clinical trial finds safe, effective treatment for children with severe post-Covid syndrome

In a small trial, Mass General Brigham researchers found a drug designed to treat Celiac disease supported a more rapid return to normal activities for patients following COVID.

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious condition that can occur after a COVID-19 infection, presenting as high fevers, gastrointestinal symptoms, and life-threatening cardiac injury. A small, randomized clinical trial led by Mass General Brigham investigators found the oral drug larazotide-an experimental drug originally designed to treat Celiac disease-was both safe and effective in treating children with MIS-C. Their results are published in Science Translational Medicine.

“While our study is small, its results are powerful and have implications not only for MIS-C, but potentially for long COVID,” said lead author Lael Yonker, MD, co-director of the Cystic Fibrosis Center, Cystic Fibrosis Therapeutic Development Center, and Pulmonary Genetics Clinic at Mass General Brigham for Children. “Our findings suggest that larazotide is safe and quickly resolves symptoms in children with MIS-C. We are now running a clinical trial to test whether larazotide may also be a useful therapy to treat patients with long COVID.”

Current MIS-C treatments are limited. Some patients receive general anti-inflammatory drugs, but many experience a rebound of symptoms after completing a course. Such drugs are not designed to target the sticky SARS-CoV-2 viral particles that may persist in the gut. Enter larazotide, an orally administered drug that does target the gut. Larazotide strengthens intestinal barriers to limit the number of materials-like SARS-CoV-2 viral particles-that exit the intestines and enter circulation.

To test larazotide’s efficacy and safety as an MIS-C treatment, researchers conducted a double-blind clinical trial with 12 children experiencing early-stage MIS-C. The study was funded in part by the National Institutes of Health. Each patient randomly received either a placebo or larazotide four times daily for 21 days, then was tracked over six months of recovery. Children who received larazotide showed faster resolution of gastrointestinal symptoms, faster clearance of SARS-CoV-2 viral particles, and more rapid return to normal activities. The findings demonstrate larazotide may be a safe and promising treatment option for children with MIS-C.

Reference:

Lael M. Yonker et al. ,Viral spike antigen clearance and augmented recovery in children with post-COVID multisystem inflammatory syndrome treated with larazotide.Sci. Transl. Med.17,eadu4284(2025).DOI:10.1126/scitranslmed.adu4284.