Investigational Celiac Treatment Found Safe, Effective for Children with Severe Post-Covid Syndrome

Lael Yonker, MD

Image credit: Mass General Brigham

A small study found the larazotide—an experimental drug originally developed to treat Celiac disease—was both safe and effective in treating children with MIS-C. The results were published in the journal, Science Translational Medicine. ¹

“Children treated with larazotide displayed faster resolution of gastrointestinal symptoms, faster clearance of spike antigen, and a faster return to usual activities,” the investigators wrote.²

“Our findings suggest that larazotide is safe and quickly resolves symptoms in children with MIS-C," 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, said in a statement. ¹

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.¹ Larazotide, an orally administered drug targets the gut. Larazotide is late-stage, investigational, oral therapy that is a novel, synthetic, eight-amino acid peptide that antagonizes zonulin, a key tight junction protein implicated in celiac disease pathogenesis.³ Larazotide strengthens intestinal barriers to limit the number of materials—like SARS-CoV-2 viral particles—that exit the intestines and enter circulation.¹

Study Specifics

The investigators 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. Children were enrolled during hospitalization for acute MISC. The media age for the participants was 5.7 years.²

Each patient randomly received either a placebo or larazotide 4 times daily for 21 days, then was tracked over 6 months of recovery. No larazotide-related adverse events were reported according to the investigators. The findings demonstrate larazotide may be a safe and promising treatment option for children with MIS-C.¹

MIS-C is a rare but serious condition associated with COVID-19, which can cause internal and external parts of the body to become inflamed. ⁴ The number of cases reported decreased from 2020 to 2023 and it affects younger children compared to older adolescents.⁴

Yonker and her colleagues are going to see if this treatment may be applicable to another COVID-19 long-term issue. “We are now running a clinical trial to test whether larazotide may also be a useful therapy to treat patients with Long COVID.”¹

References
1. Clinical Trial Finds Safe, Effective Treatment for Children with Severe Post-COVID Syndrome. Mass General Brigham press release. July 30, 2025. Accessed July 30, 2025.
https://www.massgeneralbrigham.org/en/about/newsroom/press-releases/clinical-trial-finds-safe-effective-treatment-for-children-with-severe-post-covid-syndrome
2.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
3. Hoilat GJ, Altowairqi AK, Ayas MF, Alhaddab NT, Alnujaidi RA, Alharbi HA, Alyahyawi N, Kamal A, Alhabeeb H, Albazee E, Almustanyir S, Abu-Zaid A. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clin Res Hepatol Gastroenterol. 2022 Jan;46(1):101782. doi: 10.1016/j.clinre.2021.101782. Epub 2021 Jul 31. PMID: 34339872.
4.About MIS. Centers for Disease Control and Prevention. Updated June 11, 2025. Accessed July 30, 2025.
https://www.cdc.gov/mis/about/index.html