Celiac Disease Drug Shows Promise in Treating COVID-19-Related MIS-C in Children

A recent study from Mass General Brigham investigators has revealed that an investigational drug, larazotide, which was originally developed for celiac disease, shows significant promise in treating children with multisystem inflammatory syndrome (MIS-C) following a SARS-CoV-2 infection. The findings, published in Science Translational Medicine, suggest a novel and effective therapeutic approach for this rare and serious condition.

Addressing the Root Cause of MIS-C

MIS-C is a hyperinflammatory syndrome that can emerge a month or more after a COVID-19 infection. Characterized by high fever and severe symptoms such as rash, abdominal pain, diarrhea, and potentially major cardiovascular injury, MIS-C currently has few available treatment options. Existing anti-inflammatory therapies often risk a disease rebound because they fail to address the underlying cause: the leakage of SARS-CoV-2 spike proteins from the gut into the bloodstream.

Larazotide, an 8-amino-acid synthetic peptide, tackles this problem directly. It works by blocking the protein zonulin, thereby strengthening the intestinal barrier and preventing the “leaky gut” that allows spike proteins to enter the bloodstream and cause hyperinflammation. Researchers hypothesized that this unique mechanism could accelerate recovery from MIS-C.

Study Results Point to Faster Recovery

The hypothesis was tested in a small, randomized, double-blind, placebo-controlled Phase 2a trial involving 12 children with acute MIS-C. The participants, with a median age of 5.7 years, were given either larazotide or a placebo four times daily for three weeks. The results were compelling:

Faster symptom resolution: Children treated with larazotide experienced a quicker resolution of their gastrointestinal symptoms.
Rapid antigen clearance: The drug led to a faster clearance of the SARS-CoV-2 spike antigen from the bloodstream.
Quicker return to normal life: Patients on larazotide were able to return to their daily activities more quickly.

Critically, the study found no adverse events related to larazotide, suggesting a strong safety profile in this pediatric population.

Broader Implications for Public Health

“While our study is small, its results are powerful and have implications not only for MIS-C, but potentially for long COVID,” said Dr. Lael Yonker, co-director of the Pulmonary Genetics Clinic at Mass General Brigham for Children. The success of larazotide in this trial could pave the way for a major shift in how public health providers manage MIS-C and potentially other post-viral inflammatory conditions.

While larger, more comprehensive studies are needed to fully confirm these findings, the early results provide a significant hint of larazotide’s capabilities beyond its original use in celiac disease. If its effectiveness is further validated, pharmacists and other healthcare providers would have a new, safe, and effective tool to manage MIS-C, and possibly even long COVID, in the future.