Mass General Brigham researchers have demonstrated that larazotide, an experimental oral drug originally developed for Celiac disease, shows significant promise as a safe and effective treatment for multisystem inflammatory syndrome in children (MIS-C), a rare but serious post-COVID condition. The findings, published in Science Translational Medicine, represent a potential breakthrough for a condition with limited treatment options.
Novel Mechanism Targets Gut-Based Viral Persistence
MIS-C is a rare but serious condition that can occur after COVID-19 infection, presenting as high fevers, gastrointestinal symptoms, and life-threatening cardiac injury. Current treatments are limited, with many patients receiving general anti-inflammatory drugs that often lead to symptom rebound after treatment completion.
Larazotide offers a different approach by targeting the gut directly. The drug strengthens intestinal barriers to limit the number of materials—including persistent SARS-CoV-2 viral particles—that exit the intestines and enter circulation. This mechanism addresses what researchers believe may be a key driver of MIS-C symptoms.
"Such drugs are not designed to target the sticky SARS-CoV-2 viral particles that may persist in the gut," the researchers noted, highlighting the limitation of current anti-inflammatory approaches.
Clinical Trial Demonstrates Rapid Symptom Resolution
The research team conducted a double-blind clinical trial with 12 children experiencing early-stage MIS-C, 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 demonstrated three key improvements compared to those receiving placebo:
- Faster resolution of gastrointestinal symptoms
- Faster clearance of SARS-CoV-2 viral particles
- More rapid return to normal activities
Implications Beyond MIS-C
Lead author Dr. Lael Yonker, co-director of the Cystic Fibrosis Center, Cystic Fibrosis Therapeutic Development Center, and Pulmonary Genetics Clinic at Mass General Brigham for Children, emphasized the broader potential of these findings.
"While our study is small, its results are powerful and have implications not only for MIS-C, but potentially for long COVID," Yonker said. "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."
Safety Profile and Future Development
The trial demonstrated that larazotide was both safe and effective in treating children with MIS-C. The drug's oral administration and established safety profile from its original development for Celiac disease may facilitate its potential adoption for MIS-C treatment.
The research was supported by the European Biomedical Research Institute of Salerno, Italy, the National Institutes of Health/National Heart Lung and Blood Institute, and the Chleck Foundation. The study involved a multidisciplinary team of researchers from Mass General Brigham, reflecting the complex nature of MIS-C and the need for comprehensive treatment approaches.
