Experimental drug shows promise reversing systemic sclerosis in lab studies

Researchers at Cedars-Sinai Health Sciences University have demonstrated in laboratory studies that an experimental drug can reverse the damage caused by systemic sclerosis, a chronic autoimmune disease that scars the skin, lungs, heart, and other vital organs. The findings, published in JCI Insight, represent a potential breakthrough for a condition that currently has no cure and affects roughly 100,000 people across the United States.

Systemic sclerosis, also known as scleroderma, is a life-threatening illness in which the body's immune system attacks connective tissue, causing progressive scarring and organ failure. Because the underlying cause remains unknown, existing treatments can only manage symptoms—they cannot stop or reverse the disease's progression. For patients living with this condition, the absence of curative options has meant decades of waiting for something fundamentally different.

The experimental drug, called TY1, is a synthetic version of a noncoding RNA molecule—a type of genetic material that regulates how cells function. Researchers at Cedars-Sinai developed TY1 after observing its potential to reduce tissue damage in heart attack models. They then asked whether the same mechanism might work against autoimmune disorders. "We chose to test TY1 in systemic sclerosis because the science of how the drug works makes sense and also because it is such a devastating disease," said Ahmed Ibrahim, an associate professor of cardiology at Cedars-Sinai and a co-investigator.

In the laboratory phase, investigators collected immune cells from patients with systemic sclerosis and exposed them to TY1. The drug reduced both inflammation and DNA damage in those cells. When the team administered TY1 to laboratory mice engineered to develop a condition mimicking systemic sclerosis, the results were more striking: heart function improved, physical activity increased, and the formation of scar tissue in organs decreased. "The basic immune system pathway driving systemic sclerosis is blocked by this new drug, making it a potential future therapy," said Eduardo Marbán, executive director of the Smidt Heart Institute and the study's corresponding author.

The pathway from laboratory success to human treatment remains long and carefully regulated. Cedars-Sinai is now preparing an investigational new drug application to submit to the U.S. Food and Drug Administration—the formal first step required before the drug can be tested in human patients. Susan Cheng, chair of the Department of Cardiology at the Smidt Heart Institute, noted that the discovery illustrates how research on one disease can yield insights applicable to another. "This innovative study illustrates how doing careful research on one disease can lead to key discoveries on another," she said, pointing to the path from heart conditions to a rare disease that has left patients waiting for better options.

If the FDA application is approved and human trials proceed, TY1 could eventually offer systemic sclerosis patients something that has not existed: a treatment that addresses the root cause rather than merely its symptoms. The next phase will determine whether what works in cells and mice can translate to people.