A triple-drug cocktail, called Trikafta, was approved by the Food and Drug Administration in late 2019 and is the first therapy shown to dramatically improve lung function in most people with cystic fibrosis, a condition that often can be fatal.

Nearly 30,000 people in the United States suffer from cystic fibrosis, an inherited disease that causes thick mucus to build up in the body. In the lungs, excess mucus makes breathing difficult and traps bacteria, leading to frequent respiratory infections. In the digestive tract, mucus obstructs the pancreas and prevents digestive enzymes from entering the intestine. This limits the absorption of key nutrients, hindering growth in children and increasing the risk of poor nutrition. While life expectancy for people with cystic fibrosis has improved over the past several decades, many don’t live past age 50 due to progressive lung damage.

“This highly effective therapy is different from other treatments in that it targets the most common molecular defect at the root of cystic fibrosis,” says Washington University pulmonologist and researcher Daniel Rosenbluth, MD, who led clinical trials evaluating the therapy.

The new treatment adds a third drug to an existing therapy—a combination of two drugs—that was not as effective. This additional drug targets a genetic defect carried by 90% of people with cystic fibrosis. Specifically, the drug fixes a malfunctioning protein, helping to thin mucus and keep it moist.

The treatment was approved for use in people age 12 and older. Clinical trials of the three-drug combination are underway in younger children. Rosenbluth suspects that therapy, especially when started early, potentially could prevent some of the worst symptoms of cystic fibrosis and lengthen survival.

“Until now, treatments for cystic fibrosis were aimed at loosening and clearing mucus from the lungs,” says Rosenbluth, who treats patients at the cystic fibrosis clinic at Barnes-Jewish Hospital. “But treating the symptoms of the illness is not very effective over time. With this new therapy, patients are feeling better, often within a few days after taking the new drug combination.”

Rosenbluth adds: “They can breathe easier, and this is having a clear effect on their everyday lives. Those who could not engage in vigorous exercise because of their poor lung function have become more active, including a young woman in her 20s who started running after taking the drug for several weeks; she is now participating in 5Ks. This is incredibly exciting.”