An experimental drug to treat rheumatoid arthritis showed promise in a new six-month trial.
Baricitinib substantially reduced symptoms and improved daily physical functioning among people who failed other treatments for the autoimmune disease, researchers found.
“If you have active disease and you’ve failed existing treatment options, you should have hope,” said lead researcher Dr. Mark Genovese. He is a professor of immunology and rheumatology at Stanford University School of Medicine in California. “There is another therapy, which will hopefully become available, that has demonstrated it can work in that situation.”
The report was published March 31 in the New England Journal of Medicine.
The trial was sponsored by Eli Lilly and Co., the manufacturer of baricitinib. Lilly is currently seeking approval of the drug from the U.S. Food and Drug Administration.
For the phase 3 trial, Genovese, who is a consultant to Lilly, and colleagues randomly assigned more than 500 patients at 178 centers in 24 countries to one of three groups. One group received 4 milligrams of baricitinib a day, the second group got 2 milligrams, and the third group received a placebo for 24 weeks.
The researchers found that about 55 percent of the patients taking the higher dose of baricitinib experienced a reduction of at least 20 percent in the number of affected joints at week 12 of the study.
For patients on the lower dose, 49 percent experienced a similar reduction. Among patients on placebo, only 27 percent saw this effect, the researchers said.
In addition, patients taking either dose of baricitinib had improved physical function and reductions in inflammation. These benefits remained after 24 weeks, according to the report.
The most common side effect of baricitinib was mild upper-respiratory infections among as many as 77 percent of patients taking the drug, compared with 64 percent of those taking the placebo, the investigators found.
Also, after 12 weeks, about 2 percent of patients in the high-dose group, versus 1 percent and 0.5 percent in the low-dose and placebo groups, respectively, developed shingles. Shingles is a painful skin rash caused by a dormant chickenpox virus.
Baricitinib also raised both high-density (“good”) and low-density (“bad”) cholesterol, the findings showed.
Rheumatoid arthritis is a progressive, inflammatory, autoimmune disease affecting about 1.5 percent of the worldwide population. It causes pain, stiffness, swelling and eventual destruction of joints, typically in the hands and feet. About three of every four people with the disease are women, the researchers said.
Baricitinib is in a new category of small-molecule drugs, available in pill form, called Janus-kinase inhibitors. These drugs work by interfering with enzymes necessary for various inflammatory substances in the body to function, Genovese explained.
Although many new drugs have been developed to treat rheumatoid arthritis, long-term use makes these drugs less effective for some patients, researchers have found.
As a result, 15 percent to 20 percent of rheumatoid arthritis patients find themselves having used up the available drugs, Genovese said.
Dr. Waseem Mir is a rheumatologist at Lenox Hill Hospital in New York City. He said that “a new drug to treat rheumatoid arthritis patients is always welcome, because when you get to treat many patients, you see that most of the drugs stop being effective.”
The study shows that baricitinib can help rheumatoid patients who have failed other drugs, he added.
“However, I do not want the rheumatoid arthritis patients to get too excited, as the study shows only a 20 percent improvement. But in combination with other rheumatoid drugs, it could be effective in helping patients,” Mir said.
For more on rheumatoid arthritis, visit the American College of Rheumatology.