Phase 3 Trial Successful for Refractory Rheumatoid Arthritis Drug

Baricitinib is a Janus-kinase inhibitor that interferes with intracellular enzymes in rheumatoid arthritis.

A phase 3 clinical trial proved successful for a novel drug that treats patients with rheumatoid arthritis (RA).

The randomized, double-blind, placebo-controlled trial enrolled 500 RA adults who lived with the disease for an average of 14 years. The trial was carried out at 178 centers in 24 countries and lasted 24 weeks.

Baricitinib is a Janus-kinase inhibitor that interferes with intracellular enzymes that signal action for various inflammatory substances, which are necessary to be effective.

“This is the first drug to demonstrate meaningful clinical benefit in patients who've failed virtually every other commercial drug for rheumatoid arthritis,” said lead study author Mark Genovese, MD.

Currently, there are several successful drugs on the market for the treatment of RA. However, there has been in increase in individuals who become refractory. The RA drugs start to have negative side effects or provide insufficient benefits, according to a study published in The New England Journal of Medicine. About 15% to 20% of patients have gone through all medications and have no further options.

The study focused on refractory patients in a new trial with moderate-to-severe RA and at least 6 affected joints currently using other medications for their disease.

Participants had failed 1 or more anti-TNF biologics, including those who failed other classes of biologics that targeted different sources of immune activation.

Patients were broken into 3 groups and received 4 milligrams of baricitinib once daily, 2 milligrams of baricitinib daily, or a placebo daily, for 24 weeks.

The results of the study showed at 12 weeks, 55% of patients administered the higher dosage saw a 20% reduction in the number of affected joints, while 40% administered the lower dosage saw similar reductions. Only 27% of patients in the placebo group saw this effect.

Improvements in both baricitinib groups largely remained at 24 weeks and saw an improvement in physical function and reductions in markers of inflammation.

“The drug worked well across all patient subgroups, independently of what they'd been taking before or how long they'd had the disease,” Genovese said.

Common adverse events were mild upper respiratory infections in both the high and low dose baricitinib groups at a rate of 77% and 71%, respectively, and 64% in the placebo group.

Serious adverse events affected 10% of the high dose group, 4% of the low-dose group, and 7% in the placebo group.

A rise in high density and low density lipoprotein levels were experienced in both baricitinib groups, while a portion of individuals in all 3 groups developed shingles.