Positive Results Announced for Rheumatoid Arthritis Drug

Patients taking baricitinib saw improvements in rheumatoid arthritis symptoms as soon as a week into treatment.

Eli Lilly and Company and Incyte Corporation recently announced positive results from a phase 3 clinical trial of baricitinib in patients with moderate-to-severe rheumatoid arthritis (RA).

Baricitinib is an investigational JAK1 and JAK2 inhibitor in late-stage clinical trials for the treatment of autoimmune and inflammatory diseases. The RA-BEACON study included 527 patients who experienced treatment failure with at least 1 biologic disease-modifying antirheumatic drug (bDMARDs), such as a tumor necrosis factor (TNF) inhibitor, and 199 patients who received treatment with 1 or more non-anti-TNF biologic agents, according to a press release from Eli Lilly.

Patients were treated with baricitinib 4-mg or 2-mg, or placebo each day from 24 weeks, in addition to continuing any background treatments.

Investigators found that treatment with the drug was associated with an increase in patient-reported outcomes compared with patients taking the placebo. Patients receiving the 4-mg dose of baricitinib had the quickest and greatest change, according to Eli Lilly.

Health-related quality of life was determined using the 36-Item Short Form Health Survey, which is a patient-reported survey that includes questions about physical function, pain, health, limitations, vitality, and social functions.

At 12 weeks, 49% of patients taking baricitinib 2-mg and 53% taking the 4-mg dose had a clinically important improvement (≥5) in the physical component score. Only 32% of patients in the placebo group achieved this goal.

At 24 weeks, 39% of patients taking the 2-mg dose of baricitinib and 45% taking the 4-mg dose achieved a clinically important improvement (≥5) in the physical component score, according to Eli Lilly. This improvement was only seen in 21% of patients in the placebo group.

Patients started seeing improvements in their physical component score as soon as 4 weeks, which was statistically significant compared with the placebo group. In both dose groups, improvement associated with baricitinib was seen through week 24.

A significant improvement in fatigue was also seen in both dose groups compared with the placebo group. Investigators also found that baricitinib also improved the duration of morning joint stiffness. Improvements were seen as early as week 1 in patients taking 4-mg of baricitinib, and was maintained throughout the study.

Improvements in pain and physical function was seen in both treatment groups both at week 12 and week 24. There were also improvements in disease activity and disability seen as early as week 1.

"In addition to symptoms associated with inflammation, patients with RA commonly suffer from impaired physical function and fatigue, which can significantly impact their quality of life," said Steven Stein, MD, chief medical officer, Incyte Corporation. "It's encouraging to see that treatment with baricitinib, at both doses studied, improves the debilitating symptoms experienced by patients with RA, especially in those for whom biologic DMARDs have not been effective."

During the study, 77% of patients taking baricitinib 4-mg and 71% of patients taking baricitinib 2-mg experienced adverse events, with 6% and 4% discontinuing treatment, respectively. Only 64% of patients in the placebo group experienced adverse events, and 4% of these patients discontinued treatment.

Common adverse events in the baricitinib group included headache, upper respiratory infection, and nasopharyngitis. Serious adverse events were reported in 10% of patients taking baricitinib 4-mg, 4% in the group taking baricitinib 2-mg, and 7% for the placebo group.

The drug has been submitted for regulatory review, and is seeking marketing approval in the US, European Union, and Japan, Eli Lilly said.

“These positive results from the RA-BEACON study, which assessed outcomes that impact health-related quality of life, fatigue and pain, reinforce baricitinib's potential to address an unmet need for patients with rheumatoid arthritis whose previous treatment with biologics failed,” said Terence Rooney, MD, Lilly's senior medical director for baricitinib. “If approved, baricitinib may help address some of the challenges patients with rheumatoid arthritis who are not achieving remission or low disease activity with their current biologic therapy face when performing daily activities."