Eli Lilly and Incyte’s experimental rheumatoid arthritis drug baricitinib has beaten the world’s biggest selling drug Humira in improving disease activity after 12 weeks’ treatment, according to data from a late-stage clinical trial.

The Phase III RA-BEAM study not only met its primary endpoint - showing that the drug scored significantly better than placebo on the ACR20 response, a standard clinical measure that represents at least a 20% improvement in RA disease activity - but also hit the secondary target of showing superiority to AbbVie’s multi-billion-dollar blockbuster Humira (adalimumab).

After 24 weeks, the once-daily JAK inhibitor was also superior to placebo in preventing progressive radiographic structural joint damage, and the drug’s treatment benefits were maintained through 52 weeks of therapy, the firms noted.

On the safety side, compared to placebo, serious adverse events rates were similar for baricitinib and lower for Humira; serious infection rates were similar across groups. The most common side effects observed with baricitinib were nasopharyngitis and bronchitis.

"RA-BEAM is the first study to demonstrate that a once-daily oral treatment was superior in improving signs and symptoms of rheumatoid arthritis compared to the current injectable standard of care," said David Ricks, president of Lilly Bio-Medicines. "If approved, baricitinib could help change expectations for people living with this debilitating disease." 

All signs for baricitinib are currently looking good; just two weeks ago data from the RA-BEGIN trial was published showing that the drug outperformed methotrexate on the ACR20 measure, which followed on from Phase III data showing efficacy in RA patients with inadequate responses to traditional disease-modifiying anti-rheumatic drugs (in the RA-BUILD trial) and biological therapies (in RA-BEACON).

Data from the four trials will be used by Lilly and Incyte to underpin regulatory submissions for the drug.