In a surprise decision, the FDA has delayed a ruling on the approval of Eli Lilly’s highly anticipated once-daily investigational rheumatoid arthritis (RA) drug baricitinib, instead issuing a complete response letter (CRL) to Lilly and its partner Incyte asking for additional clinical data on dosing and safety concerns. Lilly and Incyte disagree with the FDA’s conclusions and said more discussion with the agency might help speed the resubmission of data for the drug.
Baricitinib is a Janus kinase inhibitor currently in clinical studies for its effect on inflammatory and autoimmune diseases. Baricitinib had generated a good deal of excitement after the February 2017 publication of a study published in The New England Journal of Medicine that showed baricitinib produced significant clinical improvements in RA symptoms compared with placebo and adalimumab (Humira) when combined with methotrexate for patients with inadequate responses to methotrexate alone. The study suggests baricitinib may be an effective oral alternative to adalimumab, which is an infusion.
“We are disappointed with this action,” the company said, remaining confident in the benefit/risk of baricitinib as a new treatment option for adults with moderate to severe RA.
Lilly and Incyte had submitted data on baricitinib to the FDA in January 2016, a majority of which was positive. The companies also submitted additional data from a long-term extension study that suggested the drug’s previously recorded positive effects could be maintained for at least 48 weeks. These positive data had led some analysts to project $1.8 billion in sales for baricitinib by 2022 if it had been approved.
The FDA had already extended its review period of baricitinib by 3 months. Analysts had expected the agency to approve the drug, especially after its European approval in February 2016.
The delay in approving baricitinib resulting from the FDA’s decision to issue a CRL will be good news, however, for Sanofi and Regeneron, whose interleukin-6 inhibitor sarilumab—another RA drug that is expected to potentially become a blockbuster—may be approved imminently by the FDA. The delay in baricitinib’s marketing also potentially benefits Pfizer’s RA drug tofacitinib citrate (Xeljanz), which was approved in 2016 but has not yet generated expected sales.