Safety Concerns Linger for Lilly’s Arthritis Drug as FDA Panel Looms

FDA staffers have expressed significant concerns about the side effects tied to Eli Lilly’s experimental rheumatoid arthritis drug baricitinib (Olumiant), which is once again up for review after the agency rejected it last year.

Next week, a panel of independent experts will convene to evaluate the merits of baricitinib. The FDA looks to these advisory panels in making regulatory decisions, though it doesn’t always agree with their insights.

Leading up to the meeting, FDA scientists on Thursday released briefing documents outlining their thinking on baricitinib. The agency cited the instance of deadly blood clots and questioned whether the higher of the two doses Lilly has tested will benefit patients—particularly since most of the safety problems were observed in patients on that dose. Assessing the risk of the drug versus its benefit at the higher 4 mg dose “is the main issue for discussion at the upcoming [advisory committee] meeting,” its staffers wrote. Lilly aims to sell the 4 mg dose, which bested blockbuster rheumatoid arthritis (RA) drug adalimumab (Humira) in a head to head study published in the New England Journal of Medicine last year.

Shares of Indianapolis-based Lilly (NYSE: [[ticker:LLY]]) dipped slightly to $79 Thursday morning following the release of the documents, then recovered to close at $79.75. Shares of Incyte (NASDAQ: [[ticker:INCY]]), the Wilmington, DE, company that licensed baricitinib to Lilly, ended the trading day at $69.05, down 1.46 percent from Wednesday’s closing price.

The FDA reviewers’ concerns are similar to those the agency raised a year ago when it rejected the drug and asked Lilly for more safety data. The agency was concerned about blood clots, and said it wasn’t clear the 4 mg dose was better than the 2 mg dose. Lilly resubmitted its application in December. The FDA scheduled an advisory panel for 8 a.m. Monday to debate the drug’s merits.

Baricitinib was tested in four Phase 3 studies. The 4 mg dose was tested in all four trials, but the lower dose was included in just two. In the studies that included both doses, the FDA said, it wasn’t clear whether the higher dose was better. Additionally, the study had a limited placebo control period and patients could cross over from the lower dose to the higher one, making it hard to assess how safe the drug was.

Lilly tried to address the FDA’s concerns by combining safety data from the various Phase 2 and 3 studies in its new approval application. It also added new data from another RA study and compared baricitinib to other RA medicines in terms of their propensity to cause blood clots. Those comparisons have limitations, the FDA review documents said, and combining safety data from various studies can’t overcome them or the other issues the agency has with Lilly’s program.

Lilly has proposed switching patients from the high to low dose if baricitinib is controlling their disease, or only giving the higher dose to patients who can’t take, or don’t respond to, more than one other RA treatment. But Lilly’s clinical trials weren’t designed to test those dosing strategies, FDA scientists countered.

Rheumatoid arthritis is an autoimmune disorder that causes swelling and pain in the tissues in the joints. The Lilly drug is a once-daily pill that blocks two Janus kinase (JAK) enzymes, proteins linked to inflammation. Lilly is trying to

Author: Frank Vinluan

Xconomy Editor Frank Vinluan is a business journalist with experience covering technology and life sciences. Based in Raleigh, he was a staff writer at the Triangle Business Journal covering technology, biotechnology and energy before joining MedCityNews.com as North Carolina bureau chief. Prior to moving to North Carolina’s Research Triangle in 2007 he held business reporting positions at The Des Moines Register and The Seattle Times.