Lilly shows more positive Crohn's data for its IL-23 inhibitor as it continues to chase down rivals
About a year and a half after presenting positive topline results in Crohn’s disease, Eli Lilly gave its experimental IL-23 anti-inflammatory mirikizumab a boost Monday with new data.
The fresh info comes from the Phase II study and is a 52-week follow-up of the original trial. Mirikizumab showed that, after the initial 12-week period, patients who continued treatment for another 40 weeks saw further improvement in endoscopic response and Patient-Reported Outcomes remission.

“We are very excited about this data; this is the first disclosure of both new efficacy and safety that shows not only an immediate response, but most importantly, a continuous efficacy response,” Lilly global immunology chief Lotus Mallbris told Endpoints News.
Originally, the trial measured three different doses for endoscopic response against a placebo at week 12. The study met the primary endpoint as higher doses progressively saw greater response, with 25.8%, 37.5%, and 43.8% of patients hitting the mark compared to 10.9 percent of placebo patients.
PRO remission was a secondary endpoint in that study portion, and it was achieved in 12.9%, 28.1% and 21.9% of patients in the three dosing arms, compared to 6.3% of patients treated with placebo.
In the follow-up period, Eli Lilly evaluated further efficacy and safety as well as two dosing methods — intravenous and subcutaneous administration. After 12 weeks, patients who showed endoscopic improvement were randomized to continue mirikizumab either through IV or or injection. Those who did not show endoscopic improvement or who had been originally randomized to placebo all received IV treatment courses.
At the end of 52 weeks, 58.5% of patients in the IV dosing group saw an endoscopic response, as well as 58.7% in the other group. Additionally, PRO remission was achieved by 46.3% of patients dosed through an IV and 45.6% dosed by injection. There was no placebo group in the follow-up period.
“Not only did we continue with the patients who were responders, the patients that were not responding in any dose including placebo got a second chance to see if they could respond,” Mallbris said. “And that’s the key here, you give the patients a second chance to get treatment.”
Eli Lilly defined endoscopic response as at least a 50% reduction in bowel lining inflammation as seen during an endoscopy. Meanwhile, PRO remission was characterized as an average daily stool frequency of less than or equal to 2.5 times and abdominal pain less than or equal to 1. Mirikizumab has since moved onto Phase III in Crohn’s disease after Eli Lilly reported the topline results.
The Indianapolis-based pharma is testing the program in two other indications as well: psoriasis and ulcerative colitis. Trials for both fields are also in Phase III, with mirikizumab showing superiority to Novartis’ IL-17 drug Cosentyx for psoriasis back in July. Phase III data in UC are expected sometime in the first half of 2021, Mallbris said, with Phase III Crohn’s data still a ways away given that the trial just began enrollment.
However, AbbVie may have beaten Lilly to the punch with its IL-23 Skyrizi, which is already approved and demonstrated even better numbers compared to Cosentyx. Eli Lilly doesn’t have any currently approved drugs in UC or Crohn’s and everything in the field is chasing the AbbVie blockbuster Humira, approved for a swath of autoimmune conditions. AbbVie is positioning Skyrizi as a potential successor to the TNF blocker, with peak sales estimated as high as $5 billion by its executive team.
Mallbris said the ultimate goal for mirikizumab is to become the first IL-23 approved for UC as that arena has seen less development than psoriasis and Crohn’s.
“There are fewer biologics [in UC]. The efficacy of those biologics is not really satisfactory,” Mallbris said.