Mirikizimab moved to Phase III after positive trial findings

Results of the SERENITY phase II study in severely active Crohn’s disease patients found that those treated with mirikizumab achieved significant reductions in clinical and endoscopic measures of disease activity at 12 weeks compared to placebo.

The results were presented at the Digestive Disease Week medical conference in California on 21 May by Eli Lilly.

Mirikizimab is an investigational antibody that targets the p19 subunit of interleukin 23.

The phase II, multi-centre, randomised, parallel-arm, double-blind, placebo-controlled trial was designed to assess the safety and efficacy of mirikizumab in patients with moderately- to severely active Crohn’s disease.

At baseline, participants were randomised with a 2:1:1:2 allocation across four treatment arms (mirikizumab 200mg, mirikizumab 600mg, mirikizumab 1,000mg, and placebo). The primary endpoint measured endoscopic response as determined by the proportion of participants achieving 50 percent reduction from baseline on the Simple Endoscopic Score for Crohn’s Disease (SES-CD) at week 12. The results were significantly higher for patients receiving the doses, with 25.8 percent, 37.5 percent and 43.8 percent of patients achieving the endpoint across the three respective doses. Comparatively, 10.9 percent of patients administered with the placebo achieved the primary endpoint. Those administered with the placebo were recorded at 10.9 achieving the endpoint.

The secondary endpoints included clinical remission, which was measured by Patient Reported Outcomes (PRO remission) and endoscopic remission. PRO remission achievement was higher for patients with the doses, who recorded their stool frequency and abdominal pain. Endoscopic remission was defined by an ileal-colonic SES-CD score and saw patients who received mirikizimab achieve higher rates of remission than those who took the placebo. The safety assessment was also a secondary endpoint, with the placebo administered patients reporting more adverse events.

Bruce E Sands, Dr. Burrill B Crohn Professor of Medicine, Chief of the Dr Henry D Janowitz Division of Gastroenterology at the Icahn School of Medicine at Mount Sinai and lead researcher said that “Mirikizimab may have the potential to be a valuable addition to the available treatment options for Crohn’s disease because of the endoscopic and symptomatic responses seen in this trial across all doses.”

Lotus Mallbrisvice president of immunology development at Lilly, said “Following last year’s presentation of positive phase II results for mirikizumab for the treatment of moderate- to severe ulcerative colitis, we are excited to return to DDW to present more positive data for mirikizumab in patients with chronic, inflammatory gastrointestinal conditions. As we continue to advance the science of gastroenterology, we are hopeful that mirikizumab helps us raise the standard and make remission possible for people living with immune-mediated diseases like Crohn’s disease. Physicians want objective signs of improvement to be able to convey to patients that they are getting better, and data from this study suggest mirikizumab may address this need. We look forward to initiating phase III trials to further evaluate mirikizumab’s benefit-risk profile for the treatment of Crohn’s disease.”