Eli Lilly announced Friday that the Phase III OASIS-2 study of mirikizumab in patients with moderate-to-severe plaque psoriasis met all of its primary and key secondary endpoints versus placebo at week 16. The experimental IgG4 monoclonal antibody, which binds to the p19 subunit of IL-23, also hit all of the trial's key secondary goals versus Novartis' Cosentyx (secukinumab) at weeks 16 and 52, including superiority in skin clearance at one year.
Patrik Jonsson, president of Lilly Bio-Medicines, said "we look forward to bringing mirikizumab to market to provide patients with an additional treatment option that has the potential to provide near complete or complete skin clearance…with sustained results at 52 weeks." The company plans to submit data from the study, as well as the OASIS-1 trial, to global regulatory bodies.
OASIS-2 included 1465 patients with moderate-to-severe plaque psoriasis who were randomised into one of four groups, including subcutaneous mirikizumab 250 mg given at multiple intervals followed by either mirikizumab 250 mg or 125 mg every eight weeks starting at week 16. Another group were administered Cosentyx, while the final set of patients were given placebo followed by Eli Lilly's drug at a dose of 250 mg every four weeks starting at week 16 through week 32, followed by dosing every eight weeks thereafter.
The primary endpoints were the proportion of patients with a Static Physician's Global Assessment (sPGA) of (0,1) with a two-point or greater improvement, and the proportion of patients achieving at least a 90% improvement from baseline on the Psoriasis Area and Severity Index (PASI 90) at week 16 compared to placebo. Similar endpoints were evaluated at week 16 as key secondary goals against Cosentyx. Meanwhile, key secondary endpoints at one year compared to Cosentyx included the proportion of patients with an sPGA of (0,1) with at least a two-point improvement, as well as PASI 90 and PASI 100.
Findings showed that nearly 80% of mirikizumab-treated patients achieved the primary endpoint of improvement on disease severity as measured by the sPGA scale, while 74.4% achieved PASI 90 (see table below). Meanwhile, in both mirikizumab cohorts, over 83% of patients achieved the sPGA endpoint at week 52, compared with 68.5% for Cosentyx. In addition, 81.4% and 82.4% of patients in the low- and high-dose mirikizumab groups, respectively, achieved the PASI 90 goal at week 52, versus 69.4% for Cosentyx.
Eli Lilly noted that the frequency of serious adverse events was comparable across treatment arms during the induction period, as well as the combined induction and maintenance periods up to 52 weeks. The full OASIS-2 study results will be disclosed at future congresses.
Phase III testing of mirikizumab, also known as LY3074828, is currently ongoing in the areas of inflammatory bowel diseases, including ulcerative colitis  and Crohn's disease. Earlier this year, Eli Lilly said  that it would temporarily suspend recruiting new patients or healthy volunteers in most of its ongoing trials due to the COVID-19 pandemic, including gastrointestinal indications for mirikizumab. The drugmaker indicated Friday that top-line results for the induction data in ulcerative colitis are expected in the spring of 2021 and Crohn's disease in 2022.