Mirikizumab demonstrated sustained efficacy at week 52 in patients with moderate-to-severe Crohn’s disease. During the maintenance period of the phase 2 SERENITY trial, few patients discontinued due to adverse events1.
Mirikizumab, a monoclonal antibody targeting the p19 subunit of IL-23, has demonstrated clinical efficacy in phase 2 trials in psoriasis and ulcerative colitis.
The phase 2 SERENITY study showed that mirikizumab was more effective than a placebo for inducing clinical and endoscopic remission and response at 12 weeks in patients with moderate-to-severe Crohn’s disease. At the UEG Week 2020, results of maintenance treatment at week 52 were presented.
Patients who received mirikizumab and achieved ≥1 point improvement at week 12 in Simple Endoscopic Score for Crohn’s Disease (SES-CD) were re-randomized into double-blind maintenance to continue intravenous (IV) treatment Q4W (IV-C; N=41) or to 300 mg mirikizumab subcutaneous (SC) Q4W (SC; N=46). Due to small sample sizes and lack of an apparent trend across doses at week 52, all IV and all SC arms were pooled.
The primary endpoint (endoscopic response at week 12) has been previously reported. Endoscopic response (50% reduction from baseline in SES-CD) for IV-C versus SC was 56.1% versus 52.2% in week 12, and 58.5% versus 58.7% in week 52. Endoscopic remission rates for IV-C versus SC were 14.6% versus 30.4% in week 12 and 19.5% versus 32.6% in week 52.
Among those with endoscopic responses at week 12, 69.6% in the IV-C group and 66.7% in the SC group also had an endoscopic response at week 52. Among those with endoscopic remission at week 12, 50.0% in the IV-C group and 64.3% in the SC group also had endoscopic remission at week 52.
Similar frequencies of treatment-emergent adverse events (AEs) and serious AEs were reported in IV-C and SC groups. One patient in each group discontinued due to an AE.
During the maintenance period of SERENITY, mirikizumab demonstrated sustained efficacy at week 52 with few discontinuations due to AEs. These phase 2 data support continued characterization of mirikizumab efficacy and safety in Crohn’s disease in an ongoing phase 3 program, called VIVID.
1. Sands BE. Efficacy and safety of mirikizumab after 52-weeks maintenance treatment in patients with moderate-to-severe Crohn’s disease. UEG Week Virtual 2020, abstract OP108.