In a mid-stage study, the candidate itolizumab achieved 23.3% clinical remission rate at 12 weeks, numerically better than Humira’s 20% at the same time point.
California biotech Equillium on Thursday unveiled topline Phase II data for its investigational anti-inflammatory therapy itolizumab in moderate to severe ulcerative colitis, touting remission rates that matched AbbVie’s blockbuster Humira.
At 12 weeks, 23.3% of patients in the itolizumab arm reached clinical remission, as defined by having a Total Mayo Score of at most 2 with none of the subscale scores reaching more than 1. Meanwhile, 20% of comparators on Humira reached this endpoint, as did 10% of placebo patients.
Equillium did not reveal its statistical analysis in its news release, promising instead to provide “additional data” at a medical congress later this year.
Clinical response, also measured using Total Mayo Score, was 63.3% in the itolizumab arm and 60% in the Humira group. Placebo comparators hit 46.7% clinical response. Endoscopic remission, as assessed via central endoscopy, was 16.7% in both the itolizumab and Humira cohorts and 6.7% in the placebo group. Equillium also found itolizumab to be safe and well-tolerated.
Chief Scientific Officer Stephen Connelly said in a statement that the biotech is “delighted with the strength of data” from the mid-stage study, which according to him “adds to itolizumab’s critical mass of safety and efficacy data across different patient populations.” Equillium co-sponsored the Phase II study with Biocon Limited.
Itolizumab is an immune-modifying monoclonal antibody that works by targeting the CD6 protein, which in turn reduces the proliferation of effector T cells while preserving regulatory T cells. This binding profile also allows itolizumab to attenuate the secretion of pro-inflammatory cytokines, including TNF-α, interferon-gamma, IL-6 and Il-17.
Additionally, itolizumab prevents the ALCAM protein from interacting with CD6, thus modulating lymphocyte trafficking and impairing the infiltration of effector T cells into inflamed tissues. Aside from ulcerative colitis, Equillium is also studying itolizumab in the Phase III EQUATOR study in acute graft-versus-host disease, for which topline data are expected this quarter.
With Thursday’s readout, Equillium hopes to join the highly competitive ulcerative colitis space—and the anti-inflammatory market more broadly. If all plays out well for the biotech, it could go up against Johnson & Johnson, which in September 2024 won FDA approval for Tremfya, allowing its use in moderate to severe ulcerative colitis.
Another potential competitor is San Francisco’s AltruBio, which in May closed an oversubscribed $225 million Series B to push its ulcerative colitis program into mid-stage studies.
