Efficacy and safety of ct-p39 compared to reference omalizumab in patients with chronic spontaneous urticaria

IntroductionCT-P39 is being developed as a biosimilar of reference omalizumab (ref-omalizumab). This is a double-blind, randomized, active-controlled, phase-3 study in patients with chronic spontaneous urticaria to compare efficacy and safety of CT-P39 to ref-omalizumab.MethodsTo demonstrate therapeutic equivalence between CT-P39 and ref-omalizumab, the patients were randomly assigned in a 1:1 ratio to receive 300 mg of CT-P39 (n=204) or ref-omalizumab (n=205) every 4 weeks up to Week 12. Primary endpoint was mean change from baseline in weekly itch severity score (ISS7) at Week 12 between CT-P39 300 mg and ref-omalizumab 300 mg groups.ResultsFor the primary efficacy evaluation, 95% confidence interval of treatment difference in terms of mean changes from baseline in ISS7 at Week 12 was entirely within the predefined equivalence margin of [−2.0, 2.0] (Table 1). Secondary efficacy endpoint results were also similar between treatments.Overall safety profiles were similar between CT-P39 300 mg and ref-omalizumab 300 mg groups. The number of patients experiencing ≥1 treatment-emergent adverse events (TEAEs) up to Week 12 was 52 (25.6%) and 54 (26.3%) in CT-P39 300 mg and ref-omalizumab 300 mg groups, respectively. Most TEAEs were grade 1 or 2 in intensity, and no deaths were reported up to Week 12. The proportions of patients who had post-treatment positive anti-drug antibody results up to Week 12 were below 3%.ConclusionThe therapeutic equivalence of CT-P39 to ref-omalizumab was demonstrated as evaluated in mean changes from baseline of ISS7 at Week 12. CT-P39 was well tolerated with a safety profile comparable to that of ref-omalizumab.