Clinical Data
The mean DAS28-CRP score at baseline was 5.71 for the 16 subjects in the treatment arm and 5.77 for the three subjects in the placebo arm. Seventeen subjects (15 in the treatment arm and two in the placebo arm) completed 12 weeks of treatment.
In this trial, ATI-450 demonstrated durable clinical activity, as defined by a marked and sustained reduction in DAS28-CRP and evaluation of ACR20/50/70 responses over 12 weeks. The mean change from baseline in DAS28-CRP score at week 12 was a 2.0 reduction in the treatment arm compared to a 0.35 increase in the placebo arm. The proportion of subjects with a DAS28-CRP score at week 12 of ≤ 3.2 (low disease activity or remission) was 40% and 0% in the treatment and placebo arms, respectively, and the proportion of subjects with a DAS28-CRP score of < 2.6 (remission) was 20% and 0% in the treatment and placebo arms, respectively.
ACR20/50/70 was observed at week 12 in 60%, 33% and 20%, respectively, of the 15 subjects in the treatment arm, and in 0% of the two subjects in the placebo arm. The median reduction from baseline in hsCRP was >40% throughout the 12 weeks of the trial in the treatment arm. A sustained median reduction from baseline in hsCRP was not observed in the placebo arm. An interim analysis (11 treatment, two placebo) of ex vivo stimulated cytokines from blood samples taken from the treatment arm showed a marked and durable inhibition of TNFα, IL1β, IL6, and IL8 over the 12 week dosing period. Similarly, analysis of endogenous cytokines also demonstrated a marked and sustained inhibition of median concentrations of TNFα, IL6, IL8, and MIP1β in the treatment arm over the 12 week period.