Synact Pharma Announces Top Line Data from the 12-Week Expand P2b Clinical Trial in Severe Active Newly Diagnosed Rheumatoid Arthritis Patients

SynAct Pharma AB SynAct Pharma AB reported topline results from the 12-week P2b EXPAND study of 100mg once-daily oral resomelagon (AP1189) in newly diagnosed rheumatoid arthritis (RA) patients experiencing severe disease activity. The study did not meet its primary endpoint of significance over placebo with the ACR20 outcome. Although resomelagon did not demonstrate a clear clinical benefit on the primary endpoint it continued to demonstrate a favorable safety profile.

Objectives measures of activity in the EXPAND trial were more in-line with the BEGIN study. SynAct management will hold a webcast to discuss this announcement later today (details below). The EXPAND (SynAct-CS007) study was a multicenter, randomized, double-blind, placebo- controlled, 12-week study in newly diagnosed, treatment naïve patients with highly active RA (Clinical Disease Activity Score (CDAI) > 22) conducted in sites in Bulgaria and Moldova.

127 patients presenting with high disease activity (CDAI > 22) were randomized 1:1 for treatmentwith once daily 100 mg resomelagon or placebo added to a background of methotrexate (MTX) therapy. 54.7% of patients treated with 100mg of once-daily oral resomelagon achieved an ACR20 response at 12-weeks as compared to 55.7% of patients receiving placebo. This unexpected finding in part was driven by high placebo responses linked to the subjective component measures of the ACR scoring system.

SynAct continues to assess this top-line study data to better understand these results. Resomelagon continued to demonstrate a favorable safety profile in this high activity patient population. The overall rate of treatment emergent serious adverse events (SAEs) was 1.6% (n=2), with 1 SAE in each group.

The overall rate of patients experiencing treatment emergent adverse events (AEs) was 44.4% and 42.2% for resomelagon and placebo treated patients respectively (all patients received MTX). There were no observed signs of immunosuppression seen in the resomelagon group over that associated with background methotrexate therapy.