EXTON, Pa.—Idera Pharmaceuticals Inc.’s recent Phase 2 clinical trial of IMO-8400 in adult patients with dermatomyositis vs. placebo failed to meet its primary endpoint of a statistically significant reduction of patients’ Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) activity scores, the company announced. The trial sought to evaluate the safety, efficacy, tolerability, pharmacokinetics, pharmacodynamics, disease-specific autoantibodies and immunogenicity of IMO-8400 in the target population in 30 subjects. The participants received either once-weekly subcutaneous injections of 0.6 mg/kg of IMO-8400, 1.8 mg/kg of IMO-8400 or placebo for up to 24 weeks. Mean CDASI activity scores were in the severe range for all cohorts, despite 17 of 30 participants having received background treatment with immunosuppressive drugs and/or systemic corticosteroids.