aTyr Pharma, Inc. announced positive topline results from its Phase 2 double-blind, placebo-controlled clinical trial of its lead therapeutic candidate, ATYR1923, in hospitalized COVID-19 patients with severe respiratory complications who do not require mechanical ventilation. The trial met its primary endpoint of safety, demonstrating that a single, intravenous (IV) dose of ATYR1923 was generally safe and well-tolerated in both the 1.0 and 3.0 mg/kg treatment groups, with no drug-related serious adverse events. The study demonstrated a preliminary signal of activity through clinical improvement in the high dose cohort with the assessment of time to recovery, defined as either achieving a WHO ordinal scale score of =3 or hospital discharge with no requirement of supplemental oxygen. Patients who received the 3.0 mg/kg dose of ATYR1923 experienced a median time to recovery of 5.5 days compared to 6 days in the placebo group. In addition, 83% of patients receiving the high dose of ATYR1923 achieved recovery by day 6, compared to 56% in the placebo arm. Patients in the 1.0 mg/kg treatment arm experienced a median time to recovery of 7 days. All patients in the study received standard of care treatment at the time of enrollment, which included remdesivir and/or dexamethasone. Adverse events were mostly mild or moderate in severity and generally assessed as unrelated to the study drug. This is in line with previous safety assessments of ATYR1923, including an interim safety analysis from an ongoing Phase 1b/2a trial in patients with pulmonary sarcoidosis, a chronic form of interstitial lung disease. There were two deaths observed in the study, both in the 1.0 mg/kg treatment arm, which were deemed not related to ATYR1923 by an independent data safety monitoring board. The Phase 2 clinical trial was a randomized, double blind, placebo-controlled study of ATYR1923 in 32 hospitalized COVID-19 patients with severe respiratory complications, who did not require mechanical ventilation, at hospitals in the U.S. and Puerto Rico. Patients enrolled in the trial were randomized 1:1:1 to a single IV dose of either 1.0 or 3.0 mg/kg of ATYR1923 or placebo. Patients were followed for 60 days post treatment. The study was not powered for statistical significance and was designed to evaluate safety and identify preliminary signs of activity of ATYR1923 as compared to placebo.