Paratek Pharmaceuticals Inc., of Boston, dosed the first patient in its second pivotal phase III study of omadacycline in patients with acute bacterial skin and skin structure infections. The study will assess the efficacy and safety of once-daily oral-only omadacycline compared with twice-daily oral-only linezolid (Zyvox, Pfizer Inc.). Omadacycline is described as a new once-daily oral and intravenous, well-tolerated, broad-spectrum antibiotic being developed for use as empiric monotherapy for patients suffering from serious community-acquired bacterial infections.