Omeros Corporation announced that it has reached agreement with the US Food and Drug Administration (FDA) on Omeros' protocol for its Phase 3 clinical trial evaluating OMS721 in patients with IgA nephropathy (IgAN). Patient enrollment is expected to begin early next month. The single Phase 3 trial is a randomized, double-blind, placebo-controlled trial in patients at least 18 years of age with biopsy-confirmed IgAN and with 24-hour urine protein excretion greater than 1 g/day at baseline on optimized renin-angiotensin system (RAS) blockade. Patients will receive an initial 12 weekly intravenous doses of study drug; additional weekly dosing can be administered for partial responders and relapsers. The primary endpoint, which could suffice for full approval, is reduction in proteinuria at 24 weeks after the start of dosing. The trial will employ an adaptive design that will allow intra-trial adjustment in sample size. FDA granted both breakthrough therapy designation and orphan drug designation for OMS721 in IgAN. Omeros' applications to the European Medicines Agency (EMA) for orphan drug status and for eligibility to the Priority Medicines (PRIME) program for OMS721 in IgAN are pending.