Achillion Pharmaceuticals, Inc. reported interim data from a Phase 2 paroxysmal nocturnal hemoglobinuria (PNH) trial assessing the safety and effectiveness of its oral small molecule factor D inhibitor ACH-4471 in combination with intravenous eculizumab at The New Era of Aplastic Anemia and PNH Meeting in Naples, Italy. This proof-of-concept, 24-week trial is ongoing. Interim data in 11 enrolled patients were assessed between 4 to 24 weeks, depending on the patient’s current treatment duration in the dose escalating trial. The oral presentation features the following data: Increases in mean hemoglobin of approximately 2 g/dL at week 4 (n=11); for the 4 patients that have reached 24 weeks their mean rise in hemoglobin is 2.6 g/dL; A reduction in blood transfusions from 34 transfusions totaling 58 units in the 24 weeks prior to screening to only 1 transfusion of 2 units during treatment with ACH-4471; Meaningful improvement in Functional Assessment of Chronic Illness Therapy (FACIT) fatigue scores versus baseline, with a mean score increase of 11 at week 4; Increase in the percentage of PNH RBC Type III clone size from 40% at baseline to 71% at week 12 (n=8); Reduction in total bilirubin from a mean of 2.17 mg/dL to 1.21 mg/dL at week 16 (n=8); Reduction in mean reticulocytes from 219 10^9/uL at baseline to 153 10^9/uL at week 16 (n=8); Further reduction of LDH into the normal range; Four patients are currently receiving the lowest study dose of 100 mg three times a day; ACH-4471 was generally well tolerated when added to eculizumab in patients with PNH.