Akari Therapeutics, Plc announced positive interim data from its Phase III PNH CAPSTONE study in complement inhibitor naïve, transfusion-dependent PNH patients. All patients treated with nomacopan achieved the primary endpoint of transfusion independence. PNH is an orphan hematological condition that, if left untreated, results in a high mortality rate. Eculizumab, a C5 complement inhibitor, is approved for the treatment of the disease. Nomacopan is also a C5 complement inhibitor which also binds the proinflammatory eicosanoid leukotriene B4 (LTB4). In the Phase III CAPSTONE trial, PNH patients, naïve to anti-complement treatment, are randomized to receive daily subcutaneous nomacopan or SOC (blood transfusion with or without anticoagulation) for six months. After six months, patients on SOC receive nomacopan for three months and patients on nomacopan continue the drug for a further three months. The trial design was agreed with the FDA following an end of Phase II meeting. The primary endpoint of this study is: haemoglobin (Hb) stabilization defined as Hb greater than the set point for each patient set during the pre-study randomization period, and the avoidance of packed red blood cell transfusions during the treatment period of 180 days. All patients receive a transfusion if they fall below the Hb set point. The interim data tabulated below shows that the four patients on nomacopan met the primary endpoint and received no transfusions for the first six months of treatment while all four patients on placebo were transfused during the first six months of treatment. Both groups had similar historic transfusion levels and mean Hb set points. The difference is statistically significant at the p=0.034 level. In the Phase II COBALT PNH study six out of eight patients were transfusion dependent prior to treatment. Three became transfusion independent during the three-month Phase II study and the remaining three became transfusion independent during treatment with nomacopan in the long-term follow-up safety study, where transfusion independence is defined as no transfusion for 6 months. Of these six patients all have now continually maintained transfusion independence for up to two years except one patient who has received one unit of PRBC in the last 12 months. In total, 14 PNH patients have been treated with nomacopan across four trials: Phase II, Phase III, PNH eculizumab resistant study, and PNH long-term safety and efficacy study. Akari is currently developing a new higher concentration formulation of nomacopan allowing a small volume 0.3mL, low viscosity injection, with an insulin pen-like injector holding one week’s daily dosing stable at room temperature, improving both patient comfort and convenience. Recruitment into the Phase III CAPSTONE study is currently deferred in order to potentially take advantage of this new formulation.