For a long time, Resverlogix talked up going after a complement-mediated disease called paroxysmal nocturnal hemoglobinuria (PNH). Last I recall, the company stated that they were still interest, but that there aren't a lot of PNH patients and that patient availability may become an obstacle. Hopefully Resverlogix gives us an update on this soon. However, they seem to have moved ahead with the planning of a Fabry's disease trial as we have been told that a Phase 1 Fabry's trial is imminent. So in terms of oprhan indications, how long will PNH be on the back burner? Recall that Alexion's Soliris is one of the most, if not the most, expensive drugs in the world.

A company called Apellis Pharmaceuticals is finishing up a couple of small PNH Phase 2 trials (3 patients and 6 patients) and plans to start Phase 3 Q4 2017. If FDA allows Apellis to get away with those kind of patient numbers in PNH Phase 2, it seems that Resverlogix shouldn't have too hard of a time getting sufficient numbers of patients for their own PNH trials. They would likely need to start in Phase 1 though. Anyways, here's a couple of articles I saw today on Apellis/PNH. 

Far from the big hubs, Apellis is steering its rival to Alexion’s Soliris into a PhIII program

Apellis Pharmaceuticals Announces Positive Data from APL-2 Studies Showing Rapid and Durable Improvements in LDH and Hemoglobin Levels in PNH