Novel approaches to hemophilia therapy. The peaks and troughs of factor levels (red) and provided hemostasis (blue) differ substantially between the classes of therapies. Current prophylaxis regimens with standard factor therapies aim for trough levels of >1% normal with dosing from every other day to twice weekly. EHL therapies decrease the frequency of administration and likely can provide higher trough levels. NFTs are ideally being dosed at an equivalent hemostatic level to prevent pathological bleeding. This may be achievable with weekly to monthly subcutaneously delivery that results in very stable hemostatic, but no factor level. Gene therapy is likely to be able to provide a sustained factor level that approaches a cure.