Disclosed is the use of a MASP-inhibitory agent which inhibits MASP-2-dependent complement activation in the manufacture of a medicament for treating a subject suffering from paroxysmal nocturnal haemoglobinuria (PNH), 5 wherein the MASP-2 inhibitory agent comprises a monoclonal MASP-2 inhibitory antibody, or antigen-binding fragment thereof, that specifically binds to a portion of SEQ ID NO:6 and selectively inhibits MASP-2-dependent complement activation without substantially inhibiting the C1q-dependent complement pathway, wherein SEQ ID NO: 6 is disclosed within the specification.
