BCX9930 + eculizumab

BCX9930 + eculizumab is a combination therapy comprising BCX9930, an oral small molecule inhibitor of **complement factor D**, and eculizumab, an intravenously administered monoclonal antibody that inhibits **complement component C5**. The combination is designed to treat **paroxysmal nocturnal hemoglobinuria (PNH)**, particularly in patients with inadequate response to C5 inhibition alone. BCX9930 blocks the alternative pathway of complement activation (by inhibiting factor D), preventing both **intravascular and extravascular hemolysis**. Eculizumab inhibits the terminal pathway (by binding C5) and prevents the formation of the membrane attack complex, thus controlling intravascular hemolysis. Together, these mechanisms offer broader control of PNH-related hemolysis than either agent alone, aiming for improved anemia, reduced fatigue, and reduced transfusion burden[1][2].