molecules of the month

February’s molecule, the Novartis factor B inhibitor LNP023, targets the serine protease factor B (FB), a key node in the complement system. The complement part of the innate immune system is a hot area for drug discovery due to its increasingly recognized role in a wide range of chronic human diseases, including age-related macular degeneration (AMD). The authors took a pathway approach to drugging a portion of the complement system called the “alternative complement pathway” (AP), evaluating three different targets including FB. While proteases are tough drug targets due to their typically polar and frequently conserved active sites, the Novartis team was able to develop an oral, reversible, blood-retinal-barrier penetrant clinical candidate from a weak (10 uM) fragment identified through biochemical screening.…