Atavistik Bio added $40 million in a Series B extension, bringing the round’s total to $160 million to support clinical testing of its lead program for hereditary hemorrhagic telangiectasia (HHT). The company pursues allosteric modulators intended to address rare bleeding disorders with no approved disease‑modifying therapies. Investors signaled continued appetite for specialized rare‑disease programs with clear unmet need; Atavistik said the proceeds will advance its HHT candidate into clinical studies. The financing underscores venture interest in precision small‑molecule strategies for vascular and hematologic conditions. HHT is an inherited disorder of blood‑vessel formation leading to frequent bleeding and arteriovenous malformations; the new funding is intended to support registration‑enabling studies in a small, well‑defined patient population.