RA Capital and other investors put $175 million into Oak Hill Bio to revive an Angelman syndrome program previously shelved by Roche. Oak Hill is positioning the therapy against competing Phase 3 efforts from Ultragenyx Pharmaceuticals and Ionis Pharmaceuticals in similar indications. The startup’s thesis is that it has the best molecule for the mechanism class and can differentiate through clinical readouts later this year as competitors advance. The funding highlights continued investor appetite for late-stage-shooting rare disease bets, even in areas with crowded development plans.