Johnson & Johnson agreed to buy Firefly Bio for $1 billion in cash, gaining a platform for degrader antibody conjugates and strengthening its oncology pipeline technology base. J&J said the acquisition would add a degrader antibody conjugate platform that aims to overcome limitations in conventional antibody-drug conjugates. Firefly Bio, a South San Francisco-based startup, is positioned around a degrader-antibody conjugate approach with a linker engineered for stability. J&J said the strategy could deliver a highly selective protein degrader into cancer tissue while aiming to spare healthy cells, with Firefly’s preclinical focus described as spanning solid tumors. The acquisition underscores pharma’s continued preference for technology-led bolt-ons in oncology, particularly as patent cliffs pressure near-term revenue and companies compete to differentiate next-gen payload delivery. The deal is expected to close later this year, with J&J framing Firefly as another step in building out next-generation conjugate capabilities.