Johnson & Johnson will pay $1 billion in cash to acquire Firefly Bio, adding “degrader-antibody conjugates” (DACs) to expand its oncology pipeline and deepen its exposure to targeted protein degradation. J&J said the platform is built to address limitations seen in some ADCs, including payload release constraints. Firefly is developing DACs aimed at KRAS-driven tumors, with its Firelink technology designed to deliver catalytic degrader payloads while reducing free payload exposure. The company’s approach includes linker chemistry intended to improve stability in circulation and support selective activity in cancer tissue. The acquisition is also framed as an effort to diversify J&J’s cancer portfolio as parts of its existing franchises face growing competitive pressure. J&J characterized the deal as technology-access and pipeline-expansion rather than a single-program purchase. Under the agreement, Firefly’s management and scientific leadership are expected to support continued development of preclinical candidates, with deal timing subject to customary closing conditions.