Regeneron entered a new $2.3 billion agreement with Parabilis Medicines to develop a new type of antibody-drug conjugate-like therapy aimed at harder-to-reach or harder-to-engage targets. Regeneron will put up $125 million in cash and make an equity investment, with additional economics tied to development and commercial milestones. The deal signals Regeneron’s effort to broaden beyond prior oncology setbacks, using Parabilis’ platform to pursue improved target binding and delivery. The partnership also builds on an earlier reported Parabilis deal structure, consolidating Regeneron’s appetite for externally sourced oncology modalities.