Regeneron entered a multi-target strategic collaboration with Parabilis Medicines built around the Helicon peptide platform, committing payments and equity investment that could total about $2.3 billion. The partnership aims to discover and develop five initial candidates, combining Regeneron’s antibody capabilities with Parabilis’ Helicon technology for intracellular protein modulation. Under the agreement, Regeneron will pay $50 million upfront and invest $75 million in Parabilis’ next equity financing, with additional development, regulatory and commercial milestone payments and tiered royalties on net sales. Regeneron will oversee development, manufacturing and worldwide commercialization after discovery-stage candidates are identified. The deal underscores biopharma’s push into “undruggable” targets using conjugate-like modalities that extend beyond standard ADC payload delivery approaches.