Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN) today announced a strategic research collaboration with Parabilis Medicines to discover and develop multiple therapeutic candidates based on Parabilis' Helicon™ peptide platform, with a particular focus on Antibody-Helicon™ Conjugates (AHCs), a novel class of therapeutics designed to target challenging and historically "undruggable" targets.  

Helicons are stabilized, cell-penetrant alpha-helical peptides designed to engage intracellular protein targets, including flat surfaces not well suited to traditional small molecule binding. The collaboration is designed to explore the use of Helicons both as stand-alone therapies and as part of AHCs.

"This collaboration reflects Regeneron's approach of advancing cutting-edge and diversified science to produce a robust portfolio of innovative medicines for patients in need," said George D. Yancopoulos, M.D., Ph.D., Board co-Chair, President and Chief Scientific Officer of Regeneron. "In addition to the potential of Helicons to address previously undruggable targets, the collaboration's intent to couple Helicons to our VelocImmune® derived-antibodies so as to precisely deliver them to cells of interest represents an exciting new approach with the potential to create an entirely new therapeutic class that can span multiple therapeutic areas."

Antibody–drug conjugates traditionally use antibodies to selectively deliver drug payloads into target cells to drive cell death from within. The AHCs envisioned by this collaboration are underpinned by the same delivery principle: pairing antibody-targeted cell access with Helicon payloads designed to selectively modulate specific intracellular proteins, including some long considered undruggable.

Under the terms of the agreement, Parabilis is to receive $125 million from Regeneron in the form of a $50 million upfront payment and a commitment to invest $75 million in Parabilis' next equity financing, subject to certain conditions. Parabilis is also eligible to receive milestone payments for development, regulatory and commercial milestones, as well as tiered royalties up to the low double-digits on future net sales of any approved medicines resulting from the collaboration. With five initial targets, the agreement provides the potential for up to approximately $2.2 billion in total milestone payments to Parabilis. Under the terms of the agreement, additional targets may be pursued upon additional option payments from Regeneron.

The agreement provides for the parties to collaborate to discover new Helicons and AHCs, which Regeneron will then be responsible for advancing through development, manufacturing and worldwide commercialization.