Regeneron and Parabilis entered a strategic collaboration to develop Antibody-Helicon Conjugates (AHCs), a novel therapeutic modality designed to deliver functional intracellular peptides against difficult-to-target proteins. The agreement includes $125 million upfront and equity financing commitments, with up to approximately $2.2 billion in cumulative milestone payments across five initial targets.
Written By: Samiksha Jadhav, BPharm
Reviewed By: Pharmacally Editorial Team
Regeneron Pharmaceuticals announced a strategic research collaboration with Parabilis Medicines to discover and develop multiple therapeutic candidates based on Parabilis’ Helicon™ peptide platform, including a new class of investigational therapies known as Antibody-Helicon™ Conjugates (AHCs).
The collaboration will focus on using Helicons, which are stabilized alpha-helical peptides engineered to penetrate cells and interact with intracellular proteins that are difficult to target with conventional medicines. According to the companies, these peptides are designed to bind flat intracellular protein surfaces that are often inaccessible to traditional small molecules.
The companies plan to evaluate Helicons both as stand-alone therapeutic agents and as payloads in AHCs. These investigational conjugates combine antibody-based targeting with intracellular delivery of Helicon peptides to modulate disease-related proteins inside cells.
Antibody-drug conjugates (ADCs) typically use antibodies to transport cytotoxic drugs into target cells. Under the new collaboration, the proposed AHC approach would instead deliver Helicon payloads intended to selectively influence intracellular proteins, including targets historically considered “undruggable.”
In a statement, George D. Yancopoulos, M.D., Ph.D., Board Co-Chair, President and Chief Scientific Officer of Regeneron said the collaboration aligns with Regeneron’s strategy of expanding its portfolio through diversified scientific platforms. He noted that coupling Helicons with Regeneron’s VelocImmune®-derived antibodies could create a new therapeutic modality with potential applications across multiple disease areas.
Mathai Mammen M.D., Ph.D., Chairman, CEO and President of Parabilis Medicines said Parabilis has already shown the ability of its Helicon peptides to inhibit or degrade difficult-to-target cancer-driving proteins in its internal research programs. He added that the collaboration with Regeneron aims to combine Helicon intracellular targeting capabilities with Regeneron’s antibody technologies to develop new therapeutic approaches for challenging disease targets.
Under the agreement terms, Parabilis will receive $125 million from Regeneron, including a $50 million upfront payment and a commitment by Regeneron to invest $75 million in Parabilis’ next equity financing, subject to specified conditions.
Parabilis is also eligible to receive development, regulatory, and commercial milestone payments, along with tiered royalties reaching low double-digit percentages on future net sales of approved products arising from the collaboration. With five initial targets included in the agreement, the deal could generate up to approximately $2.2 billion in total milestone payments for Parabilis. Additional targets may be added through further option payments by Regeneron.
The companies will jointly conduct discovery activities for new Helicons and AHCs. Regeneron will lead subsequent development, manufacturing, and global commercialization activities for candidates emerging from the collaboration.
References
About the Writer
Samiksha Vikram Jadhav (LinkedIn) is a B. Pharm graduate with a strong academic foundation in pharmaceutical sciences, pharmacology, and drug development. She specializes in pharma market research, with a focused interest in mergers and acquisitions, strategic partnerships, and global pharma and biotech deals. Her work centers on analyzing industry transactions, market positioning, and business strategies, translating complex developments into clear, accurate, and insightful scientific and commercial reporting.
