TARRYTOWN, N.Y., May 18, 2026
Regeneron Pharmaceuticals has announced a major strategic collaboration with Parabilis Medicines valued at up to approximately $2.3 billion to develop next-generation Antibody-Helicon™ Conjugates (AHCs) across multiple therapeutic areas, potentially opening a new frontier in the treatment of historically “undruggable” diseases. The collaboration combines Regeneron’s advanced antibody engineering technologies with Parabilis’ proprietary Helicon™ peptide platform, aiming to create innovative intracellular-targeting therapies for cancer, inflammatory disorders, neurological diseases, and other serious conditions.
Regeneron Expands Precision Medicine Strategy with Novel Therapeutic Platform
Under the terms of the agreement, Parabilis Medicines will receive $125 million upfront, including a $50 million cash payment and a $75 million equity investment commitment from Regeneron. The deal also includes eligibility for approximately $2.2 billion in additional milestone payments tied to development, regulatory, and commercial achievements, along with tiered royalties on future product sales. Initially, the companies will pursue five therapeutic targets, with options to expand the collaboration further.
The partnership reflects the growing pharmaceutical industry focus on next-generation biologics and precision-targeted therapies capable of addressing intracellular disease mechanisms that have remained difficult to target using traditional small molecules or conventional antibody therapies. According to Regeneron, the collaboration aligns with its long-term strategy of combining cutting-edge science platforms to create differentiated medicines with broad therapeutic potential.
Antibody-Helicon Conjugates Target Historically “Undruggable” Proteins
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At the center of the collaboration is Parabilis’ Helicon™ technology, which consists of stabilized, cell-penetrating alpha-helical peptides engineered to interact with intracellular protein targets, including flat protein surfaces typically inaccessible to standard therapeutic modalities. By coupling Helicon payloads with Regeneron’s VelocImmune®-derived antibodies, the companies aim to selectively deliver therapeutic peptides directly into targeted cells.
Unlike traditional antibody-drug conjugates (ADCs), which generally deliver cytotoxic agents to destroy cancer cells, the envisioned Antibody-Helicon Conjugates (AHCs) are designed to modulate intracellular proteins with greater precision while potentially expanding treatment opportunities across oncology and other disease areas. Scientists believe this approach could establish an entirely new therapeutic class capable of addressing previously unreachable biological targets.
George D. Yancopoulos, M.D., Ph.D., Regeneron’s President and Chief Scientific Officer, stated that combining Regeneron’s antibody expertise with Helicon technology could create highly selective therapies capable of transforming treatment strategies across multiple indications. The companies will jointly conduct early discovery work, while Regeneron will oversee global clinical development, manufacturing, and commercialization activities for resulting product candidates.
Multi-Billion-Dollar Collaboration Signals Growing Interest in Advanced Biologics
The collaboration highlights increasing pharmaceutical investment in advanced biologic platforms, intracellular targeting technologies, and engineered peptide therapeutics. Industry experts view the agreement as another indication that large biopharmaceutical companies are aggressively expanding beyond conventional monoclonal antibody strategies into more complex precision-medicine platforms capable of tackling challenging disease biology.
Regeneron continues to strengthen its position as one of the biotechnology industry’s leading innovation-driven companies, leveraging proprietary technologies including VelociSuite®, genetic medicine platforms, and data-driven drug discovery approaches to accelerate next-generation therapeutic development.
Source: Regeneron, Parabilis Medicines press release
