PeptiDream and Alnylam Announce Achievement of Key Milestone in siRNA Conjugate Discovery Collaboration Demonstrating Peptide-Ligand Mediated Targeted siRNA Delivery to Specific Extrahepatic Tissues

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KAWASAKI, Japan--(BUSINESS WIRE)--Dec 18, 2025--

PeptiDream Inc., a public Japan-based biopharmaceutical company (President: Patrick C. Reid, hereinafter “PeptiDream”)(Tokyo: 4587), announced the achievement of a preclinical development milestone in its collaboration with Alnylam Pharmaceuticals, Inc. (“Alnylam”). The significant milestone marks a key step in building a modular therapeutic platform for precision siRNA delivery using macrocyclic peptides that is adaptable across numerous therapeutic areas and offers a scalable solution to expand to scope of RNAi therapeutics.

This milestone underscores the transformative potential of PeptiDream’s proprietary Peptide Discovery Platform System ® (PDPS) in enabling receptor-mediated uptake of siRNA therapeutics into organs beyond the liver—a long-standing challenge in the field of RNA interference (RNAi). The peptide-siRNA conjugate demonstrated robust and specific uptake with deep target gene knockdown in wild-type animal models via subcutaneous administration, with negligible activity in receptor knockout models, confirming the specificity of the targeting mechanism.

“ This milestone is a powerful validation of our modality’s ability to unlock siRNA delivery to specific tissues and opens the door to a new generation of precision RNAi medicines ” said Patrick C. Reid, PhD, President and CEO of PeptiDream.

“ We are pleased with our collaboration with PeptiDream and this milestone underscores our trust in the preferred approach of pursuing GalNAc-like ligands that are small in size, allow subcutaneous dosing and are expected to be better for scale-up and characterization ” said Vasant Jadhav, PhD, Chief Technology Officer of Alnylam.

PeptiDream and Alnylam initiated the collaboration in 2021, aiming to combine PeptiDream’s proprietary PDPS discovery platform and optimization expertise with Alnylam’s pioneering expertise in RNAi therapeutics to discover and develop peptide-siRNA conjugates to create multiple opportunities to deliver RNAi therapeutics to diverse cell types and tissues beyond the liver.

Under the terms of the agreement, PeptiDream will receive an undisclosed milestone payment from Alnylam and remains eligible to receive additional development, regulatory, and commercial milestones, as well as low-to-mid single-digit royalties on sales of any resulting Alnylam products.

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CONTACT: Inquiries:

PeptiDream Inc.

Contact: Yuko Okimoto, IR & Public Affairs

Email:[email protected]

Website:https://www.peptidream.com/en/

X:https://x.com/PeptidreamInc

KEYWORD: MASSACHUSETTS UNITED STATES JAPAN NORTH AMERICA ASIA PACIFIC

INDUSTRY KEYWORD: BIOTECHNOLOGY HEALTH SCIENCE PHARMACEUTICAL RESEARCH

SOURCE: PeptiDream Inc.

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PUB: 12/18/2025 07:00 AM/DISC: 12/18/2025 07:00 AM

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