Codexis Enters into an Agreement with Pioneering siRNA Drug Innovator to Leverage the ECO Synthesis Manufacturing Platform to Create Stereo-defined siRNA

What was announced

Codexis announced an agreement with a pioneering siRNA drug innovator to use its ECO Synthesis Manufacturing Platform to explore stereo-defined fragment synthesis. Under the agreement, Codexis will produce stereo-defined oligonucleotide fragments through a fully enzymatic process and supply those fragments to the innovator for assembly into the final duplex via ligation. The companies will compare enzymatically synthesized fragments with conventional solid-phase oligonucleotide synthesis (SPOS) on measures including purity, product quality, and ligation performance. Inference: results of the comparison could influence the innovator’s assessment of manufacturing approaches for future clinical development programs.

Sources: S1

Technical background and prior demonstration

Codexis says the agreement builds on advances presented at TIDES USA 2026 where it demonstrated full-length siRNA synthesis with precise control of phosphorothioate stereochemistry via StereoSelect, a capability of ECO Synthesis. The company describes ECO Synthesis as an aqueous enzymatic process being developed as a scalable alternative to traditional solid phase organic synthesis for oligonucleotide manufacturing, and lists potential manufacturing benefits such as higher yields, increased purity, reduced energy usage and waste generation, stereoisomer control of siRNA, and improved overall capacity with lower capital requirements.

Sources: S1

Issuer commentary

Codexis’ President and CEO, Alison Moore, is quoted regarding the agreement as an important step in applying ECO Synthesis capabilities to a customer and to demonstrate stereochemical control that may offer superior product quality and therapeutic performance compared with traditional solid phase chemistry methods. The release frames the collaboration as part of Codexis’ broader strategy to industrialize scalable manufacturing solutions for complex oligonucleotide therapeutics and notes an initial application focus on RNAi therapeutics.

Sources: S1

What remains uncertain

• All technical and commercial descriptions come from a Codexis press release and represent issuer claims without independent verification in the supplied sources.
• The agreement’s financial terms, timelines, and specific deliverables are not disclosed in the supplied source.
• The release describes potential manufacturing benefits of ECO Synthesis in non-definitive language (for example, using phrases such as "may offer"), and potential future clinical development remains subject to additional testing and decision-making by the innovator.
• Comparative performance outcomes versus SPOS are to be evaluated; the supplied source does not include results of those comparisons.