The agreement builds on advances presented at TIDES USA 2026, where for the first time, Codexis demonstrated full-length siRNA synthesis with precise control of phosphorothioate stereochemistry via StereoSelectSM, a capability of ECO Synthesis.

Under the agreement, Codexis will use its ECO Synthesis platform to produce stereo-defined oligonucleotide fragments through a fully enzymatic process. The fragments will be supplied to the innovator to assemble into the final duplex via ligation, an approach that is gaining momentum as a next-generation manufacturing paradigm for oligonucleotides due to its potential to enhance scalability, efficiency, and product quality.

The collaboration will also compare enzymatically synthesized fragments with conventional solid-phase oligonucleotide synthesis (SPOS), evaluating purity, product quality, and ligation performance. The results will allow the innovator to assess the technology's potential for future clinical development programs.

Alison Moore, PhD., President and CEO at Codexis, said: "This agreement is an important next step in bringing our latest ECO Synthesis capabilities to a customer. Working with a pioneer in the siRNA field offers an exciting opportunity to demonstrate how ECO Synthesis can deliver stereochemical control, which may offer both superior product quality and therapeutic performance to an innovator’s pipeline over assets produced using traditional solid phase chemistry methods."

Codexis continues to advance the ECO Synthesis Manufacturing Platform as part of its strategy to industrialize scalable manufacturing solutions for complex oligonucleotide therapeutics.