The quiet revolution in heart disease: How siRNA is becoming cardiology’s most powerful new weapon

A small Codexis manufacturing deal is a minor footnote — but it points to one of the biggest stories in pharma right now

On Thursday, Codexis (NASDAQ: CDXS) announced it had signed an agreement to manufacture 50 grams of small interfering RNA — siRNA — for an unnamed pharmaceutical partner targeting a cardiovascular indication, using its proprietary ECO Synthesis manufacturing platform. The partner wasn’t named. The drug target wasn’t disclosed. The clinical stage wasn’t revealed.

As a standalone story, it tells you almost nothing. As a signal of where cardiovascular medicine is heading, it tells you a lot.

Pharmaceutical Daily has reached out to Codexis for additional details on the partnership, including the identity of the target indication, the development stage of the program, and what the 50-gram batch represents in terms of potential commercial scale. We will update this story when we receive a response.

What siRNA actually does — and why it matters for your heart

For readers unfamiliar with the technology: siRNA works by silencing specific genes before they produce harmful proteins. Instead of blocking a protein after it’s already circulating in your bloodstream — which is how statins and most traditional cardiovascular drugs work — siRNA intercepts the instruction that tells your liver to make that protein in the first place. The goal is to stop the problem in the source.

The implications for cardiovascular disease are profound. Heart disease remains the leading cause of death globally, and despite decades of statins, studies estimate that roughly 60% to 80% of people with atherosclerotic cardiovascular disease in the United States are still not reaching guideline-recommended LDL cholesterol goals. siRNA therapeutics offer something statins don’t: deep, durable reduction in atherogenic lipoproteins from just two injections per year.

The field is moving fast in 2026

The proof of concept is already approved and in patients. Inclisiran, developed by Novartis, is the first approved siRNA drug for hypercholesterolemia — targeting PCSK9 gene expression and reducing LDL-C.

Long-term data from the ORION-3 trial showed sustained LDL-C reductions of 44.2% on average over four years, with just nine injections total. For a condition where daily pill fatigue is a documented clinical problem, that’s a transformative compliance profile.

But inclisiran is not all. There is more in 2026. Amgen’s zerlasiran, targeting the LPA gene responsible for elevated lipoprotein(a) — an independent cardiovascular risk factor with no currently approved therapy — is in the OCEAN(a) outcomes trial, with completion expected in December 2026. A positive result there would open a completely new therapeutic category, given that current standard lipid-lowering therapies have no meaningful effect on Lp(a) levels, and according to some studies, statins can increase them by 10-20%.

Meanwhile, Rona Therapeutics entered clinical development in early 2026 with RN5681, the its bi-valent siRNA designed to simultaneously silence both PCSK9 and LPA — addressing two genetically validated cardiovascular risk drivers with a single molecule. If that approach delivers, it would represent a generational leap beyond anything currently approved.

The manufacturing bottleneck nobody talks about

This is where the Codexis deal becomes relevant — not as news in itself, but as infrastructure context.

Making siRNA at scale is genuinely hard. The molecules are complex, chemically fragile, and expensive to synthesize using traditional solid-phase methods. As cardiovascular indications expand the patient populations from thousands to potentially millions, the manufacturing demands increase by orders of magnitude. A drug like inclisiran, dosed twice yearly in tens of millions of high-risk patients globally, requires industrial-scale RNA production that the industry is still building capacity for.

Codexis’ ECO Synthesis platform — enzymatic rather than chemical synthesis — is designed to address exactly this bottleneck. The fact that an unnamed partner is already using it for a cardiovascular preclinical program suggests the technology is being evaluated seriously by companies that expect to need it at scale.

The investor angle

For investors, the cardiovascular siRNA space sits at a compelling intersection of proven science, massive unmet need, and a pipeline that could deliver multiple major readouts in the next 18-24 months. The OCEAN(a) outcomes trial result for zerlasiran alone could reshape the entire Lp(a) therapeutic landscape — a market with no approved treatments and an estimated 20% of the global population carrying elevated levels.

The Codexis deal is a footnote. The revolution it points to is not.