RNA Alliance: CRISPR and Sirius Redefine Precision Therapy

A CRISPR–Sirius alliance aims to advance siRNA therapies for safer clot prevention

11 Nov 2025

CRISPR Therapeutics and Sirius Therapeutics are teaming up to tackle one of medicine’s toughest challenges: how to silence harmful genes without permanently altering DNA.

The two biotech firms announced their partnership in May 2025, setting their sights on small interfering RNA (siRNA) therapies for blood-clotting disorders. These treatments aim to temporarily switch off genes linked to excessive clotting, offering patients safer and more flexible options than traditional drugs.

Their first target is Factor XI, a gene that drives clot formation. By quieting its activity, the companies hope to prevent dangerous clots while avoiding the bleeding risks that come with many current medications.

Under the agreement, CRISPR will invest $25 million in cash and $70 million in equity, with the potential to expand into other siRNA programs. CRISPR will handle U.S. commercialization, while Sirius oversees operations in Greater China, a move designed to speed global access and take advantage of local expertise.

Analysts see the partnership as a sign of where genetic medicine is headed. “Integrating editing, silencing, and delivery technologies creates a more adaptable path to precision therapies,” said one industry observer.

The deal also underscores America’s growing influence in gene-based innovation, aligning with the Food and Drug Administration’s push to modernize oversight of RNA and gene-editing treatments.

Of course, challenges remain. Manufacturing complexity, precise delivery, and long-term safety are all hurdles still to clear. Yet optimism surrounds the collaboration. Many view it as a thoughtful blend of ambition and pragmatism, a blueprint for how biotech companies can combine strengths to accelerate breakthroughs.

If the CRISPR and Sirius effort delivers, it could mark a turning point in gene therapy, one where temporary, reversible treatments reshape how we think about curing disease.