CRISPR Therapeutics, a biopharmaceutical company focused on transformative gene-based medicines, and Sirius Therapeutics, a clinical-stage biotechnology firm developing innovative small interfering RNA (siRNA) therapies, have announced a strategic collaboration to develop and commercialize siRNA-based treatments.

As part of the collaboration, the companies will jointly advance SRSD107, Sirius’ next-generation, long-acting siRNA candidate targeting coagulation Factor XI (FXI), a key player in thrombosis with minimal impact on normal hemostasis. The therapy is designed to reduce thrombotic risk while offering a potentially lower bleeding profile compared to traditional anticoagulants, along with infrequent dosing and the possibility of reversibility.

CRISPR Therapeutics’ CEO Dr. Samarth Kulkarni highlighted the opportunity to expand the company’s cardiovascular portfolio, referencing promising recent data for CTX310, which targets ANGPTL3. He noted that Factor XI is an especially compelling target for thrombotic disorders and praised Sirius’ siRNA platform as a strong complement to CRISPR’s gene-editing capabilities.

Sirius Therapeutics’ CEO Dr. Qunsheng Ji underscored the collaboration’s significance, citing unmet needs in thrombotic diseases and promising Phase 1 data for SRSD107. The molecule showed over 93% reductions in FXI levels and activity, with sustained effects for up to six months following a single dose, and was well tolerated. Results were recently presented at major cardiology and hematology conferences.

Cardiologist Dr. Christian T. Ruff of Harvard Medical School commented on SRSD107’s clinical potential, emphasizing its promise for safer anticoagulation in high-risk patients with comorbidities such as malignancy or renal disease, where current therapies pose challenges due to bleeding risk or compliance issues.

The collaboration includes the initiation of a Phase 2 clinical trial evaluating SRSD107 for prevention of venous thromboembolism (VTE) in patients undergoing total knee arthroplasty. The trial will assess safety, efficacy, and inform future dosing strategies.

Key Collaboration Terms:

CRISPR Therapeutics will provide Sirius with $25 million in upfront cash and $70 million in equity.

The companies will co-develop SRSD107 under a 50/50 cost and profit-sharing agreement.

CRISPR will lead commercialization in the U.S., while Sirius will handle Greater China.

CRISPR also gains the option to nominate up to two additional siRNA targets for joint development, with Sirius eligible for milestone payments and tiered royalties.

This partnership strengthens both companies’ pipelines and highlights the growing convergence between gene-editing and RNA-based therapeutic platforms in addressing complex diseases.

Source: https://ir.crisprtx.com/news-releases/news-release-details/crispr-therapeutics-and-sirius-therapeutics-announce-multi