Core Insights - CRISPR Therapeutics and Sirius Therapeutics have initiated a Phase 2 clinical trial for SRSD107, a long-acting Factor XI siRNA aimed at preventing venous thromboembolism in patients undergoing total knee arthroplasty [1][2] Company Overview - CRISPR Therapeutics is focused on developing gene-based medicines for serious diseases and has a diverse portfolio that includes CRISPR/Cas9 gene editing therapies [8] - Sirius Therapeutics is a clinical-stage biotech company developing innovative siRNA therapies, with a pipeline targeting coagulation disorders and other chronic diseases [10][11] Clinical Trial Details - The Phase 2 trial is a randomized, multicenter, global study assessing the safety and efficacy of SRSD107 for VTE prevention in TKA patients [2] - SRSD107 aims to selectively inhibit FXI, a key factor in pathological thrombosis, while minimizing effects on normal hemostasis [3] Previous Trial Results - In Phase 1 trials, SRSD107 demonstrated strong pharmacodynamic effects, achieving over 93% reduction in FXI levels and more than twofold increase in activated partial thromboplastin time [3] Collaboration Insights - The strategic collaboration between CRISPR Therapeutics and Sirius Therapeutics was established in 2025 to co-develop siRNA therapies, sharing costs and profits equally [6][7] - CRISPR Therapeutics will lead commercialization efforts in the U.S., while Sirius will focus on Greater China [6] Market Potential - The addressable population for SRSD107 includes patients with various conditions such as atrial fibrillation, VTE, and chronic coronary artery disease, where existing therapies have limitations due to bleeding risks [3]

Core Insights - CRISPR Therapeutics and Sirius Therapeutics have formed a strategic partnership to co-develop and commercialize SRSD107, a long-acting Factor XI (FXI) small interfering RNA (siRNA) for thromboembolic disorders [1][2] - SRSD107 has shown promising results in Phase 1 clinical trials, achieving over 93% reduction in FXI activity and more than twofold increase in activated partial thromboplastin time (aPTT), with effects lasting up to 6 months post-dosing [1][3] - The collaboration includes an upfront payment of $25 million in cash and $70 million in equity from CRISPR to Sirius, with a 50-50 cost and profit-sharing structure for SRSD107 [1][8] Company Overview - CRISPR Therapeutics is focused on creating transformative gene-based medicines and has a diverse portfolio across various disease areas, including cardiovascular diseases [10] - Sirius Therapeutics is a clinical-stage biotech company developing innovative siRNA therapies, with SRSD107 being its most advanced product targeting thromboembolic disorders [17][18] Clinical Development - The clinical program for SRSD107 includes two Phase 1 trials demonstrating safety and robust pharmacodynamic effects, with a Phase 2 trial planned to evaluate its efficacy in preventing venous thromboembolism (VTE) in total knee arthroplasty patients [3][7] - SRSD107 is designed to selectively inhibit FXI, aiming to reduce thrombotic events while minimizing bleeding risks, offering a differentiated approach compared to existing therapies [2][16] Market Potential - Thromboembolic disorders are a significant global health issue, affecting millions and representing a substantial unmet medical need [2][15] - The addressable patient population for SRSD107 includes those with atrial fibrillation, venous thromboembolism, cancer-associated thrombosis, and other conditions where existing therapies pose bleeding risks [2][3]