Pune, India | August 29, 2025– Regeneron Pharmaceuticals has released promising Phase 3 trial results for cemdisiran. This investigational RNA interference (RNAi) therapy targets generalized myasthenia gravis (gMG). gMG is a rare autoimmune disorder that weakens skeletal muscles and limits daily functioning. Notably, cemdisiran met its primary trial endpoint, helping patients improve essential tasks such as speaking, chewing, and swallowing over 24 weeks.
The study compared cemdisiran alone with a combination of cemdisiran and pozelimab. Pozelimab is an FDA-approved C5 monoclonal antibody marketed as Veopoz. Patients on cemdisiran alone showed a 74% reduction in C5 protein levels. In comparison, those on the combination therapy saw a nearly 99% reduction. Interestingly, the monotherapy group slightly outperformed the combination group in daily function scores. Therefore, cemdisiran appears effective even without additional antibody support.
The treatment also showed a strong safety profile. No patients stopped treatment due to side effects. As a result, Regeneron plans to submit a Biologics License Application (BLA) to the FDA in early 2026. If approved, cemdisiran could become a valuable new treatment for people with gMG.
In gMG, the immune system blocks nerve-to-muscle signals. This leads to weakness in the limbs, face, eyes, and respiratory muscles. To counter this, cemdisiran silences the gene that produces C5 in the liver. This approach allows for long-term protein suppression with less frequent dosing.
Moreover, patients may receive the drug through subcutaneous injections once every three months. This offers a major benefit compared to current treatments, which often require hospital visits. Consequently, the ability to dose at home may reduce the treatment burden for many.
Regeneron considers this delivery method a competitive advantage. In contrast, existing drugs like Vyvgart Hytrulo (Argenx), Imaavy (Johnson & Johnson), and Soliris (AstraZeneca) need more frequent or clinic-based administration. Because of this, analysts believe cemdisiran’s durability and convenience could help it capture a large share of the gMG market.
Following the announcement, Regeneron saw a modest rise in its stock. This reflects investor confidence in the company’s rare disease pipeline. In addition to gMG, cemdisiran—used alone or with pozelimab—is also being studied in other diseases tied to complement system dysfunction. These include paroxysmal nocturnal hemoglobinuria (PNH) and geographic atrophy, which can cause vision loss.
Cemdisiran plays a central role in Regeneron’s strategy to target the complement system using precision therapies. Its RNAi technology enables sustained suppression of C5 protein without continuous antibody treatment. Although pozelimab works differently, it complements cemdisiran’s mechanism. Thus, doctors gain more flexibility in how they treat patients.
By exploring both monotherapy and combination approaches, Regeneron reinforces its patient-centered care model. Ultimately, quarterly dosing can improve outcomes while reducing emotional and logistical burdens.
Beyond that, cemdisiran highlights Regeneron’s growing investment in gene-silencing technology. This move signals a shift away from reliance on monoclonal antibodies. As a result, cemdisiran stands out as a user-friendly, next-generation option in an evolving market.
Healthcare professionals and patient groups welcomed the Phase 3 results. Specifically, they highlighted cemdisiran’s potential to improve the quality of life while maintaining safety and ease of use. Meanwhile, as Regeneron prepares its FDA application, it is also planning for global regulatory discussions, ensuring supply chain readiness, and implementing educational outreach.
Backed by strong clinical data and a broad development pipeline, Regeneron is on track to launch the first RNAi therapy for gMG. The success of this trial confirms its leadership in rare disease innovation. Most importantly, it brings new hope to patients with limited options. Through a combination of scientific advancement and patient-first values, Regeneron continues to develop therapies that aim to change lives.
