In its phase III NIMBLE trial, Regeneron has demonstrated that cemdisiran, an investigational siRNA targeting complement factor 5, delivered significant clinical benefit in adults with generalized myasthenia gravis (gMG), a rare autoimmune disorder that causes muscle weakness throughout the body. It occurs when the immune system produces antibodies that block or damage receptors needed for nerve-to-muscle communication.
Unlike the ocular form, which affects only the eye muscles, gMG can involve the arms, legs, face, throat, and even the muscles used for breathing. Symptoms often include drooping eyelids, difficulty swallowing or speaking, limb weakness, and shortness of breath. Because the condition can fluctuate in severity, patients may face periods of stability punctuated by sudden worsening, sometimes leading to a medical emergency known as a myasthenic crisis.
Regeneron’s Umesh Chaudhari, Executive Medical Director, Global Program Head of the complement factor 5 (C5) programs, said, “We understand people living with gMG are managing a significant burden. Our goal is to provide services that can support patients and their families throughout their treatment journey.”
With both the primary and key secondary endpoints met, Regeneron is now preparing to submit for US regulatory approval in Q1 2026, pending FDA discussions.
Beyond gMG, Chaudhari elaborated on Regeneron’s approach, noting: “Our C5 strategy is focused on researching potential new treatments for several complement-mediated diseases. Our C5-inhibiting portfolio exemplifies our strategy of integrating our deep understanding of disease biology with cutting-edge, platform-agnostic technologies like siRNA as well as novel combinations to address unmet needs. We have previously released data from the lead-in portion of our paroxysmal nocturnal hemoglobinuria (PNH) phase III trial, supporting the potential for cemdisiran in combination with pozelimab, a fully human monoclonal antibody designed to block the activity of C5, in PNH. We are also investigating cemdisiran monotherapy and the combination in our phase III program for geographic atrophy secondary to age-related macular degeneration.”
When asked about what support is available for gMG patients in the meantime, Chaudhari said, “We have worked with the MG community throughout the development and execution of this program to understand the patient journey, areas of unmet need and ensure the outcomes we measure in our trial are clinically meaningful. From patients and clinicians, we know that the burden of the disease itself is high. In addition to that, treatment-related challenges, including frequent clinic visits, inconsistent symptom control, and lack of durable treatment effects, can further affect quality of life and long-term disease management. This is where we believe cemdisiran has the potential to impact daily life for patients. We plan to share additional data from the NIMBLE trial, including quality of life measures, in future presentations.”
Newsletters
Receive the latest pharmaceutical news, personalities, education, and career development – weekly to your inbox.
