Los Angeles Dodgers' first baseman Freddie Freeman's son's battle with Guillain-Barré syndrome (GBS) has brought increased attention to this rare neurological disorder, as Annexon Biosciences advances its lead candidate, ANX005, as a potential treatment.
GBS is a rare autoimmune condition where the immune system attacks the peripheral nervous system, leading to rapid onset of weakness and potential paralysis. According to the CDC, GBS impacts 3,000-6,000 people in the U.S. each year. Current treatments, like off-label intravenous immunoglobulin therapy (IVIG), have limited effectiveness, especially in severe cases.
ANX005: A Novel Approach
Annexon Biosciences has successfully completed a pivotal Phase 3 trial for ANX005, an immunotherapy designed to block C1q, a key molecule in the classical complement pathway associated with GBS. This approach differs from other complement programs by targeting upstream complement activity, localizing and activating complement or inflammation right on disease tissue.
According to Douglas Love, president and CEO of Annexon Biosciences, ANX005 is designed to block C1q immediately upon administration, quickly shutting down the disease process and allowing patients to move from a state of decline. A June Phase 3 readout showed statistically significant results on key endpoints, including the GBS disability scale.
Clinical and Commercial Implications
Unlike IVIG, which is administered over five days, ANX005 is given via a quick IV infusion. Annexon plans to file its biologics license application for ANX005 in the first half of 2025. If approved, ANX005 would be the first FDA-approved treatment for GBS.
Love noted the high compliance rate in treating GBS (90%) and the concentration of cases in a few large states and hospitals, allowing for an efficient commercial footprint.
Beyond GBS
ANX005 isn't the only product in Annexon’s pipeline targeting C1q. Other programs are in geographic atrophy and complement-mediated autoimmune diseases, as well as programs in Huntington’s disease, ALS and lupus nephritis.
Love stated that by targeting C1q, Annexon can pursue a wide range of indications not typically seen with other complement programs.
