Annexon (NASDAQ:ANNX) executives used a Goldman Sachs Healthcare Conference session to outline the company’s upcoming clinical and regulatory catalysts, led by pivotal Phase III data expected in the fourth quarter for vonaprument in geographic atrophy, a form of advanced dry age-related macular degeneration.
Doug Love, Annexon’s chief executive officer and president, said the company views vonaprument as differentiated from currently approved geographic atrophy therapies because it is designed as a neuroprotective approach aimed at preserving vision rather than targeting lesion growth alone. He said the drug is a small antibody Fab fragment with low viscosity and a 25-microliter injection volume, which he contrasted with larger-volume approved therapies.
Geographic atrophy trial focus shifts to vision preservation
The executives addressed questions about Annexon’s Phase II study, which did not meet its primary endpoint on geographic atrophy lesion growth. Lloyd Clark, senior vice president of ophthalmology strategy, said photoreceptors are lost before retinal pigment epithelium, or RPE, cells in geographic atrophy, making RPE atrophy a lagging indicator of disease activity.
Clark said C1q, the target of vonaprument, is known to localize on photoreceptors that are lost in geographic atrophy. By inhibiting C1q, he said Annexon aims to protect photoreceptors first, which could lead to later protection of RPE cells. Clark noted that while the Phase II study did not show a statistically significant benefit in RPE lesion growth, it showed a 10.5% reduction in the final six months of the program.
Looking ahead to Phase III, Love said a favorable result would be statistical significance on BCVA 15-letter loss, which he described as the “gold standard” and clinically relevant based on discussions with regulators and physicians. Clark said Annexon’s expectations for the sham event rate are heavily informed by the company’s Phase II data and patient-level analysis.
The executives also said the Phase III program is designed with patient selection in mind. Clark said geographic atrophy includes an early phase with little vision loss, a late phase after major subfoveal damage, and a middle phase in which patients lose vision more rapidly. He said Annexon’s inclusion criteria are intended to select patients in that middle phase for regulatory evaluation.
Commercial strategy centers on retina specialists
Love said Annexon expects a vision-preserving therapy, if approved, could displace existing geographic atrophy treatments and expand the market. He said only about 20% to 25% of geographic atrophy patients are currently receiving therapy, and Clark said only about 20% of U.S. retina specialists are participating in the market.
Clark said he believes the market remains underdeveloped because physicians and patients have not experienced a functional benefit from existing therapies. Love said Annexon plans to commercialize vonaprument itself in the United States, citing what he described as an efficient commercial footprint of about 3,000 retina doctors, with a limited number of large practices controlling a substantial share of prescriptions.
Guillain-Barré syndrome program advances toward filings
Annexon also discussed tanruprubart, its drug candidate for Guillain-Barré syndrome. Love said the company’s Phase III study showed about 90% of patients benefited by week one, with a two-and-a-half-times greater likelihood of improvement by week eight, the primary endpoint, and a two-and-a-half-times greater likelihood of being normal by month six.
Love said the Phase III program was conducted outside the United States, including in Southeast Asia, because placebo-controlled studies were considered unethical in the U.S. He said Annexon aligned with regulators in Europe and the U.S. around the need to demonstrate substantial evidence of effectiveness and the generalizability of the study population to Western patients.
The company is on file in Europe and expects an approval decision in the early part of 2027, Love said. He added that Annexon expects to file shortly in the U.S. The company also initiated an open-label U.S. and European study called FORGE to provide experience with the drug and additional information for regulators. Love said data from FORGE are expected later this summer and that early observations appear consistent with the Phase III study in pharmacokinetics, pharmacodynamics, safety and efficacy.
For commercialization, Love said Annexon expects to partner or pursue a distribution arrangement outside the United States, while commercializing tanruprubart itself in the U.S. He said about 8,000 patients a year develop Guillain-Barré syndrome, and about 95% are currently treated with standard-of-care IVIG, which he said is unapproved for the disease.
Pipeline and balance sheet
Love also highlighted ANX1502, an oral small molecule designed to target the activated form of C1s in the classical complement pathway. He said the company is running a small proof-of-concept study intended to show target engagement and evaluate disease markers, including bilirubin. Data are expected in the second half of the year, before the geographic atrophy readout.
On funding, Love said Annexon reported $225 million in cash at its most recent earnings update, providing runway well into the second half of 2027. He said that runway covers key catalysts, including Guillain-Barré syndrome filings and potential approval, ANX1502 proof-of-concept data and the Phase III geographic atrophy readout. He added that the company is pursuing non-dilutive opportunities, including potential ex-U.S. arrangements for assets it does not plan to commercialize directly.
Love described the current period as a “win season” for Annexon, saying the company is focused on execution and education around its upstream complement approach across multiple diseases.
About Annexon (NASDAQ:ANNX)
Annexon Inc is a clinical-stage biotechnology company focused on the discovery and development of complement-targeted therapies for patients with neurodegenerative and neuroimmune diseases. The company’s research platform centers on the inhibition of the C1 complex, a key initiator of the classical complement pathway implicated in several rare and life-threatening disorders. By selectively targeting upstream complement activation, Annexon aims to prevent the aberrant immune-mediated damage that characterizes conditions such as Guillain-Barré syndrome (GBS) and autoimmune neuropathies.
At the core of Annexon’s pipeline is ANX005, a humanized monoclonal antibody directed against the C1q subcomponent, currently in Phase 2 clinical trials for acute GBS and chronic neurodegenerative indications.
