Annexon (NASDAQ:ANNX) highlighted progress across three programs targeting the classical complement pathway during a fireside chat at TD Cowen’s 46th Annual Healthcare Conference, with President and CEO Douglas Love emphasizing upcoming clinical catalysts, ongoing regulatory work, and preparations for potential commercialization.
Company focus and pipeline priorities
Love said Annexon is pursuing a “next-generation neuroinflammatory approach” focused on inhibiting the classical pathway, which he described as providing “the most complete protection against complement, classical complement-driven inflammation.” He outlined two late-stage programs—geographic atrophy (GA) and Guillain-Barré syndrome (GBS)—and a third program built around a first-in-kind oral small molecule candidate, ANX1502.
Geographic atrophy: Phase II results and Phase III design
Discussing GA, Love pointed to a 270-patient, sham-controlled Phase II proof-of-concept study, stating that Annexon’s program is “the only program to demonstrate significant vision preservation.” He said the study showed statistically significant and dose-dependent protection on best corrected visual acuity (BCVA), which he called the gold-standard endpoint, as well as consistency across other measures including low luminance visual acuity and low luminance visual deficit.
Love argued the functional vision findings were supported by structural data, saying the company observed protection of photoreceptor neurons—particularly in the central retina—which he described as responsible for visual acuity. He cited “50%–60% protection in the central retina” at 12 months.
On safety, Love said conversion to wet age-related macular degeneration (wet AMD) or choroidal neovascularization (CNV) was “pretty similar across all treatment groups,” with “really no difference between sham versus treatment arms.” He contrasted that with what he described as conversion rates “in the neighborhood of the low teens” for other approved therapies.
Love also addressed why Annexon believes inhibiting C1q could preserve vision compared with downstream complement targets such as C3 or C5. He said C1q initiates the classical pathway and localizes on diseased tissue, including photoreceptor cells and synapses in GA, and that blocking C1q stops classical pathway inflammation at the source. In contrast, he described C3 and C5 as downstream targets more associated with debris removal and retinal pigment epithelium (RPE) lesion growth, which he characterized as a “lagging indicator” relative to loss of photoreceptors and vision.
For the pivotal study, Love described a 659-patient Phase III program with a single protocol, enrolling both foveal and non-foveal GA (an “all-comer” design). The primary endpoint is BCVA, and he said Annexon has alignment with regulators in the U.S. and Europe on that endpoint. The readout is expected at month 15, and Love said enrollment and study conduct are “well underway.”
He also said Annexon adjusted the Phase III population based on Phase II learnings, noting that about 20% of Phase II patients were too advanced for vision preservation. Love said Annexon excluded that profile in Phase III and described the approach as an enrichment strategy aimed at treating patients in a window where vision loss can be meaningfully slowed.
On readiness for a potential filing, Love said the company is working with Lonza on manufacturing and has run multiple campaigns, with commercial campaigns in process. He said Annexon believes it will be ready upon approval.
GBS: Phase III outcome, regulatory path, and commercialization planning
Love described GBS as the leading cause of acute neuromuscular paralysis, estimating it affects roughly 7,000 patients annually in the U.S. and 15,000 in Europe. He outlined the disease course as rapid and severe, citing that 20% of patients enter an ICU, one in four require a ventilator, and 20% are unable to walk after a year.
Annexon’s GBS program, tanruprubart, also targets classical complement-driven inflammation, which Love said localizes on peripheral nerves in this condition. He described the Phase III study as a “resounding” and “landmark” win, stating the trial met the primary endpoint and other measures. Love said approximately 90% of patients improved by week one, which he described as unprecedented in the disease.
He said the data showed improvements versus placebo and also versus standard-of-care outcomes evaluated in real-world evidence (RWE) analyses involving IVIG, which he noted is widely used but unapproved. Love cited several outcomes he said were observed in the Phase III dataset:
- Improved muscle strength by week one
- More than two times likelihood of improvement by week 4 on the GBS Disability Scale and week 8 (the primary endpoint)
- More than 2.5 times likelihood of returning to normal or full recovery by month 6
On regulatory status, Love said the company has filed in Europe and is preparing for a U.S. filing. He identified generalizability of the Phase III data to Western populations as the key open topic with the FDA. To address that, Love said Annexon conducted an RWE analysis using propensity score matching against a 2,000-patient natural history dataset from Erasmus, and also compared outcomes against patients treated with IVIG, saying the company observed improvement versus IVIG across measures. He said the RWE data is expected to be published “shortly.”
For additional support in the U.S. filing, Love said Annexon is collecting supplemental open-label data in the FORGE study in the U.S. and Europe, where all patients receive tanruprubart. He said early results are encouraging and that the company plans to share those data and include them in its FDA submission. He added that the number of patients to include in the FDA filing has not been finalized, but he suggested it could be “in the neighborhood of 5–10 patients,” citing the strength and consistency of the week-one improvement signal and the importance of PK/PD consistency.
Commercially, Love said GBS is a “ready-made market” because essentially all diagnosed patients are treated. He said the U.S. opportunity is driven by identifying patients and focusing on a concentrated set of treatment centers, stating that roughly 50 large practices control about half of U.S. patients. Love said the company is building its U.S. commercial effort, emphasizing education of 50–75 targeted practices, adding that no one has historically promoted in GBS and calling it “greenfields.” He also highlighted formulary and reimbursement work, noting that about two-thirds of patients have commercial reimbursement.
On pricing, Love said Annexon has not disclosed a price but referenced analyst expectations of $100,000–$150,000 per course, calling that range “not unreasonable” and potentially conservative given claimed cost offsets from shorter ICU stays, ventilation time, and hospitalizations. He said GBS costs more than $7 billion annually to treat in the U.S. and that Annexon expects to publish health economics papers over the next one to two quarters.
ANX1502: oral small molecule proof-of-concept and formulation work
Love described ANX1502 as a first-in-kind oral small molecule targeting the classical pathway, aimed at antibody-mediated neuromuscular autoimmune diseases such as myasthenia gravis and CIDP. He said the current proof-of-concept study is in cold agglutinin disease, chosen for objective measures rather than as a target commercial indication.
He said proof-of-concept markers include normalization of hemolysis measures such as bilirubin, normalization of elevated classical complement markers including C4, and safety/tolerability. Love also discussed formulation development, noting the program initially encountered nausea with a film-coated version and transitioned to an enteric-coated formulation, which he said appears to have addressed nausea.
However, he said the company is observing a food effect: when taken with food, exposure appears limited, while dosing without food produces “3, 4, 5-fold” target drug levels. He said Annexon is now studying dosing where both twice-daily doses are taken without food and indicated the company will evaluate whether to advance the current formulation or pursue additional work to reduce or eliminate the food effect.
Capital position and partnering approach
Love said Annexon ended the period with more than $200 million in cash and expects a runway into the “late second half 2027.” He said that runway extends beyond key near-term catalysts, including the GA Phase III readout, an ANX1502 readout later this year, and the GBS regulatory process.
On strategy, Love said Annexon intends to advance and commercialize the programs itself, particularly in the U.S., while remaining open to ex-U.S. partnerships. He also outlined additional potential follow-on opportunities he said are mechanistically related to the company’s current “beachhead indications,” including intermediate GA, an aggressive form of glaucoma, chronic neuromuscular diseases related to GBS, and potential relevance to broader neurodegenerative disorders.
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.
