RESEARCH MONOGRAPH · KDC-MN-333

Anavex 2-73 (Blarcamesine)

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 2 min read

Our opinion on this compound

65/100

Sigma-1 modulator with one of the more interesting phase 2-3 stories in current Alzheimer's pipeline

Anavex 2-73 (blarcamesine) is the molecule that's currently the most clinically advanced sigma-1 agonist anywhere in development, and the recent phase 2/3 data in Alzheimer's has been more interesting than the AD field's collective shrug suggests. Worth paying attention to.

Mechanism is sigma-1 receptor agonism with additional muscarinic M1-M2-M4 partial agonist activity (which is the part that makes it pharmacologically distinct from cutamesine or pridopidine). The thinking is that the sigma-1 agonism does the neuroprotective/restorative work via ER-mitochondrial calcium signaling and autophagy modulation, while the muscarinic component adds symptomatic cholinergic enhancement. Combined target hypothesis, which has obvious medicinal-chemistry appeal and obvious interpretability problems.

The phase 2b/3 ATTENTION-AD trial (Macfarlane et al, results out 2022-2024) showed modest but statistically significant slowing of cognitive decline on ADAS-Cog13 in mild-to-moderate Alzheimer's, with biomarker signals on plasma p-tau181 and brain volume measures that bracket the cognitive effect plausibly. Not earth-shaking effect sizes, but in the AD space where lecanemab and donanemab are getting approval on similar magnitudes, blarcamesine is at least in the conversation. The European regulatory submission is the next test.

The mechanistic narrative is honestly one of the more compelling in current AD: sigma-1 agonism induces autophagy, reduces misfolded protein burden, restores mitochondrial calcium handling, all of which sits upstream of the amyloid/tau pathology rather than removing extant plaques. If it works, it works for different reasons than the anti-amyloid antibodies.

What people miss: blarcamesine also has a Rett syndrome program (different patient population, smaller trials, results have been mixed), and the broader sigma-1 modulator class is getting renewed attention because of the COVID-era fluvoxamine work that suggested sigma-1 agonism might be antiinflammatory in real ways.

For research the muscarinic polypharmacology makes blarcamesine messier than cutamesine as a clean sigma-1 probe. You'd use it specifically when you want the combined sigma-1 plus muscarinic profile.

Sourcing: research-grade material exists but is harder to obtain than older sigma-1 tools, expect HPLC and NMR verification to add to the cost.

What we like: real clinical signal, interesting mechanism, well-developed PK and safety package.

What we dont like: polypharmacology makes mechanism studies confounded, and the AD effect size is modest even if real.

One of the more interesting clinical-stage molecules in current rotation.

Evidence: 65
Mechanism: 65
Reliability: 60
Safety: 75
Sourcing: 55
Value: 55
Signal: 70
Staying power: 72

Plain-language summary Intrigue 66 / 100

Anavex 2-73 (blarcamesine) is a sigma-1 agonist with additional muscarinic acetylcholine receptor activity, developed by the small biotech Anavex Life Sciences. The dual mechanism (sigma-1 chaperone activation plus cholinergic enhancement) is genuinely distinctive in a CNS drug landscape dominated by single-target compounds. Phase 2 trials in Alzheimer disease and Rett syndrome (a rare X-linked neurodevelopmental disorder) have produced encouraging signals, and a pivotal Rett trial reported positive results that the company is using to pursue regulatory approval. Independent replication remains limited and the company is small, so the data quality is not yet at the level of major Alzheimer trials. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Sigma-1 agonist + muscarinic modulator

A sigma-1 agonist with muscarinic acetylcholine receptor activity; investigated for Alzheimer disease, Parkinson dementia, and Rett syndrome.

Abstract

Anavex 2-73 (blarcamesine, AVN-101; CAS 195615-83-9; molecular formula C16H21NO; molecular weight 243.34) is a multi-target sigma-1 agonist with muscarinic acetylcholine receptor activity, developed by Anavex Life Sciences. Sigma-1 affinity is approximately 860 nM (lower than cutamesine but functionally meaningful); the compound additionally interacts with muscarinic M1 and M2 receptors. Phase 2 trials in Alzheimer disease and Parkinson disease dementia demonstrated dose-dependent improvements in some cognitive endpoints. Phase 3 in Rett syndrome (EXCELLENCE trial) reported positive results in 2024 for select endpoints. Plasma half-life is approximately 14 hours. Used as a multi-target research compound for sigma-1 and muscarinic neuropharmacology.

Mechanism of action

Sigma-1 receptor agonist combined with muscarinic M1/M2 activity. Multi-target neuroprotective profile.

Reported research dose ranges

Trial doses 10 to 50 mg in the published literature.

References

Vamvakides A. Mechanism of action of A2-73, a putative cognitive enhancer with anxiolytic and anti-amnesic activities. Ann Pharm Fr 2002.
Hampel H, et al. Phase 2 trial of blarcamesine (Anavex 2-73) in mild-to-moderate Alzheimer's disease. J Prev Alzheimers Dis 2020.
Macfarlane S, et al. Anavex 2-73 in Rett syndrome (AVATAR/EXCELLENCE programs). Mol Psychiatry 2024.

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KDC-MN-333

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

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Anavex 2-73 (Blarcamesine)

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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