None of those sigma-1 agonists fix mitochondria.
Those listed sigma-1 agonists simply do not have the health-restoring capabilities of Anavex 2-73.
Donepezil (trade name Aricept) merely slows or briefly halts the morbid progression of Alzheimer's symptoms. It is in no way a competitor with Anavex 2-73, which (among other things) restores homeostatic mitochondrial/rough endoplasmic reticulum connections, allowing the rough ER to properly fold health-giving neuron enzymes. Aricept does not do this. It is merely a weak, short-lived Alzheimer's treatment that only slows symptomatic progression for a few weeks or months. Death ensues.
None of the other listed sigma-1 agonists restore neuron mitochondrial function, either.
It would be nice to have (as will be the case) Aricept as the accepted Standard of Care for Alzheimer's. Anavex 2-73 clinical data (as already in the Australian study) will show a multitude of lasting, safe efficacies the Standard of Care Aricept cannot match. With Aricept as the competitor, against which Anavex 2-73 will be compared, coupled with validated (Phase 3) clinical data, FDA approval of Anavex 2-73 is assured, to become the new Alzheimer's Standard of Care.
Sigma-1 agonism is not the central factor; rather, it's Anavex's unique sigma-1 agonist that uniquely restores neuron homeostasis (normal biochemical function). There may be many other sigma-1 agonists; but none of them demonstrate restoration of neuron homeostasis. None of them restore normal mitochondrial function. None of them effectively treat Alzheimer's disease. Anavex 2-73 does.