Tesofensine (also known as NS-2330) is a novel triple monoamine reuptake inhibitor with intrinsic inhibitory activity on norepinephrine (NE), serotonin (5-HT), and dopamine (DA) transporter function. It was development by NeuroSearch as a potential therapy for Alzheimer's disease (AD) and Parkinson's diseases, but these efforts have been discontinued. In phase II clinical trials with tesofensine in obese individuals, dose-related reductions in body weight, body fat and waist circumference, as well as improvements in other obesity-related endocrine factors were observed and the FDA recently endorsed the phase III trial program for this agent.

Altinicline (SIB-1508Y, SIB-1765F) is a drug which acts as an agonist at neural nicotinic acetylcholine receptors with high selectivity for the α4β2 subtype. It stimulates release of dopamine and acetylcholine in the brain in both rodent and primate models, and progressed as far as Phase II clinical trials for Parkinson's disease, where "no antiparkinsonian or cognitive-enhancing effects were demonstrated", although its current status is unclear.

Eliprodil, also known as SL 82-0715, is a non-competitive NMDA glutamate receptor antagonist, which targets the polyamine modulatory site and is selective for NR2B subunit-containing receptors. Eliprodil was in phase III clinical trial for the treatment of stroke or traumatic brain injury. However, these investigations were failed. One reason suggested for failure was that eliprodil had blocked the synaptic transmission mediated by NMDA receptors, hindering neuronal survival. In addition, eliprodil has been studied in phase II clinical trials for the treatment of Parkinson's disease.

Ibiglustat (GZ/SAR402671 or Genz-682452) is a small molecule inhibitor of glucosylceramide synthase. Ibiglustat has been demonstrated to effectively lower glycosphingolipid synthesis. Genzyme, a Sanofi Company is developing Ibiglustat for the treatment of Parkinson's Disease, Gaucher Disease, and Fabry Disease.

Mofegiline (MDL 72,974A or (E)-2-(4-fluorophenethyl)-3-fluoroallylamine, hydrochloride), is a selective and irreversible inhibitor of monoamine oxidase type B (MAO-B) both in vitro and in vivo. In addition, mofegiline inhibits semicarbazide-sensitive amine oxidase activity from human serum and saphenous vein. In phase II studies, MDL 72,974A is proving to be a useful adjunct to conventional therapy of Parkinson's disease. It seems mofegiline development was discontinued.

AE-37 (ANAVEX2-73, Tetrahydro-N, N-dimethyl-2, 2-diphenyl-3-furanemethanamine) is an orally available drug candidate developed to potentially modify Alzheimer’s disease rather than temporarily address its symptoms. It has a clean Phase 1 data profile and shows a reversal of memory loss (anti-amnesic properties) and neuroprotection in several models of Alzheimer’s disease. This drug is in Phase II trials for Alzheimer's disease, phase I trials for epilepsy, and in preclinical trials for amyotrophic lateral sclerosis, Parkinson's disease, Rett syndrome, stroke. AE-37 may function as a pro-drug for ANAVEX19-144 and acts as a muscarinic receptor and a moderate sigma1 receptor agonist.

Sumanirole is a novel dopamine agonist with high affinity and efficacy at D2 dopamine receptors and has a substantial degree of selectivity for the D2 receptor over other dopamine receptor subtypes. It had been in clinical trials for the treatment of Parkinson’s disease and restless leg syndrome but these studies were terminated for the efficacy reason.

Phenserine, a derivative of physostigmine, was first described as an inhibitor of acetylcholinesterase (AChE) and was shown to improve cognition in various experimental paradigms in rodents and dogs. It was clinically tested for Alzheimer's disease, with moderate success in initial Phase II studies. Phenserine is also unique because of differing actions of its enantiomers: (-)-phenserine is the active enantiomer for inhibition of AChE, whereas ( )-phenserine (Posiphen®) has weak activity as an AChE inhibitor and can be dosed much higher. Posiphen® is a small, hydrophobic, orally available molecule that enters the brain readily. It is the only drug ever described that inhibits more than one neurotoxic aggregating protein. Posiphen® inhibits synthesis of amyloid precursor protein (APP), tau and α-Synuclein. mRNA translation of neurotoxic aggregating proteins is up-regulated by iron (Fe) and down-regulated by iron regulatory protein-1 (IRP1). Posiphen® interferes with this second step of the common cascade of the aggregating proteins. It enhances the binding and/or activity of IRP1 to the iron response element (IRE) stem loop in the 5’UTR of the mRNAs of neurotoxic aggregating proteins, therefore specifically lowering their synthesis. By potentiating the IRE/IRP1 complex, Posiphen® lowers the level of free mRNA to be translated by the ribosome. Posiphen® is in development for the treatment neurodegenerative diseases.

GNE0877, aminopyrazole derivative, is a highly potent, selective, brain-penetrable LRRK2 inhibitor and an investigational drug for Parkinson's disease therapy. It inhibits LRRK2 Ser1292 autophosphorylation in BAC transgenic mice expressing human LRRK2 protein with the G2019S Parkinson’s disease mutation with an IC50 value of 3 nM in vivo. GNE0877 demonstrated metabolic stability, good oral bioavailability (88%) and brain penetration across multiple species.

Adrogolide is a chemically stable prodrug of the dopamine D1 receptor agonist A-86929. Adrogolide is rapidly converted in plasma to A-86929. A-86929 has high affinity and functional selectivity for the dopamine D1 receptor. Adrogolide has been in phase II clinical trials for the treatment of Parkinson's disease and cocaine abuse. However, this research has been discontinued. The adverse events associated with its use of adrogolide were of mild-to-moderate severity and included injection site reaction, asthenia, headache, nausea, vomiting, postural hypotension, vasodilitation, and dizziness.