Dexpramipexole (also known as KNS-760704/R-pramipexole) was originally developed by University of Virginia researchers to treat Amyotrophic Lateral Sclerosis and then was licensed to global biotechnology company Biogen Idec for further development. However, on phase III clinical trial the study of this drug was discontinued. Biogen said the drug neither slowed the loss of muscle function nor prolonged the lives of patients with ALS, often called Lou Gehrig’s disease. Nor did it show any efficacy in secondary endpoints of the clinical trial, or work in any sub-group of patients—about a big a failure as a company could have a Phase III trial. In addition, was discovered, that dexpramipexole was able to bind to beta-subunit of the mitochondrial F1/FO ATP synthase complex and increased its activity, thus reduced ischemic brain injury. These findings, together with the excellent brain penetration and favorable safety profile in humans, make dexpramipexole a drug with realistic translational potential for the treatment of stroke.

Ensaculin is related to naturally occurring benzopyranones like scoparone. The compound is a potent functional antagonist of excitatory amino acid-induced convulsions and mortality. In receptor-binding studies, Ensaculin showed high affinity to dopaminergic (D2, D3), serotoninergic (5-HT1A, 5-HT7), and adrenergic (A1a, A1b) receptors in the nanomolar range. Ensaculin antagonizes NMDA responses in a voltage-dependent manner. Various studies support the notion that this compound could indeed have a broad range of nootropic properties. Although few patients presented postural hypotension and dizziness after receiving ensaculin in phase I clinical trials, this drug candidate was further discontinued in phase III due to potential side effects.

Taltrimide, a taurine derivative that was developed as an anticonvulsive agent. Taltrimide strongly inhibits the sodium-independent binding of taurine to synaptic membranes of the brain and it does not appear to bind to GABAA and benzodiazepine receptor. The drug was studied in phase II clinical trial Finland as an anticonvulsant agent to treat epilepsy. However, the further development of this drug was discontinued.

Ternidazole is a nitroimidazolealkanol derivative patented by Societe des usines chimiques Rhone-Poulenc as antitrichomonas agent useful for the treatment of Protozoal infections and other conditions.

Elinafide (LU 79553) is a bisintercalating naphthalamide and a topoisomerase II inhibitor has demonstrated a higher binding affinity for DNA and significant antitumour efficacy against a panel of established tumour cell lines, including several multidrug resistant-positive sublines. Elinafide had been in phase II clinical trial for the treatment of ovarian cancer and phase I trials for the treatment of various solid tumours. The major haematological toxicities observed were anaemia and neutropenia. The major non-haematological toxicities observed in the 3-weekly schedule were neuro-muscular presenting clinically as a mixed syndrome of severe weakness (sometimes with pain in both legs), myalgia and arthralgia, asthenia/fatigue/malaise. One fatality was considered related to LU 79553, as the patient had fever and neutropenia. Clinical study of this drug candidate was discontinued due to its neuromuscular dose-limiting toxicity.

Lanperisone (NK433) is muscle relaxant. It acts by blocking voltage-gated sodium channels.

Mespiperone C-11 (3-N-[11C] methylspiperone) is a radiolabeled 3-N-methylspiperone. 3-N-methylspiperone is high-affinity D2/3 dopamine and 5-HT2A serotonin receptor antagonist. It has been studied as a positron emission tomography (PET) tracer for imaging D2/3 and 5HT2A receptor densities.

Rimcazole is a carbazole derivative that acts as a sigma receptor antagonist and studied as potential antipsychotic agent for the treatment of acute schizophrenic patients. In open-clinical trials Rimcazole (BW 234U) appears to be effective in acute schizophrenic patients. However, subsequent clinical trials demonstrated that rimcazole lacked efficacy in schizophrenic patients and it is now primarily used as an experimental tool. In addition to its actions as  receptor antagonist, rimcazole also has high affinity for dopamine transporters, and inrecent years it has served as a lead compound for the development of novel dopamine transporter ligands.

Batabulin or T138067 (2-fluoro-1-methoxy-4-pentafluorophenylsulfonamidobenzene) covalently and selectively modifies the beta1, beta2, and beta4 isotypes of beta-tubulin at a conserved cysteine residue, thereby disrupting microtubule polymerization. Cells exposed to batabulin become altered in shape, indicating a collapse of the cytoskeleton, and show an increase in chromosomal ploidy. Batabulin is equally efficacious in inhibiting the growth of sensitive and multidrug-resistant human tumor xenografts in athymic nude mice. Batabulin has been in clinical trials for the treatment of cancers (breast cancer, colorectal cancer, glioma, hepatocellular carcinoma, non-small cell lung cancer). It does not have clinical activity in the treatment of colorectal cancer and glioma. Batabulin development was discontinued.

Nocodazole is an anti-mitotic drug that has long been used as an experimental tool in cell biology. Nocodazole is known to bind with high affinity to tubulin and to inhibit microtubule assembly. The tubulin molecule is a α/β heterodimer; both α and β exist as various isotypes whose distribution and drug-binding properties are significantly different. Nocodazole has the highest affinity for αβIV and the lowest affinity for αβIII. In addition, nocodazole was investigated as an anticancer drug on xenografts model and it was revealed, that nocodazole possessed a high-affinity for the cancer-related kinases ABL, c-KIT, BRAF, and MEK, and inhibited Abl, Abl(E255K) and Abl(T315I).