Talampanel (TLP) was developed as a noncompetitive (allosteric) antagonist of the AMPA receptor. Talampanel does not act directly on the AMPA receptor, but at an allosteric site referred to as the GYKI receptor. Talampanel is being studied in the treatment of brain tumors and other brain disorders, such as epilepsy, Parkinson disease, amyotrophic lateral sclerosis, dyskinesias, glioblastoma, multiple sclerosis. It is a type of AMPA receptor antagonist. Dizziness has been the most commonly reported adverse event, with some sedation and ataxia, drowsiness and headaches reported at higher doses.

Patupilone is a compound isolated from the myxobacterium Sorangium cellulosum. Similar to paclitaxel, Patupilone induces microtubule polymerization and stabilizes microtubules against depolymerization conditions. In addition to promoting tubulin polymerization and stabilization of microtubules, this agent is cytotoxic for cells overexpressing P-glycoprotein, a characteristic that distinguishes it from the taxanes. Epothilone B may cause complete cell-cycle arrest. Patupilone failed a phase III trial for ovarian cancer in 2010.

Bitopertin is a Glycine transporter type 1 inhibitor which was developed by Hoffmann-La Roche for the treatment of patients with schizophrenia. The drug was shown to be potent in vitro, however it failed to meet primary endpoints in phase III. Bitopertin was also tested for the treatment of obsessive-compulsive disorder, but the development stopped in phase II.

Spebrutinib (CC-292, AVL-292) is a selective inhibitor of BTK that was under clinical development for the treatment of rheumatoid arthritis (phase II) and B-cell Lymphoma (phase I). The drug was discovered by Avila Therapeutics, but then acquired by Celgene. Spebrutinib covalently binds to Cys 481 in BTK, blocking the ATP-binding pocket of the enzyme. The drug is no longer in Celgene's pipeline and its development is supposed to be terminated.

Enisoprost is a prostaglandin E1 analog. Enisoprost exerts immunosuppressive activity and gastric antisecretory effect. Enisoprost was being studied for the treatment of peptic ulcer and transplant rejection. Enisoprost development has been discontinued.

Perfosfamide is the active metabolite of the nitrogen mustard cyclophosphamide with potent antineoplastic and immunosuppressive properties. Perfosfamide alkylates DNA, thereby inhibiting DNA replication and RNA and protein synthesis. The incubation of normal human marrow cells with perfosfamide has a toxic effect on granulocyte-macrophage progenitor cells that is dose as well as white blood cell concentration dependent. It is likely that this dependency of the perfosfamide stem cell effect is caused not only by the target white blood cell concentration but by the suspension’s total protein concentration. Autologous bone marrow transplantation with perfosfamide purging in patients with acute myeloid leukemia in second complete remission produced results similar to that reported with allogeneic bone marrow transplantation. Perfosfamide had been in phase III clinical trial for the treatment of acute myeloid leukemia. However, this development was discontinued.

Alisertib (MLN8237) is an orally available selective aurora A kinase inhibitor developed by Takeda. Alisertib inhibited AAK over ABK with a selectivity of more than 200-fold in cells and produced a dose-dependent decrease in bipolar and aligned chromosomes in the HCT-116 xenograft model, a phenotype consistent with AAK inhibition. Alisertib inhibited proliferation of human tumor cell lines in vitro and produced tumor growth inhibition in solid tumor xenograft models and regressions in in vivo lymphoma models. It is currently in phase II clinical trials for acute myeloid leukaemia; B cell lymphoma; brain cancer; mesothelioma; prostate cancer; small cell lung cancer.

Dinaciclib (SCH 727965) is a small molecule inhibitor of cyclin-dependent kinases. Dinaciclib demostrates potent and selective inhibition of CDK2, CDK5, CDK1, and CDK9 activity. Dinaciclib inhibits cell cycle progression and proliferation in various tumor cell lines in vitro. Dinaciclib is a product of a drug discovery collaboration between Pharmacopeia (later Ligand Pharmaceuticals) and Schering-Plough (later Merck & Co.) that began in 1998. Dinaciclib showed promising effect in treating haematological malignancies and solid tumors.

Avoralstat, a small molecule inhibitor of plasma kallikrein, participated in clinical trials phase III to prevent hereditary angioedema, but these studied were discontinued due to insufficient efficacy study. Recently published article has described that avoralstat could improve the quality of life in C1‐INH‐HAE patients. Hereditary angioedema (HAE) with C1 inhibitor deficiency (C1‐INH‐HAE) is an autosomal dominant disorder characterized by recurrent episodes of swelling of the skin, pharynx, gastrointestinal tract, genitals, and is due primarily to mutations in the SERPING1 gene that results in insufficient production of the natural plasma kallikrein inhibitor, C1 inhibitor (C1‐INH).

Tideglusib (NP031112, NP-12, Nypta, Noscira SA, Madrid, Spain), a drug, which belongs to the thiadiazolidinone family, is a GSK-3β inhibitor. Tideglusib was in phase II clinical trials for the treatment of Alzheimer disease (AD) and progressive supranuclear palsy. Participants showed no benefit on either of the primary outcome measures or exploratory endpoints and further development in the drug was halted for these two disease. However, Tideglusib is on phase II clinical trial to determine whether drug is safe and efficacious in the treatment of adolescents and adults with congenital and juvenile-onset Myotonic Dystrophy.