Semapimod (CNI-1493) is a cytokine inhibitor and synthetic guanylhydrazone mitogen-activated protein kinase blocker, is being developed by Cytokine PharmaSciences as a potential treatment for Crohn's disease and other inflammatory conditions. As of December 2001, a phase I study demonstrating the safety of the compound had been completed and phase II trials for psoriasis and Crohn's disease were ongoing. In April 2003, preclinical and early clinical studies were underway for a variety of indications, including congestive heart failure and pancreatitis. Semapimod inhibits activation of p38 MAPK and NF-κB and induction of cyclooxygenase-2 by TLR ligands, but not by IL-1β or stresses. Semapimod inhibits TLR4 signaling (IC50 ≈0.3 umol) and acts by desensitizing cells to LPS; it fails to block responses to LPS concentrations of ≥5 ug/ml. Semapimod had been in phase II clinical trials by Ferring Pharmaceuticals for the treatment of Crohn's disease. However, this research has been discontinued. Semapimod is in phase I clinical trials for the treatment of autoimmune disorders and inflammation.

Tazomeline (also known as LY 287041), a neuropsychiatric agent, is a muscarinic M1 acetylcholine receptor agonist that was studied in patients with cognitive dysfunction. Tazomeline participated in clinical trials for the treatment of Alzheimer’s disease and dementia. However, all these studied were discontinued for unknown reasons.

Espatropate (UK 88060) is an antagonist of M3 muscarinic receptors. Espatropate is a bronchodilator with anticholinergic activity. It was undergoing preclinical development with Pfizer for the treatment of asthma.

GTS-21 (also known as DMBX-A), a selective alpha-7 nicotinic acetylcholine receptor agonist that has demonstrated memory and cognition enhancement activity in human clinical trials. GTS-21 has been studied in Phase II in patients with schizophrenia and in patients with Alzheimer disease. However, these studies were discontinued. GTS-21 was also involved in phase II to reduce negative affect, improve cognition and/or reduce smoking relapse in healthy adult men and women who are chronic cigarette smokers. However, this study was withdrawn. Besides, GTS-21 has participated in phase II to investigate safety and efficacy in adults with attention-deficit hyperactivity disorder.

ISPRONICLINE is a partial agonist at the a4b2 subtype of nicotinic acetylcholine receptors (nAChRs) without interaction with other nAChRs or other receptor systems. It has antidepressant, nootropic, and neuroprotective effects. It progressed to phase II clinical trials for the treatment of dementia and Alzheimer's disease but is no longer under development.

Vedaclidine [LY 297802, NNC 101053, NNC 111053, butylthio[2.2.2]], a quinuclidine, is a muscarinic receptor agonist being developed by Novo Nordisk and Eli Lilly as an analgesic drug. Vedaclidine is a muscarinic receptor ligand which is equiefficacious to morphine in producing antinociception. In vitro, Vedaclidine had high affinity for muscarinic receptors in brain homogenates, but had substantially less or no affinity for several other neurotransmiter receptors and uptake sites. Its pharmacological profile suggests that it may have clinical utility in the management of pain as an alternative to opioids.

Rivanicline (also known as RJR-2403 or TC-2403) is a partial neuronal nicotinic acetylcholine receptor agonist. This compound binds primarily to the α4β2 receptor subtype. Rivanicline was originally developed for Alzheimer’s disease and shows pronounced anti-amnesic and increased recognition memory in rats. Because rivanicline also inhibits Interleukin-8 production, it has been further developed as a potential anti-inflammatory treatment for ulcerative colitis (in which nicotine is of therapeutic value but has adverse events). Rivanicline effectively inhibited TNF- and LPS-induced IL-8 production in different cell types, without toxic effects. Rivanicline was also evaluated as a potential compound for the development of nicotinic therapeutics to treat neurological diseases in cases of compromised cholinergic neurotransmission.