Mequitamium iodide (LG 30435) is a quaternary ammonium phenothiazine. Mequitamium iodide was found to bind with high affinity only to histamine H1 receptors and to muscarinic acetylcholine receptors. The (+)-(S)-enantiomer is 10-fold more potent than (-)-(R)-enantiomer as a histamine antagonist, while the two enantiomers show the same antimuscarinic activity in vitro. In animal models, it exerts antiasthmatic and antiallergic properties. It was being clinically investigated as a treatment of asthma and rhinitis.

Quinuclium Bromide Anhydrous is quinuclidinium derivative with potential analgesic activity. In preclinical studies, Quinuclium possessed significant chronic antihypertensive activity in mecamylamine- and renal-hypertensive dogs. Quinuclium was approximately 4 times more potent than guanethidine in the former model and 3 times as potent in the latter. Quinuclium reduced orthostatic blood pressure responses in unanesthetized rabbits but was approximately 10 times less potent than guanethidine. Quinuclium did not affect cardiac output, heart rate or stroke volume in anesthetized open-chest dogs and moderately increased mean blood pressure and total peripheral resistance. It produced diuresis and saluresis in anesthetized dogs but did not influence water or electrolyte urinary excretion in conscious rats. Quinuclium was more effective than guanethidine in blocking adrenergic neurons and depleting heart norepinephrine levels in experimental animals.

Mocetinostat is an rationally designed, orally available, Class 1-selective, small molecule, 2-aminobenzamide HDAC inhibitor with potential antineoplastic activity. Mocetinostat binds to and inhibits Class 1 isoforms of HDAC, specifically HDAC 1, 2 and 3, which may result in epigenetic changes in tumor cells and so tumor cell death; although the exact mechanism has yet to be defined, tumor cell death may occur through the induction of apoptosis, differentiation, cell cycle arrest, inhibition of DNA repair, upregulation of tumor suppressors, down regulation of growth factors, oxidative stress, and autophagy, among others. It is undergoing clinical trials for treatment of various cancers including bladder cancer, diffuse large B cell lymphoma, follicular lymphoma, myelodysplastic syndromes, non-small cell lung cancer. Fatigue, weight loss or anorexia were most common treatment-related adverse events.

Aminoquinuride (Surfen) binds to glycosaminoglycans (GAGs) and has been shown to influence their function, and the function of proteoglycans (complexes of GAGs linked to a core protein). Surfen was first described in 1938 as a component of depot insulin; however, subsequent studies have revealed its efficacy in binding to glycosaminoglycans (GAGs). Surfen contains four quinoline rings that contain positively charged amino or methyl groups. Surfen was found to bind with greatest avidity to heparin. There are now a handful of studies on the biological effects of surfen, many of which relate to its ability to block the interaction between GAGs and signaling proteins, including effects on growth factors (fibroblast growth factor and vascular endothelial growth factor) and fibrils associated with the binding of human immunodeficiency virus (HIV)-1 to target cells. Surfen inhibits the action of SEVI (semen-derived enhancer of HIV viral infection). Because SEVI can increase HIV infectivity by several orders of magnitude, supplementing current HIV microbicide candidates with SEVI inhibitors, such as surfen, might greatly increase their potency. Surfen has also been shown to reduce inflammation but inhibits remyelination in murine models of multiple sclerosis.

Dizocilpine (MK-801) is an antagonist of the N-methyl-D-aspartate (NMDA) receptor in the glutamate category involved with the central nervous system (CNS). The drug displays a variety of physiological actions, many of which involve the CNS, such as anesthetic and anticonvulsant properties. It penetrates readily into CNS and was described as the agent with central sympathomimetic properties. Co-administration of dizocilpine with psychostimulants, such as cocaine, amphetamine and nicotine, has been reported to prevent the development of behavioural sensitization to these drugs as well as associated neuroadaptations in rodents. However, studies with bromocriptine have suggested that co-administration of dizocilpine might merely cause sensitization to become state-dependent. A single injection of MK-801 to rats models both positive and negative symptoms of schizophrenia. Treatment of mice with dizocilpine induced learning impairment.

Zaltidine (CP-57,361) is a guanidinothiazolylimidazole compound which is a highly specific H2-receptor antagonist. It potently inhibits gastric acid secretion. Zaltidine appears to be an effective treatment of duodenal ulcer in human studies. However, the incidence of hepatic damage (8%) seems higher than with commonly used H2-receptor antagonists.

Napsagatran [RO 466240], a reversible and highly selective thrombin inhibitor, was in development with Roche for use in myocardial infarction and thrombosis. Napsagatran efficiently inhibits and delays thrombin generation in human coagulating plasma. This reduced thrombin generation might be caused by inhibition of thrombin-mediated feedback reactions during blood coagulation. Ro 46-6240 inhibited clot-bound thrombin three times more potently than fluid-phase thrombin (IC50 19 vs 56 ng/ml) while hirudin was two times (IC50 8 vs 3 ng/ml) and heparin six times (IC50 1,205 vs 200 ng/ml) less active against clot-bound thrombin compared with fluid-phase thrombin.

MP-412 (AV-412) is a potent dual inhibitor of EGFR and ErbB2 tyrosine kinases, including the mutant EGFR (L858R,T790M), which is clinically resistant to the EGFR-specific kinase inhibitors erlotinib and gefitinib. AV-412 has potential as a therapeutic agent for the treatment of cancers expressing EGFR and ErbB2, especially those resistant to the first generation of small-molecule inhibitors.AVEO Pharmaceuticals was developing AV-412 for the treatment of cancer, however development has been discontinued.

Millennium (a wholly-owned subsidiary of Takeda) was developing TAK- 901 for the treatment of cancer. TAK-901 is an inhibitor of Aurora A/B with IC50 of 21 nM/15 nM. It is not a potent inhibitor of cellular JAK2, c-Src or Abl. TAK-901 is in phase I clinical trials by Millennium Pharmaceuticals for the treatment of advanced hematological malignancies. TAK-901 had been in phase I clinical trials for solid tumors. However, this study was discontinued.