ACP-104 or N-Desmethylclozapine (NDMC), or norclozapine is a major metabolite of clozapine, which was developed like a small molecule drug candidate by ACADIA for treatment schizophrenia. ACP-104 combines M1 muscarinic agonist, 5-HT2A inverse agonist, and D2 and D3 dopamine partial agonist in a single compound and, therefore, uniquely addresses what ACADIA believed are the three most promising target mechanisms for treating schizophrenia. Then drug was discontinued, because the study did not meet its primary endpoint of antipsychotic efficacy or any of the secondary endpoints. Neither dose of ACP-104 demonstrated improved efficacy as compared to placebo. The most common adverse events in the treatment arms relative to placebo were increased salivation, tachycardia, and dyspepsia, which were noted to be dose-related. There was no clinically significant decrease in neutrophil counts in the study drug arms.

Dexanabinol is the synthetic cannabinoid. It is inactive as a cannabimimetic, but exhibits pharmacological properties characteristic of an N-methyl-D-aspartate (NMDA)-receptor antagonist. It blocks NMDA-receptors stereospecifically by interacting with a site close to, but distinct from, that of uncompetitive NMDA-receptor antagonists and from the recognition sites of glutamate, glycine, and polyamines. This agent also scavenges peroxy radicals and protects neurons from the damages of reactive oxygen species. Furthermore, dexanabinol inhibits the activity of nuclear factor kappa B (NF-kB), thereby preventing the expression of NF-kB target genes, such as tumor necrosis factor alpha, cytokines and inducible nitric oxide synthase. Dexanabinol is a potent cerebroprotective agent, with a therapeutic window of about 4 h. Dexanabinol is safe, but is not efficacious in the treatment of traumatic brain injury. It was introduced into clinical trials for breast cancer and advanced solid tumors.

Mureletecan is a water-soluble prodrug, consisting of camptothecin covalently linked to polymeric backbone methacryloylglycynamide, with potential antineoplastic activity. After entering tumor cells, the active moiety camptothecin is slowly released from mureletecan via hydrolysis of the ester linkage. Camptothecin, the active moiety, is an alkaloid isolatable from the Chinese tree Camptotheca acuminata. Camptothecin itself suffers from poor solubility, which is why it is often investigated with a solubilizing conjugate; such as in Mureletecan. Camptothecin binds to and stabilizes the topoisomerase I-DNA covalent complex producing potentially lethal double-stranded DNA breaks when encountered by DNA replication machinery. Camptothecin has also been shown to inhibit HIF1a. Camptothecin has been investigated with a number of solubilizing conjugates as a potential treatment in various forms of cancer.

Tibalosin is a phenylethylamine derivative patented by Continental Pharma as a potent vasodilator. Tibalosine interacts specifically with alpha- and beta-adrenergic receptors and calcium channel binding sites. In preclinical models, Tibalosin exerts favor influences on arterial pressure in the hypertensive animal. The drug has acceptable toxicity in experimental animals and has been well tolerated by normal human subjects in daily doses of up to 200 mg.

Piriprost (U-60, 257) is a structural analog of prostaglandin I2 (PGI2) with low IP receptor-mediated activity. It inhibits 5-LO (5-lipoxygenase). Piriprost inhibits the release of histamine and leukotrienes, implicating its role in inflammation and allergic responses. However, it was shown, that piriprost did not influence the airway responses after allergen in asthma. Nevertheless, even more, the drug was irritant to the respiratory tract than was placebo.

R-etodolac (SDX-101) is the non-cyclooxygenase 2-inhibiting R-enantiomer of the non-steroid anti-inflammatory drug etodolac (1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid). The absolute configuration of the enantiomer is R-(-)-etodolac. R-etodolac specifically bound retinoid X receptor (RXRalpha), inhibited RXRalpha transcriptional activity, and induced its degradation by a ubiquitin and proteasome-dependent pathway. In addition R-etodolac can disrupt the beta-catenin signaling pathway. R-etodolac exerts antineoplastic properties. R-etodolac was in phase 2 studies for the treatment of hematologic malignancies however development was discontinued.

Cobristone is a locally acting chloride channel activator that works to stimulate and protect the mucosal barrier function. Cobristone is being developed by the Sucampo Pharmaceuticals, Inc. for the prevention of oral mucositis and for the treatment of non-erosive reflux disease (NERD), a major subtype of gastroesophageal reflux disease. The development of the drug was terminated after phase 2 clinical trials failed to meet its primary endpoints.

GW406381 is an investigational, highly selective cyclooxygenase-2 (COX-2) inhibitor for inflammatory pain treatment. It showed effectiveness in animal models of central sensitization such as chronic constriction injury and capsaicin-induced hyperalgesia. It's effect was also evaluated in several clinical trials in patients with peripheral nerve injury (Phase I ), rheumatoid arthritis (Phase III), the signs and symptoms of osteoarthritis of the knee to control of pain and improvement in function (Phase III), and in treating the signs and symptoms of dental pain following third molar tooth extraction (Phase III). Possessing favourable pharmacokinetic profiles and analgesic activity in vivo, GW406381 have also demonstrated relatively high brain penetration in the rat compared with the clinically available compounds, which may ultimately prove beneficial in the treatment of pain.

Furazolium, an antibacterial agent, was studied for the management of skin infections. However, information about the current use of this drug is not available.

Homopipramol, a neuroleptic agent, was used as an antidepressant. This compound has never been marketed.