Etoprine, a diaminopyrimidine, is a lipid-soluble inhibitor of dihydrofolate reductase. Etoprine inhibits incorporation of deoxyuridine into the DNA. In male rodents, it affected spermatogenesis and induces infertility. Etoprine is considered to exert antineoplastic activity.

Amonafide L-malate (AS1413, Xanafide) is a DNA intercalator and topoisomerase II inhibitor that induces apoptosis by disrupting chromatin organisation independently of ATP. This is different from classical topoisomerase II inhibitors which induce apoptosis by causing extensive DNA damage. Amonafide L-malate is also able to evade P-glycoprotein and related transporters that contribute to multi-drug resistance. AS1413 had orphan drug status in both the U.S. and the E.U. for the treatment of AML and also received Fast Track status from the U.S. FDA for the treatment of secondary AML. Amonafide L-malate was originated by Xanthus Pharmaceuticals. It was added to Antisoma's pipeline through the acquisition of Xanthus Pharmaceuticals, Inc. in June 2008. Antisoma discontinued development of Amonafide L-malate after data from the open-label, international Phase III ACCEDE trial in over 420 patients showed that 600 mg/m 2 IV amonafide for 5 days plus cytarabine missed the primary endpoint of significantly improving initial remission rate, defined as the proportion of patients who achieve CR or CRi, vs. daunorubicin plus cytarabine.

Cyheptamide is anticonvulsant compound, developed by the Canadian company Ayerst Research Laboratories in the 1960s. Oral administration of compound at 14-25 mg/kg protected mice against the tonic phase of pentylenetetrazole convulsion and maximal electroshock seizure. Anticonvulsant activity of cyheptamide was confirmed in initial clinical studies, but the compound was not marketed.

Metoquizine is a muscarinic acetylcholine receptor antagonist that was used as anti-ulcerative. Information about the current use of this compound is not available.

Citenamide is tricyclic drug, an analog of the anticonvulsant cyheptamide.

Pirazolac is a pyrazole-acetic acid derived from indomethacin. It is a nonsteroidal anti-inflammatory agent. Pirazolac concentration-relatedly inhibited the accumulation of prostanoids in incubates of human gastric mucosa, but this inhibition was less than that by indomethacin and other commonly used non-steroidal anti-inflammatory drugs. Pirazolac was at least as effective as sulindac in the treatment of patients with rheumatoid arthritis. The abnormal activity of neutrophils from patients with rheumatoid arthritis was partially corrected with pirazolac. Patients with ankylosing spondylitis benefited similarly from treatment with pirazolac and indomethacin. Pirazolac was developed in an effort to overcome the adverse gastrointestinal effects of indomethacin. However, more patients with ankylosing spondylitis withdrew from treatment because of intolerable adverse events with pirazolac than with indomethacin in a clinical trial. In patients with rheumatoid arthritis, pirazolac had similar tolerability to sulindac.

Gaboxadol (or THIP) is a direct GABA mimetic ligand at delta-containing receptors. Gaboxadol went into human clinical trials to test if the drug promoted sleep. It was generally well tolerated. Gaboxadol enhances delta power in NREM sleep in humans. Gaboxadol failed in Phase III for sleep studies. The side effects of Gaboxadol have been described as mild and similar in quality to those of other GABA-mimetics. Gaboxadol is in development with Ovid Therapeutics as a treatment for Angelman syndrome, fragile X syndrome and epilepsy.

Descinolone acetonide (an analog of triamcinolone acetonide) is a glucocorticoid which was developed for the treatment of skin disorders. It was tested on patients with psoriasis and atopic dermatitis, however there is no information about its further development.

Butacetin is an anilide derivative with potent analgesic and antipyretic activity. Butacetin shows marked analgesic and anti-inflammatory potencies in the mouse abdominal constriction assay and the carrageenan-induced rat paw edema. Butacetin has the advantage of demonstrating much lower gastro-toxicity than currently available NSAIDs.