Revamilast is an orally active, potent and selective phosphodiesterase 4 (PDE 4) inhibitor that is being studied for its potential in treatment of inflammatory disorders. PDE 4 inhibitors attenuate the inflammatory response and suppress many cytokines, including TNF-α production in mononuclear cells. Initial studies showed no serious adverse events in healthy volunteers and phase II studies have evaluated the effect of revamilast on long function and rheumatoid arthritis.

Adozelesin (U 73975, adolezesin) is an experimental antitumor drug of the duocarmycin class. Adozelesin is a highly potent alkylating agent that undergoes binding in the minor groove of double-stranded DNA (ds-DNA) at A-T-rich sequences followed by covalent bonding with N-3 of adenine in preferred sequences. Adozelesin is therapeutically active against a broad spectrum of tumours and was in phase II clinical trials with Pharmacia Corporation (now Pfizer) in the US for breast cancer treatment. Phase I and Phase II clinical trials were conducted in 2000s, however, it was found adozelesin had marginal efficacy in the treatment of metastatic breast cancer at the dosage and schedule used.

Adelmidrol is the synthetic derivate of azelaic acid, a naturally occurring saturated dicarboxylic acid, that is found in some whole grains and in trace amounts in the human body. Chemically, ademidrol is the N,N-bis (2-hydroxyethyl) non anediamide and it is an amphiphilic or amphipathic compound, possessing both hydrophilic and hydrophobic properties, that favor its solubility both in aqueous and organic media. Adelmidrol belongs to the aliamide family, a group of fatty acid derivatives with cannabimimetic properties, able to control mast cell (MC) hyperreactivity in several pathophysiological and pathological conditions. Pro-inflammatory NF-κB pathway were markedly reduced by treatment with adelmidrol. The anti-inflammatory effect of adelmidrol appeared to be related on PPAR-gamma activation. Adelmidrol is topically effective for human inflammatory skin disorders and is able to modulate the inflammatory response in human keratinocytes. The combination of hyaluronic acid and adelmidrol improves the signs of osteoarthritis induced by monosodium iodoacetate.

Acetergamine is a derivative of ergoline, it is an oxytocic agent. Acetergamine is alpha-1 blocker and vasodilator. It has been investigated as a treatment for cerebellar ataxia.

Taziprinone was studied as an antitussive agent. Information about the current use of this compound is not available.

Tasidotin (also known as ILX-651), an orally active synthetic microtubule-targeted derivative of the marine depsipeptide dolastatin-15. It was suggested, that tasidotin has a unique mechanism of action. The drug inhibits cell proliferation by suppressing spindle microtubule dynamics through a reduction of the shortening rate, reduction of the switching frequency from growth to shortening, and reduction of the time microtubules grow. Tasidotin was studied in clinical trials phase II in patients with locally advanced or metastatic non-small cell lung carcinoma, in patients with hormone-refractory prostate cancer, and in patients with inoperable locally advanced or metastatic melanoma. However, no new results were published last 5 years. It was suggested that tasidotin is no longer being used as single or even components of multiple agents today.

Sunepitron (CP-93,393) is an anxiolytic drug with highly selective serotonin 5-hydroxytryptamine 1A autoreceptor agonist, alpha2-adrenergic antagonist, and dopamine D2 agonist properties. Sunepitron hydrochloride had been in Phase III clinical trials by Pfizer for the treatment of anxiety disorder and depression. However, this research has been discontinued.

Sulazuril (also known as Hoe 092 V) is a phenyltriazolone derivative patented by Hoechst A.-G. as agrochemical protozoacide. Sulazuril is effective against a broad spectrum of fish and crustacean parasites.

Sparfosate (PALA) is a stable transition state analogue for an aspartate transcarbamylase- cartalyzed reaction with antineoplastic activity. PALA is a potent inhibitor of aspartate transcarbamylase (Ki about 10(-8) M for ACTases of various origins), which in whole cells blocks the de novo synthesis of pyrimidines. Thus PALA inhibits de novo pyrimidine biosynthesis and increases the extent to which fluorouracil metabolites are incorporated into RNA. In vivo, low doses of PALA inhibit whole body pyrimidine synthesis. While this action is cytotoxic in vitro, extensive human testing demonstrates that PALA alone is devoid of selective antitumor activity. Interest in the therapeutic action of PALA derives from the demonstration that its action potentiates the cytotoxicity of several cytotoxic drugs, notably 5-fluorouracil (5-FU). Development of Sparfosate for cancer and Hepatitis B treatment is assumed to have been discontinued.