An orally bioavailable inhibitor of cyclin-dependent kinases (CDKs) and thropomyosin receptor kinase A (TRKA), with potential antineoplastic activity. CDK2/TRKA inhibitor PHA-848125 AC potently inhibits cyclin-dependent kinase 2 (CDK2) and exhibits activity against other CDKs including CDK1 and CDK4, in addition to TRKA. Inhibition of these kinases may result in cell cycle arrest and apoptosis of tumor cells that express these kinases. Milciclib is currently in phase II clinical trials for thymic carcinoma, glioma and liver cancer. The most common adverse events are nausea and asthenia, vomiting, myasthenic syndrome, dehydration, hypophosphatemia, cytolytic hepatitis and plantar fasciitis.

Cariporide is a selective sodium-hydrogen antiporter inhibitor patented by a pharmaceutical company Hoechst A.-G. for treatment myocardial ischemia-reperfusion injury. The sodium-hydrogen exchanger is an important player in the pathophysiology of myocardial ischemia-reperfusion injury. The accumulation of hydrogen ions in the myocyte cytosol; during ischemia creates a proton gradient that promotes the efflux of hydrogen ions in exchange for the influx of sodium ions. This sodium buildup can secondary activates the sodium-calcium exchanger to operate in the reverse mode, resulting in a net calcium accumulation in myocyte cytosol, which leads to dysfunction and cell death. By inhibiting sodium-hydrogen exchange, Cariporide can prevent the accumulation of calcium in the cytosol, therefore reduce the infarct size. In clinical trials, Cariporide shows a statistically significant decline in myocardial infarction but increases mortality. Due to the increase in mortality, cariporide did not pass clinical trials.

Pravadoline is the anti-nociceptive agent, which has analgesic efficacy against postoperative pain in humans. Pravadoline inhibits the enzyme cyclooxygenase, but in contrast to cyclooxygenase-inhibiting NSAIDs does not produce gastrointestinal irritation. Pravadoline inhibited the synthesis of prostaglandins in mouse brain both in vitro and ex vivo. Pravadoline demonstrated only weak anti-inflammatory activity relative to its anti-nociceptive potency. Single doses of pravadoline were safe and effective in humans, without serious adverse events. Single oral administration of pravadoline maleate induced acute tubular necrosis in male and female beagle dogs.

Albaconazole is a triazole antifungal. Azoles are important antifungal compounds, and all drugs in this class inhibit ergosterol synthesis by blocking the 14-α-demethylase enzyme, resulting in the accumulation of toxic methylsterols that may culminate in fungal death. Albaconazole, an oral agent that has demonstrated high levels of bioavailability and potent antifungal activity. It was under development for the treatment of onychomycosis, vulvovaginal candidiasis. Also, albaconazole was evaluated in phase I, a randomized, placebo-controlled clinical trial in patients with tinea pedis. No serious adverse effects occurred in the studies involving albaconazole. However, this researches on this drug were discontinued.

Racemetirosine is an orally active inhibitor of the enzyme tyrosine 3-monooxygenase, and consequently of the synthesis of catecholamine. At dosages of 600 to 3500mg daily, it is effective in controlling the hypertensive episodes and symptoms of catecholamine excess in phaeochromocytoma during preparation for surgery. Oral Racemetirosine is well absorbed and absorption appears constant in each individual over a wide dosage range. The drug is largely excreted via the kidneys, but extrarenal elimination has not been studied. Case reports on the clinical use of Racemetirosine in phaeochromocytoma indicate that the drug controls hypertension and symptoms of catecholamine excess in most patients during preparation for surgical removal of a tumor. In some cases, the addition of Racemetirosine to phenoxybenzamine plus propranolol has resulted in adequate control of symptoms previously unresponsive to the adrenergic blocking regimen. Drowsiness and sedation have been the most frequently reported side effects of Racemetirosine treatment.

Ambasilide, a class III antiarrhythmic, has been shown to block multiple cardiac channels in a variety of animals including humans. Ambasilide is a potassium channel antagonist. Ambasilide has multichannel blocking properties including beta-adrenergic antagonism.

Darbufelone mesylate is a dual inhibitor of cellular prostaglandin and leukotriene production. Darbufelone potently inhibits PGHS-2 (IC50 = 0.19 uM) but is much less potent with PGHS-1 (IC50= 20 uM). Darbufelone is a dual inhibitor of cellular PGF2R and LTB4 production. Darbufelone is orally active and nonulcerogenic in animal models of inflammation and arthritis. Darbufelone mesylate was in phase III clinical trials by Pfizer and Zhuhai United Laboratories for the treatment of rheumatoid arthritis.

Cipropride is an anti-emetic drug of the substituted benzamide class. It was discovered by Synthelabo in the early 1980s. The drug acts by blocking the dopamine receptor and thus affecting the chemo-receptor trigger zone for vomiting. Clinical trials showed that cipropride was effective for the prevention of nausea and vomiting induced by cytotoxic chemotherapy agents dacarbazine and Cis-platinum. The subsequent development of the drug was not reported.

Falnidamol is an epidermal growth factor receptor inhibitor, developed by Boehringer Ingelheim. Falnidamol demonstrated anticancer activity in vitro. The phase I trial was discontinued due to a dose-limiting increase of liver enzymes, low bioavailability of the drug and the detection of a pharmacologically inactive metabolite.

Eniporide belongs to the new class of drugs that specifically inhibit the Sodium/hydrogen exchanger 1 (NHE-1) isoform, which is the predominant isoform in the cardiac myocytes. Extensive preclinical studies, in vitro and in animals, have suggested that NHE inhibition with eniporide before the onset of ischemia is a very effective and reproducible means of limiting the extent of infarction and that this agent provides protective benefit even when given just before reperfusion. Eniporide had been in phase II clinical trial for the treatment of myocardial infarction. Administration of the eniporide, before reperfusion therapy in patients with acute ST-elevation myocardial infarction, did not limit infarct size or improve clinical outcome.