Valspodar (PSC-833) is a derivative of cyclosporin but devoid of the immunosuppressive and nephrotoxic properties seen in cyclosporin A. It exhibited high-affinity binding to Mdr1 P-glycoprotein (P-gp) and demonstrated multidrug resistance-reversing activity superior to cyclosporin A and verapamil both in vitro and in vivo. Preclinical and phase I/II clinical data have indicated that plasma levels of PSC-833 with multidrug resistance-reversing activities are achievable. Potent inhibition of intestinal, hepatobiliary and blood-brain barrier P-gp function has been demonstrated. The toxicity profiles of valspodar are acceptable and dose-limited by transient and reversible cerebellar ataxia. It has shown multidrug resistance-modulating activities towards acute myeloid leukemia, multiple myeloma and ovarian cancer in phase I/II clinical trials. However, the company discontinued development of valspodar in April 2001 following disappointing results reported from several multicentre phase III studies.

Firategrast (SB683699) is an orally bioavailable alpha4 beta1/alpha4 beta7 integrin antagonist designed to reduce trafficking of lymphocytes into the central nervous system (CNS), that had been studied in phase II trials at GlaxoSmithKline under a license from Mitsubishi Tanabe Pharma for the oral treatment of multiple sclerosis (MS) in Europe. GlaxoSmithKline and Tanabe Seiyaku (now Mitsubishi Tanabe Pharma) had been studying the drug candidate for the treatment of asthma, rheumatoid arthritis (RA) and Crohn’s disease, but these studies had being discontinued. Firategrast is a drug for the treatment of multiple sclerosis (MS) which is found to be caused by the migration of leucocytes (such as monocytes, T cells, B cells and dendritic cells) into CNS. And the integrin α4β1 is found to take participate in the migration through activating the leucocytes. Firategrast has a much shorter half-life than natalizumab with about 2.5 hours to 4.5 hours. It is found to inhibit the binding of the integrins to the associated ligands, including vascular cell adhesion protein 1 and mucosal addressin cell adhesion molecule 1. In CNS, firategrast treatment caused moderate decreases of total lymphocyte count, lymphocyte subset count and the ratio of CD4 to CD8. In peripheral blood, firategrast treatment resulted in the increases of total lymphocyte count, all lymphocyte subset count as well as the peripheral CD34+ early haematopoietic progenitor cell count. Firategrast was well tolerated at the maximum doses of 1200 mg for men and 900 mg for women. Firategrast showed no side effects, such as PML or JC-virus reactivation, at these doses. In Phase I clinical trials, the administration of firategrast significantly reduced the cumulative number of new gadolinium-enhancing lesions in patients with relapsing remitting MS.

Ethyl dibunate is a non-narcotic antitussive agent.

Tonapofylline is a selective oral adenosine A, receptor antagonist, for the potential treatment of congestive heart failure. Oral tonapofylline over the dose range of 3 to 225 mg/day produced significant increases in sodium excretion in patients with stable heart failure without causing kaliuresis or reducing renal function. Tonapofylline may be useful in the clinical setting for the prevention of kidney failure induced by nephrotoxic agents such as cisplatin. Tonapofylline may be renoprotective in the setting of concomitant treatment with a loop-diuretic. Adverse effects were generally mild. Tonapofylline had been in phase III clinical trial for the treatment of acute heart failure. However, this development was discontinued.

Nocloprost is a stable prostaglandin E2 analog with gastroprotective and ulcer-healing properties. It shows very high gastroprotective potency, relatively weak gastric inhibitory activity, and low systemic bioavailability after oral administration. Schering AG have discontinued development of the drug, which was in phase II clinical trials for the treatment of peptic ulcer.

Abitesartan is an angiotensin II receptor antagonist, antihypertensive (non-peptidic) agent.

Prorenoate Potassium is a water-soluble synthetic aldosterone antagonist patented by Merck and Co., Inc. as an antihypertensive agent. In preclinical studies a significant natriuretic response was obtained at dosages of 1 mg/kg and approximately 1.8 mg/kg in the dog and rat, respectively. Prorenoate is relatively inactive at the renal level in adrenalectomized rats without mineralocorticoid replacement. Prorenoate possesses no more than 2% of the natriuretic activity of hydrochlorothiazide in the intact animal. Clearance studies in dogs indicate a direct renal tubular site of interaction between prorenoate and aldosterone independent of changes in renal hemodynamics. The natriuretic response occurred within 100 minutes after a single oral dose and was sustained for at least 7 hours. In clinical trials Prorenoate reversing the renal effects of the synthetic mineralocorticoid fludrocortisone in healthy individuals. Prorenoate was significantly more potent in retaining K+ than in increasing Na+ excretion.

Nafcaproic acid (DA-808) is a synthetic choleretic agent.

Camonagrel is a novel selective thromboxane synthetase inhibitor patented by Ferrer Internacional S. A. Camonagrel reduced platelet-subendothelium interaction under flow conditions, showing this effect in a range of concentrations lower than in inhibition of platelet aggregation.