Panuramine, a selective inhibitor of uptake of 5-hydroxytryptamine that was studied as an antidepressant, however, has never been marketed.

Folitixorin, a thymidylate synthase inhibitor is a substrate used by the enzyme methylenetetrahydrofolate reductase (MTHFR) to generate 5-methyltetrahydrofolate. Folitixorin was studied in clinical trials for the treatment of breast cancer, metastatic colorectal cancer and for the treatment of advanced pancreatic cancer. Folitixorin had been granted orphan drug status for the treatment of pancreatic cancer in both the U.S. and EU. However, further development of this drug was discontinued.

Dinazafone exhibits anticonvulsant, anxiolytic and myorelaxant effects. Diazepam and N-desmethyl-diazepam formed after dinazafone certainly contributed to its antileptazol effect.

KW-2449, a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase, is under investigation to treat leukaemia patients. KW-2449 is a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase with IC50 values of 6.6nM, 14nM, 4nM and 48nM, respectively. KW-2449 has potent growth inhibitory activity against various types of leukaemia by several mechanisms of action. Kyowa Hakko Kirin Pharma Inc. (a US subsidiary of Kyowa Hakko Kirin Co) was developing KW-2449 for the treatment of acute lymphoblastic leukaemia; acute myeloid leukaemia; chronic myeloid leukaemia; myelodysplastic syndromes, but later these studies were discontinued.

Talotrexin (also known as PT-523) was developed as a nonpolyglutamatable antifolate drug for the treatment of various types of tumors. It is known that antifolates are a class of cytotoxic or antineoplastic agents, which inhibit or prevent the maturation and proliferation of malignant cells. Talotrexin was studied in clinical trials for the treatment of brain and central nervous system tumors, leukemia, lymphoma, unspecified childhood solid tumor. However, this study was withdrawn because of toxicity. In addition, was studied in phase I/II multicenter clinical trial in patients with non-small-cell Lung carcinoma, this study was also withdrawn. The withdrawal was related to incidences of dose-limiting mucositis and myelosuppression. However, on May 22, 2006, was announced that the U.S. Food and Drug Administration has granted orphan drug designation for talotrexin in patients with acute lymphoblastic leukemia (ALL).

Oxazafone was studied as an anticonvulsant and anxiolytic agent. Information about the further development of this compound is not available.

LAMIFIBAN is a potent and selective nonpeptide glycoprotein IIb/IIIa antagonist. It inhibits platelet aggregation and thrombus formation by preventing the binding of fibrinogen to platelets. It was in clinical development as an injectable antithrombotic agent for treating and preventing acute coronary syndromes but showed no significant effects on clinical outcomes.

Naroparcil [LF 90055], the lead compound in a series of orally-active antithrombotics, is an analogue of LF 1351, a compound shown to have antithrombotic action. Antithrombotic activity of naroparcil is dependent on modification in the plasma GAG profile which inactivates thrombin via heparin cofactor II (HCII).

Oxindanac, a non-steroidal anti-inflammatory drug, and is a weak cyclooxygenase inhibitor possessed antipyretic activity. This drug is used as a veterinary inflammatory drug. In addition, oxindanac was studied in phase III clinical trials for the treatment of rheumatic disorders. However, this study was discontinued.