LY-156735 (TIK-301) is a melatonergic agonist and serotonergic antagonist drug. In May 2004 the FDA granted orphan drug designation to TIK-301 for the treatment of circadian sleep disorders in totally blind individuals as well as in individuals with tardive dyskinesia. Theoretically, it has an antidepressant effect.

Echinocandin B is a naturally occurring antibiotic, isolated from Aspergillus nidulans. It acts as an inhibitor of fungal β-1,3-glucan synthase thereby disrupting the formation of the fungal cell wall. The drug itself was not developed in the clinic, but instead, it was used in the production of other echinocandin derivatives.

7β-hydroxycholesteryl-3-oleate has been shown to inhibit astrogliosis and intracranial glioblastoma growth. Local administration of 7β-hydroxycholesteryl-3-oleate inhibits growth of experimental rat C6 glioblastoma. These data suggest that 7β-hydroxycholesteryl-3-oleate might be useful for local glioblastoma chemotherapy. 7β-hydroxycholesteryl-3-oleate is a potent inhibitor of the endogenous cholesterol biosynthesis in brain showing a correlation between cholesterogenesis and reactive astrocyte proliferation. 7β-hydroxycholesteryl-3-oleate can reduce the astrocytic reaction following spinal cord injury, promoting the serotonergic reinnervation of a denervated territory. On 17 December 2010, orphan designation (EU/3/10/816) was granted by the European Commission to Intsel Chimos SA, France, for 7-beta-hydroxy cholesteryl-3-beta-oleate for the treatment of glioma. The substance is going to be injected directly into the brain tumour contained within liposomes, which are expected to carry the medicine into the glioma cells.

Ribavirin elaidate (CP-4033; TRX-201), a Lipid Vector Technology derivative of ribavirin. It inhibits elongation factor F4E (elF4E), which stimulates cell growth. Translational Therapeutics Inc. received orphan drug status from the U.S. Food and Drug Administration (FDA) in 2011 for ribavirin elaidate in the treatment of aggressive follicular, medullary and anaplastic thyroid carcinoma.

GUANOSINE 5'-DIPHOSPHO-β-L-FUCOSE is classified as a member of the Purine nucleotide sugars. Guanosine 5'-diphospho-β-L-fucose sodium salt sodium salt is a substrate for fucosyltransferase.

5,6-dihydro-5-azacytidine (DHAC) is a hydrolytically stable congener of 5-azacytidine. It exerts cytostatic action in vitro. DHAC induces DNA hypomethylation. DHAC inhibits DNA methyltransferase, thereby interfering with abnormal DNA methylation patterns that are associated with genetic instability in some tumor cells. Inhibition of this enzyme may restore expression of tumor-suppressor genes and result in antitumor activity. It was in phase II studies for the treatment of several cancers such as malignant melanoma, mesothelioma and others.

Etiocholanedione is a natural metabolite of dehydroepiandrosterone with potent antiobesity activity. Etiocholanedione has been identified as a metabolite of an altered androgen metabolism that eventually leads hepatocellular carcinoma to impaired hormone responsiveness in human. Etiocholanedione has been identified as a metabolite of 17alpha-hydroxyprogesterone in some patients affected by congenital adrenal hyperplasia, although it doesn't appear to account for the masculinization observed in congenital hyperplasia.

Allopurinol riboside is a metabolite of allopurinol, a xanthine oxidase inhibitor indicated for the management of patients with leukemia, lymphoma, and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels and who cannot tolerate oral therapy. Allopurinol riboside is not an inhibitor of xanthine oxidase. Allopurinol riboside is commonly thought to be directly synthesized by purine nucleoside phosphorylase (PNP) in vivo. Allopurinol riboside competitively inhibits the action of PNP on inosine in vitro. Allopurinol riboside potently inhibits growth in vitro of promastigotes of Leishmania species. Patients with American cutaneous leishmaniasis who received allopurinol riboside had clinical improvement. In addition, allopurinol riboside demonstrated some effectivity against Trypanosoma cruzi infections in animals.