2-(4,6-DIMETHYLPYRIMIDIN-2-YL)-5-((2-FLUORO-6-(2H-1,2,3-TRIAZOL-2-YL)PHENYL)CARBONYL)OCTAHYDROPYRROLO(3,4-C)PYRROLE (Seltorexant, MIN 202), a small molecule, selective orexin receptor type-2 antagonist, is being developed by Minerva Neurosciences and Janssen Research & Development for the treatment of insomnia and major depressive disorder. Seltorexant has shown high in vitro affinity (affinity pKi =8.0 and 6.1 for OX2R and OX1R respectively) for the human OX2R and approximates two logs selectivity ratio versus its affinity for the OX1R. Seltorexant demonstrated a dose-dependent normalization of sleep and a trend towards improvement of subjective depressive symptoms in antidepressant-treated MDD patients with residual insomnia. Additionally, seltorexant’s favorable PK profile as a potential sedative-hypnotic drug was confirmed in a MDD population and did not demonstrate unacceptable adverse events or unwanted next-day CNS effects. Seltorexant is in phase II clinical trials for both insomnia and MDD.

Swainsonine is an indolizidine alkaloid found in Australian Swainsona canescens, North American plants of the genera Astragalus and Oxytropis and also in the fungus Rhizoctonia leguminocola. It is competitive inhibitor of Golgi alpha-mannosidase II and lysosomal alpha-mannosidases. This compound has been reported to be a potent antiproliferative and immunomodulatory agent. However, no evidence of anti-tumor activity of swainsonine was seen in phase II clinical trial, in patients with locally advanced or metastatic renal cell carcinoma. Adverse events such as fatigue, nausea and diarrhea were common but generally mild. Swainsonine is locoweed toxin. Locoweed poisoning is seen throughout the world and annually costs the livestock industry millions of dollars. Swainsonine inhibits lysosomal alpha-mannosidase and Golgi mannosidase II. Poisoned animals are lethargic, anorexic, emaciated, and have neurologic signs that range from subtle apprehension to seizures.

Saprisartan (formerly known as GR 138950) was developed as a potent long-lasting angiotensin II (AT1) receptor antagonist with high oral bioavailability. The drug was used for the treatment of hypertension and heart failure. However, these studies were discontinued.

Acridine carboxamide (XR5000) is a tricyclic acridine-based (or carboxamide-based) drug with dual topoisomerase inhibitor and potential antineoplastic activities. Acridine carboxamide inhibits both topoisomerases I and II and intercalates into DNA, resulting in DNA damage, the disruption of DNA repair and replication, the inhibition of RNA and protein synthesis, and cell death. Acridine carboxamide has been used in trials studying the treatment of lung cancer and brain and central nervous system tumors. In clinical trials acridine carboxamide did not show efficacy when tested against various types of cancers.

Fostriecin, an antitumor antibiotic produced by Streptomyces pulveraceus, is a strong inhibitor of serine/threonine protein phosphatases type 2A and type 4, and inhibits the catalytic activity of partially purified Topo II (type II topoisomerase) in a non-competitive manner.

Daniquidone, also known as Batracylin, is a water-insoluble heterocyclic amide with potential antineoplastic activity. Daniquidone inhibits topoisomerases I and II, thereby inhibiting DNA replication and repair, and RNA and protein synthesis. Batracylin advanced as an anticancer agent to Phase I clinical trials where dose limiting hemorrhagic cystitis (bladder inflammation and bleeding) was observed.

Phencyclidine is an illegal, hallucinogenic drug that was initially used as an anesthetic agent in the 1950s and early 1960s, but was then withdrawn in 1965 because of dissociative hallucinogenic effects that were often disturbing and sometimes severe and prolonged. Phencyclidine is a noncompetitive NMDA (N-methyl-D-aspartate) receptor antagonist and glutamate receptor antagonist, but also interacts with other receptor sites, and may have effects with dopamine, opioid and nicotinic receptors. Phencyclidine disrupts the functioning of receptors for the neurotransmitter glutamate, which plays a major role in the perception of pain as well as in learning, memory, and emotion. It also influences the actions of the neurotransmitter dopamine, which causes the euphoria associated with drug use. Phencyclidine overdose deaths may occur after taking a large dose, though many phencyclidine related deaths result from delusions and other psychological consequences of the drug’s use. There have been reports of death due to accidental drowning, leaping from high places, and motor vehicle accidents in addition to violent episodes of self-mutilation, suicides, and homicides.

Tafluposide (also known as F 11782) is an epipodophyllotoxin derivative patented by Pierre Fabre Medicament as an antitumor agent. Tafluposide acts as a catalytic inhibitor of topoisomerases I and II, that capable of completely inhibiting the DNA-binding activity of topoisomerase. In preclinical models single or multiple i.p. doses of Tafluposide proves highly active against the s.c. grafted B16 melanoma, significantly increasing survival and inhibiting tumor growth. Tafluposide inhibits the number of pulmonary metastatic foci of the melanoma by 99%. In human tumor xenograft studies, multiple i.p. doses of Tafluposide results in major inhibitory activity against breast) tumors, as well as causing definite tumor regression. Significant activity was also recorded Tafluposide against the refractory lung xenografts.